Esophageal cancer practice guidelines 2022 edited by the Japan Esophageal Society: part 2

Survival Impact of Inflammation-based Prognostic Scores in Metastatic or Unresectable Esophageal Cancer Treated With Pembrolizumab Plus Chemotherapy

Pembrolizumab plus chemotherapy has been indicated as the first-line treatment for metastatic or unresectable locally advanced esophageal cancer. However, pretreatment biomarkers for predicting clinical outcomes remain unclear. We investigated the predictive value of inflammation-based prognostic scores in patients treated with pembrolizumab and chemotherapy. The Prognostic Nutritional Index (PNI), C-reactive protein/albumin ratio (CAR), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR) were calculated before initial treatment in 65 eligible patients with metastatic or unresectable locally advanced esophageal cancer receiving pembrolizumab plus CF therapy, and the relationship between these biomarkers and clinical outcomes was analyzed. The objective response rate (ORR) and progression disease (PD) were observed in 51% and 21% of all patients. Patients with PNI<39 have significantly worse treatment responses than those with PNI≥39 (ORR; 28% vs. 60%, PD; 44% vs. 13%, P=0.020). Progression-free survival (PFS) is significantly associated with the PNI and CAR (P<0.001 and P=0.004, respectively). Overall survival (OS) is associated with PNI, CAR, and PLR (P<0.001, P=0.008, and P=0.018, respectively). The PNI cutoff value of 39 is identified as an independent factor for PFS (odds ratio=0.27, 95% CI: 0.18-0.81, P=0.012) and OS (odds ratio=0.22, 95% CI: 0.08-0.59, P=0.003). Patients with PNI<39 have significantly worse 6-month PFS and 1-year OS than those with PNI≥39 (27.8% vs. 66.7%, 27.2% vs. 81.1%, respectively). In conclusion, inflammation-based prognostic scores are associated with survival in patients treated with pembrolizumab plus CF therapy. Pretreatment PNI is a promising candidate for predicting treatment response and survival.

Identifying intense inflammatory subtype of esophageal squamous cell carcinoma using clustering approach

OBJECTIVE

To establish a risk-stratification system for predicting the postoperative recurrence of esophageal squamous cell carcinoma, this study aimed to evaluate the prognostic value of clusters based on blood inflammation and coagulation markers and investigate their correlation with serum cytokines and genetic alteration.

METHOD

This single-center, retrospective cohort study enrolled 491 patients with esophageal cancer who underwent subtotal esophagectomy between 2004 and 2012. For cluster exploration, nonhierarchical cluster analysis and k-means were applied using serum C-reactive protein, albumin, fibrinogen, and platelet-lymphocyte ratio as variables. Then, multivariate survival analysis was conducted to investigate the association of clusters with recurrence-free survival. To characterize the clusters, serum interleukin-6, interleukin-8, and genetic alteration in primary tumors, the PleSSision-Rapid panel, which can evaluate 160 representative driver genes, was used.

RESULTS

Patients were classified into clusters 1, 2, and 3, which included 24 (5%), 161 (33%), and 306 (62%) patients, respectively. Compared with cluster 3, cluster 1 or 2 had significantly worse recurrence-free survival. Based on the multivariable analysis using cluster, pStage, and age as covariates, cluster was an independent prognostic factor for recurrence-free survival (hazard ratio, 1.55; 95% confidence interval, 1.08-2.21; P = 0.02). The percentage of serum interleukin-6 and interleukin-8 levels was the highest in cluster 1, followed by clusters 2 and 3. In 23 patients with available genomic profiles, no significant difference in representative genomic alterations was observed.

CONCLUSIONS

Non-biased clustering using inflammation and coagulation markers identified the intense inflammatory subtype, which had an independent prognostic effect on recurrence-free survival.

