Robot-assisted minimally invasive esophagectomy for esophageal cancer in the left lateral decubitus position.

BACKGROUND: The use of robot-assisted minimally invasive esophagectomy (RAMIE) in the prone position for esophageal cancer has been currently increasing worldwide. In future, as surgical-assisted robots become more widespread, it is estimated that only two methods of transthoracic approach will remain: RAMIE and open thoracotomy for thoracic esophageal cancer. RAMIE in the left lateral decubitus position (RAMIE-LLDP) has the same field of view as open thoracotomy, is safe in emergency situations, and provides education on open thoracotomy. METHODS: Between September 2020 and April 2024, RAMIE-LLDP was performed in 64 consecutive patients with esophageal cancer. RAMIE-LLDP was performed with the operating table rotated and tilted 45° to the ventral side under artificial pneumothorax. The hand-control setting of the surgical-assist robot system was reversed left to right when the Patient Cart was rolled from the same direction as the RAMIE in the prone position. RESULTS: The mean total surgery and console times during the thoracic procedure were 254-min overall and 225 min in the last 24 cases and 195-min overall and 178- min in the last 24 cases, respectively. The mean amount of blood loss was 203.4 g overall and 28.3 g in the last 24 cases. Postoperative recurrent laryngeal nerve palsy with Clavien-Dindo classification (CD) was ≥ 2 in six patients (9.4%). Postoperative pneumonia with CD ≥ 2 was observed in 11 patients (17.2%). Conversion to open thoracotomy was observed in three patients (4.7%). In all three patients, an immediate conversion to thoracotomy without patients' position change was actually possible and no serious complications were noted. No mortality occurred within 30 days postoperatively. CONCLUSION: RAMIE-LLDP which facilitates emergency thoracotomy has perioperative results comparable to those of conventional thoracoscopic esophagectomy and is educational for open surgery. RAMIE-LLDP is the safest and most optimal surgery for esophageal cancer.

Prognostic Impact of Tumor Growth Rate During Second-line Chemotherapy in Patients With Gastric Cancer.

Background/Aim: Despite the remarkable developments in chemotherapy for gastric cancer (GC), rapid tumor growth is sometimes experienced during chemotherapy. This study investigated the association of tumor growth rate (TGR) during second-line chemotherapy with the prognosis of patients with GC. Patients and Methods: We retrospectively reviewed 29 patients with GC treated with nab-paclitaxel plus ramucirumab as second-line chemotherapy between 2017 and 2019 at Osaka Metropolitan University. Of them, 13 cases with target lesions were classified into two groups according to TGR using a cutoff value of 0.25. Clinicopathological factors and survival outcomes were compared between the high TGR (n=5) and low TGR (n=8) groups. Results: The median duration of first-line chemotherapy was significantly longer in the high TGR group than in the low TGR group [median 298 days vs. 72.5 days, p=0.030]. Progressive disease (PD) was observed in 60% of patients with high TGR, whereas stable disease (SD) was observed in 75% patients with low TGR. The median survival time (MST) after starting chemotherapy was 488 days in the low TGR group but was not reached in the high TGR group (log rank p=0.215). The MST after PD was 145 days in the low TGR group but was not estimated in the high TGR group (log rank p=0.345). Conclusion: Based on the absence of significant differences in survival outcomes between the high and low TGR groups, sequential late-line chemotherapy might be considered important, even for patients with high TGR.

Successful resection of a rectal gastrointestinal stromal tumor using a transperineal approach: a case report.

BACKGROUND: Rectal gastrointestinal stromal tumors (GISTs) complicate surgical approaches because of their anatomical position. We herein report a patient with rectal GIST on the anterior wall of the lower rectum, hat was successfully resected using a transperineal approach. CASE PRESENTATION: This report describes a unique case of a 73-year-old man who was diagnosed with rectal GIST on the anterior wall of the lower rectum. The tumor was located within 3 cm of the anal verge, a location that would require highly invasive surgery. A transperineal approach was planned to preserve the anal function. Under general anesthesia, the patient was placed in a lithotomy position and a Mercedes-Benz incision was made in the perineum. Excision of the tumor was performed. The post-operative course was uneventful, and the patient remained free from recurrence. CONCLUSION: This case highlights the importance of performing minimally invasive and safe surgery. With some surgical refinements, a transperineal approach may be an option for surgical procedures in patients with rectal GIST on the anterior wall of the lower rectum.

