676 Background: Organ preservation (avoiding TME surgery) for T2 T3 a-b rectal cancer is a field of active clinical research. Contact X Ray CXB combined with external beam radiotherapy (EBRT) ± concurrent chemotherapy (CRT) is an attractive method to achieve clinical complete response (cCR) and consequently rectal preservation. We report an overview of 120 patients treated with CXB+EBRT over a 25 year period in Lyon since 1986 and then in Nice until 2012. Methods: Between 1986 and 2012, 120 patients presenting rectal adenocarcinoma T2 T3a-b (distal rectum: 87; middle rectum: 33) were treated with CXB +EBRT with conservative intent. In Lyon (1986-2001), 80 patients median age: 73y; T2:52; T3:28) risk were treated using CXB (80-110 Gy/3-4 fr/4-6 weeks) followed by EBRT (39 Gy/13 fr/18 days) and 192 Iridium implant boost (20 Gy). When cCR was achieved, close surveillance was proposed. In Nice (2002-2012), 40 patients (median age 81y; T2:22; T3:18) received CXB same regimen as in Lyon (using new Papillon 50 machine since 2009) + EBRT (45-50 Gy/5weeks) with concurrent chemotherapy (5-FU or Capecitabine). When cCR was achieved close surveillance was proposed or local excision (13 pts). Results: Median follow-up time 58 months in both groups. Local relapse occurred mainly in the 2 first years. Isolated lymph node recurrence <5%. Bowel function good or excellent when rectum preserved. Main clinical outcomes in table (some improved results in Nice possibly due to better treatment approach and patient selection). Conclusions: CXB with EBRT and concurrent capecitabine achieve safely high rate of cCR with organ preservation. The OPERA randomized trial will reproduce Lyon R 96 trial (Gerard JP, JCO 2004;22:2404) and test the superiority of CXB boost for organ preservation. [Table: see text]
P-225 Clinico-epidemiological and therapeutic profile of rectal cancer: Experience of the department of radiation oncology EHSO ORAN