Impacts of tumor microenvironment during neoadjuvant chemotherapy in patients with esophageal squamous cell carcinoma

With the advent of immune checkpoint inhibitors (ICIs), a better understanding of tumor microenvironment (TME) is becoming crucial in managing esophageal squamous cell carcinoma (ESCC) patients. We investigated the survival impact of TME status and changes in patients with ESCC who underwent neoadjuvant chemotherapy (NAC) followed by surgery (n = 264). We examined immunohistochemical status (CD4+, CD8+, CD20+, Foxp3+, HLA class-1+, CD204+, and programmed death ligand-1 [PD-L1+]) on 264 pre-NAC and 204 paired post-NAC specimens. Patients were classified by their pre- and post-NAC immune cell status and their changes following NAC. Our findings showed that pre-NAC TME status was not significantly associated with survival outcomes. In contrast, post-NAC TME status, such as low level of T cells, CD4+ T cells, and high PD-L1 combined positive score (CPS), were significantly associated with poor overall survival (OS). Notably, TME changes through NAC exerted significant survival impacts; patients with consistently low levels of T cells, low levels of CD4+ T cells, or high levels of PD-L1 (CPS) had very poor OS (3-year OS: 35.5%, 40.2%, and 33.3%, respectively). Tumor microenvironment changes of consistently low T cells, low CD4+ T cells, and high PD-L1 were independent predictors of poor OS in multivariate Cox hazards analyses, while factors indicating post-NAC status (T cells, CD4+, and PD-L1 [CPS]) alone were not. Therefore, we suggest that the consistently low T/high PD-L1 group could benefit from additional therapies, such as ICIs, and the importance of stratification by the TME, which has recently been recognized.

Indications for neoadjuvant chemotherapy in older patients undergoing esophagectomy for esophageal cancer

PURPOSE

To investigate the indications for neoadjuvant chemotherapy (NAC) in esophageal cancer patients aged 75 years or older.

METHODS

We analyzed data, retrospectively, from 155 patients over 75 years old, who underwent esophagectomy for esophageal cancer between 2010 and 2020. Forty-one patients underwent upfront surgery (US group) and 114 were treated with NAC followed by surgery (NAC group). We compared the patient backgrounds and perioperative outcomes including prognosis, between the two groups.

RESULTS

The NAC group patients were significantly younger and had significantly more advanced clinical stage disease than the US group patients. The incidence of postoperative complications was similar in the two groups. Patients with a good pathological response to NAC had a significantly better prognosis than those with a poor response and those in the US group. Among patients with a performance status (PS) of 0, the 5-year OS rate was 56.5% in the NAC group and 38.1% in the US group (HR = 0.63, 95% CI 0.35-1.12). Among those with a PS of 1-2, the 5-year OS rates were 28.1% and 57.1%, respectively (HR = 1.69, 95% CI 0.99-2.89; P = 0.037 for interaction).

CONCLUSIONS

NAC did not improve the postoperative prognosis of older esophageal cancer patients with a PS of 1 or higher.

Identifying the Trends of Urinary microRNAs within Extracellular Vesicles for Esophageal Cancer

Background: The advancement of multidisciplinary treatment has increased the need to develop tests to monitor tumor burden during treatment. We herein analyzed urinary microRNAs within extracellular vesicles from patients with esophageal squamous cell carcinoma (ESCC) and normal individuals using a microarray. Methods: Patients with advanced ESCC who underwent esophagectomy (A), endoscopic submucosal resection (ESD) (B), and healthy donors (C) were included. Based on microRNA expression among the groups (Analysis 1), microRNAs with significant differences between groups A and C were selected (Analysis 2). Of these candidates, microRNAs in which the change between A and C was consistent with the change between B and C were selected for downstream analysis (Analysis 3). Finally, microRNA expression was validated in patients with recurrence from A (exploratory analysis). Results: For analysis 1, 205 microRNAs were selected. For Analyses 2 and 3, the changes in 18 microRNAs were consistent with changes in tumor burden as determined by clinical imaging and pathological findings. The AUC for the detection of ESCC using 18 microRNAs was 0.72. In exploratory analysis, three of eighteen microRNAs exhibited a concordant trend with recurrence. Conclusions: The current study identified the urinary microRNAs which were significantly expressed in ESCC patients. Validation study is warranted to evaluate whether these microRNAs could reflect tumor burden during multidisciplinary treatment for ESCC.

