[A case of gastric cancer treated with nivolumab in which the sIL-2R/ lymphocyte ratio changed with tumor status].

A 90-year-old woman diagnosed with stage IV gastric cancer (pT4a[SE]N2M1 [P, CY1]) after distal gastrectomy for her tarry stool was treated with S-1 monotherapy for 7 months, nab-PTX monotherapy for 3 months, and wPTX+RAM therapy for 3 months. Ascending colon tumor was revealed as peritoneal recurrence treated via right hemicolectomy. The nivolumab therapy was started as the fourth treatment. As the tumor progressed, sIL-2R, a destruction product of regulatory T cell surface antigens, tended to increase and the lymphocyte count tended to decrease, with the sIL-2R/lymphocyte count ratio changing in parallel with CA19-9. Throughout the course after gastrectomy, NLR increased and LMR decreased as the tumor status and general condition worsened.