ASPO Abstracts
FIT-based colorectal cancer screening in Veracruz, Mexico
Category: Early Detection & Risk Prediction
Conference Year: 2019
Abstract Body:
Purpose: To describe an initial experience in fecal immunochemical test (FIT)-based colorectal cancer (CRC) screening in Mexico where coverage for treatment for CRC was recently expanded. Methods: We recruited 473 women and men aged 50 and more who were eligible for CRC screening in Veracruz, Mexico. We interviewed eligible patients for information on demographic characteristics, gastrointestinal symptoms, and risk factors for colorectal cancer. Participants received a FIT (OC FIT-CHEK®) with printed instructions for sample collection. Returned samples were processed centrally by a commercial lab. We used a cutoff point of >100 ng of hemoglobin/mL (or 20 μg of hemoglobin/g) as the threshold to define a positive FIT test and referral to colonoscopy. Biopsies was performed in patients with polypoid lesions and analyzed by a pathologist. Results: A total of 56 participants (11.8%) did not return the FIT and for eleven (2.3%) the fecal sample was considered insufficient. The mean age (SD) of participants with a valid FIT (n=406) was 61.3(±7.6) years, 31.8% (n=129) were men, and 18.7% (n=76) reported a family history of CRC. We found that 24 participants (5.9%) had positive FIT (>100 ng of hemoglobin/mL). Eighteen participants (4.4%) had >150 ng hemoglobin/mL and 14 (3.4%) >200 ng hemoglobin/mL. The 24 individuals with a positive FIT were referred to a follow-up colonoscopy (three of them declined). In the remaining 21 participants we found seven premalignant lesions (tubular and serrated adenomas, 1.7%), ten benign lesions (diverticulosis, hemorrhoidal disease, polyps, ulcerative colitis, and angiodysplasia), and no apparent lesions were found in four participants. The positive predictive value of FIT >100 ng hemoglobin/mL for premalignant lesions was 30%.Conclusion: In this initial experience FIT-based CRC screening for average risk individuals resulted in an indication of relatively few colonoscopies and on the identification of a number of premalignant lesions that is comparable to high-income countries. Research on FIT performance, appropriate screening population, and availability of diagnostic resources in this context is necessary to undertake CRC screening in Mexico.
Keywords: fecal immunochemical test, FIT, colorectal cancer, screening