A silicone disc for liver retraction in laparoscopic gastrectomy reduces the postoperative increase in the liver enzyme level

PURPOSE

To compare changes in liver enzyme levels on postoperative day 1 between patients with and without silicone disc (SD) use during liver retraction in laparoscopic gastrectomy for gastric cancer and laparoscopic gastric mobilization for esophageal cancer.

METHODS

This prospective randomized controlled phase II trial was conducted between June 30, 2020, and November 30, 2022, to investigate the benefits of using an SD with a Nathanson liver retractor (NLR) compared with those using an NLR in laparoscopic gastrectomy and gastric mobilization. The primary endpoint was the change in transaminase level on postoperative day 1.

RESULTS

A total of 86 patients received randomized assignments and were included in the analysis, with 44 assigned to the SD (-) group and 42 to the SD (+) group. On postoperative day 1, the SD (+) group showed a significantly lower increase in the aspartate aminotransferase levels than the SD (-) group (SD [+], 94.4% vs. SD [-], 179.8%; p = 0.012). Similarly, the SD (+) group showed a significantly lower increase in alanine aminotransferase levels than the SD (-) group (SD [+], 71.6% vs. SD [-], 201.5%; p = 0.014).

CONCLUSION

In laparoscopic gastrectomy, the use of an SD combined with an NLR appears to mitigate postoperative liver dysfunction.

Risk factors for lymph node metastasis in superficial esophageal squamous cell carcinoma

In this editorial, we comment on the article by Wang et al published in the recent issue of the World Journal of Gastroenterology in 2023. We focused on identifying risk factors for lymph node metastasis (LNM) in superficial esophageal squamous cell carcinoma (SESCC) patients and how to construct a simple and reliable clinical prediction model to assess the risk of LNM in SESCC patients, thereby helping to guide the selection of an appropriate treatment plan. The current standard treatment for SESCC is radical esophagectomy with lymph node dissection. However, esophagectomy is associated with considerable morbidity and mortality. Endoscopic resection (ER) offers a safer and less invasive alternative to surgical resection and can enable the patient's quality of life to be maintained while providing a satisfactory outcome. However, since ER is a localized treatment that does not allow for lymph node dissection, the risk of LNM in SESCC limits the effectiveness of ER. Understanding LNM status can aid in determining whether patients with SESCC can be cured by ER without the need for additional esophagectomy. Previous studies have shown that tumor size, macroscopic type of tumor, degree of differentiation, depth of tumor invasion, and lymphovascular invasion are factors associated with LNM in patients with SESCC. In addition, tumor budding is commonly associated with LNM, recurrence, and distant metastasis, but this topic has been less covered in previous studies. By comprehensively evaluating the above risk factors for LNM, useful evidence can be obtained for doctors to select appropriate treatments for SESCC patients.

The relationship between the treatment course and prognosis of oligometastasis after esophageal squamous cell carcinoma resection

PURPOSE

The concept of oligometastasis, which represents limited metastatic disease, has recently gained interest, accompanied by a more detailed classification. This study aims to investigate the relationship between the treatment course and prognosis in patients with a recurrence of esophageal squamous cell carcinoma (ESCC) after curative esophagectomy.

METHODS

126 patients with ESCC recurrence after curative resection were enrolled in this study. Oligometastasis was defined as fewer than five recurrences in a single organ. Patients were classified as having oligometastatic recurrence (OLR) or polymetastatic recurrence (PLR). Patients were further classified into four subgroups according to lesion progression: persistent oligorecurrence (PER-OLR), converted polyrecurrence (CON-PLR), induced oligorecurrence (IND-OLR), and persistent polyrecurrence (PER-PLR). We analyzed the relationship between the recurrence patterns and prognosis according to the progression of oligometastatic lesions.

RESULTS

OLR was identified in 58 (46%) of 126 patients with recurrence. Patients with OLR had a significantly better prognosis than those with PLR (P < 0.0001). A further subgroup analysis revealed that patients who underwent IND-OLR had a similar prognosis to those who underwent PER-OLR.

CONCLUSIONS

This study suggests that OLR is a prognostic factor after recurrence following resection of ESCC and that PLR can be converted to OLR by therapeutic intervention to achieve a long-term survival.

