To compare the prognosis between neoadjuvant chemotherapy (NAC) and adjuvant chemotherapy (AC) in patients with node-positive luminal A breast cancer.

The clinical data of 13 447 node-positive luminal A breast cancer patients with complete follow-up results in the Surveillance, Epidemiology, and Results (SEER) database (8.4.0.1) from January 1, 2010 to December 31, 2012 were retrospectively analyzed, including 1 534 patients in the NAC group and 11 913 patients in the AC group. A total of 2 974 patients with node-positive luminal A breast cancer were obtained by the propensity score matching (1∶1 nearest neighbor matching) to balance confounding factors, including 1 487 patients in the NAC group and 1487 patients in the AC group. The Kaplan-Meier method was used to draw survival curves, and the log-rank test was used for comparison. The Cox proportional risk regression model was used to analyze the prognostic factors.

There were significant differences in age at diagnosis, tumor stage, T stage, N stage, histological grade, race, marital status and pathological type between two groups before PSM (Z=-8.877, -19.168, -28.034, -5.807, -9.575, χ²=18.205, 14.460, 4.600; all P<0.050), while no significant difference was found in clinicopathological characteristics between the NAC group and the AC group after PSM (all P >0.050). The 5-year OS was 78.9% and 86.5% in the NAC and AC group, respectively. Survival analysis showed that the patients in the AC group had a significantly better prognosis compared with the NAC group (χ²=34.575, P<0.001). Subgroup analysis showed that the later the N stage, the poorer the prognosis in both groups (NAC group: χ²=96.422, P<0.001; AC group: χ²=47.205, P<0.001). In the patients with different N stage, the prognosis of the AC group was significantly better than that of the NAC group (N₁: χ²=11.585, P=0.001; N₂: χ²=13.060, P<0.001; N₃: χ²=12.245, P<0.001). In the patients at N₂stage, the patients who received radiation therapy had a significantly better prognosis than those who did not receive radiation therapy (χ²=12.426, P<0.001). Multivariate Cox proportional risk regression model analysis showed that AC improved the prognosis better than NAC did (HR=0.613, 95%CI: 0.523-0.719, P<0.001); the age at diagnosis, race, T stage, N stage and histological grade were all independent prognostic factors (>60 years vs <45 years: HR=1.438, 95%CI: 1.158-1.785, P=0.001; black vs white: HR=1.323, 95%CI: 1.076-1.627, P=0.008; other races vs white people: HR=0.474, 95%CI: 0.339-0.664, P<0.001; T₁ vs T₀: HR=0.111, 95%CI: 0.034-0.360, P<0.001; T₂ vs T₀: HR=0.183, 95%CI: 0.058-0.576, P=0.004; N₃ vs N₁: HR=2.007, 95%CI: 1.582-2.547, P<0.001; G₃ vs G₁: HR=2.296, 95%CI: 1.640-3.215, P<0.001).

The efficacy of AC is better than NAC in patients with node-positive luminal A breast cancer; however, the clinicians should make individualized treatment plans considering the risk factors of recurrence.