Background/Aim: Programmed death-1 ligand 1 (PD-L1) induces apoptosis of tumor-reactive T-cells, that enables tumors to evade immune defense and thus furthers their growth. Our aim was to determine whether PD-L1 expression status correlates with prognosis in patients with advanced thoracic esophageal squamous cell carcinoma. Patients and Methods: The PD-L1 expression status of 177 patients treated with esophagectomy without preoperative therapy was evaluated immunohistochemically using tissue microarray. We then statistically analyzed the relationships between PD-L1 expression status and clinicopathological features and survival. Results: In patients undergoing surgery alone, PD-L1 expression was significantly positivity associated with a better prognosis. By contrast, there were no significant correlations between PD-L1 expression and clinicopathological features or outcomes in patients treated with surgery plus postoperative adjuvant chemotherapy. Conclusion: PD-L1 positivity in advanced thoracic esophageal squamous cell carcinoma may be predictive of a positive prognosis in patients treated without adjuvant chemotherapy.

Background: Neoadjuvant chemoradiotherapy (NACRT) followed by esophagectomy is now the standard treatment for patients with resectable advanced thoracic esophageal squamous cell carcinoma (ESCC) worldwide. However, the efficacy of NACRT followed by esophagectomy with three-field lymph node dissection for clinical Stage III patients and for clinical Stage IVB patients with supraclavicular LN metastasis has not yet been determined. Methods: Between 2008 and 2018, 94 ESCC patients diagnosed as clinical Stage III and 18 patients diagnosed as clinical Stage IVB with supraclavicular LN metastasis as the only distant metastatic factor were treated with NACRT followed by esophagectomy with extended lymph node dissection at Akita University Hospital. Long-term survival and the patterns of recurrence in these 112 patients were analyzed. Results: The median follow-up period of censored cases was 60 months. The five-year OS and DSS rates among the clinical Stage III patients were 57.6% and 66.6%, respectively. The five-year OS and DSS rates among the clinical Stage IVB patients were 41.3% and 51.6%, respectively. The most frequent recurrence pattern was distant metastasis (69.2%) in the Stage III patients and LN metastasis (75.0%) in the Stage IVB patients. Conclusion: NACRT followed by esophagectomy with three-field LN dissection is feasible and offers the potential for long-term survival of clinical Stage III ESCC patients and even clinical Stage IVB patients with supraclavicular LN metastasis as the only distant metastatic factor. At least in patients with upper and middle thoracic ESCC, treating supraclavicular LNs as regional LNs seems to be appropriate.

Background: Preoperative clinical diagnosis of lymph node (LN) metastasis and subsequent pathological diagnosis are often not in agreement. Detection of false-negative LNs is essential in selecting an optimal treatment strategy, and most importantly, the presence of false-negative LN is itself a significant prognostic indicator. Therefore, at present, there is an urgent need to establish more accurate and individualized evaluation methods for LN metastasis. Methods: Of 213 cN0 patients who underwent curative esophagectomy without preoperative neoadjuvant treatment, 60 (28%) had LN metastasis diagnosed pathologically. There were 129 false-negative LNs, of which 85 were detectable by preoperative computed tomography (CT). We retrospectively investigated the distribution, frequency, and characteristics of pathologically positive nodes in patients with clinically N0 esophageal cancer. Results: The paracardial region was the most frequent region of false-negative LNs, accounting for 26% (22 LNs) of the total incidence. False-negative LNs distributed widely from the neck to the abdomen in patients with a primary tumor in the middle thoracic esophagus. In patients with a primary tumor in the lower thoracic esophagus, four false-negative LNs were detected in the superior mediastinum. When the short-axis diameter, shape, and attenuation patterns of the LNs were used as criteria for metastasis diagnosis, they were insufficient for an accurate diagnosis. However, false-negative LNs in the most frequently occurring sites are characterized by smaller short-axis, suggesting that accurate diagnosis cannot be made unless the diagnostic criteria for the short-axis are reduced in addition to shape and attenuation. Conclusions: Although restrictive to the most frequent regions of false-negative LNs occur, reducing size criterion and consideration of their shape and attenuation may contribute to improved diagnosis.

Aim: Because the optimal treatment strategy for borderline resectable (cT3br) thoracic esophageal cancer patients remains unclear, it is of great interest whether preoperative neoadjuvant therapy for cT3br could achieve results comparable to those seen with resectable T3 cancer (cT3r). We speculated that preoperative neoadjuvant chemoradiotherapy (NACRT) would be particularly effective in cT3br thoracic esophageal cancer patients and compared to cT3br and cT3r.Methods: Of 186 cT3 thoracic esophageal cancer patients treated with intended NACRT, 162 received radical esophagectomy. More than 97% were squamous cell carcinomas. Patients were partitioned into two groups according to whether invasion of adjacent organs was suspected (cT3br and cT3r). Treatment outcomes and survival were analyzed.Results: Sixty‐eight patients (36.6%) were classified as cT3br and 118 (63.4%) as cT3r. The cT3br group had significantly more tumors in the upper and middle mediastinum (p < 0.0001) and more cases with cM1 (lymph node) (p = 0.0104) than the cT3r group. In addition, the cT3br patients receiving esophagectomy exhibited a significantly lower pathological complete response rate than the cT3r patients (p = 0.0374). However, the R0 resection rate did not differ between the cT3br and cT3r patients (p = 0.0978), and the two groups treated with intended NACRT had similar 5‐year overall (OS) and disease‐specific survival (DSS) (p = 0.3831 and p = 0.9020). In addition, the incidence and patterns of recurrence did not differ between the cT3br and cT3r patients receiving esophagectomy (p = 0.8109 and p = 0.3128).Conclusions: Preoperative neoadjuvant chemoradiotherapy appears to be a promising treatment for patients with borderline resectable thoracic esophageal squamous cell carcinoma.