Prognostic Significance of Pre- and Postoperative Lymphocyte Counts in Patients with Gastric Cancer

Abstract

<b><i>Background:</i></b> Although preoperative lymphopenia is reportedly a prognostic factor in cancer patients, the association between postoperative lymphopenia and patient prognosis has not been widely studied. <b><i>Methods:</i></b> We enrolled 352 patients who underwent surgery for gastric cancer (GC) between January 2005 and April 2013 to analyze correlations among pre- and postoperative lymphocyte counts (LCs) and prognosis in GC patients. <b><i>Results:</i></b> Pre- and postoperative (obtained 1 day after surgery) LCs were significantly correlated (<i>r</i> = 0.496, <i>p</i> < 0.0001). Pre- and postoperative LCs of elderly patients were significantly lower than those of non-elderly patients. Postoperative lymphocyte count was significantly lower in patients with a differentiated tumor than in those with an undifferentiated tumor. Based on the results of receiver operating characteristic analysis, patients were classified into subgroups as: preoperative LC ≥1,676 (pre-LC<sup>High</sup>), preoperative LC <1,676 (pre-LC<sup>Low</sup>); and as postoperative LC ≥855 (post-LC<sup>High</sup>), and postoperative LC <855 (post-LC<sup>Low</sup>). Five-year overall survival rates significantly differed between pre-LC<sup>High</sup> (82.5%) and pre-LC<sup>Low</sup> (71.6%) groups (<i>p =</i> 0.023); and also between the post-LC<sup>High</sup> (81.5%) and post-LC<sup>Low</sup> (69.5%) groups (<i>p</i> = 0.0072). The 5-year disease specific survival rates were 91.3 and 82.4% in patients with post-LC<sup>High</sup> and those with post-LC<sup>Low</sup>, respectively, and differences were statistically significant (<i>p</i> = 0.015). Multivariate analysis indicated that postoperative lymphocyte count was an independent prognostic indicator, along with age, gender, tumor size, lymph node metastasis, and venous invasion. <b><i>Conclusions:</i></b> Postoperative lymphocyte count is a useful predictive factor for prognosis in GC patients.