Prognostic nutritional index (PNI), independent of frailty is associated with six-month postoperative mortality

Abstract

IntroductionPrognostic Nutritional Index (PNI) is associated with disease and overall survival in patients with cancer. We aimed to assess the relationship between PNI, frailty, and six-month postoperative survival in older patients with cancer. MethodsIn this retrospective study, patients with cancer aged ≥75 who underwent geriatric preoperative evaluation and then proceeded with elective surgery with hospital length of stay of ≥1 day and had six-month follow-up were included. PNI is measured by preoperative [10 × albumin(gr/dl)] + [0.005 × absolute lymphocyte count (per mm3)]. Higher PNI is suggestive of better nutritional status. Frailty was assessed by geriatric assessment. PNI among patients with and without each age-related impairment was evaluated. Pearson correlation coefficient was used to assess the correlation between the number of age-related impairments and PNI. Multivariable regression analysis was used to assess the relationship between six-month mortality and PNI. ResultsPNI ranged from 19 to 49 (average 40) among 1025 patients (average age 80). Patients with impairment in Karnofsky Performance Status, falls in the past year, prolonged timed up and go test, limited social activity, significant weight loss, polypharmacy, polycomorbid conditions, depression, and dependent for basic and instrumental activities of daily living had lower PNI than fit patients. The correlation coefficient between PNI and number of aging impairments was −0.28 (p < .001). Each unit increase in PNI was associated with 10% reduction in 6-month mortality (OR = 0.90, p < .001). ConclusionPNI independent of frailty, age, American Society of Anesthesiologist Performance Scale (ASA-PS), and metastatic disease is associated with six-month postoperative mortality. Future studies should assess the interventions aimed at improving PNI and its impact on surgical outcomes.