MUMBAI: Researchers from the US and the Tata Memorial Hospital have identified two common genetic mutations that increase an individual's risk of suffering from gall bladder cancer by 1.5 times. The findings are being touted as pathbreaking that can give crucial leads to clinicians and scientists to understand and treat the disease better. The scientific community had
very limited information about genetic factors behind gall bladder cancer, whose prevalence varies widely globally as well as within the country. The study, which was jointly carried out by the Centre for Cancer Epidemiology at Tata and the US National Cancer Institute, identified a high-risk genetic region with genes ABCB4 and ABCB1, which simply means their presence could predispose an individual to gall bladder cancer.
One of the US investigators, Dr Preetha Rajaraman, explained that the study, published in Lancet Oncology recently, was conducted by comparing genetic markers and learning how it differed between people who have cancer and people who don't. "We did not look for rare mutations but rather the common ones and came across these regions," she said. The genomic make-up of 1,000 gall bladder cancer patients from the Tata Hospital were compared with those of 1,700 people who didn't have cancer.
"The findings are not just statistically important but also biologically. These genes are sort of transporters. They carry lipid from the liver to the gall bladder. So if there is any disruption in this mechanism, the concentration of bile changes. And if that type of bile gets stored in the gall bladder, it's possible that it may injure the internal membrane of the gall bladder.
We think this may be one of the ways it causes cancer, but it needs to be studied further," said Dr Rajesh Dikshit of Tata Hospital.
Gall bladder cancer, in India, is mostly prevalent in the Gangetic belt along the north and northeastern states, including Assam. It is twice more common in women than men. In the study, 46% of cases were from the north while 33% were from the northeast. Tata Hospital receives over 700 fresh cases of gall bladder cancer every year.
Dr Soumya Swaminathan, head of Indian Council of Medical Research (ICMR) said the cancer has a wide variability in distribution in India. "After genetic pre-disposition, we now have to study the role of environmental factors.
There could be toxins, diet-related and behavioural factors such as alcohol consumption leading to the incidence," she said, adding that ICMR would be keen on larger population-based studies.
Dr Dikshit said that Tata will tie up with Baneras Hindu University and B Borooah Cancer Institute in Guwahati for the second phase of the study.
Source: Times of India