A new prognostic index associated with pathological complete response in rectal cancer

Abstract

Purpose: Approximately half of rectal cancer cases are diagnosed at a locally advanced stage. It is important to identify biomarkers that can predict pathological complete response in patients undergoing surgery following neoadjuvant chemoradiotherapy. Materials and Methods: This retrospective study included 205 patients with locally advanced rectal cancer who underwent surgery and adjuvant chemotherapy following neoadjuvant chemoradiotherapy. Inflammatory biomarkers were assayed in the complete blood count before neoadjuvant therapy. Results: A pathological complete response was detected in 20.5% of the patients. The neutrophil-lymphocyte ratio, platelet-lymphocyte ratio, and pan-immune inflammation value were significantly lower in the pathological complete response (+) group than in the pathological complete response (-) group. The cut-off of the pan-immune inflammation value was ≤ 331.2, and this parameter had the best diagnostic performance of 90.4%. Conclusion: Neoadjuvant chemoradiotherapy followed by surgery and adjuvant chemotherapy remains the standard treatment approach for rectal cancer. Since pathological complete response improves oncological outcomes, it is important to identify biomarkers that can predict pathological complete response in rectal cancer