Association of tumor infiltrating lymphocyte quantity with survival in patients (pts) with metastatic breast cancer (MBC) receiving microtubule-targeting agents: Post hoc analysis CALGB 40502 (Alliance).

• DOI: 10.1200/jco.2023.41.16_suppl.1010
• Publication Date: 2023-06-04T14:10:33Z
• Authors: Daniel G. Stover; Roberto Salgado; Oleksandr Savenkov; Karla V. Ballman; Mark Jesus Mendoz...; Sherene Loi; Erica L. Mayer; Mark Vater; Kristyn Glover; Mark A Watson; Yujia Wen; W. Fraser Fraser ...; Charles Perou; Lisa A. Carey; Ann H. Partridge; Hope S. Rugo
• Keywords: Post-hoc analysis

1010 Background: Stromal tumor infiltrating lymphocyte (sTIL) quantity is prognostic in primary breast cancer, yet MBC characterized by lower sTILs. No study has definitively evaluated the association of sTIL with survival outcome metastatic (met) setting without checkpoint blockade. CALGB (Alliance) 40502 was a randomized phase 3 trial 799 pts receiving first-line chemotherapy, comparing paclitaxel, nab-paclitaxel or ixabepilone bevacizumab. We hypothesized that sTILs associated MBC. Methods: 582 submitted hematoxylin and eosin slide images from 443 unique were evaluable for accordance International TILs Working Group methods. Analysis based on most recent available tissue, 161/443 (36.3%) having recurrent/met tissue. Using prespecified thresholds <5% (low) vs ≥5% (high) distribution met setting, associations between low/high as continuous variable baseline characteristics outcome. The objective to evaluate progression-free (PFS) overall (OS), chemotherapy arm covariate. Results: High more frequent among hormone receptor (HR)-negative disease (64% HRneg 34% HRpos, p<0.001), no significant treatment arm, age, menopausal status, race/ethnicity, body mass index (BMI). Among all slides, mean higher tumors than (mean 13.3% 8.4% met, p=3e-4). non-lymph node sites, ranged 1.3% (bone) 9.5% (lung). 100 paired had significantly greater (10.5% 7.7%, p=0.008). For objective, Cox proportional hazard model low high worse PFS (HR 1.34; 95% CI 1.1-1.63, p=0.004) OS 1.32; 1.07-1.63, p=0.009) when controlling arm. When both HR demonstrated similar trends but did not reach statistical significance 1.2; 0.97-1.47, p=0.09) 1.14; 0.91-1.43, p=0.2). There interaction (all p-interaction >0.05). Conclusions: Immune activation measured cancer varies site. In this trial, chemotherapy-treated MBC, trend toward independent value adjusted other features. Clinical information: NCT00785291 .