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-LCHigh, n = 234), preoperative LC < 1,280 (pre-LCLow, n = 145); and as postoperative LC ≥680 (post-LCHigh, n = 246), and postoperative LC < 680 (post-LCLow, n = 133). Five-year disease-specific survival rates significantly differed between pre-LCHigh (88.6%) and pre-LCLow (72.5%) groups (p < 0.0001); and also between the post-LCHigh (88.5%) and post-LCLow (71.1%) groups (p < 0.0001). Five-year disease-specific survival rates of patients who were both pre-LCLow and post-LCLow was significantly lower than those for patients who were either pre-LCHigh or post-LCHigh or pre-LCHigh/post-LCHigh (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.