Through genetic sequencing of the whole exome in 44 samples of gallbladder cancer, researchers at the Tata Memorial Centre in Mumbai have discovered mutations that lead to the development of the disease. Furthermore, the team is optimistic in treating the malignancy with existing colorectal cancer therapies.
While global rates are quite low, China and India have a particularly high incidence of gallbladder cancers. Social and economic issues in these areas only exacerbate the problem. The highest ratio is among women in Delhi, almost 340 new cases each year. Its aggressive nature and tendency to quickly spread to other organs result in a five-year survival rate of only 20%. Even worse is the fact that most patients have little to no treatment options.
With Dr. Amit Dutt at the helm, scientists at the Integrated Cancer Genomics Laboratory at ACTREC, TMC were able to identify a certain signaling pathway (ErbB/HER) that was altered in more than 40% of the specimens. Changes in this gene are also responsible for causing colorectal cancer. Inhibiting ErbB2 could stop the development of tumors.
“Based on genomic analysis we found that not all patients with ErbB2 mutation will benefit from the anti-EGFR therapy. That is because patients having a specific mutation in the KRAS gene (another member of the ErbB/HER pathway) that co-occurs with the ErbB2 mutation will not respond to the drug”, noted Dr. Dutt.
By using genetic profiling, doctors will be able to recommend anti-EGFR drugs to patients that would benefit from this courses and also prevent unnecessary chemotherapy toxicity in those that present certain mutations.
“The study gives a potential new target in precision medicine. It’s a step forward for treating early-stage gallbladder cancer and has clear practical application. It forms a basis to evaluate the drug in patients through clinical trials. And if the trial is successful then we can make it a standard of care,” added Dr. Shailesh V. Shrikhandem one of the co-authors of the study.