Goserelin plus tamoxifen compared to chemotherapy followed by tamoxifen in premenopausal patients with early stage-, lymph node-negative breast cancer of luminal A subtype

Objectives To study the outcomes of adjuvant goserelin combined with tamoxifen (GosTam) compared to chemotherapy followed by tamoxifen (ChemTam) in premenopausal patients with early stage, luminal A breast cancer. Methods From 2008 until 2013, data were retrospectively collected for premenopausal patients who underwent surgery for invasive tumors that were ≤2.0 cm, node-negative, strongly positive for estrogen and progesterone receptors, HER-2-negative, and Ki-67 < 25%. The patients were divided into two groups according to adjuvant regimen, either GosTam or ChemTam. All patients who underwent different adjuvant regimens were excluded. Results In total, 235 patients underwent GosTam and 171 patients underwent ChemTam. There were significantly more patients younger than 40 years in the GosTam group (32% GosTam vs. 22% ChemTam, p = 0.031). Mean tumor size was significantly smaller (1.19 cm vs. 1.48 cm, p < 0.001), Ki-67 significantly lower (p = 0.049), and nuclear grade was low in a significant number of patients in the GosTam group (2% vs. 13%, p < 0.001). After a median follow-up of 51.3 months, there was no mortality in either group. There was no significant difference in 5-year disease-free survival (DFS) between the two groups even after univariate analysis considering age, tumor size, nuclear grade, and P53% (GosTam = 98.9% vs. ChemTam = 95.7%, HR = 0.404, 95% CI = [0.073, 2.222], p = 0.248). Conclusion There was no difference between treatment groups, and neither chemotherapy nor ovarian suppression seemed to improve the outcome. Thus, tamoxifen alone might be a sufficient option for this low-risk patient population.