A previous study evaluated therapy-induced changes in tumor glucose metabolism by positron emission tomography.
This study used the glucose analog 18F fluorodeoxyglucose.
The study suggested that this method selects patients most likely to benefit from preoperative chemotherapy in adenocarcinomas of the esophagogastric junction.
Dr Katja Ott and colleagues from Germany prospectively validated these findings by using an a priori definition of metabolic response.
The research team included 65 patients with locally advanced adenocarcinomas of the esophagogastric junction.
|Metabolic nonresponders had a 3-year survival rate of 35%|
|Journal of Clinical Oncology|
Tumor glucose utilization was quantitatively assessed by fluorodeoxyglucose-positron emission tomography before chemotherapy.
The team also measured tumor glucose utilization 14 days after initiation of therapy.
Patients who were metabolic responders had a 35% decrease of metabolic activity of the primary tumor at the time of the second positron emission tomography.
The researchers found that metabolic responders showed a high histopathologic response rate, of 44% with a 3-year survival rate of 70%.
In contrast, prognosis was poor for metabolic nonresponders with a histopathologic response rate of 5%, and a 3-year survival rate of 35%.
The team used multivariate analysis to demonstrate that metabolic response was the only factor predicting recurrence in completely resected patients.
Dr Ott's team concludes, “This study prospectively demonstrates that changes in tumor metabolic activity during chemotherapy predict response, prognosis, and recurrence.”
“These data provide the basis for clinical trials in which preoperative treatment is changed for patients without a metabolic response early in the course of therapy.”
“Positron emission tomography-guided induction therapy may even be applicable to earlier tumor stages because surgery is only minimally delayed in nonresponding patients.”