Introduction Previous studies have reported a pre-operative elevated neutrophil lymphocyte ratio (NLR) is associated with poor prognosis in colorectal cancer (CRC) patients. The aim of this study was to assess if elevated NLR can predict the response to neo-adjuvant long course chemo-radiotherapy (CRT) in rectal cancer as assessed by Mandard Regression score and its ultimate outcome of disease free survival (DFS) and overall survival (OS).

Method Patients who received neo-adjuvant long course chemo-radiotherapy followed by resection for primary rectal cancer from January 2005 till December 2010 were identified from prospectively maintained cancer database. The NLR was calculated from pre-treatment blood tests. The relationship between the NLR and clinicopathological parameters was analysed. Modified receiver operating characteristic curve were constructed to determine the optimum cut-off NLR to dichotomise the data for pathological response, DFS and OS. The measured cut-off was 2.7.

Results There were 143 male and 76 female patients with a median age at diagnosis of 65 (Range 25–85 years). Patients were grouped into favourable response with Mandard regression score of 1 and 2 and unfavourable response with Mandard regression score of 3, 4 and 5. The sensitivity and specificity of NLR to predict complete pathological response or favourable response was 66% and 46%, for disease recurrence was 60% and 39% and for survival was 70% and 50%. NLR did not prove to be a significant predictor of tumour response to CRT and ultimate oncological outcomes. Kaplan Meier survival graph showed a little better OS (p = 0.001) for patients with NLR <2.7 but it had no impact on DFS (p = 0.180).

Conclusion Pre-operative NLR does not appear to offer useful predictive ability for response to CRT, disease free survival and overall survival following rectal cancer resection in patients who received neo-adjuvant long course chemo-radiotherapy.

Disclosure of interest None Declared.