Risk of colorectal cancer in women with a prior diagnosis of gynecologic malignancy.

GOALS AND BACKGROUND

Earlier studies regarding the risk of colorectal cancer (CRC) in women with a prior diagnosis of gynecologic malignancies have revealed conflicting results. We sought to further clarify this association.

METHODS

A retrospective cohort study was performed using the General Practice Research Database of the United Kingdom. Patients with a prior diagnosis of ovarian, uterine, or cervical cancers were compared with control patients without a prior gynecologic malignancy. The primary outcome was a diagnosis of CRC. Poisson regression analysis was used to assess the effects of potential confounders.

RESULTS

The study included 1995 ovarian, 1348 uterine, and 1101 cervical cancer patients and 7980, 5392, and 4404 matched control patients, respectively. The adjusted incidence rate ratio (IRR) of CRC among ovarian cancer patients was 2.90 [95% confidence intervals (CI) 1.45-5.82]. Five of 10 cases of CRC in ovarian cancer patients were diagnosed within 6 months of the cancer diagnosis with an adjusted IRR of 8.0 (95% CI 1.9-33.6). Excluding the initial 6 months of follow-up after the diagnosis of ovarian cancer, the adjusted IRR was 1.6 (95% CI 0.76-5.03). The adjusted IRR of CRC in patients with a prior diagnosis of uterine and cervical cancer was 0.79 (95% CI 0.24-2.61) and 1.50 (95% CI 0.43-5.21), respectively.

CONCLUSIONS

Women with a prior diagnosis of ovarian cancer are at an increased risk of CRC. The risk of CRC was not increased among patients with a prior history of uterine and cervical cancer.