Completion and toxicity rates of adjuvant chemotherapy in rectal cancer patients previously treated with neoadjuvant therapy and resection.

Abstract

609 Background: Adjuvant chemotherapy is recommended after rectal cancer surgery. Yet the success and complication rates of this adjuvant treatment are poorly studied. The purpose of this study is to determine the success rate and define the toxicity profile of adjuvant chemotherapy in rectal cancer patients previously treated with neoadjuvant chemotherapy. Methods: Study design is a retrospective review of patients from December 2002-December 2007 from the City of Hope database. Data is available with 66 patients diagnosed with locally advanced rectal cancer treated with neoadjuvant chemo radiation and resection. Data points analyzed included demographics, chemotherapy-related toxicity and survival. Results: Adjuvant chemotherapy was started in 35/66 (53%) of patients. In 31 cases chemotherapy was not given because of patient refusal or physician preference. 9 patients were lost to follow-up. Follow-up ranged from 9-59 months with median follow-up of 27 months. In the 26 patients with adequate follow up there were a total of 165 episodes of toxic events 3a grade 1. Most of the events were mild to moderate grade 1-2. In 10 patients (28%) 22 major toxicities 3a grade 3 episodes were observed. The median Karnofsky performance scale (KPS) showed no significant difference in patients before and after adjuvant chemotherapy (p = 0.071). The rates of 1-year, 3-year and 5-year survival were 100%, 90%, and 60%, respectively; corresponding disease-free survival was 88%, 83%, and 69% respectively. Conclusions: These preliminary data suggest that only a fraction of rectal cancer patients previously treated with neoadjuvant CRT complete a full course of adjuvant chemotherapy. Future studies will help confirm these preliminary findings and generate an outcome comparison between patients receiving and not receiving adjuvant therapy. No significant financial relationships to disclose.