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Breast cancer is one of the most common types of cancer affecting American women. On average, 13% of American women will develop this invasive condition.
Many genetic and environmental factors can increase or decrease a person’s risk of developing breast cancer.
One such factor is the amount of fat you consume.
Dietary fat is a macronutrient needed in the right amounts to keep the body healthy and nourished.
The fat you consume is usually stored as a reserve in the adipose tissue and used as an energy source when you consume fewer calories than what the body needs.
Fat also helps absorb fat-soluble vitamins like vitamin A, D, E, and K.
Fats play a role in protecting your internal organs, keeping you warm, and controlling the action of different hormones.
High levels of dietary fat may increase the sex hormones in a woman’s body (estrogen and progesterone). Some researchers assume that this may be why fats increase the risk of breast cancer, especially hormone-receptor-positive breast cancers.
High dietary fat intake also increases the risk of obesity. Obesity, in turn, increases postmenopausal ER-positive breast cancer risk by increasing estrogen production in the body.
A 2003 study assessed the risk of breast cancer in 90,655 premenopausal women between the ages of 26 and 46. This 8-year study identified 714 cases of breast cancer during the follow-up.
According to the study, women who had consumed high animal dietary fats had a slightly increased risk for breast cancer. The study identified that red meat, animal fat, and dairy products specifically increased cancer risk.
Does The Type of Fat Matter?
There are four major types of dietary fatty acids.
Saturated and trans fat are considered unhealthy fats as they increase blood cholesterol levels and lead to heart conditions.
Unsaturated fats are healthy as they bring down cholesterol levels and also boost heart health.
When it comes to breast cancer risk, the type of fat you consume definitely matters. Many studies relate saturated fats and trans fats to an increased risk for breast cancer. Conversely, some unsaturated fats seem to be protective against breast cancer.
A 2003 meta analysis studies the risk of breast cancer in people who consumed excess dietary fats.
According to the meta-analysis, short-term and long-term studies found that people who consumed excessive saturated fats and meat had a 13% higher risk of breast cancer.
Another combined analysis study that included data from 12 case-controlled studies found a positive relationship between saturated fat intake and breast cancer.
This study also reports that with changes in the diet, up to 24% of postmenopausal women and 16% of premenopausal women in North America decreased their risk of developing breast cancer.
Industrial Trans Fatty Acids (ITFAs) are trans fats produced in industries and added to various dairy products, snacks, and pastries. Ruminant Trans Fatty Acids (RTFAs) are made in the bodies of cows, goats, sheep, and other animals as a result of bacterial action. RTFAs are present in most animal fats, and consuming these fats increase RTFA levels in the body.
The European Prospective Investigation into Cancer and Nutrition (EPIC) found a positive relationship between ITFA and RTFA consumption and the risk of breast cancer in 318,607 women.
A 2005 study analyzed the effects of unsaturated fatty acids on breast cancer risk. The study reported that omega-3 fatty acids, a type of polyunsaturated fatty acid, brought down the risk of breast cancer.
In contrast, omega-6 fatty acids, a different kind of polyunsaturated fatty acid, increased the risk of breast cancer.
A 2015 article observed the interaction of omega-3 fatty acids and omega-6 fatty acids in the development of breast cancer in 1463 breast cancer patients and 1500 controls. The study suggests that American women can reduce their risk of breast cancer by increasing their omega-3 fatty acid intake (omega-3 has anti-inflammatory properties) and decreasing the consumption of omega-6 fatty acids (Omega-6 induces inflammation).
When it comes to MUFAs, the type of food plays a role in increasing or decreasing cancer risk.
A 1993 meta-analysis study reported that MUFAs also increase a woman’s risk of developing breast cancer.
Another study reported that oleic acid and palmitic acid, types of monounsaturated fatty acids, increased the risk of breast cancer in women.
Olive oil, which is rich in MUFA, seems to protect against cancers, though. People who chose olive oil over other lipids like butter had high levels of protection against all cancers, including breast cancer.
The DOCK1 gene (Dedicator of cytokinesis gene) helps create the DOCK180 protein that plays a role in signaling between cells.
rs113847670 is a single nucleotide polymorphism or SNP in the DOCK1 gene. It is associated with breast cancer risk. The T allele of this SNP results in 5 times higher risk of developing breast cancer on excess intake of saturated fats.
| Allele | Implications |
| T | 5-times higher risk of developing breast cancer on excess intake of saturated fats |
| C | Normal risk of breast cancer on excess intake of saturated fats |
Obesity is one of the factors that can contribute to increased breast cancer risk. Excess intake of fats can lead to weight gain and obesity too. As a result, the combination of obesity and excess fat intake can aggravate breast cancer risk.
