Early rectal cancer: a choice between local excision and transabdominal resection. A review of the literature and current guidelines.

INTRODUCTION: Indication for Local Excision (LE) or Trans Abdominal Resections with Total Mesorectal Excision (TAR) in Early Rectal Cancer (ERC) are still controversial. MATERIAL OF STUDY: We reviewed meta-analyses, scientific societies guidelines, randomized and controlled clinical trials from 1999 to 2016 for a total of 146,231 patients. We included in our analysis the accuracy of different tools of investigation, the reliability of the endoscopic biopsies and compared the results of the various LE and TAR. RESULTS: The Endo Rectal Ultra Sound (ERUS) is the most accurate technique for the preoperative staging with an 18% of understaging and a 17.3% of overstaging. Endoscopic biopsies do not provide reliable data on unfavorable histopathological features in a significant percentage of cases. The Transanal Excision Microsurgery (TEM) is the best technique among LE but with worse overall results than TAR in terms of R0, local recurrence and overall 5-years survival in T2 cancers. DISCUSSION: The ERUS is the diagnostic technique most appropriate in the preoperative staging of the ERC; the employment of Magnetic Resonance Imaging (MRI) has to be limited to uncertain T2 patients. The ERUS shows significant understaging rate which expose to inadequate treatment, particularly in T2 patients. Endoscopic biopsies risk to disregard unfavorable histological features, resulting in inadequate therapeutic indications to LE. The use of TAR guarantees overall better results than the use of LE on T2 and T1 with unfavorable histological findings. CONCLUSIONS: The TAR still shows best results in the ERC treatment especially in T2 and T1 with unfavorable histological findings.