A critical review of the role of local excision in the treatment of early (T1 and T2) rectal tumors

The optimal treatment of early (T1 and T2) rectal adenocarcinomas remains controversial. Local excision and radical resection with total mesorectal excision are the two surgical techniques for excising early rectal cancer. Each has their respective benefits, with local excision allowing for decreased operative morbidity and mortality while radical resection provides an oncologically complete treatment through lymphadenectomy. Local excision can be accomplished via transanal endoscopic microsurgery or transanal excision. There is no significant difference in the recurrence rates (21% vs. 33%) or overall survival (80% vs. 66%) between the two local excision modalities; however, transanal endoscopic microsurgery does allow for a higher rate of R0 resection. Current selection criteria for local excision include well to moderately differentiated tumors without high-risk features such as lymphovascular invasion, perineural invasion, or mucinous components. In addition, tumors should ideally be <3 cm in size, excised with a clear margin, occupy less than 1/3 of the circumference of the bowel and be mobile/nonfixed. Despite these stringent inclusion criteria, local excision continues to be plagued with a high recurrence rate in both T1 and T2 tumors due to a significant rate of occult locoregional metastases (20% to 33%). For both tumor groups, the recurrence rate in the local excision group is more than double compared to radical resection. However, the overall survival is not significantly different between those with and without metastases. With intense postoperative surveillance, these recurrences can be identified early while they are confined to the pelvis allowing for salvage surgical options. Recently, neoadjuvant therapy followed by local excision has shown favorable short and long-term oncological outcomes to radical resection in the treatment of T2 rectal cancer. Ultimately, the management of early rectal cancer must be individualized to each patient’s expectations of quality and quantity of life. With informed consent, patients may be willing to accept a higher failure rate and an increased post-operative surveillance regimen to preserve a perceived increased quality of life.