P-0150 Comparative Efficiency of Colorectal Cancer Detection by 2 Different Screening Protocols

Abstract

ABSTRACT Introduction The OC-Sensor™ (Eiken, Tokyo, Japan) immunochemical fecal occult blood test (I-FOBT) with automated processing, provides a semi-quantitated outcome as the positive cut-off point. This makes it possible to search for the optimal balance between sensitivity and specificity for colorectal cancer (CRC) while providing the balance between optimal efficiency, minimal cost, least demand on resources and inconvenience to the screenee. Methods 5210 patients (Group 1) aged 50-74 years at average risk for CRC were screened with 2 consecutive tests and 13,140 patients (Group 2) of similar age and CRC risk, with a single test. Those with an IFOBT value ≥100-ngHb/mL of buffer underwent colonoscopy. Detection rates of neoplasms were calculated as % of participants with pathology-confirmed CRC (TNM stages I-IV) or carcinoma-in-situ (CIS) or adenoma. Comparative efficiency of these two groups was calculated by two-tailed statistical test. Results More women participated than men, (69%) in Group 1 and 61.8% in Group 2. A positive IFOBT was found in 456 subjects of Group 1 (8.8%) and 972 of Group 2 (7.4%). CRC was detected in 18 (4.0%) and in 38 (3.9%); CIS in 8 (1.8%) and 13 (1.3%); adenomas in 96 (21.1%) and 230 (23.7%) of Group 1 & 2, respectively. These results were not significantly different, CRC [OR=1.010;CI (0.5699-1.790); P=1.000], CIS [OR=1.317;CI (0.5420-3.2020); P=0.6376] & adenoma [OR=0.8603;CI (0.6571-1.126); P=0.2802]. Conclusion The efficiency of CRC or adenoma screening by single semi-quantitated IFOBT (value ≥100-ngHb/mL of buffer) is not significant different from screening by 2 consecutive tests. The single semi-quantitated IFOBT is an effective, easy to use screening tool for clinical practice, with less demand on screenee and cheaper.