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GUWAHATI
A new study has found a connection between cholesterol-rich gallstones exposed to toxic metals and gallbladder cancer (GBC) in Assam, one of the most affected regions globally.
The study, led by a Tezpur University team, published in the American Chemical Society’s Chemical Research in Toxicology, reveals how heavy metals and gallstone structural properties drive this deadly disease.
Also read: Cause of gallstone disease in Indians found to be genetic
Pankaj Barah and Cinmoyee Baruah from Tezpur University’s Department of Molecular Biology and Biotechnology spearheaded the study. The other authors are the university’s Nabanita Roy; Gayatri Gogoi and Utpal Dutta from Assam Medical College in Dibrugarh; Anupam Sarma from the Dr. Bhubaneswar Borooah Cancer Institute in Guwahati; Akshai Kumar from the Indian Institute of Technology-Guwahati; Roshan M. Borkar, and Sachin B. Jorvekar from the National Institute of Pharmaceutical Education and Research in Guwahati, and Subhash Khanna from the Swagat Super Speciality and Surgical Hospital in Guwahati.
Gallstones are small, pebble-like formations in the gallbladder caused by changes in bile composition. These changes promote the crystallization of cholesterol, calcium, and other biliary pigments, disrupting bile homeostasis and affecting gallbladder dynamics.
Gallstones are symptomatic or asymptomatic, and symptomatic cases are known as gallstone disease (GSD) or cholelithiasis, which causes severe pain.
The team used advanced spectroscopic tools to do a comparative analysis of gallstones from 30 GSD patients and 10 GBC patients in Assam. The gallstones from the GSD patients were found to be composed of cholesterol (70%), mixed (13.3%), pigment (6.7%), and calcium carbonate (10%).
Call for urgent measures
The gallstones from the GBC patients did not have pigment and calcium carbonate types, but contained up to 15 times the normal levels of carcinogenic metals – arsenic, chromium, mercury, iron, and lead – prevalent in the Brahmaputra Basin groundwater, alongside plate-like microstructural arrangements that may damage the gallbladder tissue.
“This toxic profile explains why 60-80% of gallstone cases in Assam progress to GBC, compared to just 1% of global risk, with women comprising 70% of the patients. These gallstones act as toxic catalysts, their distinct makeup creating a deadly recipe for cancer,” Dr. Barah said.
Dr. Gogoi said early ultrasound screening could save lives, but 80% of the cases are detected too late for surgery.
“This clarifies why Assam bears a disproportionate burden compared to other Indian regions,” Dr. Khanna said.
According to Dr. Sarma, a cancer specialist, the silent progression of GBC underscores the critical need for community screening programmes in high-risk zones.
The study has advocated immediate measures to address Assam’s gallbladder cancer crisis, such as widespread ultrasound screening to enable early detection, robust policy reforms to improve water quality and reduce toxic metal contamination, comparative studies of gallstones across India to uncover regional differences, and public awareness campaigns to educate communities about early symptoms.
The authors underscored the need for further research into cholesterol dysregulation and its link to elemental toxicity.
“We plan to examine gallstones from patients in other Indian regions to determine whether the toxic profile – marked by high levels of carcinogenic metals and unique crystalline structural arrangements – found in Assam’s patients is distinct or part of a broader national pattern,” Dr. Barah said.
Published – April 03, 2025 07:08 pm IST
