Eisuke Booka

Background/Objectives: Thoracoscopic esophagectomy is an accepted minimally invasive approach for resectable esophageal and esophagogastric junction cancer in Japan. Whether robot-assisted minimally invasive esophagectomy (RAMIE) improves short- and long-term outcomes compared with video-assisted thoracoscopic esophagectomy (VATS) remains clinically relevant. Methods: We retrospectively reviewed patients who underwent VATS or RAMIE between January 2017 and April 2026. Patients who underwent open esophagectomy, non-gastric conduit reconstruction, or staged operation were excluded. Propensity score matching (PSM) was performed using age, sex, body mass index, histology, tumor location, clinical stage, preoperative therapy, extent of lymph node dissection, abdominal approach, and reconstruction route. Long-term outcomes were explored in a PSM cohort limited to patients treated between January 2017 and December 2023. Results: The main cohort included 369 patients (VATS, n = 186; RAMIE, n = 183). Overall complications of Clavien–Dindo (CD) grade ≥ II were comparable between VATS and RAMIE (32.8% vs. 32.8%, p = 0.999), whereas RLNP CD ≥ I (9.7% vs. 3.8%, p = 0.025) and RLNP CD ≥ II (3.8% vs. 0.5%, p = 0.034) were less frequent after RAMIE. PSM yielded 128 matched pairs; RLNP remained less frequent after RAMIE (CD ≥ I, 10.9% vs. 3.1%, p = 0.015; CD ≥ II, 4.7% vs. 0%, p = 0.013), while other short-term outcomes were comparable. In the survival PSM cohort (79 pairs), 3-year overall survival (66.0% vs. 73.4%, p = 0.203) and recurrence-free survival (62.3% vs. 59.3%, p = 0.651) did not differ significantly between VATS and RAMIE. Conclusions: RAMIE showed comparable short-term safety to VATS and was associated with lower RLNP after adjustment for clinicopathological, treatment-related, and surgical factors. Exploratory long-term analysis was limited by cohort size and follow-up duration but suggested that RAMIE did not compromise oncologic outcomes.

Background Alcohol consumption is a common risk factor for esophageal squamous cell carcinoma (ESCC) and hepatic fibrosis. Mac-2 binding protein glycosylated isomer (M2BPGi), a sensitive marker of fibrosis, may predict postoperative skeletal muscle loss by reflecting the metabolic link between liver function and muscle maintenance. Methods Eighty-nine patients with ESCC undergoing esophagectomy (June 2021–July 2024) with alcohol use and pretherapeutic M2BPGi levels were included; the cutoff was 0.66. Muscle mass was assessed by bioelectrical impedance analysis. Results The study population was stratified by M2BPGi levels into low (n = 59) and high (n = 30) groups. No significant differences were observed in sex, clinical stage, preoperative skeletal muscle mass, surgical approach, or intraoperative fluid balance. The high M2BPGi group showed lower preoperative albumin levels (4.2 vs. 4.0 g/dL, p = 0.01) and higher CRP (0.1 vs. 0.4 mg/dL, p < 0.01) and ICG R15 values (9.2% vs. 12.8%, p = 0.04). Although there was no difference in the incidence of complications, the decrease in skeletal muscle mass at 3 months was significantly greater in the high M2BPGi group (− 7.6% vs. − 12.0%, p = 0.02). In the propensity score–matched cohort (low n = 40; high n = 20), the high M2BPGi group showed significantly greater muscle loss at 3 months (− 7.5% vs. − 12.6%, p = 0.04) and a trend toward longer hospital stays (22 vs. 25.5 days, p = 0.06). Conclusion High pretherapeutic M2BPGi levels are independently associated with postoperative skeletal muscle loss at 3 months.

Programmed death-ligand 1 (PD-L1) plays a central role in immune regulation in esophageal squamous cell carcinoma (ESCC) and has been widely used as a biomarker for immune checkpoint inhibitor therapy. However, the biological and clinical significance of PD-L1 expression remains controversial, partly due to its marked spatial heterogeneity and dynamic regulation within the tumor immune microenvironment (TIME). In particular, conventional assessment methods do not sufficiently distinguish between PD-L1 expression in tumor cells and that in the surrounding stromal compartment. Accumulating evidence indicates that tumoral and stromal PD-L1 expression reflect distinct biological processes and may have contrasting prognostic and therapeutic implications. Tumoral PD-L1 expression often represents adaptive immune resistance induced by cytotoxic T-cell-derived cytokines and may serve as a surrogate marker of an immune-active tumor. In contrast, stromal PD-L1 expression integrates signals from immune cells, cancer-associated fibroblasts, and other non-neoplastic components, frequently reflecting an immune-enriched microenvironment associated with restrained tumor progression and sustained chemotherapy efficacy. Recent advances in digital pathology and artificial intelligence-assisted image analysis have enabled quantitative, compartment-specific evaluation of PD-L1 expression across whole-slide images, providing new insights into its spatial distribution and clinical relevance. These approaches facilitate refined interpretation beyond binary scoring systems such as the combined positive score or tumor proportion score. In this review, we summarize current knowledge on the regulation and pathological assessment of PD-L1 in ESCC, with particular emphasis on its compartment-specific roles in tumor cells and the stroma. By integrating biological mechanisms, methodological advances, and clinical implications, we propose a conceptual framework for spatially resolved PD-L1 evaluation that may improve prognostic stratification and support more personalized treatment strategies in ESCC.

