The characteristics of malignant breast tumors in hormone replacement therapy users versus nonusers

Background: The purpose of this study was to investigate the characteristics of breast cancer in hormone replacement therapy (HRT) users vs. nonusers. Methods: We investigated the characteristics of all patients between the ages of 50 and 75 years with breast tumors. Then, an age-adjusted group of 55 nonusers was chosen to match and compare with HRT users. Results: Of the 243 patients available for evaluation, 55 (22.6%) used HRT. Disease stages in HRT users vs. nonusers were as follows: ductal carcinoma in situ (DCIS), 20% and 17.1%; stage I, 45.5% and 41.7%; stage II, 30.9% and 26.2%; stage III, 3.6% and 13.4%; and stage IV, 0% and 1.6% (P=.27). In the age-adjusted cohort, stages in nonusers were as follows: DCIS, 7.3%; stage I, 47.3%; stage II, 25.5%; stage III, 20%; and stage IV, 0% (P=.03). Tumor grades in HRT users vs. nonusers were as follows: grade I, 30.4% and 15.7%; grade II, 52.2% and 52.2%; and grade III, 17.4% and 32.1% (P=.035). Grades in cohort nonusers were as follows: I, 13.2%; II, 52.8%; and III, 34% (P=.05). In the invasive tumors, the positive estrogen receptor (ER) rates were 81.6% and 85.7% (P=.89); positive progesterone receptor (PR) rates were 53.1% and 54% (P=.95); and Her 85.7% (P=.89); positive progesterone receptor (PR) rates were 53.1% and 54% (P=.95); and Her 2-neu positive rates were 18.4% and 17.6% (P=.95), respectively. No significant difference was found in intratumor DCIS, vascular invasion, and Ki-67 (P=.14, .9, and .79, respectively). The rate to lobular and favorable histological types was higher in the HRT user group: 26.6% vs. 15%. Conclusions: Breast tumors in HRT users vs. nonusers were of a significantly lower stage and grade and accounted for a higher number of favorable histological types, but all other parameters were similar in the two groups.