A new study by scientists from the International Agency for Research on Cancer (IARC), in collaboration with researchers in the European Prospective Investigation into Cancer and Nutrition (EPIC) study and at Fred Hutchinson Cancer Research Center, found that higher circulating levels of bilirubin were positively associated with the risk of developing colorectal cancer in men.
This is the first study to examine the potential causal relationship between circulating bilirubin levels and risk of colorectal cancer using a Mendelian randomization approach, which was complemented with serological analyses. The study included data from 52 775 colorectal cancer cases and 45 940 matched controls in the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), the Colon Cancer Family Registry (CCFR), and the Colorectal Transdisciplinary (CORECT) study.
Both serological and Mendelian randomization analyses suggested that increased risk of colorectal cancer was confined to men with a genetic predisposition to high bilirubin levels. In women, the inverse relationship between circulating bilirubin levels and risk of colorectal cancer observed in the serological analyses was not supported in the Mendelian randomization approach. However, additional insight into the relationship between circulating bilirubin levels and colorectal cancer is needed in order to conclude on a potential causal role of bilirubin in development of colorectal cancer.
Seyed Khoei N, Jenab M, Murphy N, Banbury BL, Carreras-Torres R, Viallon V, et al.
Circulating bilirubin levels and risk of colorectal cancer: serological and Mendelian randomization analyses
BMC Med, Published online 3 September 2020;