High prevalence of adenomatous colorectal polyps in young cancer survivors treated with abdominal radiation therapy: results of a prospective trial.

OBJECTIVE: Cancer survivors treated with abdominal/pelvic radiation therapy (ART) have increased the risks of colorectal cancer (CRC), although evidence supporting early CRC screening for these patients is lacking. We sought to determine whether there is an elevated prevalence of adenomatous colorectal polyps in young survivors prior to the age when screening would be routinely recommended. DESIGN: We conducted a prospective study of early colonoscopic screening in cancer survivors aged 35-49 who had received ART ≥10 years previously. 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. RESULTS: Colonoscopy was performed in 54 survivors, at a median age of 45 years (range 36-49) and after median interval from radiation treatment of 19 years (10.6-43.5). Forty-nine polyps were detected in 24 patients, with 15 patients (27.8%; 95% CI 17.6% to 40.9%) having potentially precancerous polyps. Fifty-three per cent of polyps were within or at the edge of the prior ART fields. CONCLUSIONS: Young survivors treated with ART 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. CLINICAL TRIAL REGISTRATION NUMBER: NCT00982059; results.

Mobilization of viable tumor cells into the circulation during radiation therapy.

PURPOSE: To determine whether radiation therapy (RT) could mobilize viable tumor cells into the circulation of non-small cell lung cancer (NSCLC) patients. METHODS AND MATERIALS: We enumerated circulating tumor cells (CTCs) by fluorescence microscopy of blood samples immunostained with conventional CTC markers. We measured their DNA damage levels using γ-H2AX, a biomarker for radiation-induced DNA double-strand breaks, either by fluorescence-activated cell sorting or by immunofluorescence microscopy. RESULTS: Twenty-seven RT-treated NSCLC patients had blood samples analyzed by 1 or more methods. We identified increased CTC numbers after commencement of RT in 7 of 9 patients treated with palliative RT, and in 4 of 8 patients treated with curative-intent RT. Circulating tumor cells were also identified, singly and in clumps in large numbers, during RT by cytopathologic examination (in all 5 cases studied). Elevated γ-H2AX signal in post-RT blood samples signified the presence of CTCs derived from irradiated tumors. Blood taken after the commencement of RT contained tumor cells that proliferated extensively in vitro (in all 6 cases studied). Circulating tumor cells formed γ-H2AX foci in response to ex vivo irradiation, providing further evidence of their viability. CONCLUSIONS: Our findings provide a rationale for the development of strategies to reduce the concentration of viable CTCs by modulating RT fractionation or by coadministering systemic therapies.

The effect of short term neo-adjuvant androgen deprivation on erectile function in patients treated with external beam radiotherapy for localised prostate cancer: an analysis of the 4- versus 8-month randomised trial (Irish Clinical Oncology Research Group 97-01).

BACKGROUND AND PURPOSE: Erectile dysfunction is a common consequence of external beam radiotherapy (EBRT) for prostate cancer. The addition of neo-adjuvant androgen deprivation (NAD) has an indeterminate additive effect. We examined the long-term effect on erectile function (EF) of two durations (4 months: arm 1 and 8 months: arm 2) of NAD prior to radiation (RT) for patients with localised prostate cancer from the Irish Clinical Oncology Research Group (ICORG 97-01) 4- versus 8-month trial. In this study we aimed to (1) analyse the overall effect on EF of NAD in an EBRT population, (2) compare the probability of retained EF over time in an EBRT population treated with either 4 or 8 months of NAD and (3) identify any variables such as risk group and age which may have an additive detrimental effect. This analysis provides unique long term follow up data. MATERIALS AND METHODS: From 1997 to 2001, 276 patients with adenocarcinoma of the prostate were randomised to 4 or 8 months of NAD before RT. EF data were recorded at baseline and at each follow-up visit by physician directed questions, using a 4-point grading system. RESULTS: Two hundred and thirty patients were included in the analysis of EF and were followed for a median of 80 months. One hundred and forty-one patients had EF at baseline. Neo-adjuvant androgen deprivation in addition to radiation therapy caused a significant reduction in EF. The most significant reduction in EF happens within the first year. The median time to grade 3-4 EF toxicity was 14.6 months, 17.6 months in arm 1 and 13.7 in arm 2. Freedom from late EF toxicity did not differ significantly between arms, overall or at 5 years (n=141). The cumulative probability of EF preservation at 5 years was 28% (22-34) in arm 1 and 24% (19-30) in arm 2. Age was a significant predictor of post-treatment EF. CONCLUSIONS: The first year post ADT and EBRT poses the greatest risk to sexual function and a continued decline may be expected. However, 26% of men can expect to retain sexual function at 5 years.