EP764 - Impact of lymphocyte-monocyte ratio (LMR) as a Prognostic Factor in cases with Unresectable Metastatic MSS Colorectal Cancer

ePoster Presenter(s)

• 

  Yosuke Wakui, MD

  Medical doctor
  Department of Gastroenterological Surgery 1, Hokkaido University
  Hokkaido University department of digestive surgery1
  Sapporo, Hokkaido, Japan

  Disclosure information not submitted.

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Author(s)

• NI

  Nobuki Ichikawa, PhD

  Assistant Professor
  Department of Gastroenterological Surgery 1, Hokkaido University
  Sapporo, Hokkaido, Japan

  Disclosure information not submitted.
• TN

  Tomomi Nishikawa, n/a

  Biostatistcian
  National Cancer Center Hospital East
  Kashiwa city, Chiba, Japan

  Disclosure information not submitted.
• HB

  Hideaki Bando, Medical Doctor

  Director
  National Cancer Center Hospital East
  Kashiwa, Chiba, Japan

  Disclosure information not submitted.
• TM

  Toshihiro Misumi, Ph.D

  Director, Department of Data Science
  Department of Data Science, National Cancer Center Hospital East
  Kashiwa, Chiba, Japan

  Disclosure information not submitted.
• AG

  Axel Grothey, MD

  Director, GI Cancer Research
  West Cancer Center
  Germantown, Tennessee, United States

  Disclosure information not submitted.
• AO

  Atsushi Ohtsu, Medical Oncology

  Senior Manager, Research Unit
  Japanese Foundation for Cancer Research
  Tokyo, Tokyo, Japan

  Disclosure information not submitted.
• AT

  Akinobu Taketomi, MD, PhD

  Professor
  Hokkaido University
  Sapporo, Hokkaido, Japan

  Disclosure information not submitted.

Senior Author(s)

• TY

  Takayuki Yoshino, MD

  Deputy Director of Hospital, Head, Division for the Promotion of Drug and Diagnostic Development
  National Cancer Center Hospital East
  Kashiwa, Chiba, Japan

  Disclosure information not submitted.

Purpose/Background: Background:

The lymphocyte-to-monocyte ratio (LMR) reflects systemic inflammatory and immune balance. Although several studies have demonstrated its prognostic value in solid tumors, its significance in metastatic colorectal cancer (mCRC), especially in chemo-refractory microsatellite-stable (MSS) cases and by tumor sidedness, remains unclear. This study aimed to elucidate the prognostic impact of baseline LMR using large-scale prospective clinical trial data from the Aide et Recherche en Cancérologie Digestive (ARCAD) database.

Methods/Interventions:

Methods:

A post-hoc analysis was conducted using data from two phase III trials (CORRECT and J003) involving patients with chemo-refractory MSS mCRC. LMR was calculated as the absolute lymphocyte-to-monocyte ratio from baseline peripheral blood counts. Patients were dichotomized into LMR-High and LMR-Low groups based on the median value (2.8). The primary endpoint was overall survival (OS); secondary endpoints included progression-free survival (PFS) and analyses stratified by primary tumor sidedness. Survival was compared by Kaplan-Meier and log-rank tests, and independent prognostic factors were evaluated using Cox proportional hazards models adjusted for clinical variables.

Results/Outcomes:

Results:

Among 47,076 patients in the ARCAD database, 587 met eligibility criteria (MSS, non-placebo, third-line therapy). The median age was 61 years; 60.8% were male, and 65.8% had right-sided primary tumors. Median OS was significantly shorter in the LMR-Low group than in the LMR-High group (5.4 vs 9.1 months, p < 0.001). The prognostic impact of LMR persisted regardless of sidedness: in left-sided tumors, median OS was 5.9 vs 12.0 months (adjusted HR vs LMR-High in left sided disease: 1.57, 95% CI 1.05-2.35), and in right-sided tumors, 4.6 vs 8.7 months (adjusted HR vs LMR-High in left sided disease: 2.31, 95% CI 1.63-3.26). LMR distribution did not differ significantly between right and left sides (median 2.7 each, p = 0.89). In multivariate analysis, both LMR-Low (HR 1.89, 95% CI 1.47-2.44, p < 0.001) and right-sided tumors (HR 1.44, 95% CI 1.11-1.88, p = 0.006) were identified as independent poor prognostic factors.

Conclusion/Discussion:

Conclusion:

Pre-treatment LMR is a simple yet robust independent prognostic biomarker in chemo-refractory MSS mCRC. Its prognostic effect was consistent across primary tumor sidedness, suggesting that LMR captures host immune competence beyond tumor location. Incorporating LMR into clinical assessment may improve risk stratification and guide individualized therapeutic strategies in advanced mCRC.

Conclusion:

Pre-treatment LMR is a simple yet robust independent prognostic biomarker in chemo-refractory MSS mCRC. Its prognostic effect was consistent across primary tumor sidedness, suggesting that LMR captures host immune competence beyond tumor location. Incorporating LMR into clinical assessment may improve risk stratification and guide individualized therapeutic strategies in advanced mCRC.

Kaplan-Meier survival curves demonstrating OS and PFS in LMR-High vs. LMR-Low patients in LMR-High vs LMR-Low.
The LMR-Low group had a significantly shorter OS compared to the LMR-High group (median OS: 5.4 months vs. 9.1 months; log-rank p < 0.001).
OS and PFS in LMR-High Left vs. LMR-High Right vs. LMR-Low Left vs. LMR-Low Right.
Overall survival (OS) according to pre-treatment LMR in patients with metastatic colorectal cancer, stratified by tumor sidedness. In left-sided tumors (n = 195), the LMR-Low group showed significantly shorter OS compared to the LMR-High group (median OS: 5.9 vs. 12.0 months; adjusted HR = 1.57, 95% CI: 1.05-2.35). This difference was even more pronounced in right-sided tumors (n = 364), where LMR-Low patients had a markedly poor prognosis (median OS: 4.6 vs. 8.7 months; adjusted HR = 2.31, 95% CI: 1.63-3.26).