Combined Pre- and Postoperative Lymphocyte Count Accurately Predicts Outcomes of Patients with Colorectal Cancer

Background: Although preoperative lymphopenia is reportedly a prognostic factor in cancer patients, the association between postoperative lymphopenia and patient prognosis has not been widely studied. Methods: We enrolled 379 patients who underwent surgery for colorectal cancer (CRC) to analyze correlations among pre- and postoperative lymphocyte counts (LCs) and prognosis in patients with CRC. Results: Pre- and postoperative LCs were significantly correlated (r = 0.615, p < 0.0001). Based on results of receiver operating characteristic analysis, patients were subgrouped as preoperative LC ≥1,280 (pre-LC<->High</->, n = 234), preoperative LC < 1,280 (pre-LC<->Low</->, n = 145); and as postoperative LC ≥680 (post-LC<->High</->, n = 246), and postoperative LC < 680 (post-LC<->Low</->, n = 133). Five-year disease-specific survival rates significantly differed between pre-LC<->High</-> (88.6%) and pre-LC<->Low</-> (72.5%) groups (p < 0.0001); and also between the post-LC<->High</-> (88.5%) and post-LC<->Low</-> (71.1%) groups (p < 0.0001). Five-year disease-specific survival rates of patients who were both pre-LC<->Low</-> and post-LC<->Low</-> was significantly lower than those for patients who were either pre-LC<->High</-> or post-LC<->High</-> or pre-LC<->High</->/post-LC<->High</-> (p = 0.0003). Multivariate analysis indicated that the combination of pre- and postoperative LC was an independent prognostic indicator. Conclusions: The combination of pre- and postoperative LC is a predictive factor for prognosis in CRC patients.