Tumor Infiltrating Lymphocytes as Prognostic Factor of Early Recurrence and Poor Prognosis of Colorectal Cancer After Radical Surgical Treatment

Abstract

Aims: The aim was to analyse the relationship of clinical and histopathological factors and TIL to determine patients with a high risk of poor overall survival and tendency to early recurrence of colorectal cancer (CRC) after radical surgery. Methods: We analysed 150 patients who underwent radical surgical procedure for CRC between the years 2004-2007. We evaluated endovascular (VI), endolymphatic (LI) and perineural infiltration (PI) by cancer cells. Lymphocytic infiltration was detected as intratumoral (ITL), intrastromal (ISL), peritumoral (PTL) and Crohnlike reaction (Crohn-like PTL). Reactive histological changes in lymph nodes (LN reactions) were detected as follicular hyperplasia (LN-FH), sinus histiocytosis (LNSH) and the presence of granulomas (LN-GR). We examined also the immuno-histochemical positivity of lymphocytes for CD4 and CD8. Results: The Spearman rank correlation coefficient did not prove any stronger correlation than a moderate correlation at LI and lymph node infiltration by metastatic process (Spearman rank correlation coeffiecient 0.56, p<0.05). Statistical analysis proved lymph node infiltration by metastatic process as statistically significant for the prognosis of overall survival. VI was proved as a negative prognostic factor of shorter overall survival. The presence of PTL, Crohn-like PTL, LN-FH was proved as a positive prognostic factor of OS. The severity of CD8+ lymphocytic infiltration was proved as a positive prognostic factor enlarging OS. CD4+ lymphocytic infiltration was proved as negative prognostic factor of OS. PI was proved as a negative prognostic factor of an earlier recurrence. CD8+ lymphocytic infiltration was proved as a positive prognostic factor enlarging DFI. Conclusion: Tumor infiltrating lymphocytes seem to be promising prognostic factors of CRC.