Stage IV AFP-producing gastric cancer responds to chemotherapy and immunotherapy

What happened, in summary

A 67-year-old man had 6 months of recurring upper-abdominal pain before imaging showed thickening of the stomach wall, enlarged lymph nodes, and multiple liver lesions. Endoscopy and biopsy confirmed a poorly differentiated gastric cancer with features of AFP-producing gastric carcinoma.

Further imaging showed extensive liver metastases, omental deposits, fluid in the abdomen, and a portal-vein tumor thrombus. The disease was Stage IV. Testing showed that the tumor was HER2-negative and mismatch-repair proficient, while his blood AFP level was markedly elevated.

He first received oxaliplatin-based chemotherapy. Because he could not tolerate the oral part of the initial regimen, treatment was changed to FOLFOX chemotherapy plus serplulimab immunotherapy. He completed 15 cycles of the combination through November 2024 and then continued maintenance serplulimab.

Follow-up scans showed progressive shrinkage of the liver and lymph-node disease, meeting criteria for a partial response. His abdominal pain improved, and the AFP level returned to the normal range. At the latest follow-up, he remained in partial response on maintenance treatment.