Changes in the CD8+ density of tumor infiltrating lymphocytes after neoadjuvant radiochemotherapy in patients with rectal adenocarcinoma
Abstract
Background: The goal of this study is to examine the effect of neoadjuvant radiochemotherapy on the density of CD8+ tumor infiltrating lymphocytes (TILs) in endoscopical bio psies and resection specimens from patients with rectal adenocarcinoma before and after therapy. Patients and Methods: In total, 53 patients with locally advanced rectal cancer were studied.
Results: The median density of CD8+ TILs in pretreatment bio psies was 12 (1-232) and that in surgical specimens after radiochemotherapy was 18 (1-319). During radiochemotherapy, the density of CD8+ TILs increased in 30 patients (57%), decreased in 18 (34%), and did not change in one.
It was not possible to assess the dynamics of CD8+ TILs density in four patients. The increased density of CD8+ TILs after radiochemotherapy was associated with a median survival rate 2.5 times longer than that associated with no increase in density.
Conclusion: In the present study, the density of CD8+ TILs in endoscopical bio psies before radiochemotherapy, the density in resection specimens after radiochemotherapy, or in changes in the density after radiochemotherapy showed no predictive or prognostic significance. However, studying a larger number of patients may show that CD8+ TILs density is of predictive or prognostic significance.