According to the American Academy of Pediatrics(AAP), exclusive breastfeeding of infants for about the first six months and continued breastfeeding for a year or longer after introducing solid foods is recommended. 

The World Health Organization(WHO) also recommends exclusive breastfeeding for the first six months of an infant’s life. 

Exclusive breastfeeding refers to giving infants only breast milk and no other solid or liquid foods. According to the Centre for Disease Control and Prevention(CDC), only one in four infants are exclusively breastfed for the first six months. 

What Are The Benefits Of Breastfeeding?

Breastfeeding is beneficial for both the infant and the mother. Benefits of breastfeeding include:

• Provides nutrition for infants
• Contains antibodies needed for the infant’s immunity
• Linked to higher IQ scores of the infant
• Lowers risk of breast and ovarian cancer in the mother
• Lowers mother’s risk of type 2 diabetes and high blood pressure
• Helps the bonding process between the infant and mother
• Reduces disease risk and help maintain a healthy weight for the infants and mother
• Reduces the risk of postpartum depression in mothers

Link Between Breastfeeding Duration & Breast Cancer

Research shows that mothers who breastfeed have a lower risk of developing pre and postmenopausal breast cancer. This benefit increases with an increase in the duration of breastfeeding for more than 6 months. 

Researchers have put forth several possible explanations to address the link between breastfeeding duration and breast cancer risk. All these explanations revolve around exposure to one of the female sex hormones, estrogen. 

Estrogen stimulates breast cell growth. Prolonged exposure to estrogen can increase the risk for breast cancer. Women have lower levels of estrogen during breastfeeding periods. This is because breastfeeding delays menstrual periods. The lifetime exposure to estrogen decreases with longer breastfeeding durations, and this decreases the risk of breast cancer.

Another reason is that the breast sheds a lot of tissue after lactation. During this process, it may also get rid of cells with damaged DNA that may lead to cancerous growth. Lactation may also lead to changes in the expression of genes found in breast cells. This can decrease the risk of cancer development.

A meta-analysis study showed that breastfeeding contributed to a 20% reduced risk for triple-negative breast cancer and a 10% reduced risk for estrogen receptor-negative breast cancer.

Breastfeeding Duration & Breast Cancer

Genetic Factors

Studies have estimated that the heritability of breastfeeding duration ranges from 44 to 54%. People with certain genetic types may tend to breastfeed their children for a longer duration than others. 

The XRCC2 Gene

The XRCC2 gene contains instructions for producing a DNA repair protein. This protein also helps maintain chromosomal stability. 

Changes in this gene are associated with increased risk of breast cancer and fanconi anemia. Fanconi anemia is a rare but serious blood disorder that prevents your bone marrow from making enough new blood cells for your body. It is passed down through families.  

rs3218536

rs3218536 is a single nucleotide polymorphism or SNP located in the DNA-repair gene XRCC2.

A 2010 study examined the role of DNA repair deficiencies in cancer development, especially in breast cancer. The study population was divided into women who breastfed and women who had never breastfed.

It was observed that among women who had never breastfed, those who carried the AG genotype of rs3218536 had a lower risk of breast cancer than those with the other genotypes.

After classifying this group according to the menopausal status, it was observed that postmenopausal women with the A allele had a lower risk of breast cancer than those with the G allele.

The MDM2 Gene

The MDM2 gene contains instructions for the production of Mouse double minute 2 homolog (MDM2) protein. It is also known as E3 ubiquitin-protein ligase Mdm2 protein. 

This protein acts as a negative regulator (suppresses the activity) of p53 tumor suppressor protein.

A study has reported that the activity of the MDM2 gene seems to be amplified in breast cancer cells. 

rs2279744

rs2279744, also known as 410T-G, has been studied for several years to determine its role in cancer. 

This SNP influences the ability of the MDM2 protein to bind to p53 tumor suppressor protein. 

The G allele of this SNP is associated with an increased risk for breast cancer, especially in women who have breastfed for less than 6 months and women who are obese. 

Non-Genetic Factors

Some factors that influence breast cancer duration include:

• Postpartum emotions: Baby blues and postpartum depression may make it hard for the mother to gather energy to breastfeed. Postpartum depression can severely impact the mother and her choice to take care of the baby or breastfeed.
• Socioeconomic status and maternal employment: Women of lower socioeconomic status tend to skip or stop breastfeeding very early. If the mother has to return to work early, she may stop breastfeeding or may find it difficult to have time to pump breast milk. 
• Mastitis: It is an inflammation of the breast tissue, which may be an infection and result in pain, swelling, redness, and fever, or chills in certain cases. Mastitis commonly affects women who are breastfeeding.
• Latching issues
• Alcohol consumption or smoking

Recommendations For Breastfeeding

Increasing Breastfeeding Duration

• Training doctors and midwives about the correct breastfeeding techniques and their importance will ensure new parents understand the process well.
• It is important to stay hydrated while breastfeeding. Have a cool drink, milk, juice, or water, by your side to hydrate yourself as you feed.
• Maintaining a healthy weight when planning pregnancy can keep BMI levels normal after delivery. This may help in the successful initiation and continuation of breastfeeding for a longer duration.

