Clinically undiagnosed malignant tumours found at autopsy.

In a series of over 20,000 autopsies carried out over a 25-year period, 700 cancers (11%) were found in patients in whom the diagnosis of cancer had not been considered relevant clinically. In over half of them the unrecognized tumour was considered an incidential finding and thus of no importance to the individual concerned, though of epidemiological concern. As expected from the literature the main organs involved were kidney and prostate, with stomach cancer in third place. In contrast, the unrecognized cancers that caused death were most often from the pancreas or lung, again with the stomach in third place. These patients with stomach or lung cancer were frequently thought to have died of other diseases in the gastrointestinal/respiratory tract, and the disease cited was often present though not the cause of death. These patients tended to be older than those with clinically recognized disease, and had been hospitalized late in the course of their fatal illness, at which time clinical recognition would not have influenced the outcome. Earlier recognition of this type of cancer is thus essential. This cannot be achieved without definition and further analysis of the entities concerned.