Colorectal cancer after a negative Haemoccult II® test and programme sensitivity after a first round of screening : The experience of the department of Calvados (France)

Colorectal cancers emerging after a negative Haemoccult II® are described in the context of a first round of mass screening in the Department of Calvados (France), from April 1991 to the end of December 1994. People with a cancer occurring after a negative test until 31 December 1995 were identified by a local cancer registry. Incidence was calculated and the programme sensitivity was estimated. The incidence of cancer emerging after a negative test was 57.7 per 100 000, i.e. half of the calculated incidence in the reference group (141.6 per 100 000). These cancers did not differ from those of either the non-responder or reference groups, in particular for the stage of extension. The programme sensitivity was globally higher than that estimated in European trials: 77.2, 66.3 and 55.9%, 1, 2 and 3 years after the test respectively. Programme sensitivity was higher for distal colon cancer 1 year after the test, which is probably due to the relatively slow growth of this subsite. © 1999 Cancer Research Campaign