No difference in time to recurrence, recurrence-free survival, or overall survival were noted for patients with rectal cancer who underwent one of three different preoperative radiotherapy regimens.
No difference in time to recurrence or recurrence-free survival were noted for patients with rectal cancer who underwent one of three different preoperative radiotherapy regimens, according to the results of the Stockholm III study published in the March issue of Lancet Oncology. Patients who received short-course radiotherapy and delayed surgery by 4 to 8 weeks had a lower frequency of postoperative complications compared with those who received immediate surgery.
“The aim of rectal cancer care today must be to retain low rates of local disease recurrence, reduce the risk of systemic recurrence, and reduce both acute and long-term side effects,” wrote Johan Erlandsson, MD, from the Karolinska Institutet and Centre of Digestive Diseases, Karolinska University Hospital, Stockholm, Sweden, and colleagues. “The results of this study suggest that short-course radiotherapy with delay is noninferior to short-course radiotherapy [with immediate surgery], that it is oncologically safe to delay surgery 4–8 weeks after short-course radiotherapy, and that it results in fewer postoperative complications.”
Stockholm III was initiated to determine the optimal fractionation of preoperative radiotherapy and timing of surgery for patients with resectable rectal cancer. From 1998 to 2013, 840 patients were enrolled and randomized.
In a three-arm part of the trial 385 patients were randomly assigned to short-course radiotherapy with immediate surgery (n = 129), short-course radiotherapy with delayed surgery (n = 128), or long-course radiotherapy with delayed surgery (n = 128).
A two-arm short-course radiotherapy randomization included 455 patients assigned to either immediate surgery (n = 228) or delayed surgery (n = 227).
At a median of 2 years follow-up, the median time from randomization to local recurrence in pooled data from the short-course radiotherapy groups was 33.4 months with immediate surgery compared with 19.3 months with delayed surgery. The median time to local recurrence was 33.3 months for patients assigned to long-course radiotherapy.
“When patients randomly assigned to short-course radiotherapy [with immediate surgery] or short-course radiotherapy with delay were analyzed separately according to whether they were part of the three-arm or two-arm randomizations, no differences in local recurrence, distant metastases, overall survival, or recurrence-free survival were noted,” the researchers wrote.
Acute radiation-induced toxicity was infrequent and reported in less than 1% of patients assigned short-course radiotherapy plus immediate surgery, 7% of patients assigned short-course radiotherapy with delayed surgery, and 5% of patients assigned long-course radiotherapy with delayed surgery. The frequency of postoperative complications was similar between all three arms of the three-arm randomization. However, when the researchers looked at just the two-arm randomization they found that the risk for postoperative complications was significantly lower after short-course radiotherapy with delayed surgery than with immediate surgery (41% vs 53%, respectively; P = .001).
In an editorial that accompanied the research, Krzysztof Bujko, MD, and Rafal Sopylo, MD, of the Maria SkÅodowska-Curie Memorial Cancer Centre in Poland, wrote that based on the results of the Stockholm III trial and other recently published results, “for patients in the intermediate-risk group, short-course radiotherapy with delayed surgery can be added to short-course radiotherapy with immediate surgery and chemoradiation as a third routine option.” However, they also added that since the majority of patients assigned to delayed surgery waited no longer than 8 weeks, “the trial’s conclusions cannot be generalized for patients treated at longer intervals.”