This is true, especially in post-menopausal women. Such women can bring down their risk of breast cancer by limiting saturated and trans-fat intake.
Other than cutting back on fats, the following dietary changes can help lower breast cancer risk:
Genetic testing will tell how harmful fat consumption is for your body. If you are at higher risk of developing breast cancer because of fat intake, talk to a nutritionist to control the risk.
Menarche marks the beginning of the first menstrual cycle. This is a significant event of puberty and helps the body prepare for reproduction. According to the National Health Statistics Report, the mean age of menarche in the United States between 2013 and 2017 was 12.5. Globally, the mean age of menarche is about 13.
Menarche marks the beginning of the production of female reproductive hormones. These hormones circulate in the body until menopause. During the reproductive years of a woman (the period between menarche and menopause), the levels of the two steroid hormones, estrogen and progesterone, keep fluctuating.
The progesterone levels increase during the luteal phase. It is the highest during the mid-luteal phase and decreases when periods start. Progesterone is responsible for thickening the endometrium walls and preparing the body for a possible pregnancy. The estrogen levels increase twice during each menstrual cycle - once during the mid-follicular phase and once during the mid-luteal phase.
The follicular phase is the phase between the first day of menstruation and the next ovulation day. It lasts between 14 and 16 days. The luteal phase is the phase after ovulation until the next menstrual cycle. This lasts for 11-17 days.
The lifetime cumulative number of menstrual cycles is a term that denotes the total number of menstrual cycles a woman experiences in her lifetime. With increased menstrual cycles, the woman’s exposure to estrogen and progesterone also increases. These hormones circulate the breast tissues and increase the risk of developing breast cancer.
Therefore, the number of menstrual cycles a woman has is a risk factor for developing breast cancer.
Studies show that women who have regular and shorter menstrual cycles have a higher risk for breast cancer than those with longer cycles.
These studies also report that women who had more menstrual cycles before their first full-term pregnancy were at higher risk for breast cancer.
A population-based study analyzed the relationship between the number of menstrual cycles a group of 6718 women had before menopause and their risk of breast cancer. The study reports that women who had more menstrual cycles and hence more exposure to estrogen were at higher risk for breast cancer.
With early menarche, women have increased exposure to estrogen and progesterone. For instance, assuming the menopausal age to be 50, a woman with a menarche age of 11 has a 39-year exposure to the hormones. On the other hand, another woman with a menarche age of 17 only has a 33-year exposure to the hormones.
A study analyzed serum estrone (E1) and estradiol (E2) levels in postmenopausal women. The study shows that women with a late menarche age (later than 17 years) had significantly lesser amounts of E1 and E2 levels after menopause. This brought down their risk of breast cancer.
A meta-analysis studied the relationship between menarche age and risk of breast cancer in 118,964 women with a breast cancer diagnosis across 117 studies. According to the meta-analysis, breast cancer risk increases slightly for each year earlier menstruation begins (by about 5%).
Another study reported that women with a menarche age of 11 or lower had a 15-20% higher chance of developing breast cancer than women with a menarche age of 15 or higher.
Changes in the functioning of specific genes (genetic polymorphisms) can increase or decrease the menarche age and, as a result, increase or decrease the risk of breast cancer.
The INHBA gene (Inhibin, beta A gene) helps produce the INHBA protein. This protein plays a role in controlling the production of the Follicle-Stimulating Hormone (FSH). FSH increases and decreases during each menstrual cycle and plays a role in the maturation of the reproductive system.
rs1079866 is a single nucleotide polymorphism or SNP in the INHBA gene. It has been associated with breast cancer risk. The C allele of this SNP has been associated with lower age of menarche and increased risk of breast cancer.
In women with a lower menarche age, the SNP rs1079866 of this gene showed an increased risk of developing breast cancer. People with this SNP had a per-risk-allele odds ratio of 1.14.
The PXMP3 gene helps produce the PXMP3 protein (peroxisomal membrane protein 3). The A allele of the SNP rs7821178 is associated with a higher risk of breast cancer in women with early menarche ages.
