Results of a recent study published online in the journal Medical Oncology showed that cervical cancer survivors who were treated with radiation therapy have an increased risk for developing second primary malignancies of the colon and rectum.1
“Previous studies have established that cervical cancer survivors treated with radiation have an increased risk for the development of second primary malignancies of the colon, rectum/anus, bladder, and ovary,” said lead author Ana Rodriguez, MD, MPH, of the University of Texas Medical Branch in Galveston. “However, no recommendations have been established in terms of which specific screening strategies should be implemented in this group of women or how those findings can be applied to women currently surviving cervical cancer.”
No Recommendations for Colorectal Cancer (CRC) Screening in Cervical Cancer Survivors
Currently, the U.S. Preventive Services Task Force recommends CRC screening using fecal occult blood testing, sigmoidoscopy, or colonoscopy beginning at age 50 and continuing through age 75 years.2 Colonoscopy is recommended every 10 years. In addition, individuals at higher risk of developing CRC should begin screening at a younger age and may need to be tested more frequently.3 However, according to Dr. Rodriguez, current guidelines do not recommend that patients with a history of cervical cancer treated with radiation therapy should start CRC screening earlier than age 50 if radiation therapy was administered before age 50.
Secondary CRCs Common
Using data from the National Cancer Institute Surveillance, Epidemiology, and End Results program (1973-2009), Dr. Rodriguez and colleagues aimed to assess the exact risk of developing secondary primary malignancies of the colon and rectum over 35 years of follow-up in 64,507 patients who received radiation treatment for cervical cancer. The investigators used chi-square tests to compare patient and tumor characteristics between patients who did or did not receive radiation treatment for cervical cancer. Risk of subsequent colon and rectal cancer was estimated by the Kaplan-Meier method and compared by log-rank test for patients with and without radiation treatment. Cox proportional hazard models were developed to estimate risk.1
The investigators found that tumors of the colon, rectum, and anus were two to four times more frequent among women that received radiation therapy for cervical cancer.1 “Based on our findings, we believe that a woman who developed cervical cancer and received radiation at a young age should not wait to start screening for colorectal cancer at the age currently recommended for low-risk women,” said Dr. Rodriguez. “Such women should start screening at approximately 8 years after treatment if cervical cancer occurs before the woman reaches the age of 50, the usual age to initiate screening in average-risk individuals.”
Early Colonoscopy Screening Recommended
Overall, Dr. Rodriguez recommends that clinicians caring for long-term cervical cancer survivors should be aware of this increased risk of CRC and should consider the implementation of early colonoscopy screening among these women.
- Rodriguez AM, Kuo YF, Goodwin J. Risk of colorectal cancer among long-term cervical cancer survivors. Med Oncol. 2014;31(943):1-7.
- U.S Preventive Services Task Force. Screening for colorectal cancer. http://www.uspreventiveservicestaskforce.org/uspstf/uspscolo.htm. Accessed May 2, 2014.
- Centers for Disease Control and Prevention. Colorectal cancer screening guidelines. http://www.cdc.gov/cancer/colorectal/basic_info/screening/guidelines.htm. Accessed May 2, 2014.