Abstract
BACKGROUND: There is no consensus on prognostic factors for advanced digestive neuroendocrine carcinoma (ADNEC). JCOG1213 was a phase III randomized trial that demonstrated equivalent overall survival (OS) between cisplatin plus etoposide and cisplatin plus irinotecan as first-line chemotherapy for ADNEC. We aimed to retrospectively explore prognostic factors for OS in patients with ADNEC using data from JCOG1213. PATIENTS AND METHODS: The patients included in this post hoc analysis had ADNEC (2019 World Health Organization classification system) that was histologically confirmed by a central pathological review whose records included all clinical data required for multivariable analysis using a Cox proportional hazards model. RESULTS: Among 170 patients enrolled in JCOG1213, a total of 129 patients with ADNEC were included in this analysis. Multivariable analysis identified elevated serum lactate dehydrogenase (LDH; >222 IU/l) as a significantly unfavorable prognostic factor for OS [hazard ratio (HR) 1.721, 95% confidence interval (CI) 1.144-2.589, P = 0.0092]. OS of patients with elevated serum LDH was shorter than that of patients without elevated serum LDH [median 9.5 months (95% CI 8.1-10.7 months) versus 15.6 months (95% CI 11.4-19.7 months); HR 1.799, 95% CI 1.242-2.604, P = 0.0019]. There were no distinct differences either in objective response rates or progression-free survival between patients with and without elevated serum LDH. CONCLUSION: Serum LDH may serve as a simple, non-invasive, and clinically informative biomarker for prognostic evaluation in patients with ADNEC undergoing first-line platinum-based chemotherapy.