Karyn A. Goodman
CHICAGO — PET scan response after induction chemotherapy may be a useful prognostic and predictive tool for esophageal cancer, according to findings presented at ASCO Annual Meeting.
“We are trying to better tailor therapy for patients with esophageal cancer because we don’t do as well as we would like and survival rates remain poor, even though the standard of care is a fairly aggressive regimen of chemotherapy and radiation followed by surgery,” Karyn A. Goodman, MD, Grohne chair of clinical oncology at University of Colorado, Denver, told HemOnc Today.
Goodman and colleagues evaluated the use of PET response after induction chemotherapy to direct changing to alternative chemotherapy during preoperative chemoradiation among 240 patients with resectable esophageal and gastroesophageal junction adenocarcinomas.
Results of the primary analysis showed improvement of pathologic complete response after changing the regimen among PET nonresponders.
The current analysis reported survival outcomes based on PET response status and the type of induction chemotherapy used.
“There is a need for early assessment for response to chemotherapy,” Goodman said. “We make use of PET for staging of esophageal cancer, so this use — as a prognostic tool based on PET response — is a novel approach.”
Eligible participants underwent baseline PET and then were randomly assigned to induction chemotherapy with modified FOLFOX-6 (oxaliplatin, leucovorin, 5-FU) on days 1, 15 and 29, or carboplatin/paclitaxel on days 1, 8, 22 and 29. Patients underwent a repeat PET scan on days 36 to 42.
PET nonresponders crossed over to the alternative chemotherapy regimen during chemoradiotherapy, with radiation given in 50.4 Gy over 28 fractions, whereas PET responders received the same chemotherapy during chemoradiation. Patients underwent surgery 6 weeks following chemoradiotherapy.
Over a median follow-up of 42.1 months, the researchers observed a median OS of 38.3 months.
Rates of OS were 61.7% at 2 years and 45.8% at 4 years.
PET responders achieved a median OS of 47.3 months compared with nonresponders at 28.9 months.
“By changing the chemotherapy regimen early on after induction chemotherapy, we saw better, longer-term survival by changing chemotherapy for patients who were initially PET nonresponders,” Goodman said. “The survival in the PET nonresponders was even better than we’ve seen in previous studies that have not changed chemotherapy in this poor-risk group.”
Other findings showed a median survival of more than 50 months for PET responders receiving induction and concurrent FOLFOX, according to Goodman.
“This represents one of the best outcomes for any patient group with esophageal cancer,” she said. “This finding possibly indicates that FOLFOX might be a better option in this population. However, our data set was not powered to evaluate a head-to-head comparison of the two induction regimens.”
Goodman concluded that the findings suggest that PET may be used as both a prognostic and predictive tool in patients with esophageal and gastroesophageal junction adenocarcinomas and can help individualize therapy for these patients with the goal of improving outcomes in this disease. – by Rob Volansky
Goodman KA, et al. Abstract 4012. Presented at: ASCO Annual Meeting; June 1-5, 2018; Chicago.
Disclosures: Goodman reports consultant/advisory roles with Pfizer and RenovoRX. Please see the abstract for all other authors’ relevant financial disclosures.