Breast cancer affects 9 % of men with faulty gene BRCA2

Cancer of the breasts can affect men too, contrary to the popular assumption that the disease is specific to women.

Certain form of breast cancer is caused due to a mutation breast cancer gene that predisposes the women for the deadly ailment.

But new studies have found that the men carrying the same gene mutation are also likely to develop breast cancer.

Certainly not all men with the mutated gene get affected by cancer of of the breasts. But the chances are one in 12 men carrying the breast cancer gene mutation. Breast cancer affects these small percentage of mutated gene carriers after the age of 80.

The culprit gene in question that develops the faulty mutation is BRCA2.

A genetic mutation linked to breast cancer in women also predisposes men to the disease, with 1 in 12 male carriers developing tumors by age 80, researchers said.

To pinpoint BRCA2 gene, researchers from Manchester and Birmingham, England, tracked 321 families who may have inherited the gene mutation.

The risk of breast cancer for unaffected men who test positive for a BRCA2 mutation is based on very few retrospective studies.

Researchers have used both retrospective and prospective analysis in 321 families with pathogenic BRCA2 mutations.

Three breast cancers occurred in male first-degree relatives after family ascertainment in 41-40 years of follow-up suggesting a risk of breast cancer to 80 years of 8.9%.

A second analysis excluding index cases identified 16 breast cancers in 905 first-degree male relatives on which Kaplan–Meier analysis was performed after assigning carrier status.

This analysis confirmed that breast cancer risk in men was 7.1% (SE 5.2–8.6%) by age 70 years and 8.4% (SE 6.2–10.6%) by age 80 years.

An analysis of the data found 7.1 percent of men with the faulty BRCA2 gene developed the disease by age 70. However, in men having completed 80 years of age the breast cancer risk due to mutated BRCA2 gene rose to almost 9 percent.

Whereas, in the case of women with mutated BRCA2 gene, almost 60 percent of them develop breast cancers.

The study conducted by Gareth Evans and his team from the Department of Genetic Medicine at Manchester Academic Health Science Centre and St. Mary’s Hospital, is considered the largest ever conducted in BRCA2-affected families that could confirm the lifetime risk of developing breast cancer in men as high as 9 percent.

“These risks are sufficient to increase awareness of breast cancer among men in BRCA2 families and to stress the importance of early presentation with breast symptoms,’’ the researchers said.

Breast cancer is the most common cancer in women. Breast cancer affect 12 percent of women over the course of a lifetime, according to the U.S. National Cancer Institute.

More than 200,000 women were diagnosed with the disease last year in the U.S., compared with less than 2,000 men, according to the American Cancer Society.

About 40,000 women and 390 men died from breast cancer in US.

What is BRCA2 gene?

BRCA2 (Breast Cancer Type 2 susceptibility protein) is a protein that in humans is encoded by the ”BRCA2” gene.

The BRCA2 gene is located on the long (q) arm of chromosome 13 at position 12.3 (13q12.3), from base pair 31,787,616 to base pair 31,871,804.

”BRCA2” belongs to the tumor suppressor gene family and the protein encoded by this gene is involved in the repair of chromosomal damage with an important role in the error-free repair of DNA double strand breaks.

An example of mutation is found in Iceland, where a single BRCA2 (999del5) mutation accounts for virtually all breast/ovarian cancer families.

In a large study examining hundreds of cancer and control individuals, this 999del5 mutation was found in 0.6% of the general population.

While 72% of patients who were found to be carriers had a moderate or strong family history of breast cancer, 28% had little or no family history of the disease.

This strongly suggests the presence of modifying genes that affect the phenotypic expression of this mutation, or possibly the interaction of the BRCA2 mutation with environmental factors.