The LEP gene helps produce a hormone called leptin. Leptin is responsible for maintaining body weight and controlling fat stores. Leptin also plays a role in fertility and the initiation of puberty.
People with the AA genotype of the SNP rs7799039 of this gene have early menarche and an increased risk of breast cancer.
Studies show an inverse relationship between Body Mass Index (BMI) levels and menarche age. Younger girls who fall under the overweight and obese categories get their first menstrual cycle very early. This can increase the risk of breast cancer in girls as they grow up. Maintaining healthy BMI levels from a very young age can help women lower breast cancer risk.
Girls who were physically active as they grew up have significantly delayed menarcheal age compared to girls who did not have much physical activity. A Canadian study reports that girls who participated in dance, swimming, figure skating, and diving competitions had a lower risk of reaching early menarcheal age. Adequate physical activity will help bring down the risk of breast cancer as the girls grow up.
A 2004 study analyzed the effects of tobacco smoke exposure in little girls and their menarcheal age. According to the study, girls who had high exposure to prenatal smoke and secondhand smoke had early menarche compared to girls who were not exposed to tobacco smoke.
Early menarche age and the inhalation of carcinogenic chemicals from tobacco smoke can both increase the girl’s risk of breast cancer when she grows up.
A small-scale study analyzed the effects of nutrition on menarche age. According to the study, girls who consumed more animal proteins than plant proteins between the ages of 3 and 5 had earlier menarche.
Another study reported that girls who consume isoflavones, a type of isoflavonoid (plant compound) produced by the bean family, experience slightly delayed menarche. Soybeans, chickpeas, peanuts, and pistachios are rich in isoflavones.
According to the 2019 National Survey on Drug Use and Health (NSDUH) report, 85.6% of people in the United States who are 18 or older had consumed alcohol at some point in life.
51% of women reported that they consumed alcohol in the past month.
While alcohol consumption causes many health problems, it is also a risk factor for breast cancer.
Breast cancer is the most common type of cancer affecting millions of women globally. In the United States, 1 in every eight women will develop invasive breast cancer in her lifetime.
There are few reasons why researchers think alcohol consumption is related to breast cancer.
When a person consumes alcohol (ethanol), it goes through multiple detoxification pathways and uses several enzymes. One such enzyme is alcohol dehydrogenase (ADH). ADH converts ethanol to AA. AA is carcinogenic (cancer-causing) and needs to be quickly eliminated from the body.
While ADH is primarily expressed in the liver, it is also found in small quantities in the breast tissue. ADH converts ethanol into AA in the breast tissues and causes abnormal DNA changes, leading to breast cancer.
Alcohol can increase estrogen levels in the body. A particular study reported that when compared to women who don’t drink, pre-menopausal women who drink have an 18% increase in serum estrogen levels.
The body uses CYP enzymes to clear out excess estrogen from the body. These enzymes convert estrogen into intermediaries that are then removed from the body. This conversion process releases free radicals that can cause cell DNA abnormalities and increase the risk of cancers, including breast cancer.
Higher levels of estrogen in the body can also increase the activity of the Estrogen Receptor α (ERα) protein. This protein attaches itself to the DNA and controls various genes. Increased ERα activity leads to increased cell division and growth (cell proliferation), increasing the chance of cell damage and resultant cancer.
Breast density or mammographic density is a measure of the type of tissues that make up the breasts. Breasts contain fat tissues, glandular tissues (tissues that help make breast milk), and connective tissues.
People with high glandular and connective tissues in the breast and less fatty tissues have high breast density. On the contrary, people with high levels of fat tissues, when compared to glandular and connective tissues, have low breast density.
According to a meta-analysis that looked into more than 42 studies, women with more than 75% breast density had up to 5 times higher risk for developing breast cancer than women with less than 5% breast density.
On mammograms (X-rays to examine human breasts), fatty tissues look dark, and connective and glandular tissues look clear or white. Cancer cells also appear white. As a result, cancer cells may be hidden on mammograms until they have grown or spread in people with higher breast density. This makes breast cancer treatments more complicated.
A study interviewed 262 women in New York and analyzed their mammograms and alcohol intake pattern. According to the study, women who drank at least seven drinks a week had a 12.3% higher breast density than women who don’t drink.
Another 2015 study analyzed the relationship between drinking patterns and breast density in 189 women. This study also reported that women who drank more than seven drinks a week had higher breast density than those who did not drink.