Utility of Assessing Early Tumor Shrinkage as an Efficacy Predictor in Patients with Non-Surgically Indicated or Recurrent Esophageal Cancer Treated with Nivolumab plus Ipilimumab.

INTRODUCTION: Nivolumab plus ipilimumab combination therapy has been administered as a first-line treatment in Japan since 2022 for patients with unresectable progressive or recurrent esophageal cancer. The efficacy and safety of this immune checkpoint inhibitor (ICI) doublet therapy are now being evaluated, and it is necessary to identify populations that benefit from this treatment at an early phase after initiation. For patients not showing early benefit, changing as soon as possible to other therapeutic strategies could improve their survival outcomes. Therefore, we attempted to identify decision-making factors such as early tumor shrinkage (ETS) based on treatment experience with ICI doublet therapy. METHODS: The study included 19 patients who received nivolumab plus ipilimumab for non-surgically indicated or recurrent esophageal cancer between July 2022 and November 2023. Tumors were assessed approximately every 2 months after treatment initiation. The effects of ETS, depth of response (DpR), and clinicopathologic features, including immune-related adverse events (irAEs), on progression-free and overall survival were evaluated using Kaplan-Meier plots and Cox proportional hazard models. RESULTS: The mean duration of ICI doublet administration was 5.89 months (range, 1-16 months). At first evaluation, patients who exhibited no tumor progression >20% indicated possible response to ICI doublet therapy, and patients whose tumors shrank even minimally exhibited favorable progression-free survival. Higher DpR at any cut-off line exhibited better progression-free survival than those with lower DpR. Fifteen patients experienced irAEs, with 13 of these patients experiencing irAEs within 3 months of treatment initiation. irAEs were associated with the efficacy of ICI doublet therapy, but efficacy could not be predicted based on early irAE experience. CONCLUSION: ETS-high, DpR-high, and irAEs might be associated with favorable responses to nivolumab plus ipilimumab. As a predictor of efficacy at an early phase, ETS >0% could be a deciding factor for continuing ICI doublet therapy.

The Efficacy of Chemical Bowel Preparation Against Incisional Surgical Site Infection in Colorectal Cancer Surgery: A Propensity Score Matching Study.

BACKGROUND/AIM: In colorectal cancer surgery, the risk of surgical site infection (SSI) is relatively high. The development of SSI is related to longer and costlier hospitalization and reduced quality of life; therefore, perioperative prevention of SSI is important. Chemical bowel preparation (CBP) combined with mechanical bowel preparation (MBP) may be more effective in preventing surgical site infection (SSI) compared to MBP alone. Since May 2021, we have been administering oral kanamycin and metronidazole as CBP, in addition to MBP, as a preoperative treatment for colorectal cancer surgery on the day before surgery. In this study, we investigated the clinical value of CBP in addition to MBP in colorectal cancer surgery using propensity score matching (PSM). PATIENTS AND METHODS: From January 2017 to December 2021, 136 consecutive patients underwent radical surgery for sigmoid colon and rectal cancer at the Osaka Metropolitan University Hospital. Patients were divided into two groups: CBP and N-CBP. In the N-CBP group, we performed only preoperative MBP, whereas in the CBP group, we performed preoperative CBP in addition to MBP. We retrospectively analyzed this relationship with PSM. RESULTS: Overall, 46 patients underwent preoperative CBP and MBP, 90 patients underwent preoperative MBP only. PSM was performed between the CBP and N-CBP groups based on the following ten factors: age, sex, diabetes mellitus, preoperative therapy, Glasgow Prognostic Score (GPS), operative time, blood loss, stoma, and pathological stage. After PSM, univariate and multivariate analyses of the relationship between SSI and clinicopathological factors were performed. Univariate analysis showed that age and CBP were correlated with the rate of SSI (p=0.039 and p=0.017, respectively), whereas sex was relatively correlated with the rate of SSI (p=0.066). The multivariate analysis of significant factors identified age of 75 or more and non-CBP as an independent risk factor for incisional SSI (HR=9.5; p=0.049 and HR=5.4×e-8; p=0.020). CONCLUSION: Preoperative CBP in addition to MBP was effective in preventing incisional SSI during colorectal cancer surgery.

