Hereditary ovarian cancer: Heterogeneity in age at onset

Hereditary ovarian cancer (HOC) is heterogeneous, with at least three distinctive syndromes, namely, hereditary site-specific ovarian cancer, hereditary breast-ovarian cancer (HBOC) syndrome, and Lynch syndrome II. Ovarian cancer, in accord with virtually all varieties of adult onset cancer, displays an increasing incidence with advancing age; however, it shows an earlier age of onset in hereditary settings.Detailed medical and pathology studies were performed on extended ovarian cancer-prone pedigrees, with special attention given to age at ovarian cancer onset.The age of onset of ovarian cancer is heterogeneous, wherein the average age of onset in HBOC is 52 years, in hereditary site-specific ovarian cancer it is 49 years, and in the Lynch syndrome II it is 45 years, in contrast to its occurrence in the general population, at an average age of 59 years.These differences are important for the initiation of surveillance and management strategies. Age of onset of ovarian cancer differences in these several hereditary subsets are less striking than they are in the case of other integral forms of cancer in the respective syndromes, such as the breast in the HBOC syndrome. In addition, the phenomenon of extremely early age of onset of ovarian cancer occurs infrequently in HOC when compared to other forms of cancer, such as the breast in HBOC or the colon in Lynch syndrome II. Knowledge about age of onset heterogeneity in HOC may harbor important clues about etiology, pathogenesis, and cancer control.