The ALDH2 gene helps produce the Aldehyde dehydrogenase (ALDH) enzyme. Changes in the gene can lead to problems in the production of the ALDH enzyme. This enzyme helps in clearing alcohol from the body.
According to studies, people with the AA and GA genotype of the Single Nucleotide Polymorphism (SNP) rs671 of this gene have a higher risk for developing breast cancer when they consume alcohol than people with the GG genotype.
| Genotype | Implication |
| AA | Increased risk of breast cancer on alcohol consumption |
| GA | Increased risk of breast cancer on alcohol consumption |
| GG | Normal risk of breast cancer on alcohol consumption |
The CYP2E1 gene helps produce the CYP2E1 enzyme. This enzyme helps in clearing up to 20% of ethanol in the brain.
According to a Korean study, women who had the CYP2E1 c2 allele and drank at least once a month had a 1.9-fold increased risk for developing breast cancer than non-drinking women with the CYP2E1 c1/c1 genotype.
The GSR gene (Glutathione-Disulfide Reductase gene) helps produce the GSR enzyme. This enzyme helps in preventing oxidative stress and cell damage in the body.
The SNP rs1002149 in this gene is associated with breast cancer risk on alcohol intake. The T-carriers of this SNP showed a 24% higher risk for developing breast cancer when they consumed more than 10 grams of alcohol a day. The GG carriers did not show such a risk.
| Genotype | Implications |
| GG | No risk of breast cancer because of alcohol consumption |
| GT | Increased risk of breast cancer on consuming more than 10g alcohol/day |
| TT | Increased risk of breast cancer on consuming more than 10g alcohol/day |
The risk for breast cancer increases with an increase in alcohol consumption. A meta-analysis of 53 reports reported the following.
The study also suggested that the risk of breast cancer increased by 7% for every additional drink the woman has had per day
It is not enough to calculate the number of drinks to analyze the risk for breast cancer. The drinking patterns should also be taken into account.
Drinking multiple alcoholic beverages in the same sitting is considered riskier than consuming moderate quantities over the week. For instance, a woman who has seven drinks over the weekend and refrains from drinking on weekdays is at higher risk for breast cancer than a woman who has one drink a day.
Studies show that early-life exposure to environmental carcinogens increases a woman’s risk of developing cancer. The age between menarche (the first menstrual cycle) and the first pregnancy is considered a high-risk period.
Women who drink excessively or take up binge drinking at an early age are more affected by alcohol during this period and are at a higher risk of being diagnosed with breast cancer in the future.
Different types of alcohol have different levels of ethanol content in them. This can increase or decrease the risk of developing breast cancer. Also, certain alcoholic beverages like red wine have antioxidant properties that can protect against cancers to an extent.
A small study reported that resveratrol, a type of polyphenol (plant-compound) found in red wine, can bring down estrogen production in the body and decrease the risk of developing breast cancer. Red wine also seems to help reduce breast density in young premenopausal women.
Another study talks about the chemoprotective effects of beer. Beer contains the pods of a coneflower called hop that gives the drink its bitterness and flavor. Hops contain substances like xanthohumol and hop-bitter acids that may have cancer-preventing abilities.
Please Be Advised: Alcohol consumption more than your daily dose can increase your risk of accident, injury or hangover.
Some people just cannot completely avoid drinking. Drinking in moderation may help in such cases. Taking one or lesser drink per day can help bring down the risk of breast cancer.
When the body suddenly processes excess alcohol, it struggles and leads to excess production of acetaldehyde and estrogen.
Avoid binge drinking and split your alcohol dosage evenly throughout the week. According to the National Institute on Alcohol Abuse and Alcoholism, binge drinking in women equals consuming more than four drinks in 2 hours.
Early exposure to alcohol, especially between the periods of menarche to the first pregnancy, can cause irreparable damage to the breast cells. Several studies have shown that the breast cells are easily damaged/altered by environmental factors in the early periods.
In the United States, the minimum drinking age is 21. However, reports show that 1 in 4 women aged between 12-20 have consumed an alcoholic beverage in the last month.
Women who have started drinking before 25 years seem to be at a higher risk for developing breast cancer than women who started later.
Avoid consuming alcohol before 21 and limit the number of drinks you consume after the legal age.
Breast cancer is a result of several genetic and environmental factors, and alcohol consumption is just one of them. Genetic testing will tell you if you are genetically at a higher risk for developing breast cancer. If so, you may want to control the environmental factors better.