Prognostic significance of connective tissue growth factor expression in stromal cells in patients with diffuse­type gastric cancer.

Connective tissue growth factor (CTGF) is a target gene of the Hippo signaling pathway. Its differential role in the histological types of gastric cancer (GC) remains unknown; therefore, the present study aimed to confirm the clinical significance of CTGF expression in cancer and stromal cells in patients with GC depending on the histological type. The present study enrolled 589 patients with GC. Immunohistochemistry was used to analyze CTGF expression in cancer and stromal cells. CTGF mRNA expression data and the corresponding clinical information of GC samples were collected from The Cancer Genome Atlas (TCGA) database. Subsequently, the associations between CTGF expression and several clinicopathological factors were investigated. In the present study, CTGF expression was mainly observed in the cytoplasm of cancer and stromal cells. CTGF expression in stromal cells was significantly associated with CTGF expression in cancer cells (P<0.001). CTGF positivity in stromal cells was also significantly associated with intestinal type, non-scirrhous type, tumor depth (T1-2), lymph node metastasis (negative), lymphatic invasion (negative) and tumor size (<5 cm). Low CTGF expression in stromal cells was independently associated with worse overall survival (OS). Furthermore, the OS of patients with low CTGF expression in stromal cells, especially in patients with diffuse-type GC, was significantly worse than patients with high CTGF expression (P=0.022). This trend was similar to that revealed by TCGA data analysis. In conclusion, low CTGF expression was associated with a significantly worse OS in patients with diffuse-type GC. These data indicated that CTGF, and its control by the Hippo pathway, may be considered potential treatment targets in diffuse-type GC.

Protocol of a pilot randomized clinical trial to evaluate nutritional support and rehabilitation on prevention of skeletal muscle mass loss during neoadjuvant chemotherapy in patients with esophageal cancer.

BACKGROUND: Subtotal esophagectomy with lymph node dissection followed by neoadjuvant chemotherapy (NAC) is the standard treatment for stage II-III esophageal cancer. Esophagectomy is still associated with high morbidity rates, and reducing these rates remains challenging. Among several complications, postoperative pneumonia (PP) is sometimes fatal, which has been reportedly caused by sarcopenia. Thus, nutritional support and rehabilitation may be promising for preventing skeletal muscle mass loss and reduce the incidence of PP. METHODS: This single-center, randomized, open-label, pilot trial will randomize a total of 40 patients with esophageal cancer in a 1:1 ratio either to ISOCAL Clear + rehabilitation arm or only rehabilitation arm. Although all patients will be educated about rehabilitation by a specialized physician and will be asked to undergo the prespecified rehabilitation program, patients treated with ISOCAL Clear + rehabilitation arm will be supplemented by 400 mL of ISOCAL Clear (Nestlé Japan Ltd, Tokyo, Japan) per day during two courses of NAC with docetaxel, cisplatin, and fluorouracil. Body composition will be assessed using Inbody (Inbody Co., Ltd., Tokyo, Japan) just before starting NAC and surgery. The primary endpoint is the change of skeletal muscle index (SMI) during NAC. Secondary endpoints include (i) body weight, total skeletal muscle mass, appendicular skeletal muscle mass, and lean body mass index changes; (ii) the percentage of ISOCAL Clear continuation; (iii) appetite evaluation; (iv) the percentage of targeted calorie achievement; (v) adverse events of NAC; (vi) postoperative complication rates; and (vii) postoperative hospital stay. DISCUSSION: This prospective trial assesses the efficacy of nutritional support in addition to rehabilitation during NAC for patients with esophageal cancer. The results will be utilized in assessing whether the effects of nutritional support by ISOCAL Clear are promising or not and in planning future larger clinical trials.

