Intratumoral T cells are associated with prognosis and chemotherapy benefit in gastric cancer.

Tumor-infiltrating lymphocytes (TILs) have been described in various malignancies and viewed as a sign of anti-tumor immunity, so they are frequently thought to be implicated in the prognosis of cancers. However, little information is available on the association of the distribution pattern of TILs with clinical outcomes in gastric cancer (GC). TIL densities at different regions were assessed immunohistochemically in 59 GC patients to analyze their relationship with clinicopathological characteristics. We found that GC patients in the high-density TIL group were significantly associated with reduced tumor invasion depth, absence of lymph node metastasis, earlier TNM stage, and improved progression-free survival (PFS). Both intratumoral CD3+ TILs and pathological T stage were identified as having an independent prognostic value. Additionally, GC patients with a high density of intratumoral CD3+ TILs were found to gain more benefit from chemotherapy. Overall, these results underscored the predictive power of intratumoral TILs in survival prognosis and chemotherapy benefit for GC.