Management of early rectal T1 and T2 cancers

The treatment of rectal cancer has undergone a tremendous surgical evolution over the past century. Initially, in the 19th century, the only possible safe treatment was a diverting colostomy, which then evolved first to local treatment, primarily via the Lisfranc and Kraske procedures (posterior approach), and later, in the 20th century, to the abdominal-perineal resection popularized by Miles. Subsequently, anterior resection and low anterior resection gained a solid foothold as the most efficacious ways to treat most cancers of the rectum. In the past 3 decades, transanal excision has reemerged as a popular treatment option for T1 and selected T2 rectal adenocarcinomas, allowing less morbidity for early cancers. The selection criteria for this treatment have often included mobile tumor, size <4 cm, favorable histology without lymphovascular invasion, and anatomic accessibility with the ability to achieve 1-cm circumferential margins. Although the use of transanal excision for T1 rectal cancer increased from 26% to approximately 44% between 1989 and 2003, multiple recent retrospective studies have suggested that locoregional recurrence after this procedure is as high as 18% for T1 cancers and 47% for T2 cancers. Of interest, limited available prospective data reveal much better results (4-5% locoregional recurrence rate for T1 and 14-16% for T2). Much of the apparent discrepancy is due to patient selection, which is far more rigid in prospective trials. Conflicting data also exist as to how this outcome affects overall survival, although surgical salvage averages approximately 50% with close follow-up. The following topics will be discussed in this article: the surgical evolution of rectal cancer, best patient selection criteria for transanal excision versus more radical operation, utility and effect of adjuvant therapy in early-stage rectal cancer, current trends in the treatment of early-stage rectal cancer, and current early-stage rectal cancer trials.