Age-adjusted relative risk (RR) of colon and rectal cancer for women who had ever used postmenopausal hormones compared with those who had never used hormones

Type of cancerNumber of studiesRR (95% CI)Heterogeneity
*Excluding studies that included premenopausal women in the “never used” group. †Significant heterogeneity existed among study results.
Colon180.80 (0.74 to 0.86)p=0.02†
13*0.76 (0.70 to 0.82)p=0.32
Rectal100.81 (0.72 to 0.92)p=0.03†
7*0.81 (CI not available)p=0.06†