History and evidence for state of the art of lymphadenectomy in esophageal cancer surgery

The current curative multimodal treatment of advanced esophageal cancers consists of neoadjuvant or perioperative chemo(radio)therapy followed by a radical surgical resection of the primary tumor and a 2- or 3-field lymphadenectomy. One of the most important predictors of long-term survival of esophageal cancer patients is lymph node involvement. The distribution pattern of lymph node metastases in esophageal cancer is unpredictable and depends on the primary tumor location, histology, T-stage and application of neoadjuvant or perioperative treatment. The optimal extent of the lymphadenectomy remains controversial; there is no global consensus on this topic yet. Some surgeons advocate an aggressive and extended lymph node dissection to remove occult metastatic disease, to optimize oncological outcomes. Others promote a more restricted lymphadenectomy, since the benefit of an extended lymphadenectomy, especially after neoadjuvant chemoradiotherapy, has not been clearly demonstrated, and morbidity may be reduced. In this review, we describe the development of lymphadenectomy, followed by a summary of current evidence for lymphadenectomy in esophageal cancer treatment.

Antimicrobial Prophylaxis With Ampicillin-sulbactam Compared With Cefazolin for Esophagectomy: Nationwide Inpatient Database Study in Japan

OBJECTIVE

To assess the effect of antimicrobial prophylaxis with ampicillin-sulbactam (ABPC/SBT) compared with cefazolin (CEZ) on the short-term outcomes after esophagectomy.

BACKGROUND

CEZ is widely used for antimicrobial prophylaxis in esophagectomy without procedure-specific evidence, whereas ABPC/SBT is preferred in some hospitals to target both aerobic and anaerobic oral bacteria.

METHODS

Data of patients who underwent esophagectomy for cancer between July 2010 and March 2019 were extracted from a nationwide Japanese inpatient database. Overlap propensity score weighting was conducted to compare the short-term outcomes [including surgical site infection (SSI), anastomotic leakage, and respiratory failure] between antimicrobial prophylaxis with CEZ and ABPC/SBT after adjusting for potential confounders. Sensitivity analyses were also performed using propensity score matching and instrumental variable analyses.

RESULTS

Among 17,772 eligible patients, 16,077 (90.5%) and 1695 (9.5%) patients were administered CEZ and ABPC/SBT, respectively. SSI, anastomotic leakage, and respiratory failure occurred in 2971 (16.7%), 2604 (14.7%), and 2754 patients (15.5%), respectively. After overlap weighting, ABPC/SBT was significantly associated with a reduction in SSI [odds ratio 0.51 (95% CI: 0.43-0.60)], anastomotic leakage [0.51 (0.43-0.61)], and respiratory failure [0.66 (0.57-0.77)]. ABPC/SBT was also associated with reduced respiratory complications, postoperative length of stay, and total hospitalization costs. The proportion of Clostridioides difficile colitis and noninfectious complications did not differ between the groups. Propensity score matching and instrumental variable analyses demonstrated equivalent results.

CONCLUSIONS

The administration of ABPC/SBT as antimicrobial prophylaxis for esophagectomy was associated with better short-term postoperative outcomes compared with CEZ.

Fixation of an esophageal stent using a novel re-openable endoclip for a tracheoesophageal fistula

Although esophageal stenting is one treatment option as a palliative treatment for tracheoesophageal fistulas, serious complications are associated with stent migration. Some reports have described stent fixation using various devices to prevent stent migration. However, these have yet to be sufficiently examined. We performed esophageal stent fixation using the MANTIS Clip (Boston Scientific), a novel re-openable endoclip. An 89-year-old man developed a tracheoesophageal fistula after radiotherapy for esophageal squamous cell carcinoma. Esophageal stenting was considered because the patient had difficulty with oral intake. However, the patient had a mild stenosis, which suggested stent migration. Therefore, we performed esophageal stent fixation by grasping the mouth side of the stent and the normal mucosa of the esophagus with the MANTIS Clip after placement of the stent. The esophageal stent closed the fistula, and the patient was able to take food orally. Upper gastrointestinal endoscopy performed 3 weeks after stenting showed residual MANTIS Clip and no evidence of stent migration. Esophageal stent fixation with MANTIS clips for tracheoesophageal fistulas may be an option to prevent stent migration.

