Study finds high prevalence of hereditary breast cancer in Pakistan.

KARACHI -- A study published in BMC, Hereditary Cancer in Clinical Practice journal, has found a high prevalence of hereditary breast cancer (HBC) in Pakistan.

Conducted by researchers from the Aga Khan University, Karachi and partnering hospitals, the study data is based on patients who visited the HBC clinics at AKU over a three-year period and proceeded with multi-gene panel testing.

Out of all patients who met the criteria for genetic testing, 22 per cent had a positive test result. This is comparable with data from other countries, where the range was between 9.4 to 29.8 per cent. This means that almost a quarter of all those referred for genetic testing had HBC.

Most breast cancers are sporadic, i.e., they occur without a known inherited/genetic or preventable cause. Thus, in majority of cases there is no risk of the cancer being passed on to children.

HBC or genetic breast cancer is less common, but still makes up 10-30 per cent of all breast cancers. People have breast cancer genes that protect them from getting breast cancer. It is when these breast cancer genes become abnormal or mutated, that they are predisposed to breast cancer. Such inherited breast cancers may be passed down within a family from a parent, mother or father, to the children.

"Our study is the first to report the spectrum of genes beyond BRCA1 and 2 found in breast cancer patients from Pakistan," said Fizza Akbar, Genetic Counsellor at the Aga Khan University Hospital and the lead author of the study. "A striking finding was that of all the patients with abnormal results, almost half had a mutation in a gene other than BRCA1 and 2. This highlights the importance of doing multi-gene testing involving all known breast cancer predisposition genes rather than just testing for BRCA1 and 2 alone."

The study also found that patients diagnosed with breast cancer at a young age were more likely to have HBC compared to older women and that 25 per cent had no family history, but had other factors...