Relationship Between the Product of Pre-Treatment Neutrophil and Monocyte Counts and Clinical Outcomes in Rectal Cancer With Suspected Lateral Lymph Node Metastasis.

Aim: A novel systemic inflammatory response marker, the neutrophil × monocyte value (NM value), has been identified as a negative predictive factor for responses to chemoradiotherapy in rectal cancer. However, the clinical implications of the NM value remain unknown. Methods: This study reviewed 352 patients with rectal cancer who received preoperative chemoradiotherapy between 2003 and 2023. The cut-off value for the pre-treatment NM value was established at the median. A pre-treatment size of lateral lymph node (LLN) ≥ 8 mm was defined as clinical LLN metastasis. The prognostic significance of the NM value was evaluated. Results: The cut-off NM value was 1 100 000; 179 patients had an NM value ≥ 1 100 000. Ninety-nine patients had LLN ≥ 8 mm. Disease-free survival (DFS) was significantly shorter in patients with an NM value ≥ 1 100 000 than in those with an NM value < 1 100 000. DFS and overall survival (OS) were shorter in patients with LLN ≥ 8 mm than in those with LLN < 8 mm. The LLN size and NM value were identified as independent prognostic factors for DFS (LLN size-hazard ratio (HR): 1.51, Conclusions: The pre-treatment NM value is an independent prognostic factor associated with DFS. In patients with LLN ≥ 8 mm, a high NM value may be a significant indicator of a poor prognosis.