Increased Infiltration of CD4+, CD8+, and CD68+ Cells at the Invasive Front Is Associated With Favorable Prognosis in
Goro Takahashi1, Seiichi Shinji1,2, Toshiyuki Ishiwata2
1Department of Gastroenterological Surgery, Nippon Medical School, Tokyo, Japan.
Background:
Obstructive colorectal cancer (OCRC) presents as an oncologic emergency with poor prognosis. Although tumor-infiltrating lymphocytes (TILs) and tumor-associated macrophages (TAMs) are known to affect colorectal cancer outcomes, their roles in OCRC remain unclear.
Methods And Results:
We retrospectively analyzed 66 patients with Stages II-III OCRC who underwent curative resection following endoscopic decompression. CD4+, CD8+, and CD68+ cell densities at the tumor center and invasive front were quantified using multiplex immunofluorescence imaging. Cancer-specific survival (CSS) was assessed in relation to immune cell infiltration. Target immune cells were significantly more abundant at the invasive front compared to the tumor center. High densities of CD4+ TILs and CD68+ TAMs at the invasive front were associated with superior CSS (p = 0.0079 and p = 0.0088, respectively). Total immune cell density-defined as the sum of CD4+, CD8+, and CD68+ cells/mm2-was the strongest independent prognostic factor (HR = 30.8, p < 0.001).
Conclusions:
High immune cell infiltration at the invasive front was associated with favorable prognosis, even in OCRC. As the invasive front represents the interface between host and tumor, assessment of the tumor immune microenvironment at this site may refine risk stratification and optimize clinical management in OCRC patients.
