ABSTRACT
OBJECTIVES: The NS-Plus automated analyzer and fecal immunochemical testing (FIT) testing system (Alfresa Pharma) was evaluated for use in Newfoundland and Labrador's provincial colorectal cancer (CRC) screening program. DESIGN AND METHODS: Various method performance characteristics were evaluated including the sample stability. The sensitivity for detecting neoplastic lesions was evaluated in 249 patients scheduled for colonoscopy. Each patient collected up to 2 samples for both guaiac based testing (Hemoccult SENSA; gFOBT) and FIT using the NS-plus system (cutoff=20 µg Hb/g feces or 100 µg Hb/L) over 2 days. Data was analyzed comparing 1- and 2-day testing strategies. RESULTS: The analyzer showed acceptable linearity, precision, and accuracy. The collection device maintained acceptable sample stability for at least 7 days at: 37 °C, room temperature (~23 °C), 4-8 °C, and -20 °C. The 2-day sampling strategy identified 30% (21 of 69) of all neoplastic lesions (low and high grade adenomas and CRC) including 2 of 4 high-grade adenomas and 2 of 2 CRCs. The single day strategy identified the same high-grade adenomas and CRCs but fewer low-grade adenomas (23% of all neoplasia). Reducing the screening cutoff to the estimated 95th percentile of FIT results in the healthy adult population (10 µg Hb/g feces), detected all high-grade adenomas in the 2-day strategy. CONCLUSIONS: The NS Plus automated analyzer system detects clinically significant neoplasms and shows acceptable performance for use in a CRC screening program with the potential for gains in sensitivity by modifying the number of days of screening or through lowering the cutoff.