An 8-mm port site hernia after robotic-assisted ileocecal resection: a case report.

BACKGROUND: Robotic-assisted surgery is steadily becoming more prominent. The majority of reports regarding port site hernias (PSHs) have involved laparoscopic procedures. Currently, it is common to suture the fascia at port sites that are 10 mm or larger; however, the closure of 5-mm port sites is not considered mandatory. The da Vinci® surgical system (Intuitive Surgical Inc., Sunnyvale, CA, USA) utilizes a distinctive 8-mm port. We report a case of an early-onset PSH at an 8-mm port site after robotic-assisted ileocecal resection. CASE PRESENTATION: A 74-year-old male patient with a body mass index of 19.7 kg/m2 was diagnosed with cecal cancer and underwent robotic-assisted ileocecal resection. A 3-cm midline incision was made at the umbilicus for insufflation. Under laparoscopic visualization, three ports (12 mm, 8 mm, and 8 mm) were inserted in the lower abdomen. An 8-mm port was inserted in the left subcostal region, and a 5-mm port was inserted in the left lateral abdomen. The procedure was performed without significant intraoperative complications. The fascia was closed only at the umbilicus and 12-mm port site; the fascia at the 8-mm port sites was not closed. The patient was initially discharged without complications; however, on postoperative day 11, the patient was urgently hospitalized again because of PSH incarceration. After manual reduction, the fascia was sutured closed under local anesthesia. The hernial defect was small and barely allowed the insertion of a little finger. There was no evidence of compression or significant damage to the fascia. On postoperative day 27, the patient was discharged after experiencing good recovery. CONCLUSIONS: Robotic-assisted colectomy could contribute to the risk of PSHs because of its surgical characteristics. Although routine closure of the fascia at 8-mm port sites is not mandatory, it may be beneficial in certain cases.

Effects of an artificial pancreas on postoperative inflammation in patients with esophageal cancer.

PURPOSES: Subtotal esophagectomy for esophageal cancer (EC) is associated with high morbidity rates. Tight glycemic control using an artificial pancreas (AP) is one of the promising strategies to reduce postoperative inflammation and morbidities. However, the effects of tight glycemic control using AP in patients with EC are yet to be fully elucidated. METHOD: This study reviewed 96 patients with EC who underwent subtotal esophagectomy. The postoperative inflammation parameters and morbidity rates were compared between patients who used the AP (n = 27) or not (control group, n = 69). AP is a closed-loop system that comprises a continuous glucose monitor and an insulin pump. RESULTS: The numbers of white blood cells (WBC) and Neutrophils (Neut) were noted to be lower in the AP group than in the control group, but with no significant difference. The ratio in which the number of WBC, Neut, and CRP on each postoperative day (POD) was divided by those tested preoperatively was used to standardize the results. The ratio of WBC and Neut on 1POD was significantly lower in the AP group than in the control group. The rate of surgical site infection was lower in the AP group than in the control group. CONCLUSION: AP significantly decreased WBC and Neut on 1POD; this suggests the beneficial effects of AP in alleviating postoperative inflammation.

Involvement of CX3CR1+ cells appearing in the abdominal cavity in the immunosuppressive environment immediately after gastric cancer surgery.

