Active surveillance improves colostomy-free survival in rectal cancer
Chemoradiotherapy followed by active surveillance appeared to confer positive outcomes for patients with rectal cancer, according to the results of a matched cohort analysis.
A large subset of patients avoided surgery without sacrificing safety, results showed.
Surgical resection is common in the management of rectal cancer; however, it has been associated with potentially fatal complications, in addition to incontinence, sexual dysfunction and permanent colostomy.
In recent years, the induction of a clinical complete response with chemoradiotherapy, followed by watch-and-wait active surveillance, has emerged as a treatment option for patients with rectal cancer, according to study background.
Andrew G. Renehan, MBChB, PhD, FRCS, professor of cancer studies and surgery at University of Manchester, and colleagues sought to compare oncological outcomes between patients managed with active surveillance and those who underwent surgical resection.
Renehan and colleagues conducted a propensity-score matched cohort study of patients with rectal cancer without distant metastases who received preoperative chemoradiotherapy (45 Gy in 25 daily fractions, with concurrent fluoropyrimidine-based chemotherapy) between January 2011 and April 2013.
Patients who achieved a clinical complete response were offered active surveillance; those who did not were offered surgical resection, if eligible.
The study further included data from patients who achieved a clinical complete response and underwent active surveillance between March 2005 and January 2015 at three regional cancer centers in the United Kingdom.
Non-regrowth DFS served as the primary endpoint. Secondary endpoints included OS and colostomy-free survival.
Median follow-up was 33 months (interquartile range, 19-43).
The study included data from 259 patients (surgical resection; n = 228; active surveillance, n = 31), as well as 98 registry patients managed with active surveillance.
Forty-four patients (34%) managed with active surveillance had local regrowths (3-year actuarial rate = 38%; 95% CI, 30-48). Among 41 patients with nonmetastatic local regrowths, 88% (n = 36) achieved successful salvage.
In a matched analysis of 109 patients from each treatment group, the researchers observed no differences in 3-year nonregrowth DFS (88% vs. 78%) and 3-year OS (96% vs. 87%; P = .024) between the active surveillance and surgery groups.
However, patients managed with active surveillance achieved a significantly higher rate of 3-year colostomy-free survival (74% vs. 47%; HR = 0.44; 95% CI, 0.31-0.63), equating to a 26% (95% CI, 13-39) absolute difference in patients who avoided permanent colostomy at 3 years.
The researchers acknowledged limitations, including the relatively short follow-up period and the lack of complete adherence to follow-up protocol among patients on active surveillance.
“Many patients who have a clinical complete response, even when explicitly informed about the experimental nature of the watch-and-wait approach, express a strong preference not to undergo major surgery,” Renehan and colleagues wrote. “The next best level of evidence is likely to come through well-documented, prospective studies, applying appropriate analytical methods to reduce confounding and biases, in large datasets such as the initiative of the International Watch and Wait database.”
Randomized clinical trials designed to investigate active surveillance vs. surgical resection may present unique challenges, Rodrigo Oliva Perez, MD, a colorectal surgeon at University of São Paulo School of Medicine, wrote in an accompanying editorial.
“The problem is that recruitment of patients into a study in which standard treatment could possibly be worse — in terms of survival and the risk for a definitive stoma — than the experimental treatment is likely to be low,” Perez wrote. “Ultimately, it comes down to whether patients would be willing to undergo radical surgery and a definitive stoma after a complete clinical response in the absence of any benefit for radical surgery.”
However, watch-and-wait strategies are likely to become popular among patients who wish to avoid complications associated with surgery, Perez wrote.
“This approach might seem obvious now and is actually not a new idea,” Perez wrote. “However, it took surgeons themselves — against their own interests — a long time to consider it as a valid strategy for rectal cancer. Hopefully the watch-and-wait approach will benefit a substantial proportion of patients as chemoradiotherapy regimens improve and progressively increase the chances of a complete response to therapy.” – by Cameron Kelsall
Disclosure: The Bowel Disease Research Foundation funded this study. One study researcher reports grants and personal fees from Sanofi Pasteur MPS outside the submitted work. The other researchers and Perez report no relevant financial disclosures.