Breast Cancer Screening

It is important to get periodic breast cancer screening done. Some screening options include mammography and breast MRI. You can check with your medical practitioner for suitable tests.

Video

Summary

1. Breastfeeding has benefits to both the mother and the child. It provides all essential nutrients for the infant and lowers the risk of many health conditions, including breast cancer in the mother.
2. Research shows that breastfeeding is linked to a reduction in the risk of breast and ovarian cancer. This is mainly due to the decreased exposure to estrogen during lactation. 
3. Genetics influences both breastfeeding duration and breast cancer risk with shorter (<6 months) breastfeeding duration.
4. Some factors that affect breastfeeding include postpartum depression, cracked or sore nipples, mastitis, latching issues, socioeconomic status, maternal employment, alcohol consumption, and smoking.
5. Regular breast cancer screening with mammography or breast MRI can help with early diagnosis and support a good prognosis. 

References

• https://www.medicalnewstoday.com/articles/318788
• https://www.breastcancer.org/risk/factors/breastfeed_hist
• https://www.wcrf.org/dietandcancer/exposures/lactation-breastfeeding
• https://www.mdanderson.org/publications/focused-on-health/breastfeeding-breast-cancer-prevention.h19-1589046.html

What Is Breast Cancer Prognosis?

Breast cancer is the most common cancer in women in the developed and developing world. Breast cancer cases have a good prognosis if detected and treated early. 

Prognosis refers to the outlook or chance of recovery from a disease. It is an estimate of the likely course and outcome of a disease - breast cancer, in this case. This includes the likelihood of recurrence and life expectancy. 

Breast cancer prognosis is based on observing large groups of people affected by the condition over the years. It can be qualitative and described as excellent, good, or poor. It can also be quantitative in the form of survival rates or hazard ratios.

What Is Cancer Survival Rate?

The survival rate is determined by observing several people affected with breast cancer for many years, usually five or ten years. Survival rates are a key part of cancer prognosis. It indicates the percentage of people alive after a certain period of time, usually five years, after they were diagnosed. 

Survival rates can help give you a better understanding of how successful your treatment may be. Two main survival rates used in breast cancer cases include 

• Breast cancer survival rate: The percentage of women who are alive for five years or longer after their diagnosis. 
• Relative survival rate: The percentage of people with breast cancer who have lived for a certain time, usually five years after diagnosis, compared with people who do not have breast cancer. 

According to the National Cancer Institute, 90 percent of women with breast cancer survive five years after diagnosis, regardless of the stage. This indicates a 90% five-year survival rate - 90 out of 100 people diagnosed with breast cancer are likely to be alive after five years. 

What Is Hazard Ratio?

Another parameter used to determine prognosis in cancer patients is the hazard ratio. Hazard ratios are used to measure survival in a group of patients who have been given a specific treatment in a clinical trial setting. 

The patient group is compared with the control group, who are given a placebo, a treatment with no therapeutic value. 

Hazard ratio can either be equal to, lesser than, or greater than one. 

No difference in survival between the two groups receiving different treatment is denoted by a hazard ratio of 1. 

A value greater than or lesser than one indicates better survival in one of the treatment groups. 

Understanding Prognosis

Prognosis in terms of survival rates or hazard ratio is just an estimate based on previous outcomes of large groups of people with specific cancer. Every case is unique, and the survival rate is not a very accurate prediction of a specific person’s prognosis. 

The statistics can be confusing and alarming in some cases. Talk to your doctor about these statistics, how they apply in your case, and what you can do about it for better clarity. 

The prognosis for breast cancer survivors and their survival depends on many factors. This can be assessed only by a qualified physician familiar with the medical history, response to treatment, type and stage of cancer, and cancer-specific characteristics. 

How Genes Influence Breast Cancer Prognosis

A family history of breast cancer increases the individual’s risk of developing breast cancer. Genetics also influences breast cancer prognosis. Changes in certain genes may be responsible for the considerable differences in survival among breast cancer patients. 

The RAD51B Gene 

The RAD51B gene contains instructions for the production of a protein involved in DNA repair. Along with other proteins of this family, the RAD51B protein is involved in repairing damaged DNA. Changes in this gene can disrupt the DNA repair process and influence breast cancer prognosis. 

rs3784099 

rs3784099 is a single nucleotide polymorphism or SNP in the RAD51B gene. Carriers of the A allele are found to have lesser survival time and unfavorable prognosis.

Non-Genetic Factors

Apart from genetic factors, your doctor will consider several other factors to determine prognosis, including:

• Medical history
• Response to treatment
• Type, stage, and grade of cancer
• Other specific characteristics of the cancer
• Menopausal status
• Smoking habit
• Alcohol consumption 
• BMI

Recommendations to Improve Breast Cancer Prognosis

The statistics, survival rates, and hazard ratio values can be confusing. A doctor familiar with your medical history can help interpret breast cancer prognosis based on genetic and non-genetic factors. Certain ways to improve the prognosis of breast cancer include

Getting sufficient sleep: Breast cancer survivors need about 7 to 9 hours of sleep every night. In a study conducted by researchers from Fred Hutchinson Cancer Research Center, Seattle, women who slept for a period of 5 hours or less every night before being diagnosed with breast cancer had a 1.5 times higher likelihood of poor prognosis when compared with women who slept for 7 to 9 hours every night.

