Defining the impact of platelet-to-lymphocyte ratio for patient survival with gastric neuroendocrine neoplasm: a retrospective cohort analysis

Backgrounds: Gastric neuroendocrine neoplasm (g-NEN) is a rare but heterogeneous neoplasm, with an increasing incidence yearly. Conventional prognostic markers of g-NEN remain limited which could only be detected after surgery. There is an urgent need to explore new prognostic markers for g-NEN patients. Methods: A retrospective cohort of patients with g-NEN from January 2001 through June 2016 was examined. The prognostic significance of PLR was determined by multiple regression analysis in different models. A stratified analysis was performed to examine the prognostic value of PLR at different BMI levels. Results: In total, 238 patients were enrolled, and those with higher PLRs tended to undergo open surgery, have larger tumor sizes, were diagnosed more frequently with neuroendocrine carcinoma, and have higher tumor grades. PLR was significantly associated with the survival of g-NEN patients. With PLR increased per standard deviation, the all-cause mortality risk of g-NEN patients increased by 67%, 63%, and 54% in the crude (HR=1.67, 95% CI 1.32-2.12, P < 0.001), minimally adjusted (HR=1.63, 95% CI 1.28-2.08, P < 0.001), and fully adjusted (HR=1.54, 95% CI 1.202-1.98, P = 0.001) models, respectively. Furthermore, there was a significant interaction effect between BMI subgroups and PLR in predicting survival of g-NEN patients. G-NEN patients with the characteristics of higher PLR (quartile 4, ≥187) and non-overweight (BMI <25 kg/m 2 ) had worse survival than the other (P <0.05). Conclusion: The inflammation marker PLR has an independent prognostic value for g-NEN patients, and high PLR combined with non-overweight increases the mortality risk of patients with g-NEN.