Table 2.
Cancer outcome | # Studies | Summary OR (95% CI) | Increase or decrease in lifetime absolute risk, % |
---|---|---|---|
Breast cancer | 23 | 1.08 (1.00-1.17) | 0.89 |
Ovarian cancer | 24 | 0.73 (0.66-0.81) | −0.54 |
Endometrial cancer | 7 | 0.57 (0.43-0.77) | −1.77 |
Colorectal cancer | 11 | 0.86 (0.79-0.95) | −0.76 |
Effects on cancer persist for 10-30 years after discontinuation of use, so comparing ever vs. never users is an appropriate global comparison.
Abbreviations: OR, odds ratio. CI, confidence interval.
Source: Gierisch JM et al. Cancer Epidemiol Biomarkers Prev 2013;22:1931-43; Havrilesky LJ et al., Obstet Gynecol 2013;122:139-47.