Regular exercise: Regular exercise improves prognosis; however, it might not be possible for everyone to exercise daily during the treatment. According to a study conducted by researchers at The University of California-San Diego Moores Cancer Center, a 12-week exercise program increased information processing speed by 2 times. This indicates cognitive benefits of exercise; however, the benefit is obtained only when the exercise program starts within 2 years of being diagnosed with breast cancer.

Alternate or Complementary Therapy: In North America, nearly 80% of breast cancer survivors depend on complementary therapy to cope with breast cancer. The most sought-after therapy is yoga. 

Yoga has been shown to reduce fatigue, improve sleep quality, physical functioning, and overall quality of life.

Lifestyle: Try to moderate or avoid smoking and alcohol consumption as these are risk factors for many types of cancer and may result in an unfavorable prognosis. Eat a healthy and balanced diet to maintain a healthy weight. 

Video

Summary 

1. Breast cancer, the most common cancer in women in the developed and developing world, has a good prognosis if detected and treated early. 
2. Prognosis is an estimate of the likely course and outcome of a disease. It can be understood as the outlook or chance of recovery from breast cancer. 
3. Prognosis can be indicated using survival rates or hazard ratios. The 5-year survival rate of women with breast cancer is found to be 90%.
4. Hazard ratios are used to measure survival in a group of patients who have been given a specific treatment in a clinical trial setting. The hazard ratio is denoted by a value equal to, less than, or greater than 1. 
5. Certain changes in genes like the RAD51B are found to influence breast cancer prognosis. 
6. Medical history, response to treatment, the type, stage, and grade of cancer, other specific characteristics of cancer, and menopausal status are the non-genetic factors that influence breast cancer prognosis. 
7. Getting sufficient sleep, doing yoga, exercising regularly, and maintaining a healthy weight are some of the ways that can help improve breast cancer prognosis. 

References

• https://www.cancer.net/cancer-types/breast-cancer/statistics
• https://www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/breast-cancer-survival-rates.html
• https://www.healthline.com/health/breast-cancer/survival-facts-statistics
• https://www.breastcancer.org/symptoms/diagnosis/prognosis
• https://www.sciencedirect.com/science/article/pii/B9780128170847000358

What Are Estrogen Receptors?

Receptors are proteins inside the target cell or on its surface that receive a chemical signal. 

Estrogen is an important hormone responsible for various female characteristics in the body, including the growth and development of breasts (or mammary glands).

Estrogen Receptors (ERs) are a type of steroid receptors that attach to estrogen in the blood and regulate the growth and multiplication of cells in the breast. These receptors pick up signals from the hormones and encourage cell growth. 

In the case of breast cancer, this growth is uncontrollable and eventually becomes cancerous.

Types of Breast Cancer

Based on the presence or absence of estrogen receptors in breast cancer cells, there are two types of breast cancers:

ER-positive

A cancer is called estrogen-receptor-positive (or ER-positive) if it has receptors for estrogen. The cancer cells receive signals from estrogen and grow in response to it. 

ER-positive is the most common form of breast cancer - around 80% of breast cancers are ER-positive. 

Anti-estrogen medications can prevent the growth of these cancer cells. 

ER-negative

Breast cancer cells that do not have estrogen receptors are known as estrogen-receptor-negative (or ER-negative) cancers. 

ER-negative breast cancer is less common and more challenging to treat. It also often has poor treatment outcomes.

Knowing whether breast cancer is ER-positive or ER-negative helps doctors plan the appropriate treatment.

Why Should Breast Cancer Be Tested For Hormone Receptors?

Every patient with a breast cancer diagnosis undergoes a hormone receptor evaluation that helps determine if the cancer cells have receptors for estrogen and progesterone. 

About 2 out of every 3 breast cancer cases test positive for hormone receptors. 

Testing breast cancer cells for hormone receptors is important to decide whether hormonal therapy will be an effective course of treatment. 

Hormone therapy involves reducing the estrogen levels in the body or blocking the cells from responding to estrogen. 

Only if the cancer is ER-positive, hormone therapy will work. 

This makes ER-negative cancers difficult to treat; non-hormonal treatments are used for these cancers.

Genetic Factors Increasing The Risk For ER-Negative Breast Cancer

The BRCA2 Gene

The BRCA2  gene provides instructions for producing a protein that acts as a tumor suppressor (proteins that prevent cells from dividing uncontrollably and rapidly). 

The BRCA2 gene is also involved in repairing damaged DNA. 

Changes in the BRCA2 gene can increase the risk of different types of cancers, including breast cancer.

