Genetic variants can cause Breast Cancer risk

Study suggests ,father's family history of Breast Cancer and Ovarian Cancer generally overlooked by both patients and doctors.

Genetic counsellor Jeanna McCuaig and her co-authors from Toronto's Princess Margaret Hospital  in Toronto and Montreal wrote in commentary in the journal “The Lancet Oncology”, Health care providers may be "unaware that these women might have inherited the mutated gene from their father …and might not routinely collect this information from their patients,"

Women don't recognize a paternal family history of cancer as a risk factor for the diseases, and are unlikely to volunteer the information unless directly questioned.

Women and Men  have 50 per cent risk of passing on mutations in the BRCA1 or BRCA2 tumour suppressor genes, which increase lifetime risk for breast Cancer and ovarian cancer.

The researchers also determined patients were 5 times more likely to be referred with a paternal, than a maternal, family history of breast or ovarian cancer.

A study, led by researchers at Memorial Sloan-Kettering Cancer Center, has suggested that genetic variants on chromosomes 10 and 20 may modify risk of breast cancer among women with a BRCA2 mutation.Researchers analysed DNA samples from 6,272 women with BRCA2 mutations in a two-stage genome-wide association study.

The chromosome 10 variant identified in the study, near the gene ZNF365, decreased the risk of breast cancer by approximately 25 percent in women also carrying a mutation of the BRCA2 gene.

Researchers suggested that health care providers should be familiar with general trends in genetic cancers, including:

Diagnosis at younger ages than sporadic cancers.

Several family members over generations might be diagnosed with cancer, particularly rare forms or breast cancer and ovarian cancer.

Diagnosis with many primary type of cancers.

According to a study, about 20 to 30 per cent of the more than 690,000 women diagnosed with breast cancer and nearly 190,000 diagnosed with ovarian cancer in developed countries have had a family history of cancer.

The BRCA1 and BRCA2 mutations are linked to aggressive hereditary breast cancers, but only account for about 15 per cent of all cases.