Neutrophil-albumin ratio as a biomarker for postoperative complications and long-term prognosis in patients with colorectal cancer undergoing surgical treatment

Abstract

Background: To explore the prognostic value of the preoperative neutrophil-albumin ratio (NAR) in patients with colorectal cancer (CRC) undergoing surgical treatment.

Materials and methods: The standardized log-rank statistic was used to determine the optimal cut-off value for NAR. A logistic regression model was used to evaluate the value of NAR in predicting postoperative complications. Cox proportional hazards models were used to assess the independent association of NAR with progression-free survival (PFS) and overall survival (OS) in CRC patients. Restricted cubic splines were used to assess the relationship between continuous NAR and survival in CRC patients. The Kaplan-Meier method and log-rank test were used to compare survival differences between low and high NAR groups. NAR-based prognostic nomograms were constructed to predict the 1-5-year PFS and OS of CRC patients. The concordance index (C-index) and calibration curve were used to evaluate the prognostic accuracy of the nomograms.

Results: A total of 1,441 CRC patients were enrolled from January 2012 to December 2016. There were 904 men (62.7%) and 537 women (37.3%), with an average age of 58.12 ± 13.15 years. High NAR was closely associated with low BMI, advanced pathological stage, colon cancer, large tumors, vascular invasion, poor differentiation, high CEA levels, long hospital stay, and recurrence and metastasis. A high NAR was an independent risk factor for postoperative complications in CRC patients (OR: 2.298, 95% CI: 1.642-3.216, p < 0.001). Patients with a high NAR had worse PFS (40.7 vs. 59.5%, p < 0.001) and OS (42.6 vs. 62.4%, p < 0.001). After adjusting for confounders, high NAR was independently associated with PFS (HR: 1.280, 95% CI: 1.031-1.589, p = 0.025) and OS (HR: 1.280; 95% CI: 1.026-1.596, p = 0.029) in CRC patients. The C-index and calibration curves showed that the NAR-based prognostic nomograms had good predictive accuracy.

Conclusion: High NAR was an independent risk factor for postoperative complications and long-term prognosis of CRC patients. NAR-based research could provide references for prognostic judgment and clinical decision-making of CRC patients.

Keywords: colorectal cancer; complication; neutrophil-albumin ratio; nutrition; prognosis; systemic inflammation.

FIGURE 1

Kaplan-Meier curve of neutrophil-albumin ratio (NAR) in colorectal cancer (CRC) patients. (A) Progression-free survival; (B) overall survival.

FIGURE 2

Stratified survival analysis of neutrophil-albumin ratio (NAR) based on tumor-node-metastasis (TNM) stage. (A) Progression-free survival of TNM I-II stage; (B) overall survival of TNM I-II stage; (C) overall survival of TNM III-IV stage; (D) overall survival of TNM III-IV stage.

FIGURE 3

The association between neutrophil-albumin ratio (NAR) and survival in patients with colorectal cancer (CRC). (A) Progression-free survival; (B) overall survival. Model a: no adjusted. Model b: adjusted for gender, age, and BMI. Model c: adjusted for gender, age, BMI, hypertension, diabetes, T stage, N stage, metastasis, tumor location, tumor size, perineural invasion, vascular invasion, macroscopic type, differentiation, surgical approach, operating time, blood loss.

FIGURE 4

Construction the neutrophil-albumin ratio (NAR)-based prognostic nomograms in colorectal cancer (CRC) patients. (A) The progression-free survival nomogram; (B) the overall survival nomogram.

FIGURE 5

Survival analysis of neutrophil-albumin ratio (NAR) in colorectal cancer (CRC) patients at internal validation cohorts. (A) Progression-free survival of NAR at validation A; (B) overall survival of NAR at validation A; (C) progression-free survival of NAR at validation B; (D) overall survival of NAR at validation B.