High platelet × C-reactive protein level multiplier is a negative prognostic marker in rectal cancer treated by neoadjuvant chemoradiotherapy.

Purpose: The clinical significance of the platelet count × C-reactive protein level multiplier (P-CRP) in patients with locally advanced rectal cancer (LARC) undergoing neoadjuvant chemoradiotherapy followed by curative surgery has not been fully evaluated.

Methods: In this retrospective study, the correlation between the P-CRP and prognosis was evaluated in 135 patients with LARC. We also performed a subgroup analysis limited to patients with pathological TNM stage III [ypN(+)] LARC.

Results: The cut-off value of the P-CRP for prognosis was set at 4.11. The high and low P-CRP groups comprised 39 (28.89%) and 96 (71.11%) patients, respectively. Among the investigated clinicopathological factors, the serum carcinoembryonic antigen level and presence of recurrence were significantly associated with the P-CRP value. In the Kaplan-Meier analysis, both overall survival (OS) and disease-free survival (DFS) were shorter in the high P-CRP group (p < 0.0001 and p = 0.0002, respectively; log-rank test). Multivariate analysis using a Cox proportional hazards model showed that a high P-CRP was an independent prognostic factor for OS [hazard ratio (HR) 29.20; 95% confidence interval (CI), 3.42-294.44; p = 0.0024] and DFS (HR 5.89; 95%CI 1.31-22.69; p = 0.023) in patients with LARC. In addition, a high P-CRP predicted poor OS and DFS in patients with pathological TNM stage III [ypN(+)] LARC (p = 0.0001 and p = 0.0012, respectively; log-rank test).

Conclusions: The P-CRP is a promising predictor of survival and recurrence in patients with LARC treated by neoadjuvant chemoradiotherapy followed by curative surgery.