Background: Feeding enterostomy is commonly created during minimally invasive esophagectomy (MIE); however, its short‐term impact remains unclear. Methods: We analyzed 19 054 patients who underwent MIE for esophageal or esophagogastric junction cancer during 2019–2022. Inverse probability of treatment weighting was applied to balance baseline characteristics, and G‐computation was used to estimate adjusted risks and means and their differences. A secondary analysis was performed to compare gastrostomy and jejunostomy in retrosternal cases. Results: Of 19 054 patients, 4599 (24.1%) received a feeding enterostomy. After adjustment, the primary outcome, postoperative bowel obstruction, did not differ significantly between enterostomy group and no‐enterostomy group (+0.2%, p = 0.132). The enterostomy group demonstrated higher rates of reoperation (+2.5%, p < 0.001) and respiratory complications, including pneumonia (+2.5%, p < 0.001) and prolonged ventilation (+0.9%, p = 0.012), than the no‐enterostomy group. Conversely, delayed gastric emptying (−0.9%, p < 0.001) and deep vein thrombosis (−0.4%, p = 0.028) occurred less frequently. Among 2723 patients who underwent retrosternal reconstruction with feeding enterostomy, jejunostomy was associated with a shorter operative time (−11.2 min, p = 0.025), whereas gastrostomy was associated with a 2.3‐day shorter hospital stay than jejunostomy ( p = 0.022). Bowel‐related events were rare, and adjusted comparisons for these outcomes were not performed. Conclusion: Feeding enterostomy during MIE may confer benefits (e.g., reduced delayed gastric emptying and deep vein thrombosis) but is also associated with increased postoperative complications. Routine or uniform placement of a feeding enterostomy should be avoided, and gastrostomy may be preferable in retrosternal reconstruction.

Background: Surgical site infection (SSI) is one of the postoperative complications. Risk factors for SSI primarily pertain to laparotomy, particularly within the field of gastroenterological surgery. It has been reported that laparoscopic surgery is associated with a lower incidence of SSI compared to open surgery; however, minimally invasive surgery (MIS) has become increasingly widespread in recent years. Therefore, the aim of this study was to examine the risk factors for SSI specifically in patients undergoing MIS. Methods: This study is a secondary analysis of 529 patients selected from a previously reported clinical trial that focused on gastroenterological surgery and included 697 participants. The patient undergoing elective MIS were divided into two groups based on the occurrence of SSI, and the risk factors associated with SSI in MIS were examined. Results: SSI within 30 days after surgery was observed in 62 patients (11.7%). In the univariate analysis, male sex, alcohol consumption, bleeding, and operation time were significantly more frequent in the SSI group ( p < 0.05). Multivariate analysis was performed including these variables as well as current smoking, immunosuppressive drugs, diabetes, and serum albumin. Only alcohol consumption showed a statistically significant association with SSI (odds ratio: 2.818, 95% confidence interval: 1.510–5.260, p = 0.001). Conclusion: The findings of this study revealed that alcohol consumption is significantly associated with SSI occurrence in patients undergoing MIS for gastroenterological indications. Whether preoperative abstinence from alcohol prevents the occurrence of SSI warrants further investigation.

Integrating tumor regression and nodal status for refined prognostication after neoadjuvant therapy in esophageal cancer: where does TRG-N fit in the evolving global landscape?