If you belong to the high-risk category, getting a mammogram periodically helps too.
Did you know that a person’s chance of developing breast cancer could be genetic? Here’s how it happens.
We inherit DNA from our parents. Our DNA is present within each of the trillions of cells in our body. DNA contains the instruction manual that determines how our bodies function.
Within the DNA, there are thousands of genes that produce all the proteins required by the body. You have two copies of every gene: one from your mum and one from your dad. The mix of your genes is different from that of another person’s. In fact, only identical twins share the same genes.
Sometimes these genes contain faults, called mutations. In most cases, these faults do not have any dangerous effects. But certain mutations alter the proteins that play vital roles in the body. It can disrupt normal development and may lead to medical conditions.
Two genes, BRCA1 and BRCA2, are associated with breast cancer. Contrary to popular belief, these genes don’t cause breast cancer. In fact, they have a protective role against cancers! In some cases, BRCA1 and BRCA2 genes have mutations that interfere with their protective role. Though these mutations may not definitely cause breast cancer, they do increase the chance for it to develop.
A faulty BRCA1 or BRCA2 gene can be passed down from one generation to the next. If either your mum or dad carries a faulty version, then the chance of you having the faulty gene is 50%. Similarly, if you inherit one faulty gene, the chance of you passing it on to each child is 50%. Breast cancer genes cannot skip generations. People who have a family history are estimated to have at least a one-in-ten chance of carrying a faulty gene.
Genetic tests analyze the BRCA gene and help family members find out whether or not they are at increased risk for breast cancer. More than 1,000 mutations in the BRCA1 and BRCA2 genes are known to increase cancer risk.
Xcode Life’s BRCA genetic analysis includes 18 breast cancer-related traits.
Most genetic ancestry companies like 23andMe, provide your DNA information in the form of a text file. This file is called the DNA raw data. Your 23andMe raw data contains several of the BRCA gene markers, which can be analyzed to find out your breast cancer risk. This data looks like a bunch of letters and numbers, which may not make much sense to you.
But, Xcode Life can interpret all this information for you!
All you need to do is upload your raw data and order the BRCA and breast cancer report. Xcode Life then analyzes your raw data in detail to provide you with a comprehensive Breast Cancer Risk analysis.
Xcode Life’s BRCA and Breast Cancer Report targets genes that are associated with cancer susceptibility. This report helps you learn about your predisposition to breast and other cancers and take preventive action.
BRCA is an abbreviation for Breast Cancer Gene.
BRCA1 and BRCA2 are the most common genes associated with breast and ovarian cancers. These genes actually help prevent tumor cell formation by repairing any DNA damage. If there are any errors or mutations in these genes, it can increase the risk of several cancers, including breast, ovarian, prostate, and pancreatic cancer.
Testing positive for a BRCA mutation means your risk of developing breast and ovarian cancer is greater than that of the average person. However, higher risk does not imply a diagnosis of cancer.
In the Breast Cancer Report, we profile genes that are shown to be associated with an increased risk of breast cancer and your response to various drugs administered for breast cancer.
In 2018, FDA approved the genetic testing of 3 specific BRCA gene mutations. Women who test positive for one of the mutations are at increased risk of developing breast and ovarian cancers. A faulty BRCA1 or BRCA2 gene can be passed down from one generation to the next. In the first section of the report, the three FDA-approved markers and other mutations in the BRCA genes associated with increased cancer risk are analyzed.
People who have a family history of breast cancer are estimated to have at least a one-in-ten chance of carrying a faulty gene.
The report also profiles other genes that indirectly affect the risk of breast cancer. Some examples are genes that affect the expression of estrogen receptors, breast size, and Estradiol Plasma Levels.
Your gene variations also influence breast cancer drug therapy. Understanding your genetic metabolism of various drugs will help you avoid potential adverse events related to ineffectiveness of, or hypersensitivity to the therapeutic agent.
The term ‘Evidence Level’ used here is a parameter that describes the strength of the association between the drugs and the genes implicated.
Evidence Level 1A describes the strongest association. This means that the relationship has been established across various studies and approved by guidelines like CPIC. Gene variants under 2A are considered to be Very Important Pharmacogenes by PharmGKB. The Functional significance here is more likely.
Please bear in mind that human traits are a result of complex interactions between multiple genes and environmental factors. The findings presented in this report are of a preliminary nature and are not meant for diagnostic purposes.
