To find the correlations between blood systemic inflammatory biomarkers at three treatment time points and clinical effects of neoadjuvant chemoradiotherapy through a retrospective study.

In total, 101 patients with locally advanced rectal cancer were included in the current study. Patients were divided into two groups based on the T-downstaging, among which 54 patients had T-downstaging. We used non-parametric tests to compare the differences between the variables in two groups. We carried out a logistic regression analysis to evaluate the predictive value of blood systemic inflammatory biomarkers.

Pre-/nadir/postsystemic immune-inflammation, nadir neutrophil-to-lymphocyte ratio, nadir/post-platelet-to-lymphocyte ratio, and post-lymphocyte have differences between groups (p ≤ 0.05 for all). We included p < 0.05 indicators and clinical related factors into the multivariate analysis, respectively, and we found that lower presystemic immune-inflammation, nadir systemic immune-inflammation/neutrophil-to-lymphocyte ratio/post-lymphocyte, and post-nadir/post-platelet-to-lymphocyte ratio were associated with better therapeutic effects (p < 0.05).

The systemic inflammatory index was indicative in predicting the therapeutic effects of locally advanced rectal cancer patients after neoadjuvant chemoradiotherapy.