1681P - The role of macrophages polarization in predicting prognosis in radically resected gastric cancer

Date 30 September 2012
Event ESMO Congress 2012
Session Poster presentation II
Topics Gastric Cancer
Pathology/Molecular Biology
Presenter Francesco Pantano
Authors F. Pantano1, P. Berti1, F.M. Guida1, S. Intagliata1, F. Graziano2, G. Perrone3, A. Onetti Muda3, B. Vincenzi4, G. Tonini1, D. Santini1
  • 1Medical Oncology, university campus bio-medico, 00128 - rome/IT
  • 2Ospedale di Urbino, IT-61029 - Urbino/IT
  • 3Department Of Pathology, university campus bio-medico, 00128 - rome/IT
  • 4university campus bio-medico, 00128 - rome/IT

Abstract

Introduction

Macrophages are one of the major populations of tumor-infiltrating immune cells. Tumor associated Macrophages (TAM) present two different phenotypes or polarizations: classical (M1) characterized by immunostimulation activity and tumor suppression; alternative (M2) characterized by angiogenesis, tumor promotion, and immune suppression. Despite these opposite properties, most of the previous studies focused merely on evaluating absolute TAM count. In this work, for the first time in literature, we evaluated the correlation between the two forms of TAM with survival time in patients affected by gastric cancer after radical surgery.

Methods

52 chemo- and radio-naïve gastric cancer patients undergone to resection for curative intent were included in this retrospective study. Two slides were prepared for each patients and double-stained for CD68/NOS2 (M1) or CD68/CD163 (M2) and five representative high-power fields (×400 magnification) per slide were evaluated for TAM count. The median value of the two macrophage populations density (M1 = 7.0; M2 = 6.4) and the median value of M1/M2 ratio (1.16) was used as cut-off.

Results

27 patients with M1 density above the median had a significantly higher survival compared to those below the median (median OS of 25.6 months, CI95%:22.33-44.85 vs 17.1 months, CI95%:13.66-27.98; P = 0.041). 26 patients with M1/M2 ratio above the median showed median OS of 27.2 months (CI95%:25.45-47.51) compared to 15.5 months (CI95%:11.36-25.50) of the patients below the median (P = 0.001). No statistically significant difference in terms of M1/M2 ratio was observed between intestinal vs diffuse histological type. No association between M2 macrophage density and patients outcome (P= 0.724) was found. In multivariate analysis M1/M2 was a positive independent predictor of survival (P= 0.001; HR 0.420, CI95%: 0.22-0.78) whereas grading, histotype and TNM stage were not statistically significant.

Conclusion

The M1 macrophage density and in particular M1/M2 ratio, as confirmed in multivariate analysis, is an independent factor that can predict patients survival time in gastric cancer after radical surgery. The role of macrophage phenotype in influencing the gastric cancer prognosis warrant further investigation.

Disclosure

All authors have declared no conflicts of interest.