Most women with BRCA2 mutations tend to develop ER-positive breast cancer. However, the prognosis may be worse for these women than for those with ER-negative breast cancer carrying BRCA2 mutations.

The MDM4 Gene

The MDM4 gene is located on chromosome 1 and produces the MDM4 protein, which regulates a tumor suppressor protein called the p53. 

Changes in this gene can affect the protein produced, which in turn interferes with the tumor suppressor activity of p53. 

When this happens, it can lead to uncontrolled cell growth resulting in cancer cell formation. 

The ZNF365 Gene

The ZNF365 gene contains instructions to produce the Zinc Finger Protein 365. This protein plays a role in repairing DNA damage. Changes in this gene increase the risk of breast cancer.

A change in the ZNF365 gene, called 19p13.1,  has been linked to ER-negative breast cancer in individuals with changes in their BRCA1 and BRCA2 genes.

Non-genetic Factors Influencing ER-negative Breast Cancer Risk

Race: There is a higher incidence of ER-negative breast cancers in women of African ancestry.

Obesity:  Pre-menopausal and menopausal women who are overweight or obese are at an increased risk of developing ER-negative breast cancer.

Alcohol consumption: Increased alcohol intake increases the risk of ER-negative breast cancer.

Younger Age: Hormone receptor-negative cancer is more commonly seen in women around 40 years of age who haven’t attained menopause

Recommendations To Reduce Risk Of ER-negative Breast Cancer

Regular Physical Activity

Physically active women who have a healthy weight and lead a healthy lifestyle have a reduced risk of developing ER-negative breast cancer.

Limited Alcohol Consumption

Even low levels of alcohol intake can increase the risk of breast cancer. The ideal upper limit for alcohol consumption to lower breast cancer risk is one drink a day (12-14 grams of alcohol).

Plant-based Diet 

Plant-based diets are packed with fiber, vitamins, and minerals. Fiber helps eliminate excess estrogen (a risk factor for breast cancer). Vitamin C, A, and selenium also play a role in lowering cancer risk. 

A 2013 study that followed approximately 30,000 post-menopausal women with no history of breast cancer for 7 years showed that following these three recommendations resulted in a 62% decreased risk of breast cancer.  

Genetic test for BRCA Mutations

The BRCA genetic test is a blood test that analyses DNA to detect the presence of harmful changes (mutations) in the BRCA1 and BRCA2 genes. Individuals with these mutations are at a high risk of developing breast cancer. Routine testing for these genes in individuals at high risk is recommended.

Video

Summary

1. Depending on the presence or absence of estrogen receptors on breast cancer cells, breast cancer can be classified as ER-positive or ER-negative.
2. ER-positive breast cancers form 80% of the total breast cancer cases and are easier to treat with hormonal treatments. ER-negative breast cancers do not respond to hormone therapies.
3. Knowing the ER status of breast cancer helps the doctor determine the treatment plan for a patient.
4. The prognosis for women carrying BRCA2 mutations and diagnosed with ER-positive breast cancer is poorer than for those with ER-negative breast cancer. 
5. Changes in the MDM4 gene can interfere with the tumor suppressor activity of p53 protein, resulting in an increased risk for breast cancer. 
6. Other factors like race, menopausal status, and alcohol intake influence a woman’s risk of developing ER-negative breast cancer.
7. Eating a healthy and nutritious plant-based diet, limiting alcohol intake, and being physically active can reduce the risk of ER-negative breast cancer.
8. BRCA genetic testing can help you assess the risk more precisely and take preventive measures.

References

• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3389841/
• https://www.cancer.org/cancer/breast-cancer/understanding-a-breast-cancer-diagnosis/breast-cancer-hormone-receptor-status.html
• https://www.webmd.com/breast-cancer/breast-cancer-types-er-positive-her2-positive
• https://www.breastcancer.org/symptoms/diagnosis/hormone_status
• https://academic.oup.com/jmcb/article/11/3/231/5301298
• https://academic.oup.com/carcin/article/30/11/1910/2629508
• https://cancer.ucsf.edu/sites/cancer.ucsf.edu/files/_docs/crc/nutrition_breast.pdf

Breast cancer is one of the most common types of cancer affecting women. According to the World Health Organization (WHO), 2.3 million women were diagnosed with breast cancer, and 685,000 lost their lives globally in 2020. 

As of 2020, 7.8 million women have been diagnosed with breast cancer and are alive in the last five years.

Breast cancer survivors are at risk for different health conditions - fatigue, mental health issues, and breast cancer recurrence - to name a few. They must also be aware of the higher risk they carry for developing a second non-breast cancer. 

People who have had breast cancer in the past are at higher risk for developing  other types of cancers, including:

• - Stomach cancer
• - Esophageal cancer
• - Colon cancer
• - Uterine cancer
• - Ovarian cancer
• - Sarcoma
• - Salivary gland cancer
• - Acute Myeloid Leukemia (AML)
• - Melanoma

A 2006 study collected data from 13 different cancer registries in places like Singapore, Canada, Australia, and Europe. The study analyzed the data of 525,527 women and followed them for 10+ years.

