OPTIMAL TIMING OF ENDOSCOPIC EVALUATION OF THE PRIMARY SITE OF ESOPHAGEAL CANCER AFTER CHEMORADIOTHERAPY OR RADIOTHERAPY: A RETROSPECTIVE ANALYSIS

Background: Although use of gastrointestinal endoscopy for response evaluation in patients with esophageal cancer undergoing chemoradiotherapy or radiotherapy (CRT/RT) treatment is widely accepted, optimal timing for evaluation has not been sufficiently investigated. Here, we investigated optimal timing of primary site response evaluation in esophageal cancer patients treated with CRT/RT. Patients and Methods: This study examined esophageal cancer patients who underwent CRT/RT between September 2002 and December 2004. Time to complete response (CR) at the primary site was assessed in patients designated as CR at the primary site, while progression-free survival at the primary site (PFSp) was assessed in patients designated as incomplete response at the primary site. Results: Eighty-three patients were enrolled in this study. Median total RT dose was 60 Gy (range, 50-60 Gy), and median RT duration was 53 days (range, 35-74 days). Mean time to CR at the primary site was 97 days (range, 52-201 days). In four patients, although initial examination of biopsy specimens found evidence of viable cancer cells within 75 days of treatment initiation, subsequent examination found no such evidence, and the patients were thus designated as CR. Median PFSp was 149 days (range, 67-399 days), and PFSp rate at 90 days was 97%. Median interval between the previous examination and initial primary progressive disease was 37 days. Conclusion: Recommended time of first response evaluation for esophageal cancer following initiation of CRT/RT was found to be between 75 and 90 days. Subsequent evaluation should be carried out approximately one month following non-CR/non-progressive disease declassification.