Cancer survivors treated with abdominal/pelvic radiation therapy have increased the risks of colorectal cancer, although evidence supporting early colorectal cancer screening for these patients is lacking.
Dr Patricia Daly and colleagues from Canada determined whether there is an elevated prevalence of adenomatous colorectal polyps in young survivors prior to the age when screening would be routinely recommended.
The researchers conducted a prospective study of early colonoscopic screening in cancer survivors aged 35–49 who had received abdominal/pelvic radiation therapy ≥10 years previously.
|53% of polyps were within or at the edge of the prior abdominal/pelvic radiation therapy fields|
The planned sample size was based on prior studies reporting a prevalence of adenomatous polyps of approximately 20% among the average-risk population ≥50 years of age, in contrast to ≤10% among those average-risk people aged 40–50 years, for whom screening is not routinely recommended.
The team performed colonoscopy in 54 survivors, at a median age of 45 years, and after median interval from radiation treatment of 19 years.
The research team detected 49 polyps in 24 patients, with 15 patients having potentially precancerous polyps.
The researchers found that 53% of polyps were within or at the edge of the prior abdominal/pelvic radiation therapy fields.
Dr Daly's team concluded,"Young survivors treated with abdominal/pelvic radiation therapy have a polyp prevalence comparable with the average-risk population aged ≥50 years and substantially higher than previously reported for the average-risk population aged 40–50 years".
"These findings lend support to the early initiation of screening in these survivors".