Pediatric Cancer Survivors Treated With Abdominopelvic RT Have Higher Risk of CRC

Pediatric cancer survivors treated with abdominopelvic region radiotherapy (ART) have an increased risk of colorectal cancer (CRC), according to research published in the Journal of Clinical Oncology.

Researchers found that patients treated with ART had an increased risk of CRC when compared to the general population and to pediatric cancer patients who did not receive ART.

For this study, the researchers evaluated data from the PanCare Childhood and Adolescent Cancer Survivor Care and Follow-Up Studies, which collected information from 5-year survivors of pediatric cancer from 13 cohorts across 12 European countries.

From this cohort, the researchers matched 143 pediatric cancer survivors who subsequently developed CRC and 143 survivors who did not develop CRC.

The cancer survivors who had been treated with ART had a 3-fold greater risk of developing CRC than those who did not receive ART (odds ratio [OR], 3.1; 95% CI, 1.4-6.6).

Survivors who received ART doses of less than 30 Gy did not have a significantly increased risk of CRC (OR, 2.4; 95% CI, 0.8-7.5), but survivors who received doses of 30 Gy or more did (OR, 3.6; 95% CI, 1.3-10.3).

The researchers also compared CRC incidence rates from the general European population to those of the pediatric cancer survivors. In the general population, the cumulative absolute risk (CAR) of developing CRC by age 60 was 0.95% for men and 0.82% for women.

In childhood cancer survivors who did not undergo ART, the CAR for developing CRC by age 60 was slightly higher than in the general population, at 1.23% for men and 0.99% for women. For cancer survivors who did undergo ART, the CAR for developing CRC by age 60 was even higher, at 3.7% for men and 3.0% for women.

By 50 years of age, people in the general population had a CAR for CRC of 0.27%. Childhood cancer survivors who underwent ART had a similar CAR for CRC by age 40, at 0.27% for men and 0.29% for women.

“We provide new evidence that the cumulative absolute risk at which CRC screening begins in the general population in most countries worldwide (age 50-60 years) is reached by childhood cancer survivors treated with ART at least a decade earlier at age 40-50 years,” the researchers wrote. “We show, for the first time, that population screening for CRC should begin at least a decade earlier among survivors of abdominopelvic irradiation than in the general population.”

Reference

Heymer EJ, Jóźwiak K, Kremer LC, et al. Cumulative absolute risk of subsequent colorectal cancer after abdominopelvic radiotherapy among childhood cancer survivors using a clinically accessible metric: A PanCareSurFup Study. J Clin Oncol. Published online November 16, 2023. doi:10.1200/JCO.23.00452

This article originally appeared on Cancer Therapy Advisor