PURPOSE:

This study was carried out to assess the risk of gynecological malignancy in colorectal cancer survivors using a population-based retrospective cohort study.

METHOD:

Using the National Health Insurance Research Database (NHIRD) of Taiwan, we identified 37,176 patients with colorectal cancer diagnosed in 1998-2009, aged 20 years and above, without other cancer history. We also randomly selected 148,700 women without any cancer in the comparison cohort, frequency matched by age and diagnosis date. Incidences and hazards of breast, cervix, endometrial and ovarian cancers were evaluated by 201l.

RESULTS:

The overall incidence of the 4 types of gynecological cancer was 39.0% higher in colorectal cancer patients than in comparisons (2.99 vs. 2.14 per 1000 person-years) with an adjusted hazard ratio (HR) of 1.46 (95% confidence interval (CI) = 1.31-1.62). Breast cancer accounted for most subsequent cancer. The multivariable Cox method measured HR was the highest for endometrial cancer (3.40, 95% CI = 2.59-4.47) for the colorectal cohort relative to comparisons, followed by ovarian cancer and breast cancer, except cervix cancer. The risk of gynecological malignancies was apparently elevated for colorectal cancer survivors <50 years of age.

CONCLUSIONS:

Follow-up measures are suggested for women with colorectal cancer for early detection and prevention of the subsequent gynecological malignancy.