Complete Neoadjuvant Treatment for REctal Cancer (CONTRE)

The purpose of this study is to find out how well patients with cancer of the rectum do if they get all of their other treatment - chemotherapy by itself followed by chemotherapy and radiation together - before surgery. Patients have recently been diagnosed with rectal cancer, and the doctors have recommended neo-adjuvant chemo treatment to try to shrink the cancer before removing it.

The goals of treatment of locally advanced (T3-4 or N1-2) rectal cancer are to eliminate the primary tumor and any involved adjacent lymph nodes, minimize the risk of distant recurrence, and, when possible, preserve anal sphincter function. Standard treatment consists of surgery, concurrent chemotherapy and radiation (RT) and adjuvant chemotherapy. As the present time, the chemoradiation portion of the treatment is often administered before, as opposed to following, surgical resection. This approach has been associated with tumor down-staging, leading to higher rates of tumor resectability and an increase in the ability to perform sphincter-saving surgeries. (1). However, while advances in treatment of the primary tumor and regional nodes, specifically administration of preoperative chemoradiation and more aggressive surgical approaches, such as total mesorectal excision (TME), have been shown to improve locoregional disease control, toxicities and complications of these treatments may result in delay or omission of adjuvant chemotherapy, which could increase the risk of distant recurrence. In this pilot study, standard adjuvant chemotherapy (8 cycles of modified FOLFOX6) will be administered prior to chemoradiation and definitive surgery, eliminating the need for post-operative systemic therapy. The investigators will evaluate the ability of patients to tolerate this treatment and its impact on achievement of pathologic complete responses (pCRs), negative surgical margins and sphincter preservation.