Analysis of the prognostic factors of triple-negative breast cancer and the clinical efficacy of postoperative radiotherapy in early cases.

e12502 Background: To explore the prognostic value of pretherapeutic peripheral blood parameters and breast imaging-reporting and data system (BI-RADS) classification of triple-negative breast cancer (TNBC) and the effect of postoperative radiotherapy in early cases. Methods: A total of 278 TNBC patients’ medical records between January 2013 and December 2018 were retrospectively collected, including white blood cells, neutrophils, lymphocytes, platelets, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), serum tumor markers, BI-RADS classification, TNM staging and therapeutic methods. We used the log-rank test and Kaplan-Meier curves to assess the progression-free survival (PFS) of enrolled patients. Multivariate prognostic analysis was performed by the Cox regression model. Results: The median PFS of all 278 patients was 20 months (4-72 months) at the end of follow-up. Operable patients who obtained adjuvant chemotherapy had a better median PFS (20 vs 18.5 months, P= 0.018, HR = 5.943, 95% CI: 1.36-25.92) than those without. Lymph node metastasis (52%) and chest well relapse (28%) were the critical failure forms followed by other metastases (12% lungs, 9.3% bones, 4% liver and 2.7% brain) with p value less than 0.001. Multivariate analysis indicated that platelet counts > 113.5×109/L (p = 0.024), PLR ≤ 111.7 (p = 0.036) and CA15-3 ≤ 8.4 U/mL (p = 0.003) were significantly associated with the favourable prognosis of PFS in TNBC patients. Furthermore, BI-RADS of grade 2-4 had a better median PFS compared with grade of 5-6(20 vs 17.5 months, p = 0.008, HR = 2.154, 95% CI: 1.219-3.805). In subgroup analysis, forty-three early cases with pN1 stage earned additional benefits from postoperative radiotherapy in terms of low risk of distant metastasis and recurrence (p = 0.014). Residual tumor after surgery was another important factor of poor prognosis (p = 0.029). Conclusions: Adjuvant chemotherapy improved median PFS for operable TNBC patients and pretherapeutic platelets, PLR, CA15-3 and BI-RADS were the independent prognostic factors of survival. Lymph node metastasis and chest well relapse were the main patterns of treatment failure. Radiotherapy could reduce the risk of disease progression for postoperative patients with N1 stage.