The report analyzes 25+ breast cancer-related parameters, grouped under categories like mammographic factors, lifestyle factors, hormonal factors, reproductive lifespan, associated comorbidities, management, and pharmacogenomics. For a comprehensive list of the traits covered, click here.
For a sample BRCA report/ preview of the report, click here.
Breast cancer usually occurs in women around the age of 50. However, in some women, breast cancer develops around 18-45 years of age, a condition called early-onset breast cancer. According to the Center for Disease Control, 1 in 10 women who are diagnosed with breast cancer is under the age of 45.
Another report from JAMA 2015 notes that 15% of deaths due to breast cancer occur in women whose disease was detected before 45 years of age. Early-onset breast cancers are generally hereditary but are often diagnosed late. Some of these cancers are also very aggressive and difficult to treat.
Since early-onset breast cancer has a strong hereditary influence, genetics plays an important role in its development. Most women diagnosed with early-onset breast cancer have a family member who has or has had breast or ovarian cancer. Having a male member with a history of breast cancer also increases their risk.
Some genes that have shown to increase risk are:
The BRCA1 Interacting Protein C-terminal Helicase 1 or BRIP1 gene contains instructions for producing tumor suppressor proteins. Changes in this gene are associated with breast cancer and Fanconi’s Anemia, a type of early childhood cancer syndrome. The BRIP1 gene, along with the BRCA1 gene, helps repair damaged DNA. The damaged parts of the DNA are removed and the remaining structure is restored to health.
The Fibroblast Growth Factor 2 or FGFR2 is a gene that produces proteins to regulate fibroblast growth factors. These growth factors participate in cell growth and multiplication. Mutations or changes in the FGFR2 gene have been associated with multiple types of cancers, including breast, lung, and ovarian cancer.
https://www.cdc.gov/cancer/videos/breast/bringyourbrave/earlyonsetbreastcancer/introduction-riskfactors/introduction-riskfactors-ADTranscript-508.pdf
https://www.hopkinsmedicine.org/breast_center/breast_cancers_other_conditions/family_history_breast_cancer.html
https://www.genecards.org/cgi-bin/carddisp.pl?gene=BRIP1
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3109611/
https://pubmed.ncbi.nlm.nih.gov/24780616/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5666331/
https://www.nature.com/articles/srep12773
https://pubmed.ncbi.nlm.nih.gov/30515698/
https://www.nature.com/articles/srep12773
https://www.cancer.org/cancer/breast-cancer/screening-tests-and-early-detection/american-cancer-society-recommendations-for-the-early-detection-of-breast-cancer.html
Breast cancer develops as a result of abnormal growth and development of cells in the breast tissue. The breast is made up of three important parts:
- Lobules: Milk-producing glands
- Ducts: Tube-like parts that carry milk from lobules to the nipples
- Connective tissues: Tissues that surround the breast
Abnormal cell growth can occur in any of the three parts but is more commonly seen in the lobules and ducts.
Sometimes the cancer cells can spread to other parts of the body via the lymph system or blood, resulting in metastasized cancer.
Around the world, breast cancer affects 12% of women. It is also the leading cause of cancer deaths in women - 14% of all cancer-related deaths in women are because of breast cancer.
Both genetic and non-genetic factors can increase a person’s risk of developing breast cancer.
About 5-10% of breast cancer cases are thought to be hereditary. Women with first-degree relatives affected with breast cancer fall under the high-risk category for developing the condition.
Changes or mutations in two genes - BRCA1 and BRCA2 are majorly associated with breast cancer risk. Both these genes help make tumor suppressor proteins and are beneficial to the body. Tumor suppressor proteins prevent the abnormal growth and division of cells.
Changes in these genes result in less or abnormal production of tumor suppressor proteins and thereby increase the risk of developing all kinds of cancers, including breast cancers.
Having a mutation in these genes does not mean that the individual will be diagnosed with breast cancer. These mutations just indicate high risk and warrant further investigation and close monitoring.
The BRCA1 gene contains instructions for the production of tumor suppressor proteins. Other than preventing abnormal cell growth, the tumor suppressor proteins also:
Interact with other proteins to repair damaged DNA
Regulate the activity of other genes
Prevent damaged DNA from getting passed on to other healthy cells
There are 25 SNPs or Single Nucleotide Polymorphisms in the BRCA1 gene, that play a role in increasing the risk of breast cancer.
