The new criteria of clinical response for the primary tumor based on the findings of histological response after chemoradiation therapy in esophageal cancer

The incidence of chemoradiation therapy (CRT) increased in order to improve the surgical resectabilty and clinical outcome. It is important to accurately assess the effect of CRT for selecting further treatment and predicting prognosis. We tried to make the new criteria for imaging diagnosis after we reevaluated the discrepancy between clinical and histological effect of CRT. Subjects were 36 patients with advanced esophageal cancer who underwent esophagectomy with lymphadenectomy after CRT that consisted of 5-fluorouracil plus cisplatin and 40 Gy of radiation. The clinical and histological response was firstly evaluated based on esophageal disease guidelines for clinical and pathologic studies on carcinoma of the esophagus by the Japanese Society of Clinical response in imaging was reassessed based on the histological response. The number of tumors judged as clinical complete response/partial response/no change (CR/PR/NC) was 0/26/10, and the histological grading 1/2/3 was 17/11/8, respectively. Imaging for Grade 1 tumors showed the existence of viable cancer cells in biopsy specimen. Of 16 patients with such finding, 14 (88%) were histologically judged as Grade 1. Imaging characteristics for grade 3 tumors was more than a 75% reduction in esophagography, and the existence of scar formation by esophagoscopy. All five (100%) patients with these findings were histologically judged as Grade 3. The findings of grade 1 and 3 based on new criteria were independent predictive factors for CRT effect. According to new criteria, it was possible to predict the histological effect by the combination of esophagography and endoscopy in more than 80% of patients after CRT. Our new criteria may offer important information on the selection of further treatment or the prediction of prognosis after CRT in patients with esophageal cancer. (author)