Postmenopausal Hormone Therapy for Chemoprevention of CRC: Does Tumor Pathway Matter?

Postmenopausal hormone therapy has been associated with reduced risk for colorectal cancer (CRC). Now, for the first time, investigators have evaluated whether this observed protective effect might differ based on the molecular pathway of CRC. The pathways of interest include chromosomal instability, which accounts for about 65% of CRCs, and the “serrated” or CpG island methylator phenotype (CIMP), which accounts for about 30%.

Using data from the population-based, prospective Iowa Women's Health Study of women aged 55 to 69, researchers identified 22,986 participants who had never used hormone therapy and 14,299 who had ever used it (4062 current users and 10,237 former users). Of 553 incident colorectal cancer cases with molecular data, 73…