2103

Proceedings of the 48th Annual ASTRO Meeting

S267

radiation with simultaneous 5-FU iv continuous infusion (45 p), oral Tegafur (62 p), or two neoadjuvant courses of FOLFOX-4 (Oxaliplatin ⫹ 5-FU) followed by CRT with oral Tegafur (64 p). Radical surgery was performed 4 – 6 weeks after the completion of CRT. Intraoperative electron boost was delivered to all patients over the presacral space (1000 –1500 cGy) using bevelled circular applicators from 5 to 9 cm diameter. Adjuvant systemic chemotherapy was electively administered to 67% of p. Results: With a median follow-up of 65 months, pelvic recurrences were pathologically documented in 13 p (7%). Anatomic topography of cancer involvement within the pelvic area was: presacral (4), anastomotic (7), posterior vaginal wall (1) and hypogastric nodes (1). Four synchronous and 5 metachronous sites of progression were observed associated to pelvic relapse. Distant failures alone were registered in 27 p (16%), showing the higher incidence in lung (8), liver (8) and multi-organ locations (9). Median time to first-site of relapse was: intrapelvic 28 months (7–52) and extrapelvic 13 months (1– 47). Surgical radical intent for recurrences rescue was attempted in 9 p (22%): pelvic resections (6) and liver (2) or lung (1) metastatectomies. The actuarial 5 years local relapse-free, disease-free and overall survival were 89%, 72% and 74%, respectively. Table describes relevant multivariate analysis results. Conclusions: In the context of neoadjuvant treatment including an intraoperative electron boost, the risk of rectal cancer relapse in the posterior pelvic cavity is minimized (2%). Peri-anastomotic tissues emerge as the new dominant site for pelvic recurrence (54%). The downstaging morphology (pT0 or pTmic categories) appears to be predictive for long term outcome, while surgical distal margin significantly impacts on local relapse-free survival.

Local Relapse-Free Survival

Downstaging morphology pT0-pTmic pTmac Surgical distal margin ⬎10 mm ⱕ 10 mm Adjuvant chemotherapy Yes No

Disease-Free Survival

Overall Survival

Hazard ratio (CI 95%)

p Value

Hazard ratio (CI 95%)

p Value

Hazard ratio (CI 95%)

p Value

2,65(0,63-11,01)

0,180

3,57 (1,71- 7,48)

0,001

3,47(1,70-7,06)

0,001

4,62(1,23-17,31)

0,022

2,88 (1,43 - 5,77)

0,002

1,42(0,71-2,85)

0,320

5,75(1,43-23,09)

0,013

1,58 (0,80 - 3,14)

0,186

3,52(1,92-6,48)

⬍0.001

Author Disclosure: J. Serrano, None; F.A. Calvo, None; M. Gomez-Espi, None; C. Iban˜ez, None; R. Garcı´a, None; J.A. Diaz-Gonzalez, None; D. De la Mata, None; J.A. Arranz, None; C. Gonzalez, None; E. Alvarez, None.

2103

Long-Term Results of Definitive Chemoradiotherapy for Clinical Stage I Squamous Cell Carcinoma of the Esophagus

Y. Ito1, S. Akatsuka2, K. Muro2, Y. Kagami1, A. Imai1, M. Sumi1, H. Mayahara1, T. Hamaguchi2, K. Shirao2, H. Ikeda1 1 Radiation Oncology Div, National Cancer Center Hospital, Tokyo, Japan, 2Gastrointestinal Oncology Div, National Cancer Center Hospital, Tokyo, Japan

Purpose/Objective(s): To assess the long-term survival and toxicity after definitive chemoradiotherapy for clinical stage I (T1N0M0) squamous cell carcinoma of the esophagus. Materials/Methods: Patients with clinical stage I squamous cell carcinoma of the esophagus treated with definitive chemoradiotherapy between Dec 1997 and Oct 2003 in our institution were recruited from our database. The staging procedures included barium swallow, endoscopy, a computed tomography scan, and endoscopic ultrasonography. The chemoradiotherapy consisted of cisplatin at a dose of 70mg/m2 on days 1, 29 and continuous infusion of 5-fluoroiracil at a dose of 700mg/m2/day on days 1– 4, 29 –32 with concurrent radiotherapy 60 Gy in 30 fractions over 6 to 7 weeks. Results: A total of 114 patients were analyzed. There were 16 females and 98 males whose median age was 65 years. Seven patients were diagnosed as having mucosal cancer and 107 patients were diagnosed as having submucosal cancer. One hundred-eight patients of the 114 patients achieved complete response (CR) after chemoradiotherapy and CR rate was 95% (95% confidence interval; 89 - 98%). Five patients of the 6 patients with residual patients were treated successfully with endoscopic mucosal resection or esophagectomy. Twenty-nine patients experienced a recurrence after CR. Twenty patients with local recurrence only were treated successfully with endoscopic mucosal resection or esophagectomy. With a median follow-up duration of 48 months, 3- and 5- year survival rates were 80% and 74%, respectively. These survival rates were comparable with those of previous reports of surgery in Japan. With regard to late toxicities, ⱖGrade 3 radiation pneumonitis, pleural effusion, and pericardial effusion were observed in 5 patients (4.4%), 4 patients (3.5%), and 4 patients (3.5%), respectively. Conclusions: Definitive chemoradiotherapy for clinical stage I esophageal cancer achieved favorable survival rates with acceptable toxicities. This schedule could be a standard treatment options in clinical stage I squamous cell carcinoma of the esophagus. Author Disclosure: Y. Ito, None; S. Akatsuka, None; K. Muro, None; Y. Kagami, None; A. Imai, None; M. Sumi, None; H. Mayahara, None; T. Hamaguchi, None; K. Shirao, None; H. Ikeda, None.