A real-world study of immune checkpoint inhibitors in advanced triple-negative breast cancer.

Abstract

e13090 Background: Triple-negative breast cancer (TNBC) is the most aggressive type of breast cancer. The lack of specific targets leads in fewer effective treatments and poor prognosis. Immunotherapy has become a new generation of treatment approach in addition to surgery, radiotherapy, chemotherapy, endocrine therapy and targeted therapy. Immune checkpoint inhibitors (ICIs) have been widely used in the clinical treatment of various tumors and changed the landscape of tumor treatment, but the data from real-world studies of ICIs for TNBC remain limited. Methods: Clinical data of patients with advanced TNBC treated with ICIs in Chinese People’s Liberation Army General Hospital were collected from January 2004 to December 2022. The effect of different factors on patient response and prognosis was analyzed using Kaplan-Meier survival curves. The relationship between clinical, pathological characteristics, hematological indicators, and efficiency were analyzed using univariate and multifactorial Cox regressions. Objective Response Rate (ORR), Disease Control Rate (DCR), Progression-free Survival (PFS), Overall survival (OS), and adverse events (AEs) were assessed. Results: Eighty-one patients were enrolled in the study. Median follow-up was 26.3 months (range, 16.0 - 36.6 months). Confirmed ORR was 32.1% and DCR was 64.2%. The median PFS was 4.2 months and the median OS was 11.0 months. Eastern Cooperative Oncology Group (ECOG) performance status score ≥ 1, applying ICIs in 2nd and later lines, with liver metastases, with more than two sites of metastases, lactate dehydrogenase (LDH) ≥ 194.3 U/L, alkaline phosphatase (ALP) ≥ 104.7 U/L, neutrophil-to-lymphocyte ratio at baseline (bNLR) ≥ 2.7, NLR before the second dose of immunotherapy (NLR2) ≥ 2.2, platelet to lymphocyte ratio before the second dose of immunotherapy (PLR2) ≥ 165.6 were associated with a poorer prognosis. Patients with effective initial treatment, tumor - infiltrating lymphocytes (TIL) ≥ 20%, derived neutrophil-to-lymphocyte ratio (dNLR) ≤ 1.9, LDH < 194.3 U/L and bNLR < 2.5 prior to ICI treatment have a better prognosis. Conclusions: ICIs were effective in advanced TNBC with tolerable adverse effects, and we have identified a series of biomarkers associated with PFS and OS. Randomized controlled clinical trials are warranted to validate our findings.