Useful Endoscopic Ultrasonography to Assess the Efficacy of Neoadjuvant Therapy for Advanced Esophageal Carcinoma: Based on the Response Evaluation Criteria in Solid Tumors

Abstract

Objective : The aim of the present study was to assess the usefulness of endoscopic ultrasonography (EUS) for evaluating the efficacy of neoadjuvant therapy for advanced esophageal carcinoma based on the Response Evaluation Criteria in Solid Tumors (RECIST). Patients and Methods : Sixty-two patients with advanced esophageal carcinoma underwent surgical resection after neoadjuvant therapy. The maximal tumor thickness was measured by EUS before and after neoadjuvant therapy, and the percent reduction was compared with the pathological response. Based on the RECIST, PD-SD (progressive disease-stable disease) was defined as < 30% reduction of tumor thickness on EUS, PR (partial response) as ≥ 30% reduction of tumor thickness, and CR (complete response) as no detectable tumor (100%). Results : The percent reduction of the thickness of Grade 0-1, Grade 2 and Grade 3 tumor was 11.5 ± 21.0%, 48.2 ± 17.0% and 74.9 ± 21.1%, respectively. There were significant differences in the extent of reduction among the three groups. Based on the RECIST, 80% of Grade 0-1 cases, 91% of Grade 2 cases and 22% of Grade 3 cases were PD-SD, PR, and CR according to EUS, respectively. EUS correctly identified 80% of non-responders and 94% of responders. Conclusions : The percentage reduction of tumor thickness on EUS closely reflected the pathological evaluation. EUS evaluation based on the RECIST seems to be useful for monitoring neoadjuvant therapy in patients with esophageal carcinoma.

Response evaluation with endoscopic ultrasound and computed tomography in esophageal squamous cell carcinoma treated by definitive chemoradiotherapy

“…Some used maximal crosssectional area reduction more than 50% as good response, 17,19,20 while others used maximal tumor thickness reduction more than 30% or 50%. 12,18 These studies had consistently found that tumor size reduction on EUS is predictive of pathological response on surgical specimen. However, the impact of EUS measurement on patient prognosis is less clear, 19,21 especially in patients with ESCC and treated by definitive CRT.…”

“…Measurement of cross-sectional area was even more difficult in good CRT responders when most tumor masses disappeared and only circumferential esophageal wall thickening was present. Therefore, we measured maximal esophageal wall thickness as reported by Ota et al 12 Our finding that post-CRT esophageal wall thickness more than 8 mm predicted poor survival suggests that these patients should receive additional treatment to improve outcome. If observation is decided in such patients, then more frequent follow-up is necessary to identify tumor recurrence as early as possible.…”

“…Although EUS is less accurate in assessing T stage (depth of tumor invasion) after CRT owing to inflammation, fibrosis, and blurring of epithelial layers, 17,18 the measurement of tumor size changes had been shown to predict pathological response on surgical specimens. 12,[17][18][19][20] Different measurements had been used to evaluate size changes after CRT. Some used maximal crosssectional area reduction more than 50% as good response, 17,19,20 while others used maximal tumor thickness reduction more than 30% or 50%.…”

“…EUS can identify residual submucosal tumors in the absence of superficial lesions. In addition, tumor size change or post‐CRT tumor size measured by EUS correlates with pathological response and predicts local recurrence after esophagectomy . CT scan is less accurate than EUS in assessing primary tumor response, but it offers an overview from neck to abdomen to assess size change in metastatic lesions .…”

“…In addition, tumor size change or post-CRT tumor size measured by EUS correlates with pathological response and predicts local recurrence after esophagectomy. [10][11][12][13] CT scan is less accurate than EUS in assessing primary tumor response, but it offers an overview from neck to abdomen to assess size change in metastatic lesions. 14,15 Previous studies had focused on analyzing the accuracy of these image modalities in predicting pathological response for patients treated by neoadjuvant CRT plus surgery.…”