Most patients with rectal cancer who follow a watch-and-wait approach successfully avoided radical surgery, according to results of a study review.
“What is striking is not only the low rate of cancer recurrence, but also that almost all the patients who had a recurrence could still be treated with surgery or radiation at the time the recurrence was detected,” Fahima Dossa, MD, surgical resident at St. Michael’s Hospital in Toronto, said in a press release.
Patients with rectal cancer can avoid the morbidity of conventional surgery with a watch-and-wait approach after achieving a clinical complete response to neoadjuvant chemoradiation. However, the safety of this approach has not been proven.
Dossa and colleagues conducted a review of MEDLINE, EMBASE and the grey literature through June 2016 to identify 23 studies that included at least some patients with rectal adenocarcinoma managed by watch-and-wait. The analysis included data from 867 patients (age range, 39-86 years; 62% men).
Five of the studies compared patients in clinical complete response who underwent watch-and-wait (n = 129) with patients in pathologic complete response who underwent radical surgery (n = 189). Three additional studies only included patients with clinical complete response who underwent watch-and-wait (n = 71) or surgery (n = 128). Clinical complete response has been used as a surrogate measure for pathologic complete response — which is only evaluable after surgery — but researchers noted their concordance is variable.
The proportion of patients who experienced local regrowth 2 years following watch-and-wait served as the study’s primary endpoint. Researchers also compared nonregrowth recurrence, cancer-specific mortality, DFS and OS in studies that compared watch-and-wait with radical surgery.
Median follow-up across studies ranged from 12 months to 68 months.
In total, 15.7% (95% CI, 11.8-20.1) of patients experienced 2-year local regrowth. Almost all of these patients (95.4%; 95% CI, 89.6-99.3) received salvage therapies.
“Despite concerns about salvageability following tumor regrowth, only three (1.9%) of 157 reported patients with local regrowth could not undergo salvage therapy due to extent of local or systemic disease,” the researchers wrote.
Patients who underwent watch-and-wait demonstrated comparable rates of nonregrowth recurrence (RR = 1.46; 95% CI, 0.7-3.05), cancer-specific mortality (RR = 0.87; 95% CI, 0.38-1.99) and OS (HR = 0.73; 95% CI, 0.35-1.51) as patients with pathologic complete response treated by resection. However, the watch-and-wait group achieved shorter DFS (HR = 0.47; 95% CI, 0.28-0.78).
The watch-and-wait group demonstrated similar outcomes as patients with clinical complete response who underwent surgery in terms of nonregrowth recurrence (RR = 0.58; 95% CI, 0.18-1.9), cancer-specific mortality (RR = 0.58; 95% CI, 0.06-5.84), DFS (HR = 0.56; 95% CI, 0.2-1.6) and OS (HR = 3.91; 95% CI, 0.57-26.72).
The evidence to support watch-and-wait for rectal cancer is growing, according to study researcher Nancy Baxter, MD, FRCSC, FACS, PhD, chief of general surgery at St. Michael’s Hospital.
“The fact that patients in these studies chose to avoid surgery despite not knowing the safety of this approach is a reminder of the various factors that go into cancer treatment decisions,” Baxter said in the release. “At the very least, we are hopeful that this study will open the door to discussions between select patients and their surgeons about the option of a watch-and-wait approach.” – by Alexandra Todak
Disclosure: The researchers report no relevant financial disclosures.
St. Michael’s Hospital in Toronto