Pretreatment elevated prognostic nutritional index predicts a favorable prognosis in patients with prostate cancer

BACKGROUND: The prognostic nutritional index (PNI), an immunity and nutrition based prognostic score, was correlated with clinical outcomes in different tumors. However, the prognostic significance of PNI has not been investigated in hormone sensitive prostate cancer (PCa). The objective of this study was to determine the prognostic significance of PNI in hormone sensitive PCa. METHODS: Two hundred eighty PCa patients undergoing androgen deprivation therapy (ADT) as first line therapy at three centers were enrolled. The serum albumin levels and peripheral lymphocyte count were measured at the time of diagnosis. PNI was calculated as 10 * serum albumin (g/dL) + 0.005 * total lymphocyte count (per mm3). Patients were categorized in two groups using a cut-off point of 50.2 as calculated by the receiver-operating curve analysis. Univariate and multivariate cox regression analyses were performed to evaluate PNI as a favorable prognostic factor for progression-free survival (PFS), cancer-specific survival (CSS) and overall survival (OS). Prognostic accuracy was evaluated with the Harrell concordance index. RESULTS: Multivariate analyses identified PNI as an independent prognostic indicator with respect to PFS (hazard ratio (HR) = 0.521, p = 0.001), CSS (HR = 0.421, p = 0.002) and OS (HR = 0.429, p = 0.001). Patients with elevated PNI had better clinical outcomes. The addition of PNI to the final models improved predictive accuracy (c-index: 0.758, 0.830 and 0.782) for PFS, CSS and OS compared with the clinicopathological base models (c-index: 0.736, 0.801 and 0.752), which included Gleason score and incidence of metastasis. CONCLUSIONS: Elevated pretreatment PNI was a favorable prognostic indicator for PCa patients treated with ADT.