BACKGROUND: Gastric cancer is primarily treated by surgery; however, little is known about the changes in the intraperitoneal immune environment and the prognostic impact of surgery. Surgical stress and cancer-associated inflammation cause immune cells to mobilize into the abdominal cavity via numerous cytokines. One such cytokine, CX3CR1, has various immune-related functions that remain to be fully explained. We characterized the intraperitoneal immune environment by investigating CX3CR1+ cells in intraperitoneal lavage fluid during gastric cancer surgery. METHODS: Lavage fluid samples were obtained from a total of 41 patients who underwent gastrectomy. The relative expression of various genes was analyzed using quantitative real-time PCR. The association of each gene expression with clinicopathological features and surgical outcomes was examined. The fraction of CX3CR1+ cells was analyzed by flow cytometry. Cytokine profiles in lavage fluid samples were investigated using a cytometric beads array. RESULTS: CX3CR1high patients exhibited higher levels of perioperative inflammation in blood tests and more recurrences than CX3CR1low patients. CX3CR1high patients tended to exhibit higher pathological T and N stage than CX3CR1low patients. CX3CR1 was primarily expressed on myeloid-derived suppressor cells and tumor-associated macrophages. In particular, polymorphonuclear myeloid-derived suppressor cells were associated with perioperative inflammation, pathological N, and recurrences. These immunosuppressive cells were associated with a trend toward unfavorable prognosis. Moreover, CX3CR1 expression was correlated with programmed death-1 expression. CONCLUSIONS: Our results suggest that CX3CR1+ cells are associated with an acute inflammatory response, tumor-promotion, and recurrence. CX3CR1 expression could be taken advantage of as a beneficial therapeutic target for improving immunosuppressive state in the future. In addition, analysis of intra-abdominal CX3CR1+ cells could be useful for characterizing the immune environment after gastric cancer surgery.

Optimal extent of lymph node dissection for high-risk gastric cancer stratified by a national clinical database risk calculator.

BACKGROUND: For patients with gastric cancer, a well-balanced treatment that considers both oncological aspects and surgical risk is demanded. This study aimed to explore the optimal extent of lymph node dissection (LND) for patients with gastric cancer according to surgical risk, stratified by the risk calculator system produced by the Japan National Clinical Database (NCD). PATIENTS AND METHODS: We retrospectively evaluated 187 patients who underwent radical gastrectomy for gastric cancer. Using the median predicted anastomotic leak rate obtained by the NCD risk calculator as the cutoff value, we classified 97 and 90 patients as having high and low risks, respectively. RESULTS: In low-risk patients, although limited LND reduced the postoperative intraabdominal infectious complications (IAIC), multivariate analysis revealed standard LND as an independent prognostic factor that improved Relapse-free survival (RFS). In high-risk patients, the rates of postoperative IAIC and RFS were similar between standard and limited LND. Pancreatic fistula was not observed in the limited dissection group. CONCLUSION: Limited LND might be the optimal treatment strategy for patients with gastric cancer with high surgical risk.

Evaluation of Intraoperative Neural Monitoring During Thoracoscopic Surgery for Esophageal Cancer.

BACKGROUND/AIM: Recurrent laryngeal nerve paralysis (RLNP) induces aspiration pneumonia and reduces the patient's quality of life. To decrease the incidence of RLNP, we performed intraoperative neural monitoring (IONM) during thoracoscopic surgery for esophageal cancer and evaluated its usefulness. PATIENTS AND METHODS: A total of 737 consecutive patients who underwent thoracoscopic surgery for esophageal cancer were enrolled in this study. Between May 1995 and March 2016, thoracoscopic esophagectomies were performed using video-assisted thoracoscopic surgery (VATS) with a small incision, whereas from April to June 2023, we used positive pressure pneumothorax with port placement only [minimum invasive esophagectomy (MIE)]. A total of 110 consecutive patients who underwent thoracoscopic surgery with IONM (IONM group) were retrospectively compared with those who underwent VATS or MIE without IONM (No-IONM group). RESULTS: The incidence of RLNP [Clavien-Dindo (CD) classification of ≥1] on postoperative day (POD) 5 was 13.9% in the IONM group, which was significantly lower than that of the no-IONM group (31.2%, p<0.001). Even when comparing only patients who underwent MIE, the incidence of RLNP on POD5 was 13.9% in the IONM group, which was significantly lower than that in the no-IONM group (26.2%, p=0.035). The incidence of postoperative pneumonia (CD ≥2) was 10.9% in the IONM group, which was significantly lower than that in the no-IONM group (26.1%, p=0.005). Bilateral RLNP did not occur in any of the IONM groups. CONCLUSION: IONM is a useful tool for reducing RLNP incidence and postoperative pneumonia after thoracoscopic surgery for esophageal cancer.

