Preoperative lymphocyte count as a prognostic factor in resected pancreatic ductal adenocarcinoma

Background and aims: Recognized prognostic factors for resected pancreatic ductal adenocarcinoma (PDAC) include tumour size, differentiation, resection margin involvement and lymph node metastases. A further prognostic factor of less certain significance is lymphocyte count. The aim of this study was to investigate whether preoperative lymphocyte count is a prognostic indicator in patients with PDAC.

Material and methods: Patients who had undergone a potentially curative pancreaticoduodenectomy (PD) for PDAC between 1998 and 2005 were analysed. Standard prognostic factors, preoperative lymphocyte count, preoperative neutrophil count and survival data were collected.

Results: Of the 44 patients studied, univariate analysis identified predictors of a poor survival as lymph node status (node positive (+ve) 10.3 [5.4-20.9] months versus node negative (-ve) 14.2 [10.9-31.4] months; p=0.038), posterior resection margin invasion (margin +ve 7.0 [5.1-15.0] months versus margin -ve 13.1 [10.0-28.3] months; p=0.025) and lymphocyte count below the reference range (<1.5 x 10(9)/litre 8.8 [7.0-13.1] months versus > or = 1.5 x 10(9)/litre 14.3 [7.0-28.3] months; p=0.029). Low preoperative lymphocyte count (p=0.027) and posterior margin invasion (p=0.023) retained significance on multivariate analysis. Preoperative neutrophil to lymphocyte ratio was not a significant prognostic factor.

Conclusion: Preoperative lymphocyte count is a significant prognostic factor in patients with PDAC.