Oncologic impact of preoperative prognostic nutritional index change in resected pancreatic cancer following neoadjuvant chemotherapy

Background: Although several studies have focused on the oncologic impact of the preoperative prognostic nutritional index (PNI), there is no study correlating the preoperative PNI changes with the oncologic outcome of resected pancreatic cancer following neoadjuvant chemotherapy (NAC). Methods: We retrospectively analyzed 107 pancreatic ductal adenocarcinoma patients who underwent NAC followed by surgical resection. ΔPNI was defined as post-NAC PNI subtracted from pre-NAC PNI. Patients were divided into high (≥-1.94, n = 54) and low ΔPNI groups (<-1.94, n = 53). Long-term oncologic outcomes, such as overall survival (OS) and disease-free survival (DFS), were compared. Univariate and multivariate analysis were used to identify independent prognostic factors. Results: The high ΔPNI group correlated with lower pre-NAC PNI (46.96 ± 4.68 vs. 51.77 ± 5.63, p < 0.001) and higher post-NAC PNI (50.05 ± 4.80 vs. 42.56 ± 7.44, p < 0.001) more than the low ΔPNI group. The high ΔPNI group was also associated with longer OS compared with the low ΔPNI group (mean OS: 63.97 months [95% CI: 49.95–77.99] vs. 41.16 months [95% CI: 27.66–54.66], p = 0.003); there was no significant difference in DFS (p > 0.05). Multivariate analysis revealed that low ΔPNI was an independent risk factor for OS (HR, 3.516; 95% CI, 1.885–6.558; p < 0.001), but not for DFS (p > 0.05). Conclusions: Low ΔPNI (<-1.94) was an independent risk factor for the overall survival of resected pancreatic cancer patients following NAC. In the preoperative setting, improving the PNI can better the long-term oncologic outcome of this condition.