Colorectal cancer in the setting of pregnancy and familial risk.

BACKGROUND AND AIMS: Women are at risk of colorectal cancer (CRC) during pregnancy but this fact is underappreciated. We performed a population-based study to evaluate the rate, predictors, and familial risk for pregnancy associated CRC in Utah. METHODS: All newly diagnosed cases of CRC between 1973 and 2014 were obtained from the Utah Cancer Registry and linked to pedigrees from the Utah Population Database. RESULTS: Of the 12,886 females diagnosed with CRC, 73 were diagnosed with CRC (0.57%) during the period of obstetric delivery/childbirth. Pregnancy associated CRC was diagnosed at a mean age of 31.9 years, and cancers were less frequently located in the proximal colon compared with women with non-pregnancy associated CRC. First-degree relatives of cases with pregnancy associated CRC had a nearly threefold higher risk of CRC (OR, 2.76; 95% CI, 1.26-6.01) compared with relatives of CRC-free individuals. CONCLUSIONS: Of women diagnosed with CRC, less than 1% were diagnosed during or soon after obstetric delivery/childbirth. Relatives of these patients have a nearly threefold greater risk of CRC than those without a family history of CRC. These results provide physicians with data to guide the care of patients and their relatives with pregnancy associated CRC.