The potential prognostic role of peritumoral eosinophils within whole tumor-associated inflammatory cells and stromal histological characteristics in colorectal cancer.

We aimed to determine the prognostic role of whole tumor-associated inflammatory cells, especially eosinophils, and stromal histological characteristics in relation to other prognostic parameters in patients with colorectal carcinoma (CRC). A total of 122 patients who underwent an operation for CRC were included in this retrospective study. Conventional (tumor grade, TNM stage and venous invasion [VI]) and other histopathological (intratumoral/peritumoral budding [ITB/PTB], desmoplasia) tumor parameters were recorded and classified by density, as were the tumor-associated inflammatory parameters (intratumoral/peritumoral lymphocytes [ITL/PTL], eosinophils [IE/PTE], overall inflammation [ITI/PTI], Crohn-like inflammation [CLI]). Cancer-specific survival data were analyzed with respect to all tumor parameters. High ITB and PTB were significantly correlated with a higher rate of pT4, VI and desmoplasia (p < 0.05). An association of moderate ITL and extensive PTL with lesser likelihood of VI and metastasis; an association of extensive CLI with a significantly lower rate of metastasis and TNM stage IV; and minimal PTE with a significantly higher rate of pT4 stage, metastasis and ITB were detected (p < 0.05 for each). Our findings revealed that low score tumoral budding and an increase in tumor-related inflammation were associated with lesser likelihood of poor prognostic tumor parameters. Nonetheless, given the association of an increase in PTE with lesser likelihood of ITB, pT4, metastasis, and with non-significantly for better survival rates, our findings emphasize the potential role of peritumoral eosinophils as an additional prognostic parameter in CRC.