Preoperative Frailty Assessed Comprehensively by a Questionnaire Predicts a Poor Survival Following Curative Resection of Gastric Cancer.

Background/Aim: The concept of frailty has been attracting attention as a comprehensive indicator of the various effects of aging, but no conclusion has been reached on how to evaluate it. The present study investigated the adverse effect of preoperative frailty on short- and long-term outcomes in patients with gastric cancer using a questionnaire about frailty. Patients and Methods: One hundred and twenty-five patients with pathological stage (p Stage) I/II/III who underwent radical gastrectomy for gastric cancer at the Department of Gastroenterological Surgery, Osaka, Japan from April 2015 to December 2016 were enrolled in this study. The frailty index (FI) was calculated by dividing the total score of 50 questions consisting of 1 point per question by 50. The study used multiple logistic regression analysis with 5-year overall survival (OS) as the endpoint to create a receiver operating characteristic (ROC) curve to determine the cut-off point for the FI. The short- and long-term outcomes of the frail and non-frail groups were then compared, and prognostic factors for OS were examined. Results: Regarding the short-term outcomes, the postoperative complication rates did not differ significantly between the two groups. Regarding the 5-year OS rates of the patients with p Stages II/III, the outcomes in the frail group were significantly poorer than those in the non-frail group. In the multivariate analysis of OS, frailty was independently associated with unfavorable outcomes in patients with p Stages II/III gastric cancer. Conclusion: Frailty evaluation in this study may be useful in predicting long-term prognosis in patients undergoing surgical treatment for advanced gastric cancer.

Usefulness of Biopsy Specimens for Evaluating CD103+ Tumor-resident Memory T Cells in Esophageal Cancer.

BACKGROUND/AIM: CD103+ tissue-resident memory T cells (TRM) in tumor sites are associated with a favorable prognosis and predict the effectiveness of immune checkpoint inhibitors. The detection of CD103+ TRM infiltration in biopsy samples could be beneficial for patients without surgical indications. However, the usefulness of TRM detection in biopsy tissue and the difference in TRM status between biopsy and surgical specimens' post-neoadjuvant chemotherapy have not been elucidated. In the present study, we aimed to elucidate whether we can detect TRM in biopsy specimens and the impact of chemotherapy on TRM infiltration. MATERIALS AND METHODS: Tissue sections were obtained from 46 patients with esophageal cancer who received neoadjuvant chemotherapy and underwent radical esophagectomy in 2017. Immunohistochemistry was performed using an anti-CD103 antibody for biopsy and surgical specimens. We examined the relationship between CD103 expression, clinicopathological features, and prognosis for each patient. RESULTS: TRM infiltration was detected in the biopsy specimens. CD103 expression in biopsy specimens correlated with that in surgical specimens. Although there was no statistical significance in clinicopathological findings between CD103high and CD103low, patients with CD103high biopsy specimens exhibited favorable prognosis. The number of CD103+ cells was increased by chemotherapy: though with no survival benefit. CONCLUSION: Regardless of surgical indication, we were able to determine the TRM status even in biopsy specimens. CD103 evaluation at biopsy may be more useful and practical than evaluation in surgical specimens, enabling prediction of prognosis and response to immune therapy.

Significance of CD103+ tissue-resident memory T cells for predicting the effectiveness of immune checkpoint inhibitors in esophageal cancer.

