Prognostic factors in rectal cancer: where is the evidence?

BACKGROUND In rectal cancer, the 5 years survival is about 53 % for all stages: it remains low in spite of the progress of diagnostic and therapeutic tools. The aim of this work was to provide evidence based answers to the following question: what are the pre, intra and post operative prognostic factors in rectal cancer? METHODS We have carried out a search in the following data bases: Pubmed, Embase, Cochrane and Scopus. The key words used were: « rectal cancer », « adenocarcinoma », « overall survival », « disease-free survival », « prognosis » and « evidence-based medicine ». The overall 5 years survival rate has been retained as primary outcome measure. Recurrence-free survival has been retained as secondary endpoint. Were included meta-analyses and systematic reviews of clinical trials dating back to less than six years. RESULTS We retrieved 270 publications, 27 articles only met the above-mentioned eligibility criteria and thereof have been retained in this work. A high operating volume, a specialized surgeon in colorectal surgery, a total mesorectal excision, an adjuvant chemotherapy given within no more than 8 weeks following the curative resection improve prognosis in rectal cancer with level I of evidence. Anastomotic leak and diabetes worsen prognosis in rectal cancer with level I of evidence. Margin of surgical resection must be RO to improve prognosis in rectal cancer with level I of evidence. CONCLUSION The main prognostic factors found in literature which we should keep in mind are those on which surgeons can  act:  neoadjuvant treatment,  high operating volume of the surgeon,  high tie of the inferior mesenteric  artery,  mesorectal excision , RO resection,  improvement of the techniques of intersphincteric resection and techniques of anastomosis   and adjuvant chemotherapy within less than 8 weeks when appropriate.