Toxin Found in Herbal Remedies and Certain Foods Linked with Upper Urinary Tract Cancer

Using whole-exome sequencing of Taiwanese upper urinary tract cancer patients exposed to aristolochic acid and patients with no suspected exposure, researchers found an average of 753 mutations in each tumor from the toxin-exposed group compared with 91 in tumors from the non-exposed group. This level of mutation is more than that found in melanomas caused by ultraviolet radiation and lung cancer caused by smoking. The predominant mutation type in the exposed tumors was an A substituted with a T, according to this and another study. The Science Translational Medicine findings illustrate how sequencing can pinpoint carcinogens involved in cancer clusters.