The prognostic nutritional index (PNI) is commonly used to determine the nutritional and immune status of patients with cancer by calculating their serum albumin concentration and peripheral blood lymphocyte count. It is also used as a prognostic factor in patients with malignant tumors and those with many forms of cancer, but PNI has been poorly studied in prostate cancer.
As little is known about its clinical utility for that disease, researchers from Japan analyzed patient data to determine the potential clinical applications of PNI for patients with metastatic hormone-sensitive prostate cancer (mHSPC).
Their retrospective, multicenter cohort study examined the clinical data of 353 patients with de novo mHSPC who had received androgen deprivation therapy (ADT) between 2000 and 2019. Researchers studied the effects of pretreatment PNI levels on treatment response, survival, and clinical parameters.
The median age of the patient cohort was 73 years old, and the median prostate-specific antigen level was 266.18 ng/mL. Patients with a low PNI were found to have shorter progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS; P<.0001). At multivariate analysis, a low PNI was an independent prognostic factor for OS (hazard ratio [HR], 1.65; P=.0027), along with advanced age (HR, 1.38; P=.049), International Society of Urological Pathology (ISUP) grade group (GG) 5 (HR, 1.69; P=.0027), and elevated lactate dehydrogenase (LDH) levels (HR, 2.08; P<.0001).
A propensity score-matching analysis showed that PNI level was a significant prognostic biomarker for PFS (P=.0263), CSS (P=.0006), and OS (P=.0015). A novel risk classification using PNI, LDH, and the ISUP GG was established during the study to classify patient prognosis. An increase in the number of risk factors was significantly associated with poor outcomes.
Overall, a low pretreatment PNI may serve as an effective biomarker of poor treatment response and survival in patients with mHSPC who are undergoing ADT.