Calcium intake and risk of colorectal cancer according to tumor-infiltrating T cells

Calcium intake has been associated with a lower risk 0.36–0.84; P_trend ¼ 0.002) for CD8^þ T-cell–low but not of colorectal cancer. Calcium signaling may enhance for CD8^þ T-cell–high tumors (HR ¼ 1.02; 95% CI, T-cell proliferation and differentiation, and contribute 0.67–1.55; P_trend ¼ 0.47). Similarly, the corresponding to T-cell–mediated antitumor immunity. In this pro-HRs (95% CIs) for calcium for low versus high T-cell–spective cohort study, we investigated the association infiltrated tumors were 0.63 (0.42–0.94; P_trend ¼ 0.01) between calcium intake and colorectal cancer risk and 0.89 (0.58–1.35; P_trend ¼ 0.20) for CD3^þ; according to tumor immunity status to provide addi-0.58 (0.39–0.87; P_trend ¼ 0.006) and 1.04 (0.69–tional insights into the role of calcium in colorectal 1.58; P_trend ¼ 0.54) for CD45RO^þ; and 0.56 (0.36–carcinogenesis. The densities of tumor-infiltrating 0.85; P_trend ¼ 0.006) and 1.10 (0.72–1.67; P_trend ¼ T-cell subsets [CD3^þ, CD8^þ, CD45RO (PTPRC)^þ, or 0.47) for FOXP3^þ, although the differences by sub-FOXP3^þ cell] were assessed using IHC and computer-types defined by T-cell density were not statistically assisted image analysis in 736 cancer cases that devel-significant. These potential differential associations oped among 136,249 individuals in two cohorts. HRs generally appeared consistent regardless of sex, source and 95% confidence intervals (CI) were calculated of calcium intake, tumor location, and tumor micro-using Cox proportional hazards regression. Total cal-satellite instability status. Our findings suggest a pos-cium intake was associated with a multivariable HR of sible role of calcium in cancer immunoprevention via 0.55 (comparing 1,200 vs. <600 mg/day; 95% CI, modulation of T-cell function.