Stage of extension and treatment for colorectal cancer after a negative test and among nonresponders in mass screening with guaiac faecal occult blood test: a French experience

Despite its proven efficacy in three randomized trials, the relevance of ma ss screening for colorectal cancer using the guaiac faecal occult blood tes t is still debated. The low sensitivity of the test and the poor participat ion rate, especially in France, are major obstacles to its effectiveness. T he aim of our study was to characterize cancers occurring after a negative test and among non-participants in the screening programme organized in the French department of Calvados. Cancers in the negative test group had a la ter stage of extension than subjects testing positively but an earlier stag e of extension than cancers in the reference group, which were not differen t from those of non-responders. The proportion of resection for non-respond ers was significantly lower than that for participants, whatever the test r esult (P < 0.001), and lower than that for reference subjects (P < 0.05). T here was no difference in treatment between negative and positive responder s. Negative responders did not have a delayed cancer diagnosis or a worse c ondition of treatment than people who were not screened. Low sensitivity re duced the efficacy of colorectal cancer screening but did not seem to incre ase the potential to do harm. (C) 2001 Lippincott Williams & Wilkins.