Treatment of diatal rectal cancer with preoperative intensity-modulated radiation therapy (IMRT) combined with chemotherapy: Updated 5-year results of 42 patients.

Abstract

e14157 Background: Preoperative chemoradiotherapy is currently the standard of care for patients with distal rectal cancer. With Intensity Modulated Radiation Therapy (IMRT), more conformal doses of radiation can be delivered to tumor while sparing normal tissue. It is our intent to present updated data showing 5 year follow up on patients treated concurrently with chemotherapy and IMRT reporting on local control, overall survival, and toxicity. Methods: From April 2007 to February of 2012 a sequential retrospective study of 42 patients at Lankenau Medical Center were treated for distal rectal cancer using IMRT. Patients staged from T2N0M0 to T3N1M0 and all received 5580 cGy to the pelvis using a 9 field plan to tumor, involved and uninvolved lymph nodes. All but one patient received 5FU based chemotherapy and four patients also received oxaliplatin. All patients then went on to surgery 8 – 12 weeks following neoadjuvant therapy. Twenty six patients underwent transabdominal transanal mesorectal (TATA) resection, 9 patients underwent a transanal endoscopic microsurgery (TEM), and 1 patient had an open low anterior resection. 3 patients have yet to go to surgery. FOLFOX was given to 25 of 42 patients adjuvently. Patients were analyzed for local control (LC), median survival (MS), overall survival (OS), and toxicity. Results: The median follow-up was 35 months. Complete pathological response was achieved in 12 (30.7%) patients, partial response was achieved in 25 (64%) patients, and 2 had stable disease at the time of surgery. There were no patients with local failure and only six (14%) patients progressed with distant metastatic disease. OS at 5 years was 92.8% with a MS of 37 months. Toxicity was acceptable with eight patients with grade 1, 5 patients with grade 2, and 3 grade 3 diarrhea. There were 3 (7%) patients with grade 1 neutropenia. Three patients experienced disease related death. Conclusions: With 5 years of follow-up data, our experience has shown that neoadjuvant chemoradiotherapy using IMRT to treat advanced stage rectal cancer is well tolerated and effective. Still further follow-up and additional studies will be required to confirm our findings.