Lymphocytic Count and Ratio as Predictive Factors for Pathological Response after Neoadjuvant Therapy in Patients with Rectal Cancer

Abstract
Background: To evaluate results of pre-operative Complete Blood Count (CBC), with special emphasis on lymphocytic count and ratio as predictive factors for rectal cancer response to neoadjuvant chemoradiotherapy and prediction of complete pathological response.
The Aim of the Study: Is to evaluate results of pre-operative complete blood count, with special emphasis on lymphocytic count and lymphocyte ratio as predictive factors of rectal cancer response to neoadjuvant chemoradiotherapy.
Patients and Methods: This research studied the associa-tion between CBC results of patients with stage II or III Locally Advanced Rectal Cancer (LARC) before neoadjuvant therapy and the pathological response found in the specimen after standard surgical management. Patients were divided into two groups; Group I included patients with complete pathological response and Group II included patients with no or partial pathological response to study the predictive factors for complete pathological response.
Results: A total of 36 patients (20 females and 16 males) were included. Mean age was 56.40±11.18 years. 19 patients (52.7%) underwent low anterior resections and 17 patients (47.2%) underwent abdomino-perineal resections. Lymphocytic count and ratio were significant predictive factors for the pathological response of the tumor to neoadjuvant therapy (p=0.011 and 0.048, respectively). Comparison between Group I and Group II showed that lymphocytic count and ratio were significant predictive factors for patients in Group I compared to Group II (p=0.001 and p=0.049, respectively).
Conclusions: Lymphocytic count and ratio can play an important role as predictive factors for pathological response to neoadjuvant therapy in patients with LARC and also as predictive factors for complete pathological response. Further multicenter studies with larger number of patients are needed.