BACKGROUND: Immune checkpoint inhibitors (ICIs), including nivolumab, have been approved to treat esophageal cancer. However, these remedies are not fit for all patients with esophageal cancer; therefore, a predictive surrogate marker is needed to assess their effectiveness. CD103+CD8+ tumor-infiltrating lymphocytes, defined as tissue-resident memory T cells (TRM), are promising indicators of response to ICIs, but it remains to be elucidated. This study investigated the association between the efficacy of ICIs and TRM. METHODS: The relationships between TRM infiltrating esophageal cancer, clinicopathological features, and prognosis after nivolumab initiation were examined using immunostaining. Tissue samples were obtained from surgically resected specimens of 37 patients with esophageal cancer who received nivolumab as a secondary or subsequent therapy. In addition, TRM infiltration was compared with programmed death-ligand 1 (PD-L1) expression and blood count parameters as predictors of nivolumab effectiveness. RESULTS: TRM-rich patients had a significant survival benefit after nivolumab initiation (12-months overall survival 70.8% vs 37.2%, p = 0.0485; 12-months progression-free survival 31.2% vs 0%, p = 0.0153) and experienced immune-related adverse events more frequently than TRM-poor patients (6 vs 2 patients). TRM infiltration was weakly correlated with PD-L1 positivity (r = 0.374, p = 0.022), but TRM may indicate more sensitive response to ICIs than PD-L1 expression in this study. Some blood test parameters also weakly correlated with TRM but did not impact prognosis. CONCLUSIONS: TRM-rich patients have a favorable prognosis after nivolumab initiation. Our results suggest that TRM are vital for antitumor immunity and are a promising predictor of ICIs effectiveness.

[The Role of Cancer-Associated Fibroblasts in Modulating Tumor Immunity in Colorectal Cancer].

Cancer-associated fibroblasts(CAFs)remodel the extracellular matrix(ECM)and shape the tumor microenvironment (TME), resulting in immune escape and the promotion of tumor metastasis. Using an orthotopic tumor model of colorectal cancers(CRCs)in mice, we demonstrated that the single-cell RNA sequencing of orthotopic rectal tumors identified a subpopulation of CAFs that modulate the immune response. In this review, we report that understanding the role of CAFs in the TME concerning tumor immunity may lead to future avenues for CAF-targeted therapy.

A case of a thoracic duct cyst extending from the mediastinum to the cisterna chyli resected using bilateral thoracoscopic surgery in the prone position.

BACKGROUND: Thoracic duct cysts are extremely rare mediastinal tumors. We report a case of a thoracic duct cyst extending from the caudal aspect of the left main bronchus to the left renal artery that was safely and completely resected via bilateral thoracoscopic surgery in the prone position. CASE PRESENTATION: A 77-year-old male was referred to our hospital for follow-up computed tomography (CT) of prostate cancer, which revealed a mediastinal tumor and fatty low-density along the posterior mediastinum of the para-aortic artery with a slightly high-density component. Magnetic resonance imaging revealed a T2-weighted image with high intensity. The preoperative radiological diagnosis was lipoma or well-differentiated liposarcoma. CT in the prone position suggested that the tumor could be resected from the thoracic cavity to the caudal side, and bilateral thoracoscopic surgery was performed in the prone position. Based on the surgical findings, the tumor was diagnosed as a thoracic duct cyst rather than a lipoma. Dissection around the thoracic duct cyst was performed using a vessel-sealing system to prevent leakage of the chyle, and reliable clipping was performed to resect the cisterna chyli. Histopathological examination revealed smooth muscle structures around the cyst, suggestive of a thoracic duct cyst. The diagnosis of a thoracic duct cyst was made based on a high triglyceride level of 1310 mg/dL on examination of the milky-white cyst fluid. The patient's postoperative course was uneventful, and he was discharged 4 days postoperatively. A CT scan performed 13 months after surgery showed no recurrence. CONCLUSIONS: A rare thoracic duct cyst extending from the mediastinum to the cisterna chyli was safely and completely resected using bilateral thoracoscopic surgery, with the patient in the prone position.

The Evaluation of Sarcopenia before Neoadjuvant Chemotherapy Is Important for Predicting Postoperative Pneumonia in Patients with Esophageal Cancer.