The tumor cell-intrinsic cGAS-STING pathway is associated with the high density of CD8+ T cells after chemotherapy in esophageal squamous cell carcinoma

BACKGROUND

Chemotherapy has the potential to induce CD8+ T-cell infiltration in the tumor microenvironment (TME) and activate the anti-tumor immune response in several cancers including esophageal squamous cell carcinoma (ESCC). The tumor cell-intrinsic cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway has been known as a critical component for regulating immune cell activation in the TME. However, its effect on the infiltration of immune cells induced by chemotherapy in the ESCC TME has not been investigated.

METHODS

We examined the effect of the tumor-cell intrinsic cGAS-STING pathway on the infiltration of CD8+ T cells induced by chemotherapy in ESCC using ESCC cell lines and surgically resected ESCC specimens from patients who received neoadjuvant chemotherapy (NAC).

RESULTS

We found that chemotherapeutic agents, including 5-fluorouracil (5-FU) and cisplatin (CDDP), activated the cGAS-STING pathway, consequently inducing the expression of type I interferon and T-cell-attracting chemokines in ESCC cells. Moreover, the tumor cell-intrinsic expression of cGAS-STING was significantly and positively associated with the density of CD8+ T cells in ESCC after NAC. However, the tumor cell-intrinsic expression of cGAS-STING did not significantly impact clinical outcomes in patients with ESCC after NAC.

CONCLUSION

Our findings suggest that the tumor cell-intrinsic cGAS-STING pathway might contribute to chemotherapy-induced immune cell activation in the ESCC TME.

Preoperative docetaxel, cisplatin, and 5-fluorouracil for resectable locally advanced esophageal and esophagogastric junctional adenocarcinoma

BACKGROUND

Chemotherapy consisting of 5-fluorouracil, leucovorin, oxaliplatin, and docetaxel is the standard perioperative treatment for resectable esophageal adenocarcinoma and esophagogastric junctional adenocarcinoma (EGJ-AC) in Western countries. Meanwhile, preoperative chemotherapy consisting of docetaxel, cisplatin, and 5-fluorouracil (DCF) has been developed for esophageal squamous cell carcinoma in Japan. However, there are few reports on the safety and efficacy of preoperative DCF for resectable EGJ-AC in the Japanese population.

METHODS

Patients with histologically confirmed resectable EGJ-AC who received preoperative DCF (docetaxel 70 mg/m2 and cisplatin 70 mg/m2 on day 1 and continuous infusion of 5-fluorouracil 750 mg/m2/day on days 1-5 every 3 weeks with a maximum of three cycles) between January 2015 and April 2020 were retrospectively evaluated. We assessed the rates of completion of ≥ 2 courses of DCF and R0 resection, histopathological response, progression-free survival (PFS), overall survival (OS), and adverse events.

RESULTS

Thirty-two patients were included. Median follow-up was 28.7 (range, 5.2-70.8) months and median age was 63 (range, 42-80) years. Twenty-one patients (66%) had a performance status of 0. The proportions of clinical stage IIA/IIB/III/IVA/IVB disease were 3%/0%/44%/44%/9%, respectively. The treatment completion rate was 84%. A histopathological response of grade 1a/1b/2/3 was obtained in 58%/26%/13%/3% of cases. Median PFS was 40.7 months (95% confidence interval 11.8-NA). Median OS was not reached (80.8% at 3 years). Grade ≥ 3 adverse events were observed in 63% of cases (neutropenia, 44%; febrile neutropenia, 13%). No treatment-related deaths occurred.

CONCLUSIONS

Preoperative DCF for resectable EGJ-AC was well tolerated and has promising efficacy.

