|BRCA2 (breast cancer susceptibility gene 2)/ Photo By petarg via Shutterstock|
Cancer is one of the leading health conditions that cause death worldwide. There were an estimated 14.1 million cancer cases around the world in 2012, of these 7.4 million cases were in men and 6.7 million in women. This number is expected to increase to 24 million by 2035 as obtained from the World Cancer Research Fund.
BRCA - What is it?
The BRCA is a tumor suppressor gene which is closely associated with breast cancer risks. It comes in 2 types: BRCA 1 and 2. Mutation in either one or both of these genes poses a greater risk in chances of having breast cancer. Everyone of us has this type of gene but others, unfortunately, might carry an inherited mutation within them which makes them at risk of acquiring this condition.
What is the difference between the two?
Male breast cancer, pancreatic cancer, testicular cancer, and early-onset prostate cancer may also be associated with pathogenic variants in BRCA1; however, male breast cancer, pancreatic cancer, and prostate cancer are more strongly associated with pathogenic variants in BRCA2.
Pathogenic variants in BRCA1 and BRCA2 appear to be responsible for disease in 45% of families with multiple cases of breast cancer only and in up to 90% of families with both breast and ovarian cancer.
Genetic testing for BRCA1 and BRCA2 pathogenic variants has been available since 1996. As more individuals have undergone testing, risk assessment models have improved. This gives providers better data to estimate an individual patient’s risk of carrying a pathogenic variant, but risk assessment is still needed. There are factors that might limit the ability to provide an accurate risk assessment (i.e., small family size, paucity of women, or ethnicity) including the specific circumstances of the individual patient (such as the history of disease or risk-reducing surgeries).
Studies show that BRCA2 has a lower risk of having male breast cancer than BRCA1. However, these may not always be the case such as in a study of 160 BRCA1 and 132 BRCA2 pathogenic variant–positive families from the Breast Cancer Family Registry where they found no evidence for increased risk among non-carriers in these families.
A number of methods are in development in order to obtain more information with regards to the changes, pathologic characteristics, and sequence variations on BRCA genes.
Among the general population, the likelihood of having any BRCA variant is as follows:
General population (excluding Ashkenazim): about 1 in 400 (~0.25%).
Women with breast cancer (any age): 1 in 50 (2%).
Women with breast cancer (younger than 40 years): 1 in 10 (10%).
Men with breast cancer (any age): 1 in 20 (5%).
Women with ovarian cancer (any age): 1 in 8 to 1 in 10 (10%–15%).
Among Ashkenazi Jews individuals, the likelihood of having any BRCA variant is as follows:
General AJ population: 1 in 40 (2.5%).
Women with breast cancer (any age): 1 in 10 (10%).
Women with breast cancer (younger than 40 years): 1 in 3 (30%–35%).
Men with breast cancer (any age): 1 in 5 (19%).
Women with ovarian cancer or primary peritoneal cancer (all ages): 1 in 3 (36%–41%).
Two large U.S. population-based studies of breast cancer patients younger than 65 years examined the prevalence of BRCA1 and BRCA2 pathogenic variants in various ethnic groups. The prevalence of BRCA1 pathogenic variants in breast cancer patients by ethnic group was 3.5% in Hispanics, 1.3% to 1.4% in African Americans, 0.5% in Asian Americans, 2.2% to 2.9% in non-AJ whites, and 8.3% to 10.2% in AJ individuals. The prevalence of BRCA2 pathogenic variants by ethnic group was 2.6% in African Americans and 2.1% in whites.
In addition, biochemical properties of amino acid changes, incorporation of information on pathologic characteristics of BRCA1- and BRCA2-related tumors (e.g., BRCA1-related breast cancers are usually estrogen receptor [ER]–negative), and functional studies to measure the influence of specific sequence variations on the activity of BRCA1 or BRCA2 proteins..
Breast Cancer - in Men
When we talk about breast cancer, most of those affected by this condition is mostly females. Often, we might not consider men being involved but the truth is males could also get this disease and might also contain risks for other cancer, just like prostate cancer.
Breast cancer in men is rare, but it does happen. Less than 1% of all breast cancers occur in men with estimated new cases of 2,550 rising in the United States alone. Researchers have some evidence that breast cancer in men has different biological features than breast cancer in women. Still, because the disease is uncommon, research is limited.
Eric Dunlap was diagnosed with breast cancer 18 years ago, since then he had undergone a mastectomy and numerous sessions of chemotherapy. Even though he had a family history, Eric never thought to take the special genetic BRCA test before he was diagnosed. The test might have shown whether he'd inherited the risk.
|BRCA1 tumor supressor protein RING domain/ Photo By petarg via Shutterstock|
Dunlap said, "My grandmother had breast cancer. My mother had breast cancer but I was never worried."
Dr. Cleetus Arciero is a surgical oncologist and says it's important to know your risks.
"Being aware of your family history, being aware of your own history in terms of different types of cancers will help you to become more aware of what your risk is of having some sort of genetic mutation," Arciero said.
It's not just about breast cancer. Following a research trial, researchers found that men with certain mutations in the BRCA genes had a higher risk of developing malignant abnormalities of the prostate, pancreas, colon, and melanoma. While women and men are both at risk, a new study reveals women take the BRCA test for breast cancer nearly three times more than men.
A study published in the Journal of Clinical Oncology, specified features which revealed the distinction of breast cancer in men. They had obtained the following results:
- The expression of genes that control the number of estrogen receptors, the rate of cell division, and the ability of cancer to invade healthy tissue were higher in breast cancers in men than in breast cancers in women.
- Men had higher rates of larger cancer tumors and grade 3 tumors compared to women.
- Invasive ductal carcinoma was the most common type of breast cancer diagnosed in both genders but was more common in men: 87.6% compared to 81.3%.
- Men were much less likely to be diagnosed with lobular breast cancer than women: 1.2% compared to 8.2%.
- While most of the people in the study had no cancer in their lymph nodes (73.2% of men and 80.1% of women), men were more likely to have one to three lymph nodes involved: 12.1% compared to 8.7%.
Because breast cancer in men is rare, it is hard to study the biology of the disease itself, as well as the best way to treat it. Most male breast cancer treatments have been modeled on treatments for women. As far as treatment is considered, various risks are also involved with regards to this disease, here as some of them:
Family health history: Definite familial tendencies are evident, with an increased incidence seen in men who have a number of female relatives with breast cancer.
Major inheritance susceptibility: An increased risk of male breast cancer has been reported in families with BRCA mutations, although the risks appear to be higher with inherited BRCA2 than with BRCA1 mutations. Genes other than BRCA may also be involved in predisposition to male breast cancer, including mutations in the PTEN tumor suppressor gene, TP53 mutations (Li-Fraumeni syndrome), PALB2 mutations, and mismatch repair mutations associated with hereditary nonpolyposis colorectal cancer.
This mutation does not always lead to cancer. But more so, we must pay attention to our bodies especially with regards to any change in our physical or mental state. Even though we can already hold a sigh of relief, we must also consider knowing our family history as well. These are vital tools for physicians as it aids in the detection of early diagnosis further.