In a European study reported in the Journal of Clinical Oncology, Heymer et al found that the risk of subsequent colorectal cancer was elevated among childhood cancer survivors who had undergone abdominopelvic radiotherapy.
Study Details
The study used data from the PanCareSurFup Study—a Pan-European case-control study nested within a 69,460 cohort of 5-year survivors of childhood cancer. Data were collected from 13 cohorts across 12 countries (Denmark, Finland, France, Hungary, Iceland, Italy, Norway, Slovenia, Sweden, Switzerland, the Netherlands, and the United Kingdom). The case-control study consisted of 143 survivors who developed colorectal cancer and 143 controls individually matched for sex, age at childhood cancer, calendar year of childhood cancer diagnosis, and retinoblastoma status.
Key Findings
Survivors treated with abdominopelvic radiotherapy were significantly more likely to develop colorectal cancer vs those who did not receive abdominopelvic radiotherapy (odds ratio [OR] = 3.1, 95% confidence interval [CI] = 1.4–6.6).
Colorectal cancer surveillance begins at age 50 in many European countries; at this age, males and females in the general population had a cumulative absolute risk of 0.27% for colorectal cancer. Among male survivors treated with abdominopelvic radiotherapy, the cumulative absolute risk of developing colorectal cancer was 0.27% (95% CI = 0.17%–0.59%) by age 40, 1.08% (95% CI = 0.69%–2.34%) by age 50 (vs 0.27% expected in the general population), and 3.7% (95% CI = 2.36%–7.80%) by age 60 (vs 0.95% expected in the general population). Among female survivors treated with abdominopelvic radiotherapy, the cumulative absolute risk of developing colorectal cancer was 0.29% (95% CI = 0.18%–0.62%) by age 40, 1.03% (95% CI = 0.65%–2.22%) by age 50 (vs 0.27% expected in the general population), and 3.0% (95% CI = 1.91%–6.37%) by age 60 (vs 0.82% expected in the general population).
The investigators concluded: “We demonstrated that by age 40 years, survivors of childhood cancer treated with abdominopelvic radiotherapy already have a similar risk of colorectal cancer as those age 50 years in the general population, for whom population-based colorectal cancer screening begins in many countries. This information should be used in the development of survivorship guidelines for the risk stratification of survivors concerning colorectal cancer risk.”
Jop C. Teepen, PhD, of Princess Máxima Center for Pediatric Oncology, Utrecht, the Netherlands, is the corresponding author of the Journal of Clinical Oncology article.
Disclosure: The study was supported by the Dutch Cancer Society and others. For full disclosures of the study authors, visit ascopubs.org.
