Genetic counseling, familial breast cancer, and the surgeon's responsibility.

Approximately 20 percent of 75 consecutive breast cancer patients evaluated in our oncology clinic have shown evidence of familial breast cancer. This determination was made on the basis of association with at least two or more affected first-degree relatives. On a national basis, this would project to about 21,000 patients (and their families) for the year 1979. Seven of these patients, whose families are in various stages of completion of detailed cancer genetic evaluations, have been selected to illustrate the logic utilized for genetic counseling and management. Cardinal aspects of familial breast cancer, including its early age of onset, excess of bilaterality, vertical transmission, and occasional familial association with other varieties of cancer, have been emphasized to depict pragmatic utility for its identification. A hypothetical pedigree, based on extensive clinical experience with familial breast cancer, has been constructed to aid the physician in determining which patients have familial cancer tendencies so that he can then integrate this information for employment of strategy in genetic counseling and management. The surgeon must be cognizant of the several crucial characteristics of familial breast cancer. When one or more of these features are present in his patient or family or both, appropriate genetic counseling and management should be provided. Therefore, the surgeon must extent his sphere of responsibility to his patient's high-risk relatives.