The BRCA2 gene also plays a role in the production of tumor suppressor proteins and has 25 SNPs associated with increased breast cancer risk.
Men and women who are more than 50 years of age are at higher risk for developing breast cancer than younger individuals. Women aged 70-74 fall under the highest risk category.
Breast cancer is most often found in women. Only 1 % of all breast cancers in the United States are diagnosed in men.
In the United States, white and black women have a higher risk for developing breast cancer than American Indians, Asians, Pacific Islanders, and Hispanics.
Tumorous cell growth is difficult to detect in women with dense breasts because of increased connective tissues. Such women are at higher risk of developing more complications because of late diagnosis.
Girls who get their menstrual periods before 12 years of age are at higher risk for developing breast cancer as they grow older. Similarly, women who experience late menopause (after 55 years of age) are at higher risk for breast cancer.
According to a worldwide study, women who give birth to their first full-term child early seem to be more protected against breast cancer. Women who had their first child after 35 had a 22% increased risk for developing breast cancer.
Women who have had breast cancer in the past are at higher risk for developing it again.
A population-based study analyzed the effects of breastfeeding on breast cancer risk in 553 women. According to the study, women who breastfed their babies for more than 13 months had a significantly lesser risk for developing breast cancer.
Women who had radiation exposure in the breasts before the age of 30 have a higher risk for developing breast cancer.
Post menopausal women who are obese are at higher risk of developing breast cancer than women with normal BMI levels. Obese women with breast cancer have worse disease progression and lower overall survival rates.
Since obesity is a risk factor for breast cancer, maintaining healthy BMI levels and staying physically active can help bring down the risk.
Women who have started smoking during adolescence are at very high risk for developing breast cancer. A study done in the United Kingdom analyzed 102,927 women who smoked. A follow-up study done after of 7.7 years, revealed that 1815 of these women had developed breast cancer.
Studies show that women who consume even moderate amounts of alcohol regularly are at 30-50% higher risk for developing breast cancer.
For women who are already in the high-risk category, alcohol consumption adds to the risk.
A study recruited 89,538 women aged 34-59 years with no prior history of cancer. The study recorded and monitored their alcohol consumption history. In the next four years, 601 cases of breast cancer were diagnosed in the study group.
The risk of breast cancer was relatively higher in women who consumed more than three drinks a week.
Genetic testing for mutations in the BRCA1 and BRCA2 genes will tell you if your breast cancer risk is higher than normal. If you are at a higher risk, talk to a counselor to understand how you can handle the risk. You may be asked to go through breast cancer screening more frequently to help with early diagnosis.
https://www.cdc.gov/cancer/breast/index.htm
https://www.cdc.gov/cancer/breast/basic_info/risk_factors.htm
https://www.cancer.org/cancer/breast-cancer/about/what-is-breast-cancer.html
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4491690/ https://www.cdc.gov/cancer/breast/men/index.htm
https://www.cancercenter.com/community/blog/2019/07/whats-the-difference-female-male-breast-cancer
https://pubmed.ncbi.nlm.nih.gov/5312521/
https://medlineplus.gov/genetics/gene/brca2/#conditions
Breast cancer is the most common invasive cancer in women in the developed and developing world. About 5 to 10% of breast cancer cases are inherited.
Inherited breast cancer results from changes or mutations in certain genes that are passed on from a parent. Breast cancer prognosis is better when the cancer is detected in the early stages.
BRCA stands for BReast CAncer gene. More than 1000 different mutations or changes in these genes have been identified to increase breast cancer risk. The role of BRCA genes in breast cancer was first identified in the 1990s. Clinical testing for BRCA mutations gained popularity when Angelina Jolie, who was tested positive for BRCA mutations, underwent preventive surgery to decrease her risk of developing breast and ovarian cancer.
In 2018, the Food and Drug Administration (FDA)approved the reporting of three specific mutations in the BRCA1/BRCA2 genes for breast cancer screening. The FDA-approved markers can be used to identify the risk for breast and ovarian cancer in women, and breast and prostate cancer in men.
In the US, these mutations are found in 2% of people of Ashkenazi (Eastern European) Jewish descent and less than 0.1% of the population overall.
Testing positive for any one of these markers indicates an increased risk of developing breast and ovarian cancers in women and breast and prostate cancers in men. On the other hand, an absence of the three tested mutations does not rule out the chances of developing any of the conditions mentioned above. These three mutations are not very common in the general population.
