Aims of combined modality therapy in rectal cancer (M0)

OPTIMIZING THE COST/BENEFIT RATIO OF TREATMENT: Evidence Based The aim of a cancer treatment is always to achieve the maximum of cure rate with a minimum of toxicity and best quality of life at an acceptable cost for the society. It is always a multifactorial challenge depending on the patient, the tumor, the doctor, and the society cultural and financial backgrounds. The goal is to find the best cost/benefit ratio between all possible strategies in agreement with a well-informed patient. In rectal cancer (M0) surgery is the cornerstone of treatment. Combined modality therapies aim at optimizing the cost/benefit ratio of possible strategies and only randomized trials can bring strong evidence regarding their results and recommendations. LESSONS FROM RANDOMIZED TRIALS: quite modest During the past decades many phase III trials have shown that: (1) neoadjuvant treatment even with "TME" surgery was better than adjuvant, (2) chemoradiotherapy (CRT) was better than RT alone, (3) long course CRT was probably more efficient (in terms of ypCR) than short course (25/5), and (4) capecitabine was as efficient as 5 FU but oxaliplatin was not adding benefit. Overall, the gains of nCRT remain modest and it is mainly a reduction in local relapse not exceeding 5 %, but no benefit in survival and neither in sphincter saving surgery has been proven. The way forwards organ preservation in case of CCR. Local control: can probably be improved for T4 tumors by RT dose escalation. Survival: can be increased by innovative medical treatment either before or after surgery.

may be reduced by a less aggressive treatment in elderly. Conservative treatment: A new field of clinical research is to achieve "organ preservation" (and not only sphincter saving). To modify the surgical approach and preserve the whole rectum, neoadjuvant treatment must achieve safely a clinical complete response. As rectal adenocarcinoma is a relatively radioresistant tumor endocavitary irradiation (contact X-Ray) is a promising safe approach and this hypothesis will be addressed by the OPERA randomized trial.