Willett, Christopher

4009 Background: An ∼65% 5-year disease-free-survival (DFS) rate from 5-FU/mitomycin/radiation for anal carcinoma needs improvement. Methods: A phase III randomized trial compared 5-FU (1,000mg/m2 days 1–4 and 29–32) plus mitomycin (10mg/m2 days 1 and 29) and radiation (45 to 59 Gy) (Arm A) to 5-FU (1,000mg/m2 days 1–4, 29–32, 57–60 and 85–88) plus cisplatin (75mg/m2 on days 1, 29, 57 and 85) and radiation (45 to 59 Gy; start day=57) (Arm B) in anal carcinoma patients. Stratification included gender, clinical N status and tumor diameter. Primary endpoint was DFS. Statistical power was 80% with two-sided test to detect 10% DFS increase for Arm B. Results: Of 682 patients accrued, 598 were analyzable. Most unanalyzed patients’ data are early. Patient characteristics were balanced. Median age was 55 years, women predominated (69%), 27.5% had >5 cm tumor diameter and 26% had clinically N+ cancer. Preliminary 5-year estimated DFS was 56% for Arm A and 48% for Arm B (p=0.28) and 5-year estimated overall survival was 69% for both arms (p=0.24). Men(p=0.04), clinically N+ cancer (p<0.0001) and tumor diameter >5 cm (p=0.005) independently prognosticated DFS in a multivariate analysis. 5-year colostomy rate was 10% for Arm A and 20% for arm B(p=0.12). Grade 3/4 toxicity rates: non-hematologic=76% for Arm A and 75% for Arm B but hematologic=67% for Arm A and 47% for Arm B(p=0.0004). Conclusions: In Intergroup-98–11, induction 5-FU/cisplatin followed by 5-FU/cisplatin/radiation failed to improve DFS compared to the standard treatment, 5-FU/mitomycin/radiation. Supported by RTOG U10 CA21661, CCOP U10 CA37422, Stat U10 CA32115. No significant financial relationships to disclose.

7 Background: The organ preserving strategy of selective esophageal resection after definitive chemoradiation was evaluated in a multi-center, prospective Phase II trial. Methods: Treatment involved induction chemotherapy with 5-FU (650 mg/mg2/d), cisplatin (15 mg/mg2/d) and paclitaxel (200 mg/mg2/d) for 2 cycles followed by concurrent chemoradiation with 50.4 Gy (1.8 Gy/fx) and daily 5-FU (300 mg/mg2/d) with cisplatin (15 mg/mg2/d) over the first 5 days. Following definitive chemoradiation, pts were evaluated for residual locoregional disease with chest and abdominal CT scans, EUS and optional PET scans. If there was no suspected residual disease patients were observed and monitored serially for recurrent disease at 3 mos x 2, 6 mos x 3 and then yrly. Esophageal resection was considered only for pts with suspected residual or recurrent locoregional esophageal cancer that did not have systemic disease. Results: 43 pts from Sept 2003 to March 2006 with non-metastatic resectable esophageal cancer were entered from 19 sites to RTOG 0246. 41 pts were eligible for analysis. 29 pts (73%) were adenocarcinoma histology with pretreatment clinical stage T3 or greater in 31 pts (76%) and N1 in 29 pts (71%). Following induction chemotherapy and chemoradiation 3 pts (7.3%) died of treatment related deaths and 1 pt died of disease progression. 21 pts (51%) underwent surgical resection following chemoradiation because of suspected residual disease 17 pts (41%), pt choice (1) or recurrent locoregional disease 3 pts (7%). 1 pt died postoperatively from esophageal anastomotic leak. 11 pts (27%) are alive and free of disease 70 to 90 months after chemoradiation, of which 5 (12%) did not have esophagectomy. With a median follow-up of 6.7 yrs (for 16 alive pts), the estimated overall 2.5 and 5-year survival rates (95% CI) are 46.3% (30.7%-60.6%) and 36.6% (22.3%-51.0%). Conclusions: The long-term results from this multi-center, prospective Phase II trial demonstrates the efficacy of a selective surgical resection approach following definitive chemoradiation in a predominantly adenocarcinoma population of locoregionally advanced esophageal cancer. Clinical trial information: NCT00081289.