Introduction: This multicenter study aimed to determine whether the pretreatment prognostic nutrition index (PNI) or a change in the index after two treatment courses could be a biomarker for predicting treatment sensitivity in patients with unresectable advanced or recurrent gastric cancer treated using chemotherapy and nivolumab as the first-line treatment.
Methods: This multicenter retrospective study with 104 patients was conducted at 12 institutions. PNI was calculated before treatment and after two courses of treatment in each case.