Screening colonoscopy according to guidelines in long-term survivors of childhood cancer-results of a population-based study

Purpose To report on findings in screening colonoscopies in long-term survivors of childhood cancer treated with abdominopelvic irradiation (RT). Methods Screening colonoscopies were introduced at the Slovenian outpatient follow-up clinic in 2015, according to the Children's Oncology Group guidelines. In January 2019, 54 patients who received abdominopelvic irradiation for Hodgkin disease, Wilms tumour or dysgerminoma at the age of 0-16 between 1968 and 1995 were eligible for screening colonoscopy, and until December 2019, twenty-eight asymptomatic patients have undergone this examination. Results Patients were 1-16 (median 13) years old at cancer diagnosis and had colonoscopy 24-47 (median 36) years after diagnosis. They received abdominopelvic irradiation with the dose 16-46 (median 30) Gy. Adenomatous lesions were found in 18 patients (64%) and advanced adenomatous lesions in one-third. Patients who received abdominopelvic RT with a dose below 30 Gy had 75% incidence of adenomatous lesions and in those who received a dose of 30 Gy or more the incidence was 60%. Alkylating agents did not have impact on this incidence. Conclusions In this first population-based study of screening colonoscopies in asymptomatic survivors of childhood cancer, we provided new evidence for 64% incidence of adenomatous lesions after abdominopelvic RT with the dose above or below 30 Gy. Implications for Cancer Survivors Screening colonoscopies are of vital importance in patients treated with abdominal RT in childhood.