Neutrophil to lymphocyte ratio ≥4 correlates with 6-month postoperative mortality in cancer patients age >75.

Abstract

e23014 Background: We assessed the correlation between elevated neutrophil to lymphocyte ratio (NLR), a pro-inflammatory biomarker, with patient frailty and post-operative 6-month mortality. Methods: Patients aged ≥75 evaluated preoperatively by the Memorial Hospital Geriatrics Service completed a geriatric assessment (GA). NLR was determined from preoperative blood work. Patients were included if they underwent elective surgery between 2015-2018 with hospital length of stay (LOS) ≥ 1 day and had ≥ 6 month follow up. Univariate analysis was used to determine correlation between GA domains and NLR. Multivariable regression (MVR) analysis was used to assess the relationship of frailty and NLR with postoperative 6-month mortality. Results: 1028 patients (median age 80) were included. 323 patients (31.4%) had NLR ≥ 4. By univariate analysis, patients with NLR ≥4 were often male ( 57% vs. 45%), had Karnofsky Performance Status (KPS) < 90 (44% vs. 37%), were dependent for instrumental activities of daily living (iADL) (53% vs. 44%), had social activity limitation (57% vs. 49%) (all p < 0.05) and Timed Up and Go test (TUG) > 10 seconds (40% vs. 33%, p = 0.06). Other conditions, particularly cognitive function, weight loss, polypharmacy did not differ between groups, nor did operative time and blood loss. Patients with NLR ≥4 experienced more major adverse surgical events (8% vs. 5% , p = 0.03) and had longer LOS (9 vs. 6.3, p < 0.001). After six months, 12% and 5% of the NLR≥4 and NLR < 4 groups respectively had died. By MVR analysis, patients with NLR≥4 were at higher risk for 6-month mortality (OR = 1.91, p = 0.01) after adjustment for gender, KPS, iADL, TUG, social activity, major adverse surgical events, LOS, and metastatic disease status. Conclusions: NLR ≥4 was associated with components of the GA but correlated with risk for major adverse surgical events and 6-month postoperative mortality. Ongoing work directed at clarifying the relationship between NLR and risk of specific complications to help plan interventions is needed.