The effect of immunonutrition on tumor infiltrative t lymphocytes and regulatory t cells in rectal tumor patients receiving neoadjuvant chemoradiotherapy: a prospective randomized clinical study

BACKGROUND/AIM: The rationale behind using immunonutrition in cancer patients is to prevent malnutrition, manage the host’s immune response, and keep cancer under control by utilizing the potential immune system available in the host against the tumor. This prospective- study aims to assess the impact of immunonutrition on tumor-infiltrating lymphocytes (TILs) and regulatory T cells (Tregs) in rectal cancer patients receiving neoadjuvant chemoradiotherapy. MATERIALS AND METHODS: This is a single-center, prospective study. Forty patients diagnosed with middle and lower rectal tumors were enrolled in the study between March 2018 and December 2019. Nutrition protocols were given to all study subjects prior to surgery. Tissue CD4, CD8, and Fox P3 expression prior to enrollment (endoscopic biopsy specimens) and following surgery (resected tissue) were compared. RESULTS: Longitudinal data was available for 30 patients. In the present study, 15 patients were given immuno-nutrition, and 15 patients received standard nutrition. The immunonutrition and standard nutrition groups were similar regarding CD4 [10 (5–20) vs. 10 (10–10), p = 0.653], CD8 [30 (20–35) vs. 30 (20–40), p = 0.870], lymphocyte counts [2 (2–3) vs. 2 (2–3), p = 0.325], fox p3 value [10 (10–10) vs. 10 (10–10), p = 0.775], and CD4/CD8 ratio [0.33 (0.29–0.66) vs. 0.50 (0.29–0.50), p = 0.870] on endoscopic biopsy. CD4 [10 (7.5–25) vs. 30 (10–50), p = 0.050], CD8 [60 (40–60) vs. 50 (40–60), p = 0.713] and Fox P3 [10 (5–10) vs. 10 (2.5–10), p = 0.935] were also similar in tissues extracted by surgery. However, the standard nutrition group had significantly higher CD4/CD8 values in their tissues removed on surgery [0.25 (0.14–0.50) vs. 0.66 (0.28–1), p = 0.026] CONCLUSION: The present study revealed that CD4/CD8 ratios were lower in the immunonutrition group in comparison to the group receiving standard nutritional supplements before surgery.