A watch-and-wait surveillance strategy conferred similar 4-year survival rates as immediate surgery among patients with stage I to stage III rectal cancer who demonstrated a complete response after chemoradiation and systemic chemotherapy, according to retrospective study results presented at the Gastrointestinal Cancers Symposium.
The findings add to evidence that suggests select patients with rectal cancer who undergo frequent follow-up exams after chemotherapy and radiation can avoid the risks and potential complications associated with surgery while still achieving excellent outcomes, researchers said.
About 40% to 50% of patients with stage I rectal cancer — and 30% to 40% of those with stage II or stage III cancers — experience complete tumor regression after initial chemoradiation therapy.
“The standard management for more than 10 years in the United States has been to treat with three components of therapy: neoadjuvant radiation to the pelvis, rectal resection and, in most patients, adjuvant chemotherapy,” Philip B. Paty, MD, surgical oncologist at Memorial Sloan Kettering Cancer Center, said during a press conference. “We know following this paradigm that, at the time of surgery when pathological analysis is performed, anywhere from 12% to 38% of patients will have no cancer cells in the final specimen. This raises the question whether surgery is always necessary in a subset of patients where the response if very favorable.”
Paty and colleagues conducted a retrospective study to assess whether watch-and-wait may be appropriate for this patient population.
The analysis included 145 patients with stage I to stage III rectal cancer treated between 2006 and 2013.
All patients achieved clinical complete response — defined as no cancer detected on imaging, endoscopy or physical exam — after neoadjuvant radiation and chemotherapy.
Rectal surgery was deferred for 73 patients. As part of the watch-and-wait strategy, they underwent digital rectal and endoscopic exams at 3- to 4-month intervals and cross-sectional imaging at 6-month intervals.
The other 72 patients underwent rectal resection.
Median follow-up was 3.5 years for both study groups.
Seventy-four percent of patients (n=54) in the watch-and-wait arm experienced durable tumor regression without rectal surgery. However, 26% (n=19) underwent rectal surgery due to mucosal/intramural regrowth (n=16) or mesenteric/nodal recurrence (n=3).
Researchers reported no significant difference in the number of distant recurrences between the watch-and-wait group (n=9) and the surgery group (n=5).
Four-year disease-specific survival was 91% in the watch-and-wait group vs. 96% in the surgery group (P=.23). Four-year OS was 91% in the watch-and-wait group and 95% in the surgery group (P=.47).
“We believe that our results will encourage more doctors to consider the watch-and-wait approach in patients with complete clinical response as an alternative to immediate rectal surgery, at least for some patients,” Paty said in a press release. “From my experience, most patients are willing to accept some risk to defer rectal surgery in hope of avoiding major surgery and preserving rectal function.”
For more information: Paty PB. Abstract #509. Presented at: Gastrointestinal Cancers Symposium; Jan. 16-18, 2015; San Francisco.
Disclosure: The study was funded in part by the Berezuk Colorectal Cancer Fund. The researchers report consultant/advisory or speakers’ bureau roles with Abbott Biotherapeutics, Bayer, Boehringer Ingelheim, Intuitive, Pfizer, Roche/Genentech and Sun Pharma; honoraria from Intuitive Surgical and Myriad Genetics; and research funding from Taiho.