What happened, in summary

An 81-year-old man presented with nausea and vomiting and was diagnosed with advanced gastric adenocarcinoma causing pyloric obstruction. Para-aortic lymph-node metastases were present, and the cancer was explicitly classified as Stage IV. He also had severe chronic kidney failure. A gastrojejunostomy was performed to bypass the obstruction before systemic treatment began.

Palliative leucovorin plus 5-fluorouracil chemotherapy was started about a month after admission. During the first cycles he repeatedly developed nausea, vomiting and hyperammonemia, a serious metabolic complication associated with 5-fluorouracil. Hemodialysis was used urgently to remove toxic metabolites, and the chemotherapy dose and timing were adjusted. In later cycles, dialysis was scheduled earlier during the infusion, preventing further major nausea and vomiting without eliminating the anticancer effect.

After 7 cycles, he achieved a partial response. Endoscopy showed improvement in the pyloric narrowing, CT showed shrinkage of the stomach-wall abnormality and para-aortic lymph nodes, and the tumor marker CEA had fallen substantially.

Two weeks after the seventh cycle, however, he developed bilateral hearing loss and was diagnosed with carcinomatous meningitis, indicating further metastatic progression. Chemotherapy was discontinued and best supportive care was provided. He died 2 months later. The case shows both a meaningful temporary response and the difficulty of balancing chemotherapy efficacy with severe kidney disease and treatment-related toxicity.