613 Background: Neoadjuvant long course chemoradiotherapy is a well recognised treatment in locally advanced rectal cancer. Patients with pelvic side wall nodes are often considered for neoadjuvant treatment. We investigated whether pelvic side wall nodes identified on pre-treatment imaging is a poor prognostic factor and whether there are different patterns of recurrence compared to patients without pelvic side wall node involvement. Methods: All patients treated with long course chemoradiotherapy between January 2008 and December 2009 were identified. Patients were excluded if treatment indication was for inoperable disease, postoperative, recurrence, or palliative intent. 231 patients were identified and a retrospective analysis performed investigating patterns of recurrence and survival for patients with pelvic side wall nodes identified on pre-treatment imaging. Results: Kaplan Meier curves are presented showing patients with pelvic side wall nodes identified on pre-treatment imaging appear to have poorer outcomes and overall survival compared with those with only mesorectal nodes or no nodes. Patterns of recurrence are presented, showing patients with pelvic side wall nodes identified on pre-treatment imaging have a non significant trend to increased rates of disease recurrence (local and distal recurrence combined, 45.7% versus 27.9% for pelvic side wall nodes versus no pelvic side wall nodes). Patients with pelvic side wall nodes identified on pre-treatment imaging appear to be more likely to develop distant metastases compared to those patients who have mesorectal nodes or no nodal involvement (37% versus 23%). Conclusions: Our study highlights that patients with pelvic side wall nodes identified on pre-treatment imaging appear to have a trend to poorer overall survival, are more likely to recur and develop distant metastases. These results were not statistically significant, due to the small number of patients, and the data is consequently limited. We intend to further investigate current management strategies for this subgroup of patients, with assessment of radiotherapy treatment plans, current use of integral boosts, and surgical procedures for this subgroup of patients.
Estimation of Risk of Nodal Involvement Following Pre-Operative Chemoradiotherapy for Locally Advanced Rectal Cancer with View to Organ Preservation
