There are still major differences in watch-and-wait strategies worldwide, but it is important that restaging be performed in all patients [with rectal cancer] who undergo chemoradiotherapy, to prevent unnecessary surgical procedures and to give patients the option for a watch-and-wait approach.— Maxime van der Valk, MD
A “watch-and-wait” approach to treating rectal cancer patients with complete responses to chemoradiotherapy resulted in a 3-year survival rate of 91%, which is similar to historic survival rates after surgical resection, according to an analysis of the International Watch & Wait Database.1 For patients who experienced local recurrence, the 3-year survival was 87%, according to Maxime van der Valk, MD, of the Leiden University Medical Center in the Netherlands.
The findings, which draw from the largest patient series to date in which surgery was omitted after initial chemoradiation, support a surveillance option. This strategy became a matter of consideration (and continuing debate), after studies from various centers showed its oncologic safety and feasibility in subsets of patients. With survival not compromised, some experts believe surgery can be omitted in selected patients with clinical complete responses.
Growing Interest in Avoiding Surgery
The results were presented at the 2017 Gastrointestinal Cancers Symposium in San Francisco. In a press briefing, moderator Nancy Baxter, MD, FRCSC, FACS, PhD, a colorectal surgeon at St. Michael’s Hospital in Toronto, noted, “Surgery is effective but has a lot of long-term consequences, so this is an exciting area of definite interest to patients.… Our patients are learning more and more about watch-and-wait approaches to rectal cancer on the Internet, and I think this study is really going to help us decide who this promising strategy should be applied to.”
Nancy Baxter, MD, FRCSC, FACS, PhD
Dr. van der Valk noted that the watch-and-wait option is currently the treatment choice in fewer than 5% of all resectable rectal cancer patients, but interest in a nonoperative approach is growing. Rectal cancer surgery is associated with high morbidity and impairment of quality of life, she noted.
While outcomes for rectal cancer have improved considerably over the past decade, primarily because of improvements in surgical techniques and the introduction of preoperative chemotherapy plus radiotherapy, surgery “is still not without consequences,” such as the need for temporary or permanent colostomy, sexual and urinary dysfunction, and/or surgical complications, she said.
Although 20% to 25% of all patients who receive chemoradiotherapy achieve a complete response, 15% to 25% of these patients develop local recurrence. “Strict follow-up, therefore, is required in these patients,” she emphasized.
The International Watch & Wait Database Consortium includes 35 institutions in 11 countries. It was established by EURECCA (the European Registration of Cancer Care) and the Champalimaud Foundation in Lisbon, with the goal of collecting data on the benefits, risks, and oncologic safety of organ-preserving strategies in rectal cancer. Dr. van der Valk said the group will be expanding its cohort and establishing an expert committee on this strategy.
The study focused on 679 patients who underwent induction therapy with chemoradiotherapy and achieved a complete clinical response. Most patients had tumor stage T2/3 (92%) and nodal status cN0/1 (75%).
Patients did not undergo surgery, but all were followed closely. During the first 2 years, patients were evaluated every 3 months with endoscopy, magnetic resonance imaging, and physical examination.
At a median follow-up of 2.6 years, local regrowth was observed in 25% (n = 167) of all patients, with 84% of these recurrences diagnosed within the first 2 years of follow-up. Local regrowth occurred endoluminally in 96% (n = 161) of patients and in the locoregional lymph nodes in 4% (n = 7). Distant metastasis occurred in 7% (n = 49).
“Despite heterogeneity in the cohort, we see an overall regrowth rate at 3 years of 25%, and this is comparable to previous studies,” she noted. “And from the literature, we know that an overall survival rate of 92% at 3 years is similar to survival rates in patients with a complete response who undergo standard surgery.”
Dr. van der Valk acknowledged that there were differences in induction therapy as well as imaging strategies but feels the analysis “provides some crude outcome data” that can be fortified and fine-tuned with further data collection.
“There are still major differences in watch-and-wait strategies worldwide, but it is important that restaging be performed in all patients who undergo chemoradiotherapy, to prevent unnecessary surgical procedures and to give patients the option for a watch-and-wait approach,” she said. ■
Disclosure: This study was supported by grants from EURECCA and the Champalimaud Foundation. Drs. van der Valk and Baxter reported no potential conflicts of interest.