Prognostic value of SUVpeak and prognostic nutritional index in patients with pleural mesothelioma treated with platinum-based chemotherapy.

BACKGROUND: Pleural mesothelioma (PM) is an aggressive malignancy with poor prognosis, and reliable prognostic biomarkers are needed to better inform clinical management. We retrospectively investigated the prognostic value of the Glasgow prognostic score (GPS), prognostic nutritional index (PNI), neutrophil-to-lymphocyte ratio (NLR), body mass index (BMI), and tumor glucose metabolism measured by 18F-fluorodeoxyglucose positron emission tomography (FDG-PET). METHODS: We retrospectively reviewed patients with PM treated with first-line platinum-pemetrexed chemotherapy at our institution (April 2007-December 2023; data cutoff, December 2024) and evaluated the prognostic value of these markers and baseline FDG-PET parameters. RESULTS: Among 79 patients diagnosed with PM, 51 who received first-line platinum-based chemotherapy with pemetrexed were analyzed. The median age was 69 (range, 42-81) years, 78% were male, and 67% had epithelioid histology. The objective response rate (ORR) was 27.5% [95% confidence interval (CI), 17.1-40.9%], and the disease control rate (DCR) was 72.5% (95% CI, 59.1-82.9%). The median progression-free survival (PFS) and overall survival (OS) were 5.8 (95% CI, 3.4-7.8) and 21.8 (95% CI, 13.4-33.5) months, respectively. Low PNI (≤45) was significantly associated with shorter OS than high PNI (>45) (18.8 vs. 28.5 months; P=0.04) and remained an independent prognostic factor in multivariable analysis (P=0.04). For 35 patients who underwent pretreatment 18F-FDG-PET, high peak standardized uptake value (SUVpeak) (>7.73) was significantly associated with worse OS than low SUVpeak (9.1 vs. 33.6 months; P<0.001) and remained an independent predictor in the multivariable analysis (P<0.001). None of the evaluated biomarkers significantly predicted PFS. GPS, NLR, and BMI showed no significant association with survival outcomes in the univariate analysis and were therefore not included in the multivariable models. CONCLUSIONS: Low PNI and high SUVpeak significantly predicted poor OS in patients with PM treated with platinum-based chemotherapy. These factors may serve as practical prognostic indicators in this population.