Abstract 509: Tumor inflammation signature (TIS) in residual disease is associated with survival in breast cancer patients with high risk of recurrence

Abstract Background: The assessment of tumor inflammation signature (TIS) quantifies the adaptive immune response in the tumor microenvironment and is emerging as a predictor of clinical benefit in breast cancer. In this study we evaluated the ability of TIS to be a prognostic biomarker of survival benefit in patients with moderated and high residual disease after neoadjuvant chemotherapy (NAC) in breast cancer patients and its correlation with residual TILS after NAC. Methods: We analyzed 46 samples of residual disease of breast cancer patients who received NAC and were under surgery between 2013 - 2018, with high risk of recurrence defined as Residual Cancer Burden (RCB) group II and III. TIS signature was evaluated using the Research Use Only version of 18-gen signature algorithm. Median of TIS score was 5.88, TIS score were categorized in four groups by quartiles and defined as low TIS score (lower quartile, score ≤ 4.82) and high TIS score (score > 4.82). In addition, we quantified the percentage of stromal TILS in residual disease, categorizing level of TILS in high and low level using median (20%) as a cut-off. Survival analysis was performed with Kaplan-Meier method and the associations with Cox regression model. Correlation between TIS and TILS was performed whit Pearson coefficient. Clinical data was collected of medical records. Results: The median age at diagnosis was 50 years (26y - 78y), 65.2% of patients were Luminal B subtype, 63% were clinical stage IIIB, 26.2% were RCB II and 73.9% RCB III. No correlation between TIS score and percentage of stromal TILS was founded (p = 0.264). After median follow-up of 60 months, estimated median PFS for high TIS score was 71.7 vs 18.2 months for low score (HR = 0.28, 95% CI [0.13-0.64], p = 0.002), and estimated median OS for high TIS score was non-reached vs 40.9 months for low score (HR = 0.28, 95% CI [0.11-0.68], p = 0.005). Did not found differences in PFS (p = 0.408) and OS (p = 0.773) by level of TILS. Conclusions: High TIS score in moderated/high residual disease after neoadjuvant chemotherapy is associated with survival benefit expressed in prolonged PFS and OS. Level of TILS in residual disease did not show differences in survival and its percentage did not have correlation with TIS score. Funding: FONDECYT-198-2015/280-INNOVATEPERU-EC-2017. Citation Format: Marco Galvez-Nino, Miluska Castillo, Luis Bernabe, Nancy Suarez, Joselyn Sanchez, Katia Roque, Silvia Neciosup, Henry Gomez, Carlos Castaneda. Tumor inflammation signature (TIS) in residual disease is associated with survival in breast cancer patients with high risk of recurrence [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 509.