Context: Aromatase, steroid sulfatase, and 17β-hydroxysteroid dehydrogenase type 1 (HSD-1) peripherally up-regulate, whereas estrogen sulfotransferase (EST) and HSD-2 down-regulate, the synthesis of active and more potent estrogens. These estrogen-metabolizing enzymes (EMEs) are important in postmenopausal breast cancers, but have never been systematically examined in breast cancers of the elderly. Objective and Design: mRNA levels of EMEs in cancerous and normal breast tissues from 39 elderly patients (age, 80-99 yr) were compared with those from 39 controls (age, 37-70 yr) or compared according to estrogen (ER)/progesterone (PR) receptor status. Results: Aromatase levels were higher in cancers of the elderly (EldCa) than in normal tissue of the elderly (P = 0.0008) or cancers of controls (P = 0.0033). In contrast, levels of steroid sulfatase and EST were higher in cancers of controls than normal tissue of controls (P = 0.0046 and P < 0.0001, respectively) or EldCa (P = 0.0001 and P < 0.0001, respectively). Levels of HSD-1 and HSD-2 did not differ significantly between any two of the categories. Among EldCa, HSD-1 levels were higher in ER/PR-positive than in ER/PR-negative carcinomas, whereas EST and HSD-2 exhibited opposite results. Conclusions: The importance of aromatase is relatively increased in EldCa. ER/PR-positive EldCa exhibited a pattern of EMEs more beneficial to the production of estrogen than did ER/PR-negative EldCa. The specific pattern exhibited in EldCa may elucidate the role of EMEs in the absence of ovarian estrogens in the pathogenesis of breast cancer.
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