Culture and Expansion of Tumor-Infiltrating Lymphocyte From Biopsy Tissue Samples of Gastric Cancer Are Feasible

Adoptive transfer of tumor-infiltrating lymphocytes (TILs) achieves promising clinical results in solid tumors. TIL trials use surgically resected tissue to isolate TILs. However, certain tissues are difficult to surgically resect, and a minimally invasive approach might be advantageous if it could achieve similar TIL yields. We tested a minimally invasive approach to culture and expand TILs using endoscopic biopsy tumors from patients with metastatic gastric cancer (GC). TILs were successfully cultured from all of the intestinal GC biopsies, while TIL populations had slow growth from diffuse GCs. Initial TIL growth was faster in intestinal GC biopsies (n=9) than in diffuse GC biopsies (n=4) ( P =0.021). All 4 biopsy TILs tested were expanded >10 10 by our rapid expansion protocol. Biopsy TILs demonstrated equivalent expansion and FACS profiles to TILs cultured from gastrectomy. Thus, clinical-grade TILs can be successfully cultured and expanded from endoscopic biopsy tumors in patients with metastatic GC.