The completeness of cancer registration in England: an assessment from the Oxford-FPA contraceptive study.

The completeness of cancer registration in England for the period 1968-85 has been assessed in a cohort of 17,000 women who reported malignancies directly to the investigators. Of 325 cancers reported, 281 (86.5%) had been registered by mid-1987. Under-registration varied considerably between regional cancer registries. Eight (18%) of the 44 unregistered cancers were treated in private hospitals. Under-registration also varied considerably with cancer site: only 8% of 150 breast cancers were not registered, and at sites accounting for 79% of all tumours, under-registration was less than 15%; however, 40% of melanomas (20 cases) and 50% of lung cancers (6 cases) were not registered. Of 281 registered tumours, only 219 (78%) were notified to the investigators from the NHSCR at Southport, with a median lag-time of 2.5 years since diagnosis. There has been a tendency for notification of registered cancers to the investigator to become more prompt but less complete.