Increased Colorectal Cancer Risk Seen Following Radiotherapy for Cervical Cancer

The University of Texas Medical Branch at Galveston (TMB; USA) investigators discovered a high occurrence of secondary colorectal tumors among cervical cancer survivors treated with radiation, and offer new recommendations that the younger women in this group start colorectal cancer screening about eight years after their first cervical cancer diagnosis instead of waiting until age 50. The study was published online April 2014 in the journal Medical Oncology.

An estimated 18% of malignancies in the United States are secondary tumors that develop in cancer survivors. Earlier research has indicated that cervical cancer survivors treated with radiation have an increased risk for second primary tumors; however, no preventive recommendations have been established.

The UTMB study analyzed 64,507 cervical cancer cases collected from 1973–2009 by the US National Cancer Institute Surveillance, Epidemiology and End Results program. Among cervical cancer survivors studied, colon, rectum, and anus tumors were found to be two to four times more evident in the group treated with radiation than in the group not treated with radiation. A breakdown of the findings include: (1) More than half (52.6%) the cervical cancer patients studied received radiation treatment. Colon cancer among those treated with radiation began appearing at significantly higher rates about eight years later. (2) After eight years, the risk for developing colon cancer was double for women who received radiation compared to those who had not. (3) Their risk of rectal cancer quadrupled after 15 years. (4) Lastly, after 35 years, women who had received cervical cancer radiation therapy were three to four times more likely to have developed colorectal cancers than women who had not.

“We are confident from our study that it is time to consider new colorectal cancer screening strategies for cervical cancer survivors,” said UTMB’s Dr. Ana M. Rodriguez, assistant professor of obstetrics and gynecology and lead author of the study. “As more people are surviving their cancer diagnosis, we need to learn more about the outcomes 10, 20, 30, even 40 years later and how to take care of their long-term medical needs.”

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University of Texas Medical Branch at Galveston