Efficacy and tolerability of first-line treatment regimens in patients with metastatic gastric cancer

Gastric cancer is one of the most common malignancies worldwide and generally has a poor prognosis. Although chemotherapy is the first-line standard approach in the treatment of metastatic gastric cancer, the efficacy and toxicity profiles of the regimens differ. The aim of this study is to evaluate the efficacy and toxicity of first-line treatment regimens administered to patients diagnosed with metastatic gastric cancer at Van Yüzüncü Yıl University Faculty of Medicine, the factors predicting response, and independent prognostic indicators for survival. A total of 92 patients with metastatic gastric cancer followed up between 1 January 2015 and 1 May 2025 were retrospectively reviewed. Demographic characteristics, body mass index, comorbidities, smoking/alcohol history, laboratory parameters, HER2 status, clinical and pathological stage, ECOG performance score, chemotherapy protocols used, and treatment-related side effects were recorded. Factors affecting survival were evaluated using univariate and multivariate analyses. The mean age of patients was 61±10 years, and 62% were male. The most commonly used chemotherapy regimens were FOLFOX and CAPOX. The overall response rate was 38%. Median progression-free survival was calculated as 6.8 months, and median overall survival as 11.2 months. In multivariate analysis, low performance score, treatment resistance, and low albumin levels were independent poor prognostic factors, while the development of nausea and vomiting side effects and receiving second- and third-line treatment were identified as long PFS positive prognostic factors (p<0.05). The most common toxicities were haematological side effects (42%) and gastrointestinal complaints (31%). Fluoropyrimidine and platinum-based combinations remain effective in the treatment of metastatic gastric cancer. However, the key factors determining survival are not only treatment regimens but also the patient's performance status, biochemical parameters, and tumour biology. Therefore, a personalised approach is important in treatment selection. Our study contributes to clinical practice in our country with realworld data. Keywords: Metastatic gastric cancer; chemotherapy; FOLFOX; CAPOX; survival; prognostic factors; treatment response; toxicity; real-world data