According to the study, when compared to women who did not have a history of breast cancer, women with past or present breast cancer had:

• - 48% increased risk for ovarian cancer
• - 35% increased risk for stomach cancer
• - 60% increased risk for thyroid cancer
• - 29% increased risk for melanoma
• - 27% increased risk for kidney cancer
• - 24% increased risk for lung cancer
• - More than 2 times increased risk for soft tissue sarcoma

Another study analyzed the risk of Secondary Non Breast Cancers (SNBCs) in 58,068 Dutch women diagnosed with breast cancer between 1989 and 2003. According to the study, women who had breast cancer in the past had a small but significant risk for developing esophageal cancer, stomach cancer, colon cancer, rectum cancer, uterus cancer, ovarian cancer, soft tissue sarcoma, acute myeloid leukemia (AML), and non-Hodgkin’s lymphoma.

Genetic Factors Influencing Risk For Breast And Other Cancer

The BRCA1 Gene 

The BRCA1 gene (BRCA1, DNA repair associated gene) produces a tumor suppressor protein. This protein is considered beneficial as it hinders uncontrolled cell division, thereby lowering cancer risk. 

Abnormal changes (or variations) in this gene can lead to low or no production of the tumor suppressor protein and increase one’s risk for developing cancers. 

A study reported that  BRCA1 variations lead to breast and ovarian cancers and also increase the risk of other cancers like colon cancer (11.1%), pancreatic cancer (3.6%), and gastric cancer (5.5%).

The BRIP1 Gene 

The BRIP1 gene (BRCA1 interacting protein C-terminal helicase 1) contains instructions for producing a protein that repairs double-strand breaks in DNA. 

Abnormal changes in this gene result in lower production of this protein, which increases the risk of many types of cancers. Cancers associated with variations in this gene are:

• - Breast cancer
• - Medulloblastoma (brain tumor)  
• - Tumors in the central and peripheral nervous systems
• - Kidney cancer
• - Bone cancer

The PALB2 Gene 

The PALB2 gene (Partner And Localizer Of BRCA2 gene) contains instructions for producing a protein that works with the BRCA2 protein to repair damaged DNA and suppress tumor growth. Abnormal changes in this gene affect the ability of the BRCA2 gene to prevent tumor cell formation. 

Apart from breast cancer,  this gene is associated with the risk for:

• - Ovarian cancer
• - Lung cancer
• - Prostate cancer

The CHEK2 Gene  

The CHEK2 gene (Checkpoint kinase 2) is also a tumor suppressor gene and produces a kinase enzyme protein called CHK2. 

Abnormal changes in this gene increase the risk of developing breast cancer by two times. It also increases the risk of:

• - Ovarian cancer
• - Colorectal cancer
• - Prostate cancer
• - Kidney cancer
• - Thyroid cancer

The PTEN Gene  

The PTEN gene produces an enzyme that acts as a tumor suppressor. Almost all tissues in the body have this enzyme in specific quantities. This enzyme prevents the abnormal division of cells by encouraging self-destruction (a process called apoptosis) of these cells. In people with past or present breast cancer diagnoses, variations in this gene can result in an increased risk of:

• - Bladder cancer
• - Head and neck squamous carcinoma
• - Lung cancer
• - Prostate cancer
• - Bile duct cancer

Non-Genetic factors

Exposure To Radiation

One of the main non-genetic factors that increase a person’s risk of developing other cancers is radiation exposure. 

There are three basic radiotherapy treatment solutions for breast cancer.

1. Three-dimensional Conformal Radiotherapy (3D-CRT)

2. Intensity-Modulated Radiotherapy (IMRT)

3. Volumetric Modulated Arc Therapy (VMAT)

Many studies report a higher risk of second cancer because of radiation exposure. 

A large study analyzed the risk of second cancers in 46,176 breast cancer survivors. According to the study, one out of 200 women who had received radiation therapy for breast cancer had a higher risk of being diagnosed with other cancers.

Type of Chemotherapy

Chemotherapy is a treatment that uses various drugs to kill abnormally growing tumor cells in the body. It is the most common treatment option for cancer.

Some types of chemo drugs given during breast cancer treatment are associated with an increased risk for developing other types of cancers. 

Chemo agents that are linked with second cancer risks are:

• - Platinum-based chemicals 
• - Anthracycline topoisomerase II inhibitors
• - Alkylating agents

Patients who go through chemotherapy for a longer time or get treated with higher doses of drugs are at a higher risk of developing other cancers. 

Age

While patients who had exposure to radiation therapy and chemotherapy were at higher risk for developing second non-breast cancers, people under the age of 40 who received these treatments were at more risk than the elderly who received treatment.

Smoking

Smoking increases the risk of breast cancer and all other cancers. Smokers diagnosed with breast cancer are at higher risk for developing other cancers in the future when compared to non-smokers.

