Interval cancers in a community-based programme of colorectal cancer screening with faecal occult blood test

Interval cancers represent the major limitation of screening for colorectal cancer with the faecal occult blood test. The aim of this study was to des cribe the characteristics of interval cancers and the sensitivity of the sc reening programme in a well-defined French population. During five screenin g rounds, 398 cancers were diagnosed in those of the population having perf ormed at least one screening test; 57.8% of them were interval cancers. The proportion of interval cancers was higher among cancers of the rectal ampu lla (72.2%) than among cancers of other sites (52.9%) (P < 0.001). The prop ortion of TNM stage I and II were higher among screen-detected cancers (73. 8%) than among interval cancers (57.4%). The overall sensitivity of the scr eening programme was 62.9% within 1 year, and 48.7% within 2 years. An impr ovement in the sensitivity of the faecal occult blood test for colorectal c ancer screening is needed, without an unacceptable loss of specificity. (C) 1999 Lippincott Williams & Wilkins.