Family history in an oncology clinic. Implications for cancer genetics.

Detailed family histories of cancer were solicited from 200 consecutively ascertained cancer patients undergoing treatment in an oncology clinic. Approximately 18% had two or more first-degree relatives with cancer of any anatomic site. In several cases, striking familial aggregations of cancer fulfilled more rigorous criteria for hereditary cancer syndromes, including early age at onset of generally late-occurring tumors, characteristic tumor patterns, vertical transmission, and collateral family lines similarly afflicted. Review of preexisting clinic charts demonstrated that, in most cases, the family history of cancer had been either omitted altogether, reported as negative despite substantial evidence to the contrary, or, if noted as positive, not pursued or acted on. Family history can be more successfully utilized in recognition of suggestive familial cancer aggregations, ultimate identification of hereditary cancer syndromes, and control of cancer in clinical practice.