Preoperative neutrophil-to-lymphocyte ratio for prognostication of patients with distal bile duct carcinomas undergoing surgery

Background: Surgical resection continues to be the current standard treatment for distal bile duct carcinoma (DBC), as no effective alternative treatment exists. However, even after resection, the long-term prognosis is poor. Simple biomarkers that can predict response or toxicity, and which are applicable to all community oncology settings worldwide, have not been identified. Differential white-cell counts, such as the neutrophil-to-lymphocyte ratio (NLR), as markers of inflammation, may be simple and readily available biomarkers. This study aimed to determine whether the NLR can be used as a predictor of surgical outcome in patients with DBC.

Materials and methods: We enrolled 91 DBC patients who had undergone pancreatoduodenectomy (PD) at a single institution between April 2000 and December 2013. Blood was sampled on admission for determination of NLR. An NLR of ≥5 was selected as the cut-off value for validation.

Results: Seventeen patients had an NLR of ≥5 (Group 1; 18.7%), while 74 had an NLR of <5 (Group 2; 81.3%). The 1-, 3- and 5-year survival rates for Group 1 patients were 75.9, 34.5 and 34.5%, respectively, while those for Group 2 patients were 94.8, 55.2 and 46.6%, respectively (p = 0.02). There were no significant inter-group differences in clinicolaboratory background factors such as the mean operation time, bleeding volume, tumor size, CRP, neutrophil count and lactate dehydrogenase (LDH) level. On the other hand, there were significant inter-group differences for albumin level (p = 0.011), lymphocyte count (p = 0.001) and NLR (p < 0.001). Multivariate analyses were performed for factors such as gender, age, maximum tumor diameter, drainage method, operation time, bleeding volume, pathology, albumin, CRP, neutrophil count, lymphocyte count, LDH and NLR. The results revealed that NLR (odds ratio, 2.032; 95% CI, 0.999-4.134; p = 0.040) was associated with postoperative overall survival.

Conclusions: An NLR of ≥5 predicts a poor outcome in patients undergoing PD for DBC. NLR is an independent indicator of overall survival for such patients.