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

Abstract

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.

Keywords: Breast cancer; Chemotherapy; GnRH; Goserelin; Tamoxifen.