Effectiveness of prehabilitation during neoadjuvant therapy for patients with esophageal or gastroesophageal junction cancer: a systematic review

Progression of the physical weakness during neoadjuvant therapy (NAT) in patients with esophageal or gastroesophageal junction cancer is a serious problem; however, prehabilitation during NAT has the potential to overcome the unmet need. Nevertheless, systematic reviews on this topic have not been summarized. Therefore, this systematic review aimed to determine prehabilitation's effectiveness, acceptability, and safety during NAT for patients with esophageal or gastroesophageal junction cancer. An electronic search was performed in the MEDLINE, Web of Science, CENTRAL, CINAHL, and PEDro databases. A meta-analysis was conducted to assess the effectiveness of prehabilitation during NAT, along with a descriptive analysis of acceptance and safety. This study analyzed data from three randomized controlled trials (RCTs) and nine non-RCTs involving 664 patients. The meta-analysis of two RCTs demonstrated that prehabilitation during NAT may be more effective than usual care in enhancing tolerance to NAT and grip strength; moreover, one RCT and three non-RCTs revealed that prehabilitation may reduce the risk of postoperative complications. The adherence rates for exercise programs in two RCTs and seven non-RCTs were 55-76%. Additionally, two studies reported a 76% adherence rate for multimodal prehabilitation programs, including exercise, dietary, and psychological care. Six studies reported no serious prehabilitation-related adverse events during NAT. Prehabilitation during NAT may be a safe and beneficial intervention strategy for patients with esophageal or gastroesophageal junction cancer. However, the investigation of strategies to enhance adherence is essential. Furthermore, additional high-quality RCTs are needed to examine the effect of prehabilitation during NAT.

Oligometastases of Esophageal Squamous Cell Carcinoma: A Review

Patients with oligometastases show distant relapse in only a limited number of regions. Local therapy such as surgical resection, radiotherapy, chemoradiotherapy, and radiofrequency ablation for the relapsed sites may thus improve patient survival. Oligometastases are divided into oligo-recurrence and sync-oligometastases. Oligo-recurrence indicates a primary lesion that is controlled, and sync-oligometastases indicate a primary lesion that is not controlled. The management of oligo-recurrence and sync-oligometastases in esophageal squamous cell carcinoma has not been clearly established, and treatment outcomes remain equivocal. We reviewed 14 articles, including three phase II trials, that were limited to squamous cell carcinoma. Multimodal treatment combining surgical resection and chemoradiotherapy for oligo-recurrence of esophageal squamous cell carcinoma appears to be a promising treatment. With the development of more effective chemotherapy and regimens that combine immune checkpoint inhibitors, it will become more likely that sync-oligometastases that were unresectable at the initial diagnosis can be brought to conversion surgery. Currently, a randomized, controlled phase III trial is being conducted in Japan to compare a strategy for performing definitive chemoradiotherapy and, if necessary, salvage surgery with a strategy for conversion surgery in patients who can be resected by induction chemotherapy.

Survival outcomes of esophageal cancer patients with recurrence after curative treatments

BACKGROUND

Little is known about predictive factors for survival outcomes of esophageal carcinoma (EC) patients who developed recurrence after undergoing multimodal therapies. We aimed to investigate long-term outcomes and identify prognostic factors in patients with relapsed EC, focusing especially on those with oligometastasis (OM).

METHODS

EC patients who developed recurrence after curative treatments (radical esophagectomy or definitive chemoradiotherapy (dCRT)) between 2010 and 2017 were reviewed. Multivariate Cox hazards models were applied to determine independent predictors of poor post-recurrence survival (PRS).

RESULTS

In total, 178 patients were included. The median PRS was 12.9 months. Of the 178 patients, 98 had OM and 80 non-OM (NOM) disease. The survival outcomes of patients with OM were significantly better than those of patients with NOM (P < 0.01). Surgical treatments provided significantly better survival outcomes than CRT or chemo-/radiotherapy alone (3-year overall survival (OS); 78.1% vs. 42.5% vs. 28.9%, P < 0.01), mainly due to prolonging survival after the recurrence (3-year PRS 62.9% vs. 16.7% vs. 16.2%, P < 0.01). Multivariable analysis focusing on patients with OM revealed cStage III-IV disease (P < 0.01), high GPS at the time of recurrence (P = 0.02) and non-curative treatments (P < 0.01), to be independently associated with poor PRS. In contrast, in patients with NOM, no independent predictors for poor PRS were identified.