Background: The cause of AL in rectal cancer surgery is multifactorial. The impact of indocyanine green fluorescence angiography (ICG-FA)-based assessment of blood flow on anastomotic leakage (AL) prevention in low- and mid-rectal cancer surgery is unclear. The aim of this meta-analysis was to evaluate that impact. Methods: The MEDLINE, Cochrane Library, and Scopus databases were searched for articles published up to September 19, 2025 in which the association between ICG-FA and outcomes of rectal cancer surgery was assessed. Data were pooled for meta-analysis. The primary outcome was the AL rate in mid- and low-rectal cancer surgery. Secondary outcomes included severity of AL, diverting-stoma construction rates, and changes in surgical plans based on ICG-FA. Subgroup analysis for low-rectal cancer surgery was performed on the AL rate. Results: Eight studies (1286 patients) met the eligibility criteria, comprising 1 randomized controlled trial, 1 before-and-after prospective study, and 6 retrospective studies. The analysis involved 560 patients in the ICG-FA group and 726 in the control group. ICG-FA was associated with a significantly lower AL rate in mid- and low-rectal cancer surgeries (odds ratio [OR], 0.34; 95% confidence interval [CI], 0.22–0.51; P < .001), grade-A AL rate (OR, 0.17; 95% CI, 0.07–0.41; P < .001), and grade-B and grade C AL rate (OR, 0.41; 95% CI, 0.18–0.91; P = .03) compared to the control group. The diverting-stoma construction rate was comparable between the ICG-FA and control groups. The weighted mean rate of change in the surgical plan based on ICG-FA was 17.0% (95% CI, 10%–29%). In the subgroup analysis, ICG-FA was associated with a significantly lower AL rate in low-rectal cancer surgeries compared to that in the control group (OR, 0.36; 95% CI, 0.21–0.62; P < .001). Conclusion: In surgery for mid- and low- rectal cancer, ICG-FA-based blood-flow assessment is an important factor in reducing AL. Further randomized controlled trials that are focused on mid- and low-rectal cancer are warranted to confirm these benefits and establish the role of ICG-FA in clinical practice.

Background/Objective: Postoperative dysphagia is a common cause of postoperative pulmonary complications (PPCs) following esophagectomy for esophageal cancer. Although the reclining posture is effective for general dysphagia, its effectiveness after esophagectomy remains unclear. Therefore, we aimed to explore effective approaches in the management of dysphagia after esophagectomy. Methods: This study included patients who underwent esophagectomy at the Department of Surgery, Hamamatsu University School of Medicine Hospital between January 2018 and March 2021. For the postoperative swallowing evaluation, the patients underwent a videofluoroscopic swallowing study by drinking 30 mL of liquid in two postures, a 45-degree reclining position (45°R) and a 90-degree upright position (90°U), and assessments were performed using the Penetration–Aspiration Scale. Results: Eighty-seven patients participated in the study. Laryngeal penetration and aspiration were, respectively, observed in 19 (21.8%) and 21 patients (24.1%) at 90°U, and in 14 (16.1%) and five patients (5.7%) at 45°R (p < 0.05). PPCs occurred in 10 patients (11.5%), and vocal cord paralysis occurred in 22 patients (25.3%). However, after adjusting the feeding conditions based on the results of the swallowing assessment, PPCs after meal initiation occurred in only five of these 10 patients (5.7%). Conclusions: Although dysphagia after esophagectomy is observed in approximately half of the patients, including those with minor dysphagia, the risk of aspiration can be reduced by changing the patient’s posture during food consumption. Thus, postural changes may be a useful approach for reducing the risk of PPCs.

Conversion therapy, defined as curative‐intent surgery or chemoradiotherapy after induction therapy, is gaining attention in patients with initially unresectable esophageal squamous cell carcinoma due to adjacent organ invasion (cT4b) or distant metastasis (M1). This systematic review aimed to assess survival outcomes, treatment strategies, and the evolving role of immune checkpoint inhibitors in this context. PubMed, Embase, and the Cochrane Library were comprehensively searched to identify studies published between 2010 and 2025 that reported conversion therapy outcomes in patients with esophageal squamous cell carcinoma with cT4b or M1. This review included 15 studies. A 2019 systematic review established the foundation for current practice in cT4b. Subsequent retrospective and prospective studies have reported 5‐year overall survival rates of up to 51.6% in patients undergoing salvage or conversion surgery, with no residual tumor (R0) resection rates reaching 98.9% in extended procedures. The ongoing JCOG1510 phase III trial is expected to clarify the optimal strategy. Selected patients undergoing conversion surgery for M1 after induction therapy achieved a 5‐year overall survival of 31.7%, with an R0 resection rate of 87%. Survival was not significantly associated with the metastatic site or treatment modality, highlighting the importance of treatment response and multidisciplinary decision‐making. The incorporation of immune checkpoint inhibitors into induction regimens expands the pool of candidates eligible for curative‐intent local therapy. Conversion therapy may provide durable survival in carefully selected patients, and further prospective studies are warranted to refine patient selection and establish standardized treatment algorithms.