WATCH AND WAIT APPROACH IN SELECTED PATIENTS WITH RECTAL CANCER

New data support the "watch-and-wait" side of the ongoing debate about the best approach to treatment for patients with rectal cancer. With improved survival now being seen after initial chemoradiation, some experts are arguing for omitting surgery in lieu of observation.

In the largest patient series to date in which surgery was omitted after induction therapy, the authors found that 3-year survival was 91%, which is similar to historic survival rates among patients who receive surgery.

For patients who experienced local recurrence, the 3-year survival was 87%.

"What we know from the literature is that these results are similar to the survival rates of patients who had a complete response and then underwent standard surgery," said study author Maxime van der Valk, MD, from the Leiden University Medical Center, the Netherlands. "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 watch-and-wait."

Dr van der Valk presented the findings at a press briefing held in advance of the upcoming 2017 Gastrointestinal Cancers Symposium in San Francisco.

"The outcome for rectal cancer has improved considerably over the last decade, and this is mainly due to improvements in surgical techniques and the introduction of preoperative radio and chemotherapy and also improvements in diagnosis," she explained during her presentation.

"However, surgery for rectal cancer is still not without consequences, such as the need for temporary or permanent colostomy, sexual and urinary dysfunction, and/or surgical complications," Dr van der Valk said.

She pointed out that 20% to 25% of all patients who receive chemoradiotherapy experience a complete response.

However, studies have also shown that local regrowth will occur in 15% to 25% of these patients, "so strict follow-up is required in these patients," she added.

The watch-and-wait option is not yet the standard of care in rectal cancer. It is estimated that it is used in fewer than 5% of all patients.

There is, however, growing interest in this strategy, as rectal cancer surgery is associated with high morbidity and impairment of quality of life.

Whether surgery can be omitted is subject to debate, with experts arguing convincingly on both sides, as reported recently by Medscape Medical News. The debate has intensified in recent years with studies reporting positive results.

One study published in 2015, for example, found the watch-and-wait approach to be as oncologically safe as radical surgery among patients who achieved a clinical complete response to chemoradiotherapy. In that study, the overall survival at 3 years was 96% of patients in the watch-and-wait group and 87% in the surgical resection group. Importantly, 74% of patients in the watch-and-wait group were colostomy free at 3 years vs 47% of those in the surgical group.

Study Details

The new data come from an analysis conducted by the International Watch and Wait Database Consortium, which includes 35 institutions in 11 countries. It was established by EURECCA (the European Registration of Cancer Care) and the Champalimaud Foundation in Lisbon, Portugal, with the goal of collecting all available data on the benefits, risks, and oncologic safety of organ-preserving strategies in rectal cancer.

"It is our aim to expand the cohort and establish an expert group on watch-and-wait strategies, and new centers are welcome to join this consortium," Dr van der Valk commented.

The current database now includes 802 patients who underwent induction therapy with chemoradiotherapy and who had achieved a complete clinical response.

All patients received watch-and-wait care. During the first 2 years, patients were evaluated every 3 months with endoscopy, MRI, and physical examinations.

"The current analysis included 679 cases with a compete clinical response," said Dr van der Valk.

"At a median follow-up time of 2.6 years, local regrowth occurred in 25% (n = 167) of all patients, with 84% diagnosed within the first 2 years of follow-up," she said.

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).

Commenting on the study, Nancy Baxter, MD, moderator of the presscast and a colorectal surgeon at St. Michael's Hospital in Toronto, Canada, noted that "surgery is very effective but has a lot of long-term consequences, so this is a very exciting area that our patients are definitely interested in.

"Our patients are learning more and more about watch-and-wait approaches to rectal cancer on the Internet, and I think this is really going to help us decide who this very promising strategy should be applied to," she added.

This study was supported by grants from EURECCA and the Champalimaud Foundation. Dr van der Valk and coauthors and Dr Baxter have disclosed no relevant financial relationships.

Gastrointestinal Cancers Symposium (GICS) 2017. Abstract 521, to be presented January 21, 2017.