Increasing attention has been given to host factors in the etiology of ovarian carcinoma. Case/control studies have shown a significant excess of this disease among primary relatives of ovarian cancer affected. Pedigree studies have demonstrated its occurrence on a site-specific basis, in association with carcinoma of the breast (breast/ovarian carcinoma syndrome), and in other hereditary disorders. The complexity of this heterogeneity clearly warrants more intensive family studies. We have described genetic and clinicopathologic nuances in two extended ovarian cancer-prone families. The absence of premonitory physical stigmata and/or biomarkers which signify the cancer-prone genotype compels the physician to employ the best posits from the pedigree to identify those patients who are at inordinately high risk for ovarian and/or syndrome-associated cancer so that surveillance strategies can be more focused. Because of limitations of current surveillance strategies for the early detection of ovarian carcinoma, the clinician's responsibility includes the identification and counseling of candidates for prophylactic oophorectomy.