CONCLUSIONS

The survival outcomes of patients with relapsed EC remain poor. Surgical treatments could provide survival benefits for patients with recurrent EC, especially for patients with OM.

Robotic-Assisted Esophagectomy: Current Situation and Future Perspectives

Robotic-assisted minimally invasive esophagectomy (RAMIE) has been rapidly spreading worldwide as a novel minimally invasive approach for esophageal cancer. This narrative review aimed to elucidate the current situation and future perspectives of RAMIE for esophageal cancer. References were searched using PubMed and Embase for studies published up to 8 April 2023. Search terms included "esophagectomy" or "esophageal cancer" and "robot" or "robotic" or "robotic-assisted." There are several different uses for the robot in esophagectomy. Overall complications are equivalent or may be less in RAMIE than in open esophagectomy and conventional (thoracoscopic) minimally invasive esophagectomy. Several meta-analyses demonstrated the possibility of RAMIE in reducing pulmonary complications, although the equivalent incidence was observed in two randomized controlled trials. RAMIE may increase the number of dissected lymph nodes, especially in the left recurrent laryngeal nerve area. Long-term outcomes are comparable between the procedures, although further research is required. Further progress in robotic technology combined with artificial intelligence is expected.

Clinical Possibility of Caenorhabditis elegans as a Novel Evaluation Tool for Esophageal Cancer Patients Receiving Chemotherapy: A Prospective Study

BACKGROUND

The nematode Caenorhabditis elegans (C. elegans) possesses a sophisticated sense of smell and is used for a novel cancer screening test that utilizes the chemotaxis index. We designed a single-institution, prospective study to confirm the ability of Nematode Nose (N-NOSE) to determine preoperative chemotherapy's efficacy for esophageal cancer patients.

PATIENTS AND METHODS

We investigated the predictability of N-NOSE screening for the clinical effects of preoperative chemotherapy for esophageal cancer patients receiving radical surgery. The index reduction score (IRS) was calculated via the chemotaxis of C. elegans at three points: before treatment, before surgery, and after surgery, and its clinical relevance was examined.

RESULT

Thirty-nine patients with esophageal cancer were enrolled from August 2020 to December 2021, and 30 patients receiving radical surgery were examined. Complete response or partial response was achieved in 23 cases (76.7%). When the target of the treatment effect was complete response only, the prediction accuracies of the IRS calculated by area under the curve was 0.85 (95% Confidence interval: 0.62-1) in clinically achieving complete response group, and the sensitivity and specificity were 1 and 0.63, respectively.

CONCLUSION

Index reduction score using N-NOSE screening may reflect the efficacy of chemotherapy for esophageal cancer patients. A large-scale prospective study at multiple centers is desired in the future.

Endoscopic Stenting for Malignant Dysphagia in Patients with Esophageal Cancer

Malignant dysphagia is a common problem in patients with esophageal cancer. Endoscopic stenting can resolve dysphagia caused by malignant stricture; however, controversy exists regarding the use of esophageal stenting for the treatment of malignant stricture, including whether stenting or radiotherapy is superior, whether stenting before or after radiotherapy is safe, whether stenting before or after chemotherapy is safe, and whether low-radial-force stents are safer than conventional stents. Among treatment options for malignant dysphagia, stenting may have some disadvantages in terms of pain relief and the risk of adverse events compared with radiotherapy and in terms of survival compared with gastrostomy. Additionally, the risk of stent-related adverse events is significantly associated with prior radiotherapy. The risk of perforation is especially high when a radiation dose of >40 Gy is delivered to the esophagus after stenting, whereas perforation is not associated with prior chemotherapy or additional chemotherapy after stenting. Nevertheless, stenting remains an important palliative option, especially for patients with a short life expectancy and a strong desire for oral intake, because stenting can facilitate a more rapid improvement in dysphagia than radiotherapy or gastrostomy. The application of a low-radial-force stent should be considered to reduce the risk of adverse events, especially in patients with prior radiotherapy.