Inter-evaluator heterogeneity of clinical diagnosis for locally advanced esophageal squamous cell carcinoma

Background: Identifying clinical resectability of locally advanced esophageal squamous cell carcinoma (ESCC) is important, although inter-evaluator heterogeneity (IEH) could exist, especially in borderline resectable (BLR) cases. To investigate the extent of heterogeneity, we conducted clinical diagnostic imaging questionnaires. Materials and methods: Five cases with clinical T3 or T4 cases, which were treated with neo-adjuvant triplet chemotherapy followed by surgery, were selected as the model. These cases were divided into two groups: curative resected cases (#1–#3) and non-curative resected cases (#4 and #5). Only imaging slides were shown without any information about patient characteristics or clinical course. The evaluators consisted of surgeons (staff and non-staff), medical oncologists, and an imaging radiologist; a total of 25 medical staff answered the questionnaire. Two questions (1: clinical T stage before chemotherapy, 2: resectability after chemotherapy) were answered. Occupational differences were assessed by comparing the results to the imaging radiologist. Results: IEH was observed for clinical diagnosis before chemotherapy in one case (clinical T4: 52%, clinical T3: 48%). In the other cases, most evaluators diagnosed them as clinical T4, with 76–88% agreement. IEH for clinical resectability after chemotherapy was relatively small. Occupational IEH was observed in both before and after chemotherapy. Conclusion: IEH in decisions about treating BLR cases in ESCC should be considered in clinical practice. Multi-disciplinary teams are essential to overcome this problem.