Age and body size as predictors of tumor aggressiveness in breast cancer

Three hundred forty-nine breast cancer patients subcategorized into age groups (under 40, 41-49, and 50 years or older) were compared for tumor aggressiveness as assessed by axillary lymph node involvement and estrogen receptivity. Body mass (Quetelet's Index) was assessed for tumor aggressiveness in the age groups below 50 years and 50 years or above. Log linear analyses showed that younger women were more likely than older women to have positive nodes independent of tumor size and were less likely to have estrogen-receptive tumors. Correlations were found between body mass and lymph node involvement, particularly in the older women, but this effect was mediated by tumor size. No correlation was found between body mass and hormone receptivity. Our data suggest that tumor aggressiveness in terms of potential for metastasis to axillary nodes and in terms of the lack of estrogen receptivity is greater in the younger age groups independent of tumor size