 A 1994 study tried to find the relationship between smoking, breast cancer, radiation therapy, and the risk of second cancers. According to the study, radiation therapy for breast cancer increased the risk of developing other cancers in smokers and non-smokers. However, in smokers, this risk was much higher.

Recommendations To Bring Down The Risk Of Breast And Other Cancers

Genetic Testing

Genetic testing can be a good aid for treatment planning and risk management if:

• - You are a cancer survivor
• - You are less than 40 years and are diagnosed with breast cancer
• - Your first and second-degree relatives have been diagnosed with breast cancer

Genetic testing will look for specific genes that can increase your risk for breast and other cancers. It will tell you if you are at higher risk for second cancer. In case you belong to the high-risk category, regular screening can help you.

Analyze The Risks In Your Chemotherapy and Radiation Therapy Procedures 

Talk to your doctor about the dosage and type of chemotherapy and radiation treatment you will be receiving for your breast cancer. Some treatments may increase your risk for breast cancer than others.

Adopt Healthy Habits

Some lifestyle changes can lower your risk of developing cancer.

• - Quit smoking
• - Limit alcohol intake to 1 drink a day
• - Stay away from processed, frozen, and packaged foods as much as possible
• - Cook fresh food at home
• - Include a lot of antioxidants in your diet to protect your cells
• - Maintain a healthy weight
• - Practice regular physical activity
• Get regular cancer screening done

Do Not Fear

The fear of breast cancer recurrence and the fear of developing second cancers can lead to high stress. Stress causes abnormal changes in the cells and can be a cause for cancer recurrence. Fear and stress lead to unwanted behaviors like alcohol abuse, smoking, and excessive eating. All these also increase the risk of developing other cancers. Practicing mindfulness and talking to a mental health expert might help you in controlling stress. 

Video

Summary

1. Breast cancer is associated with a higher risk of developing a second non-breast cancer. 
2. Certain types of cancer like stomach cancer, colon cancer, uterus cancer, ovarian cancer, sarcoma, and Acute Myeloid Leukemia (AML) can develop after a breast cancer diagnosis.
3. Both genetic and non-genetic influences increase a breast cancer survivor’s risk for developing other types of cancers.
4. Abnormal changes in genes like the CHEK2, BRCA1, PTEN, ATM, and TP53 can increase the risk of breast and other cancers. 
5. Non-genetic factors like age, radiation exposure, the intensity of chemotherapy, and lifestyle habits like smoking also increase the risk of developing second non-breast cancers.
6. A genetic test can tell you if you are at risk for developing a second non-breast cancer after a breast cancer diagnosis.
7. Following a healthy lifestyle, keeping away fear, and choosing the right radiation and chemotherapy procedures can help bring down the risk of second cancer considerably. 

References

• https://www.medscape.com/viewarticle/834659
• https://www.webmd.com/breast-cancer/features/life-after-breast-cancer-treatment
• https://www.cancer.org/treatment/treatments-and-side-effects/treatment-types/chemotherapy.html
• https://www.cancer.org/treatment/treatments-and-side-effects/physical-side-effects/second-cancers-in-adults/treatment-risks.html
• https://www.cancer.org/cancer/breast-cancer/living-as-a-breast-cancer-survivor/second-cancers-after-breast-cancer.html

How Smoking Can Lead To Cancer Development

Smoking remains one of the biggest causes of preventable deaths globally. According to the Centers for Disease Control and Prevention (CDC), smoking accounts for 1 in about five deaths in the United States every year.

As of 2019, 14% of the adult population in the country are smokers.

The American Lung Association states that there are more than 600 ingredients present in a cigarette. Each cigarette releases about 7000 chemicals when it is burnt. Out of these, close to 70 chemicals are proven carcinogens (cancer-causing substances). Some of them are:

• Nicotine
• Tar
• Arsenic
• Ammonia
• Acetone
• Formaldehyde
• Carbon monoxide
• Lead
• Benzene
• Naphthalene 

When a person inhales cigarette smoke, these carcinogens and other chemicals reach the lungs and are distributed throughout the body. 

Once these carcinogenic chemicals enter the body, they are detoxified by the cytochrome P450 group of enzymes (CYPs). 

These CYP enzymes convert these carcinogens into a more active intermediary form called DNA adducts. DNA adducts are parts of the DNA that attach themself to these cancer-causing chemicals. 

The intermediaries lead to DNA damage and abnormal cell multiplication and have to be quickly detoxified by other enzymatic processes. Unfortunately, in some people, the number of cancerous intermediaries builds up at a faster rate than they are eliminated. This leads to cancer. 

There are other carcinogens in cigarette smoke that directly form DNA adducts without the help of the CYP enzymes. These lead to direct DNA damage and cell abnormalities, and resultant cancer. 

Smoking - A Risk Factor for Breast Cancer

While smoking is a risk factor for all types of cancer, it is significantly associated with breast cancer in women. 

In the United States, 1 in every eight women will be diagnosed with breast cancer in her lifetime. Smoking increases this risk drastically. 

A study published in the BioMed Central Ltd forum analyzed the risk of breast cancer in women who smoked.

