As reported in the Journal of Clinical Oncology by Karyn A. Goodman, MD, and colleagues, mature results of the phase II CALGB 80803/Alliance trial indicated that treatment guided by early positron-emission tomography (PET) assessment of response to induction neoadjuvant chemotherapy improved pathologic complete response rates in patients with esophageal cancer. Median overall survival was not reached in patients continuing FOLFOX (oxaliplatin, leucovorin, and fluorouracil) in chemoradiation therapy based on PET response.
Study Details
In the U.S. multicenter trial, a total of 225 patients with a baseline PET scan who had been randomly assigned between November 2011 and May 2015 to receive induction chemotherapy with modified FOLFOX6 given every 2 weeks for three cycles (n = 111) or carboplatin/paclitaxel given every 3 weeks for two cycles (n = 114) received assigned chemotherapy and had an interpretable PET scan after completing induction chemotherapy.
Early response assessment using PET imaging as a biomarker to individualize therapy for patients with esophageal and esophagogastric junction adenocarcinoma was effective, improving pCR rates in PET nonresponders. PET responders to induction FOLFOX who continued on FOLFOX during chemoradiation achieved a promising 5-year overall survival of 53%.— Karyn A. Goodman, MD, and colleagues
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Patients with response on PET scans performed at the end of induction chemotherapy, defined as ≥ 35% reduction in maximum standardized uptake value (SUV) from baseline, continued assigned chemotherapy concurrent with radiotherapy. PET nonresponders were switched to the alternative chemotherapy as part of concurrent chemoradiation. Patients underwent surgery at 6 weeks postchemoradiation. The primary endpoint was pathologic complete response (pCR) rate in PET nonresponders after switching chemotherapy.
Key Findings
PET response after induction chemotherapy was observed in 72 patients (64.9%) in the FOLFOX induction group vs 64 (56.1%) in the carboplatin/paclitaxel induction group (P = .22).
The pCR rates were 40.3% (95% confidence interval [CI] = 28.9%–52.5%) in induction FOLFOX responders and 14.1% (95% CI = 6.6%–25.0%) in induction carboplatin/paclitaxel responders.
pCR was achieved in 18.0% (95% CI = 7.5%–33.5%) of 39 FOLFOX nonresponders who crossed over to carboplatin/paclitaxel chemoradiation and in 20% (95% CI = 10%–33.7%) of 50 carboplatin/paclitaxel nonresponders who crossed over to FOLFOX chemoradiation.
After a median follow-up of 5.2 years, median overall survival was 48.8 months (95% CI = 33.2 months–not estimable) among all PET responders and 27.4 months (95% CI = 19.4 months–not estimable) among all nonresponders.
Among FOLFOX PET responders who continued on FOLFOX during chemoradiation, median survival was not reached, and 5-year overall survival was 53.0% (95% CI = 42.5%–66.1%). Among carboplatin/paclitaxel PET responders who continued on carboplatin/paclitaxel during chemoradiation, median overall survival was 38.7 months and 5-year overall survival was 43.9% (95% CI = 33.1%–58.2%).
Among FOLFOX nonresponders who crossed over to carboplatin/paclitaxel chemoradiation, 5-year overall survival was 37.5 months (95% CI = 24.8–56.5 months). Among carboplatin/paclitaxel nonresponders who crossed over to FOLFOX chemoradiation, 5-year overall survival was 40.4 months (95% CI = 28.7–56.9 months)
The investigators concluded, “Early response assessment using PET imaging as a biomarker to individualize therapy for patients with esophageal and esophagogastric junction adenocarcinoma was effective, improving pCR rates in PET nonresponders. PET responders to induction FOLFOX who continued on FOLFOX during chemoradiation achieved a promising 5-year overall survival of 53%.”
Dr. Goodman, of the Department of Radiation Oncology, Icahn School of Medicine at Mount Sinai, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by the National Cancer Institute. For full disclosures of the study authors, visit ascopubs.org.