INTRODUCTION: Sarcopenia is often observed in patients with esophageal cancer (EC). However, the influence of sarcopenia during neoadjuvant chemotherapy (NAC) on complications has not been fully investigated. Thus, we aimed to investigate the best way of evaluating sarcopenia for predicting complications, especially postoperative pneumonia (PP), in patients with EC undergoing NAC and esophagectomy. METHODS: We retrospectively reviewed 113 patients. The skeletal muscle mass index (SMI) was evaluated by bioelectrical impedance analysis and/or computed tomography. Patients were diagnosed with sarcopenia at pre-NAC and preoperative timing. Different criteria were compared in terms of the predictability of PP. Next, we evaluated which factors were related to sarcopenia with the best PP predictability. RESULTS: Fifteen (13.2%) patients developed grade III or higher PP. Pre-NAC modified European Working Group on Sarcopenia in Older People (EWGSOP) criteria showed the highest sensitivity (100%) and acceptable specificity (75.8%) for predicting PP. Low pre-NAC body mass index and %VC were significantly associated with sarcopenia by the modified EWGSOP criteria. CONCLUSION: Pre-NAC sarcopenia by modified EWGSOP was a significant predictor of PP after esophagectomy. Appropriate interventions for these patients should be explored to prevent PP.

Dorsal Subcutaneous Fat Thickness as a Risk Factor for Pancreatic Fistula After Gastric Cancer Surgery.

BACKGROUND/AIM: Recently, there have been many reports on the use of preoperative body composition analysis to predict postoperative complications in gastric cancer surgery, most of which used 3D image analysis software for the measurements. This study aimed to evaluate the risk of postoperative infectious complications (PICs), especially pancreatic fistulas, using a simple measurement method incorporating only preoperative computed tomography images. PATIENTS AND METHODS: A total of 265 patients with gastric cancer underwent laparoscopic or robot-assisted gastrectomy with lymph node dissection at Osaka Metropolitan University Hospital between 2016 and 2020. To simplify the measurement method, we measured the length of each region of the subcutaneous fat area (SFA). Each area included a) umbilical depth, b) thickness of the longest ventral subcutaneous fat, c) thickness of the longest dorsal subcutaneous fat, and d) thickness of the median dorsal subcutaneous fat (MDSF) measurements. RESULTS: PICs occurred in 27 of 265 cases, of which pancreatic fistula was present in 9. SFA for pancreatic fistulas showed high diagnostic accuracy (area under the curve=0.922). Among the subcutaneous fat lengths, the MDSF was the most useful, and the optimal cut-off value was 16 mm. MDSF and non-expert surgeons were found to be independent risk factors for pancreatic fistula. CONCLUSION: Since the possibility of developing pancreatic fistula is high in cases with MDSF ≥16 mm, careful surgical strategies, such as having a skilled physician, are necessary.

Prognostic relevance of tumor-resident memory T cells in metastatic lymph nodes of esophageal squamous cell carcinoma.

Tumor-resident memory T (TRM ) cells in primary tumors are reportedly associated with a favorable prognosis in several malignancies. However, the behaviors and functions of TRM cells in regional lymph nodes (LNs) of esophageal cancer remain poorly understood. The aim of this study was to elucidate the effects of TRM cells in regional LNs of esophageal cancer on clinicopathological findings and prognosis. Specimens of esophageal cancer and primary metastatic LNs (recurrent nerve LNs) were obtained from 84 patients who underwent radical esophagectomy between 2011 and 2017. We performed immunohistochemistry to enumerate and analyze TRM cells, and used flow cytometry to investigate the function of TRM cells. TRM cells were observed in both metastatic LNs and primary tumors. TRM cell-rich specimens exhibited reduced lymphatic invasion and LN metastasis and prolonged survival compared with TRM cell-poor specimens. TRM cells in metastatic LNs were more significantly associated with enhanced survival than TRM cells in primary tumors. TRM cells expressed high levels of granzyme B as a cytotoxicity marker. Our results suggested that high TRM cell infiltration in metastatic LNs improves survival even though LN metastasis is commonly associated with poor prognosis. TRM cells possibly contribute to antitumor immunity in regional LNs.