102,927 women were chosen and monitored for 7.7 years. In the end, 1815 women developed invasive breast cancer. The study found that smokers had a 14% higher risk of developing breast cancer than non-smokers. 

Learn More: How Genes Influence Your Risk for Nicotine Dependence?

This study also mentions that women who start smoking before 17 had a significantly higher risk (24%) for breast cancer. 

Another study analyzed the risk of breast cancer in 111,140 active smokers and 36,017 passive smokers (people who don’t smoke themselves but are exposed to other people’s cigarette smoke).

According to the study, some factors that increase the risk of breast cancer are:

• Smoking at a younger age
• Number of years of smoking
• Smoking before the first pregnancy

Does Secondhand Smoke Increase Breast Cancer Risk?

Secondhand smoke is also called passive smoking and is smoke that a person inhales unintentionally. For example, people can inhale tobacco smoke by just being around others who smoke. According to the California Air Resources Board, secondhand smoke is a proven carcinogen. 

The smoke that is released from the burning ends of cigarettes is called sidestream smoke. Sidestream smoke is unfiltered and hence contains more harmful substances than the smoke that a smoker breathes out. 

A 2013 study analyzed the risk of breast cancer in 322,988 active, passive, and non-smokers. 

Compared to non-smoking women, those exposed to passive smoke at home or work had a higher risk of developing breast cancer. 

How Does Genetics Influence Smoking And Breast Cancer Risk?

The GSTM1 Gene

The GSTM1 gene (glutathione S-transferase mu 1 gene) helps produce the glutathione S-transferase enzyme that belongs to the Mu class. The Mu class of enzymes helps in eliminating carcinogens and other environmental toxins from the body.

rs366631 is a single nucleotide polymorphism or SNP in the GSTM1 gene. 

People with the GSTM1 null genotype have a higher risk of developing breast cancer when exposed to cigarette smoke. 

Null genotype is the non-functional variant of the gene that results in total loss of function of the gene. 

Here, the TT genotype is the null genotype.

The risk of breast cancer was also more severe in postmenopausal smokers with the GSTM1 null genotype. 

The SLC4A7 Gene

The SLC4A7 gene (Solute Carrier Family 4 Member 7 gene) helps produce a protein that transports sodium and bicarbonate ions. It also plays a role in the metabolism of different acids, ions, and amine compounds.

rs4973768  is an SNP in the SLC4A7 gene. A meta-analysis has reported an increased risk for breast cancer upon smoking in T allele carriers. 

Reducing Smoking to Lower Breast Cancer Risk

Get Help To Quit Smoking

There are so many government and private bodies that help people with tobacco addiction. You can get help from some of these rehab centers to stop or limit smoking. It takes time and effort to curb the craving. Here are some pointers that can help you with this.

• Take help from friends and family
• Keep yourself busy
• Take professional help if you are unable to quit on your own
• Consider de-addiction medications

Avoid Smoking Triggers

For people who have been smoking for years together, some places, smells, habits, or environments can create an urge to smoke. Understand these triggers and stay away from them. Practice the below activities to make quitting smoking easier.

• Throw away your cigarettes and lighters
• Keep your body hydrated
• Eat healthy food and stay away from caffeinated drinks and alcohol as they can increase the urge to smoke

Stay Away From Secondhand Smoking

Secondhand smoking ends up harmful to non-smokers. Here are ways you can limit/eliminate secondhand smoke exposure.

• Stand a few feet away from smokers.
• Do not allow people to smoke inside your house or in closed workspaces.
• Restrict people from smoking in your car.
• Avoid visiting restaurants, pubs, and bars that put smokers and non-smokers in the same space.

Get Genetic Testing Done

Genetic testing helps identify genetic factors that could increase your breast cancer risk. If you do have a high genetic risk, regular screening may help. 

Video

Summary

1. Smoking is one of the major causes of preventable deaths globally. Smoking leads to a variety of health problems, including cancers.
2. The chemicals in cigarette smoke can alter DNA and encourage the formation of DNA adducts. This leads to abnormal cell division and growth, causing cancer.
3. Women who start smoking at a younger age, have increased lifetime exposure to smoking, or smoke excessively before the first pregnancy are more likely to develop breast cancer. 
4. Secondhand smoking or passive smoking also increases a woman’s risk of developing breast cancer. 
5. Changes in the GSTM1 and SLC4A7 genes can both increase a woman’s risk of developing breast cancer due to smoking.
6. Getting help to quit smoking, staying away from triggers, and protecting oneself from secondhand smoke can all bring down the effect of smoking on breast cancer.
7. Opting for genetic testing will tell if a woman is at a higher risk of developing breast cancer because of smoking. If so, taking help to limit/quit smoking and getting screened for cancer regularly help.

