Current adjuvant hormone therapy in postmenopausal women with breast cancer is debatable between upfront aromatase inhibitors (AIs) and sequential treatment with tamoxifen. A major concern is the higher rate of early recurrences observed with sequential treatment. The authors conducted a retrospective analysis to identify risk factors of early recurrences in hormone receptor (HR)-positive, postmenopausal women within the first 3 years of adjuvant tamoxifen.
Between 1986 and 2000, operable breast cancer patients who received exclusively adjuvant tamoxifen for at least 3 years were selected from the authors' institutional database. Age, histology, pathologic tumor size, modified Scarff-Bloom-Richardson (mSBR) grade, mitotic index, tumor necrosis, peritumoral vascular emboli (PVE), HR status, and the number of involved axillary lymph-node were considered as prognostic factors of recurrence.
Among 715 patients who met the inclusion criteria, a distant recurrence occurred in 38 patients (5.3%) within the first 3 years of tamoxifen therapy. Significant prognostic factors of early recurrence were mSBR, axillary lymph node involvement, tumor necrosis, mitotic index, PVE, and pathologic tumor size. Grade 1 and/or lymph node-negative tumors were excluded from the multivariate analysis (1 recurrence in 208 patients). In this model, mSBR grade 3 was the only significant predictive factor of early recurrence (hazard ratio, 3.72; P < .001).
In this study, a subset of patients was identified that was at low-risk of early recurrence (mSBR grade 1 and/or negative lymph node status). Women in that subset could be treated using sequential hormone therapy with tamoxifen and AIs. In women with mSBR grade 3 or lymph node-positive tumors, an upfront treatment with AIs seemed to be the current optimal strategy. Cancer 2007. © 2007 American Cancer Society.