In Reply: Dr Odell suggests that an increase in colorectal cancer incidence in women should be expected now that use of postmenopausal hormone therapy has declined. Although we do not share his opinion that this is the most important implication of the postintervention report from the WHI, we agree that vigilance in this area is warranted.
We reported in the WHI randomized trial that 44% fewer invasive colorectal cancers were diagnosed in participants in the conjugated equine estrogen plus medroxyprogesterone acetate group compared with those in the placebo group.1 However, we also noted that the colorectal cancers were found at higher stage, and a role for delayed assessment of clinical symptoms could not be excluded as a factor influencing this finding.1 In contrast, the incidence of invasive breast cancer was significantly increased by combined hormone therapy in the same trial2; in the present study, although more breast cancers continue to be seen in the hormone group, after the intervention ended a downward inflection in the temporal trend in cumulative hazard ratios for breast cancer was observed.
Chlebowski RT. Colorectal Cancer in Women After Stopping Postmenopausal Hormone Therapy—Reply. JAMA. 2008;299(23):2744-2745. doi:10.1001/jama.299.23.2744-b