Abstract 4653: Platelet to lymphocyte ratio and platelet count: new frontiers as prognostic factors in metastatic colorectal cancer patients receiving anti-angiogenic drugs

Background: Anti-angiogenic drugs represent a milestone of metastatic colorectal cancer (mCRC) pts) treatment. To date, no validated prognostic biomarkers are available. Recently, hematological parameters became of particular interest in solid tumors, including mcRC. Here, we present the results of our research in order to identify potential prognostic factors among clinical and laboratory parameters in mCRC pts receiving anti-angiogenic agents at our Centre. Patients and Methods: We retrospectively collected clinical and laboratory data of mCRC pts treated with anti-angiogenic drugs at the Medical Oncology Unit of Cagliari University Hospital (2018-04/2024) in order to identify a potential prognostic tool. Statistical analysis was performed with MedCalc (survival distribution: Kaplan-Meier; survival comparison: log-rank test; cut-off: ROC curves). Results: Globally, 42 mCRC pts were included in our study. 25 were male, 17 female; 17 had a RAS wild-type tumor, 30 had a left-sided primary). 14 pts received anti-angiogenic agents in the the first-line, 15 in the second-line (4 bevacizumab and 11 aflibercept) and 13 in the first and further lines. Median OS was 31.4 months (95% CI: 18.3 -39.5). When assessing the correlation between clinical and laboratory parameters and prognosis of the study population, a statistically significant improvement in overall survival (OS) was found in patients with platelet to lymphocyte ratio (PLR) equal or lower than 179.23 (31.4 months [95% CI: 20.3-47.1] versus 10.5 months [95%: CI 6.8 - 39.5], p=0.0315, HR= 0.27) and platelet count equal or lower than 360/μl (31.4 months [95% CI: 20.3-41.8] versus 10.3 months [95%: CI 6.8-10.5], p<0.0001, HR=0.0002). Then, according to these findings, we separated pts in two prognostic groups: good prognostic group (no unfavorable variables) and poor prognostic group (≥1 unfavorable variables). We observed a trend for longer OS in patients belonging to the good prognostic group (31.4 months [95% CI: 20.3-41.8] versus 10.5 months [95% CI: 6.8 - 39.5], p=0.0521, HR=0.3166). Conclusions: Our research showed a promising prognostic role of baseline platelet count and PLR in mCRC patients receiving with anti-angiogenic drugs in a limited population at our center. Citation Format: Platelet to lymphocyte ratio and platelet count: new frontiers as prognostic factors in metastatic colorectal cancer patients receiving anti-angiogenic drugs. Platelet to lymphocyte ratio and platelet count: new frontiers as prognostic factors in metastatic colorectal cancer patients receiving anti-angiogenic drugs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4653.