Impact of the perioperative neutrophil-to-lymphocyte ratio on the long-term survival following an elective resection of colorectal carcinoma

The present study was designed to evaluate the prognostic value of the perioperative neutrophil-to-lymphocyte ratio (NLR) for the long-term survival in patients with colorectal cancer. This was a retrospective study of 524 patients with histologically proven stage II or III colorectal cancer who underwent curative colorectal resection. We classified patients into a low NLR group or high NLR group base on their NLR values at three time points (before surgery (Pre), on the first postoperative day (POD1), and on the third or fourth postoperative day (POD3)) and evaluated the survival according to the group. The cancer-specific survival was significantly longer in the groups with a low NLR on POD3. The disease-free survival was significantly longer in the group with a low NLR on Pre. We subsequently allocated a score of 1 to patients with a high NLR at each point and reclassified patients into those with a low perioperative NLR group (score of 0 or 1) and high perioperative NLR group (score of 2 or 3). Both the cancer-specific survival and disease-free survival rates were significantly different between the two perioperative NLR groups. Both univariate and multivariate analyses demonstrated that being in the high perioperative NLR group was an independent risk factor for both the cancer-specific survival and disease-free survival. Not only the preoperative but also the postoperative NTR is thus considered to be a predictor of the long-time survival in patients with colorectal cancer.