Novel Clinical-Pathological Score Correlates With Global Outcome Of Locally Advanced Rectal Cancer Patients Receiving Neoadjuvant Chemo-Radiotherapy

3667 Background: The treatment of locally advanced rectal cancer consists of a multimodality approach, but which multimodality strategy is to be used still remains a point of controversy. Furthermore it is difficult to predict the outcome of this setting of patients. Methods: The study includes all the consecutive patients with locally advanced rectal cancer who underwent neoadjuvant treatment (chemotherapy and/or radiotherapy) in different Italian Centers from June 1996 to December 2003. Results: Three hundreds and seventeen patients were eligible for our analysis. Median age at diagnosis was 64 years (range 26–88); male/female ratio was 184/133. Two hundreds and eighty-five patients (89.9%) were diagnosed with adenocarcinoma, whilst 32/317 (10.1%) with mucinous adenocarcinoma. Neoadjuvant treatments performed were as follows: radiotherapy alone in 74/317 patients (23.3%), radiotherapy plus chemotherapy in 242/317 patients (76.7%). In order to determine the importance of downstaging after neoadjuvant treatment we gave a negative or positive point respectively to each degree of increase or decrease from clinical to pathological T and N status and we identified a novel score, calculated by the sum of them. An univariate and multivariate analysis including the following factors: age, sex, type of neadjuvant treatment (radiotherapy vs chemo-radiotherapy), histotype (mucinous vs non-mucinous) was performed. An higher score was observed in males (p=0.02) and in those patients receiving neoadjuvant chemo-radiotherapy (p=0.0001). A worse time to progression was observed in patients with an higher score (p=0.04). Conclusions: Our results suggest that a novel score, calculated from pre-clinical and pathological tumor and lymph-nodal status, could represent an important parameter able to predict the outcome in patients receiving neoadjuvant treatment for rectal cancer. This information could be useful in order to select patients to receive adjuvant chemotherapy after neoadjuvant treatment and surgery for locally advanced rectal cancer. No significant financial relationships to disclose.