Background: We have developed a treatment protocol for esophageal cancer involving a single course of induction chemotherapy followed by chemoradiotherapy. This study aimed to determine if it was possible to predict the effects of chemoradiotherapy on the basis of the response to induction chemotherapy, assessed by positron emission tomography (PET).
Methods: Sixteen patients with Stage II-IVA esophageal cancer were treated using this protocol from April 2007 to July 2010. Chemotherapy involved a fluorouracil and platinum-based combination regimen. All patients received PET scans before and 12-24 days after the beginning of induction chemotherapy. Associations between the response to induction chemotherapy assessed by PET and the effects of chemoradiotherapy were evaluated.
Results: Induction chemotherapy followed by chemoradiotherapy resulted in complete response (CR) in 10 of the 16 patients. The reduction in maximum standardized uptake value (SUV(max)) was 58 ± 12% in patients with CR (n = 10), compared with 14 ± 16% in patients without CR (n = 6) (P < 0.0001). Using a cut-off value of 55% for SUV(max) reduction rate, eight of 10 cancers with CR and six of six cancers without CR were correctly identified, providing a sensitivity and specificity of 80 and 100%, respectively. The overall 1-year survival rates for patients with an SUV(max) reduction rate >55% (responders) were 100%, compared with 60% for patients with an SUV(max) reduction rate ≤55% (non-responders), respectively.
Conclusions: The response to a single course of induction therapy assessed by PET was significantly associated with the effects of chemoradiotherapy.