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Outcomes in patients with early‐stage breast cancer who underwent a 21‐gene expression assay
Author(s) -
Barcenas Carlos H.,
Raghavendra Akshara,
Sinha Arup K.,
Syed Masood Pasha,
Hsu Limin,
Patangan Modesto G.,
ChavezMacGregor Mariana,
Shen Yu,
Hortobagyi Gabriel H.,
Valero Vicente,
Giordano Sharon H.,
Ueno Naoto T.,
Tripathy Debu
Publication year - 2017
Publication title -
cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/cncr.30618
Subject(s) - medicine , hazard ratio , breast cancer , oncology , proportional hazards model , chemotherapy , stage (stratigraphy) , confidence interval , cancer , hormone receptor , paleontology , biology
BACKGROUND Invasive disease‐free survival (IDFS) rates are excellent in patients with breast cancer (BC) with hormone receptor‐positive (HR+), human epidermal growth factor receptor 2‐negative (HER2‐), axillary lymph node‐negative (LN‐) tumors with a 21‐gene expression assay recurrence score (RS) of 0 to 10. However, to the authors' knowledge, the outcomes among patients with an RS of 11 to 25 who are treated with endocrine therapy alone are unknown. METHODS In this retrospective single‐institution study, the authors described the characteristics of patients with HR+, HER2‐, LN‐ BC who underwent a 21‐gene expression assay. In addition, among those individuals diagnosed between 2005 and 2011, we measured IDFS, recurrence‐free survival, distant recurrence‐free survival, and overall survival rates, focusing on patients with an RS of 11 to 25 by receipt of chemotherapy. The Kaplan‐Meier method was used to estimate survival rates and multivariable Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals (95% CIs). RESULTS Among 1424 patients, the RS distribution was 0 to 10 in 297 patients (21%), 11 to 25 in 894 patients (63%), and >25 in 233 patients (16%); of these, 1.7%, 15%, and 73.4% of patients, respectively, received chemotherapy. With a median follow‐up of 58 months, those patients with an RS of 11 to 25 had an IDFS rate at 5 years of 92.6% (95% CI, 89.6%‐94.7%), which was comparable between those who received chemotherapy and those who did not. The hazard ratios of the effect of chemotherapy were 1.64 for IDFS (95% CI, 0.73‐3.71), 1.46 for recurrence‐free survival (95% CI, 0.41‐5.23), 1.25 for distant recurrence‐free survival (95% CI, 0.32‐4.92), and 2.19 for overall survival (95% CI, 0.44‐11.0). CONCLUSIONS The results of the current study demonstrate similar outcomes with or without chemotherapy in patients with HR+, HER2‐, LN‐ BC who have an RS of 11 to 25, but a benefit from chemotherapy in this group cannot be ruled out. Cancer 2017;123:2422–31. © 2017 American Cancer Society .