Preoperative chemoradiotherapy extends survival in esophagogastric junction adenocarcinoma
CHICAGO — Preoperative chemoradiotherapy conferred better survival outcomes than chemotherapy alone among patients with locally advanced esophagogastric junction adenocarcinoma, according to results of the phase 3 POET trial presented at the ASCO Annual Meeting.
“Results with chemotherapy alone are not sufficient. We should be able to improve [on them], and chemoradiation is one of the ways we can do that,” Michael Stahl, MD, director of the department of medical oncology at Kliniken Essen-Mitte in Germany, told HemOnc Today.
Phase 3 trial results published in 2009 showed the addition of preoperative radiotherapy to chemotherapy for patients with locally advanced esophagogastric junction adenocarcinoma increased 3-year survival from 28% to 48%; however, this result did not reach statistical significance.
The POET study included 119 patients with locally advanced disease who were randomly assigned to preoperative chemotherapy (n = 59) or chemoradiotherapy (n = 60). Rates of R0 resection were comparable between treatment groups (68% vs. 72%).
Median follow-up was 10.5 years.
Results revealed a trend toward improved 5-year survival in the chemoradiotherapy group (39.5% vs. 24.4%; HR = 0.65; 95% CI, 0.42-1.01).
Researchers also reported a significant improvement in local PFS after complete resection (HR = 0.42; 95% CI, 0.19-0.93) and improved DFS after complete resection (HR = 0.61; 95% CI, 0.36-1.01) among patients assigned chemoradiotherapy.
“The biggest implication is that we improved local control. By that, we improve long-term survival, and this is really long-term data,” Stahl said.
Results showed significant survival differences by treatment assignment among patients with Siewert type I or type II cancers; however, patients with type II cancer appeared to derive more benefit (HR for type I = 0.71; HR for type II = 0.6).
Stahl and colleagues intend to conduct a confirmatory trial in hopes of establishing preoperative chemoradiotherapy as a standard treatment.
“Another important step would be if we can predict which patients may [benefit most] from immunotherapy,” Stahl added. “It would be very nice to use immunotherapy in the adjuvant setting instead of chemotherapy.” – by Kristie L. Kahl
Reference: Stahl M, et al. Abstract 4031. Presented at: ASCO Annual Meeting; June 3-7, 2016; Chicago.
Disclosures: Stahl reports honoraria from Celgene, Merck Serono, Roche Pharma AG and Sanofi; consultant roles with Baxalta and Merck Sharp & Dohme; and travel, accommodations or expenses from Amgen.