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

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.

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.

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.

IEH in decisions about treating BLR cases in ESCC should be considered in clinical practice. Multi-disciplinary teams are essential to overcome this problem.