Changes in the BRCA genes have been linked to an increased risk of breast cancer. Genetic changes can accumulate over time as cells divide. Some of these changes lead to uncontrolled cell division, increasing a person’s risk of developing cancer.
Not all cancers are inherited, but a parent carrying a change in the BRCA genes can pass it on to their children and increase their lifetime risk of developing cancer.
The BRCA1 gene or BReast CAncer 1 gene carries instructions for producing a tumor suppressor protein that helps prevent uncontrolled cell growth and division. This protein also plays a role in repairing damaged DNA, which is crucial for maintaining genome stability.
The BRCA2 gene or BReast CAncer 2 gene is also a tumor suppressor gene.
https://www.cancer.org/latest-news/fda-approves-consumer-test-for-certain-brca-mutations.html
https://www.fda.gov/news-events/press-announcements/fda-authorizes-special-controls-direct-consumer-test-reports-three-mutations-brca-breast-cancer
https://www.23andme.com/brca/
https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet
https://medlineplus.gov/genetics/gene/brca1/
https://medlineplus.gov/genetics/gene/brca2/
The name “BRCA” is an abbreviation for the “BReast CAncer gene.” BRCA1 and BRCA2 are two different genes found to impact a person’s chances of developing breast cancer.
Despite what their names might suggest, BRCA genes do not cause breast cancer. These genes normally play a big role in preventing breast cancer.
The BRCA genes carry instructions for the production of proteins that are responsible for preventing uncontrolled cell growth. These proteins are called tumor suppressor proteins. If these proteins do not function properly, it results in uncontrollable growth of cells, which may end up being cancerous.
The BRCA proteins also help repair damaged DNA, thereby maintaining the stability of genetic information. DNA damage can occur due to errors during the DNA replication process or by environmental agents like UV or ionizing radiation.
Certain changes or mutations in the BRCA genes prevent the proteins from doing their job properly and may lead to uncontrolled cell division, increasing a person’s risk of developing cancer. These genetic changes are called harmful or pathogenic variants.
Not all cancers are inherited, but a person carrying a change in the BRCA1 or BRCA2 gene can pass it on to their children and increase their lifetime risk of developing cancer. If either your mother or father has a BRCA1 or BRCA2 gene mutation, you have a 50% chance of having the same gene mutation.
About 1 in every 500 women in the United States has a mutation in either her BRCA1 or BRCA2 gene.
Inherited mutations in the BRCA1 gene are responsible for about 40-45% of hereditary breast cancers.
BRCA2 germline mutations, which are mutations inherited from either parent, are seen in approximately 35% of families with incidences of early-onset breast cancer in their women.
According to the National Cancer Institute, NIH, 55-72% of women who inherit a harmful BRCA1 mutation and 45-69% of women who inherit a harmful BRCA2 mutation will develop breast cancer by 70-80 years of age.
39%-49% of women who inherit a harmful BRCA1 mutation and 11-17% of women who inherit a harmful BRCA2 mutation will develop ovarian cancer by 70-80 years of age.
Harmful variants in the BRCA1 gene are also linked to a risk of fallopian tube (tubes that connect the ovaries to the uterus) cancer, primary peritoneal cancer that occurs in the lining of the abdomen, pancreatic cancer, and prostate cancer. However, the risk of developing these types of cancer is lower than that of breast cancer.
Mutations in the BRCA genes increase the risk of breast cancer in males too. Men with a BRCA2 gene mutation have a 7 in 100 chance of developing breast cancer, while men with a BRCA1 gene mutation have a 1 in 100 chance of developing breast cancer.
The likelihood of carrying an inherited mutation in BRCA1 or BRCA2 varies across different ethnicities. In the general population, BRCA mutation(s) can be seen in about 1 in 400 people. This number increases to 2 in 100 in people of Ashkenazi Jewish descent. The mutations found in this population are usually one of three FDA-approved variants.
Different population groups also carry different variants - for example, African Americans carry a particular variant in the BRCA1 gene that is not found in the other ethnic groups in the U.S.
https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5524247/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3720154/
https://www.cdc.gov/genomics/disease/breast_ovarian_cancer/genes_hboc.htm
https://www.cancer.net/cancer-types/breast-cancer-men/risk-factors
https://pubmed.ncbi.nlm.nih.gov/32259785/
