Published online Sep 27, 2020. doi: 10.4240/wjgs.v12.i9.390
Peer-review started: February 27, 2020
First decision: April 22, 2020
Revised: May 11, 2020
Accepted: August 16, 2020
Article in press: August 16, 2020
Published online: September 27, 2020
The systemic inflammatory response is increased in cancer. The level of the systemic inflammatory response is indicated by the concentration of C-reactive protein or the Glasgow prognostic score. However, these laboratory markers are not routinely measured. The neutrophil-to-lymphocyte ratio (NLR), the monocyte-to-lymphocyte ratio (MLR) and the platelet-to-lymphocyte ratio (PLR) from the complete blood count are prognostic for various cancers.
The NLR, MLR and PLR are associated with poor oncological outcomes in rectal cancer. However, the predictive role of these markers in patients receiving preoperative chemoradiation is inconclusive.
We evaluated the predictive roles of pretreatment NLR, MLR, and PLR in patients with locally advanced rectal cancer receiving neoadjuvant chemoradiation.
The records of patients with locally advanced rectal cancer who underwent neoadjuvant chemoradiation followed by surgical resection at Siriraj Hospital between 2012 and 2018 were retrospectively analyzed. The associations between posttreatment pathological stages, neoadjuvant rectal (NAR) score and the pretreatment ratios of markers of inflammation (NLR, MLR, and PLR) were analyzed.
Among 111 patients, the clinical stages determined using computed tomography, magnetic resonance imaging, or both were as follows: T4 (n = 16), T3 (n = 94), and T2 (n = 1). The frequency of clinically positive lymph nodes was 14.4%. The NAR scores were categorized as high (> 8) in 23.4%, intermediate (8–16) in 41.4%, and low (< 8) in 35.2%. The mean values of the NLR of pathological stages 0, 1, 2, and 3 were 2.36, 2.42, 2.83 and 3.07, respectively (P = 0.40) (Figure 1). The mean values of the MLR of pathological stages 0, 1, 2 and 3 were 0.24, 0.27, 0.28, and 0.36, respectively (P = 0.18). The mean values of the PLR of pathological stages 0, 1, 2, and 3 were 10.15, 13.27, 14.20 and 15.56, respectively (P = 0.54). The mean values of the NLR were 2.52, 2.61, and 3.08 for low, intermediate, and high NAR scores, respectively (P = 0.58). The mean values of the MLR were 0.25, 0.27, and 0.37, respectively (P = 0.32). The mean values of the PLR were 11.40, 13.20, and 16.00, respectively (P = 0.61).
The pretreatment NLR, MLR, and PLR of patients with locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy followed by total mesorectal excision were higher in patients with advanced pathological stages, although the differences were not statistically significant.
This study demonstrated the association between higher numbers of pretreatment inflammatory markers and higher advanced stages. Furthermore, higher numbers of pretreatment NLR, MLR, and PLR were associated with poorer response to neadjuvant chemoradiation (high NAR score). Unfortunately, this is a retrospective analysis of a small number of patients at a single center. Therefore, there were no statistically significant results. Further studies of larger populations are required to evaluate the significance of these inflammatory markers in predicting the response.