References

• https://pubmed.ncbi.nlm.nih.gov/16172223/
• https://www.webmd.com/breast-cancer/news/20050311/secondhand-smoke-linked-to-breast-cancer
• https://www.cdc.gov/tobacco/campaign/tips/diseases/cancer.html
• https://pubmed.ncbi.nlm.nih.gov/2404408/
• https://smokefree.gov/quit-smoking/getting-started/steps-to-manage-quit-day
• https://www.cdc.gov/tobacco/campaign/tips/quit-smoking/index.html
• https://onlinelibrary.wiley.com/doi/full/10.1002/ijc.28508
• https://www.frontiersin.org/articles/10.3389/fonc.2019.00044/fullhttps://pubmed.ncbi.nlm.nih.gov/33913154/ 

All of us know that eating a combo of cheesy supersize pizza, bulging burger, and an ice cream sundae is bad for our health. Yet, the craving for the yummy big Mac burger and a tasty cream cake from a roadside shop doesn’t seem to lessen.

Genetic implications of junk food

Are you someone who has repeatedly tried to control your sweet tooth but remain succumbed to the lures of junk food?

Maybe it is not your fault at all!

Scientists from the National Institute of Allergy and Infectious Diseases in Maryland say so.

According to their findings eating junk food on a regular basis can lead to already known risks of cancer, inflammation, infections, allergic reactions, and permanent scarring in your DNA.

Yes, it is true.

Junk food can alter your DNA and carry on the scar for generations to come altering the mini-ecosystem that exists in our body forever.

It is the foremost cause of obesity and leads to various problems in the immune system and disturbs the intricate chemical makeup of the stomach.

But permanent damage to DNA comes as a shocker as well as a waking call for all the junk food lovers out there!

Gut bacteria and junk food

Our body has evolved over time to adjust to its surroundings and the same goes for the bacteria in the gut.

When you munch on too much junk food, the bacteria in your stomach get affected.

Research has shown that they have already undergone a lot of changes in their gene expressions due to our unhealthy food habits.

Even our DNA has been encoded with our poor dietary choices.

These changes are directly passed on to our off springs stretching across generations.

How it affects your DNA

A mother’s eating habits have a great potential in shaping her child’s flavor and preferences even before birth and determines the child’s choice of food, sugar or vegetable.

The new study also reveals the effect of paternal DNA in molding a child’s food habit.

The developmental imbalances created during a child’s critical developmental period could leave the baby’s immune system weak and may cause autoimmune and allergic diseases.

Save the future generations from obesity

The only way to counteract this alarming condition is a radical change of lifestyle.

The transfer of strained DNA can be stopped only if the present generation moves towards a healthier diet.

Food without salt is tasteless and unappetizing. But, too much salt intake is not good for health. Of course, our body needs salt but not as much as we consume. Only one gram of salt is essential for an adult in a day and even lesser is the need for salt in children. But people take a lot more salt than is medically recommended which is a concern.

Hence to reduce health hazards and to lead a normal life it is advisable that people eat more fresh food rather than tinned and junk food as they  all have huge quantities of salt in them and thereby increasing your overall salt consumption levels.

Gene-Environment Interaction

Our traits are basically divided into genetic and environmental. Genetic factors are the ones a person is born with, and a large chunk of these factors are inherited from the previous generations. Environmental factors include chemical, physical, nutritional, infectious and behavioural factors. Many prevailing diseases such as diabetes and cancer are caused by the complex interplay of genetic and environmental factors. Both the factors will play a part in influencing the diseases. Some may be more influenced by the genetic factors while others will be largely affected by the environmental factors. But, most of the diseases are always associated with the genetic makeup and many inherited diseases can be influenced by environmental conditions.

Some genetic effects are seen only in certain environmental conditions

If you have a genetic predisposition to antisocial behaviour, you may not demonstrate the trait until you experience abuse or neglect in your childhood. If you have had a stress-free and normal  childhood, you will never express this specific genetic trait. The expression of a specific trait towards which you are genetically predisposed  can be prevented by protective environmental factors. If you have a predisposition to alcohol abuse and live in an alcohol-prohibited environment, it may not express itself. Thus, protective genetic factors have a comparatively less significant  effect if environmental exposure is strong.

Few environmental effects are visible only under certain genetic conditions

Response to environmental exposure depends on the genotype, which is a term that defines your genetic make-up for a specific trait/disease. If you have had stress in your early life, it may cause depression in later years. This is only when certain genotypes are present. A person’s genotype can also determine their response to specific medications and their side-effects through various biochemical mechanisms. There is an entire branch of science that studies this called Pharmacogenomics.

Sometimes, genetic effects can influence your environment too

•         If you are an extrovert, you will prefer different social environments than introverts.
•         If you are a person who likes art and have artistic abilities, you will seek an environment that allows development and expression of           your talent.
•         If you are genetically prone to easily fall prey to depression, it may cause conflicts in relationships.
•         Some scientists theorize that genes also confer susceptibility to stress.

If we can identify our genes and characterize their interactions with the environment, we can have intervention strategies to target them. Therefore, when studying the genetic make-up of individuals to determine their natural predisposition towards certain traits and diseases, it is very important to take into consideration the environmental factors like diet, lifestyle, work environment etc, to be able to characterize their inclination towards these traits and their risk for developing specific diseases.