PROGNOSTIC VALUE OF THE DENSITY OF TUMOR-INFILTRATING LYMPHOCYTES AND ITS ASSOCIATION WITH CLINICAL-MORPHOLOGICAL FEATURES OF COLON ADENOCARCINOMAS.

Aim: To study the prognostic value of the density of tumor-infiltrating lymphocytes (TILs) and its association with other clinical-morphological parameters in colon adenocarcinomas (CAC).

Materials and methods: 236 CAC samples were examined. TILs density was estimated as the percentage of tumor stromal area occupied by TILs. By the index of TILs density, the patients were divided into 3 groups: TILs 0-9% (n = 88); TILs 10-39% (n = 106); TILs > 40% (n = 42). Dependent on this index, their overall survival (OS) was analyzed.

Results: Kaplan - Meier curves revealed a significant (p < 0.001) difference in the OS for patients with different TILs infiltration intensities. Multivariate Cox's proportional hazard regression model analysis has confirmed that patients with moderate TILs density (HR 0.57, 95% CI 0.34-0.96, p = 0.035) had better OS rates compared to low TILs density. TILs were associated with the stage (p < 0.001), lymph node metastasis pN (p < 0.001), distant metastasis M (p < 0.001), and the patient's outcome (p < 0.001).

Conclusion: TILs can be considered an additional prognostic tool during regular histological examination and are strongly associated with the most significant clinical-morphological features of CAC.