SUMMARY: The American Cancer Society estimates 39,910 new cases of Rectal Cancer will be diagnosed in the United States in 2017. Rectal cancer diagnosed at an early stage such as Stage II (T3-T4, N0) or Stage III (Node positive disease without distant metastases) is potentially curable and often treated with a combination of neoadjuvant (preoperative) chemoradiation and surgery and postoperative chemotherapy. Unlike colon cancer, the risk of locoregional recurrence is high in Rectal Cancer due to its close proximity to the surrounding pelvic organs and difficulty in obtaining a clear surgical margins. Further, there is no serosal tissue surrounding the rectum. For all these reasons, preoperative Radiation Therapy (RT) with concurrent Fluoropyrimidine based chemotherapy as a radiosensitizer, followed by postoperative chemotherapy, has been the standard intervention. Radiation consists of 45 Gy delivered in 25 fractions 5 days a week with a 5.4 Gy boost. Concurrent chemotherapy in the US has included 5-FU/Leucovorin, single agent 5-FU or single agent XELODA® (Capecitabine). Complete Response is seen in approximately 25% of the patients who receive chemoradiation. However, 15% to 25% of these patients develop local recurrence. Surgery following chemoradiation may result in long term complications and may necessitate temporary or permanent colostomy in addition to sexual and urinary dysfunction.
The International Watch & Wait Database Consortium was established in 2014 by EURECCA (the European Registration of Cancer Care) and the Champalimaud Foundation in Lisbon. This Consortium which includes 35 institutions in 11 countries was established mainly to collect all available data and expand knowledge on the benefits, risks and oncological safety of organ preserving strategies, in Rectal Cancer. This database as of August 2016 included 775 patients and majority of these patients had stage T2/3 disease (92%) with clinical N0/1 nodal status (75%). Ninety percent of these patients (N=679) had a clinical Complete Response following induction therapy with chemoradiation. These patients did not undergo surgery and were followed up for a median of 2.6 years.
It was noted that 25% of all patients had local recurrence and 84% of these occurred in the first 2 years of follow up. Local recurrence was endoluminal in 96% of the patients and in the loco-regional lymph nodes in 4%. Distant metastasis occurred in 7% of the patients. The 3-year Overall Survival rate was 91% among all patients, and was 87% for patients who experienced local recurrence. These findings are comparable to survival rates seen in patients with a Complete Response, who undergo standard surgery.
It was concluded that in this largest series of patients to date with Rectal Cancer, a “watch-and-wait” strategy to treating Rectal Cancer without surgery, following Complete Response to chemoradiation, resulted in outcomes comparable to historical controls. As more information is gathered, it is important that restaging be performed in all patients with Rectal Cancer who undergo chemoradiotherapy, to prevent unnecessary surgical procedures, and give patients the option for a watch-and-wait approach. The International Watch & Wait database (IWWD) for rectal cancer: An update. van der Valk M for the International Watch and Wait Database Consortium. J Clin Oncol 35, 2017 (suppl 4S; abstract 521)
