Comparative characteristics of the relationship between clinical manifestations, quality of life and electrolyte disturbances in patients with metastatic gastric cancer receiving immunotherapy with a history of gastric resection

Introduction. Patients with metastatic gastric cancer and a history of gastric resection represent a distinct clinical subgroup at high risk of developing severe nutritional deficiencies, electrolyte disturbances, and decreased quality of life. Immunotherapy (IT) with immune checkpoint inhibitors (ICIs), despite its effectiveness in patients with PD-L1+ or MSI-H status, may worsen metabolic and electrolyte disturbances. At the same time, comprehensive rehabilitation, including nutritional support, physical activity, and psychological assistance, can not only correct these disorders but also improve quality of life and tolerance to therapy. The aim of this study was to compare clinical manifestations, quality of life and electrolyte status in patients with metastatic gastric cancer after resection receiving IT, taking into account the use of comprehensive rehabilitation. Materials and methods. A prospective randomized controlled study included 84 patients with histologically confirmed metastatic gastric cancer and a history of gastric resection (gastrectomy – 62, subtotal resection – 22). All patients received pembrolizumab or nivolumab. Groups: IT + comprehensive rehabilitation (n = 41) and IT (n = 43). Assessment was performed at study inclusion and after 6 months using the PNI, NRS-2002, EORTC QLQ-C30 scales, as well as laboratory parameters (Ca², Mg², nitrogen balance). Results. After 6 months, the experimental group showed a significant improvement in PNI (56,2 ± 4,3 vs. 26,5 ± 3,2; p < 0,001), normalization of nitrogen balance (+5,2 ± 2,7 vs. –3,1 ± 2,3; p = 0,03), an increase in the level of Ca² (2,31 ± 0,14 vs. 2,05 ± 0,17 mmol/l; p < 0,05) and Mg² (0,87 ± 0,11 vs. 0,70 ± 0,13 mmol/l; p < 0,05). Quality of life according to the EORTC QLQ-C30 improved significantly: physical functioning (+14,8 %), emotional (+12,1 %), overall quality of life (+15,2 %; all p < 0,05). In the control group, a deterioration in all parameters was observed. The incidence of immune-mediated adverse events (IMEs) of grades 1–2 tended to decrease in the experimental group (e.g., hepatotoxicity – 2,4 % vs. 3,5 %). No IMEs of grade ≥3 were detected. Conclusion. The obtained data confirm that in patients with metastatic gastric cancer and a history of resection, complex rehabilitation against the background of IT significantly improves nutritional and electrolyte status, reduces symptomatic burden and improves quality of life. The results substantiate the need for early inclusion of rehabilitation programs in the standards of care for this category of patients.