Protocol for a phase II study to evaluate the efficacy and safety of nivolumab as a postoperative adjuvant therapy for patients with esophageal cancer treated with preoperative docetaxel, cisplatin plus 5-fluorouracil treatment (PENTAGON trial)

BACKGROUND

In Japan, preoperative adjuvant chemotherapy followed by surgical resection is the standard treatment for patients with locally advanced esophageal squamous cell carcinoma. However, the risk of recurrence after surgical resection remains high. Although a randomized controlled trial evaluating the efficacy of nivolumab, a fully human monoclonal anti-programmed death 1 antibody, as postoperative adjuvant therapy after neoadjuvant chemoradiotherapy and surgery established its superior efficacy as adjuvant therapy, the efficacy for patients who received preoperative adjuvant chemotherapy has not been demonstrated. This study aims to elucidate the efficacy and safety of nivolumab as postoperative adjuvant therapy for patients with esophageal squamous cell carcinoma after preoperative adjuvant chemotherapy with docetaxel and cisplatin plus 5-fluorouracil followed by surgical resection.

METHODS

This study is a multi-institutional, single-arm, Phase II trial. We plan to recruit 130 esophageal squamous cell carcinoma patients, who have undergone preoperative adjuvant chemotherapy with docetaxel and cisplatin plus 5-fluorouracil followed by surgical resection. If the patient did not have a pathological complete response, nivolumab is started as a postoperative adjuvant therapy within 4-16 weeks after surgery. The nivolumab dose is 480 mg/day every four weeks. Nivolumab is administered for up to 12 months. The primary endpoint is disease-free survival; the secondary endpoints are overall survival, distant metastasis-free survival, and incidence of adverse events.

DISCUSSION

To our knowledge this study is the first trial establishing the efficacy of nivolumab as postoperative adjuvant therapy for patients with esophageal squamous cell carcinoma after preoperative adjuvant chemotherapy with docetaxel and cisplatin plus 5-fluorouracil followed by surgical resection. In Japan, preoperative adjuvant chemotherapy followed by surgery is a well-established standard treatment for resectable, locally advanced esophageal squamous cell carcinoma. Therefore, developing an effective postoperative adjuvant therapy has been essential for improving oncological outcomes.

Impact of Tumor Size on Survival Outcome in Esophageal Squamous Cell Carcinoma After Esophagectomy Following Neoadjuvant Chemotherapy

BACKGROUND

Large tumor size is a prognostic factor in esophageal squamous cell carcinoma (ESCC). However, the effect of tumor size on outcomes following neoadjuvant chemotherapy (NAC) has not been evaluated. This study aimed to assess the influence of tumor size on prognosis of patients undergoing esophagectomy after NAC.

PATIENTS AND METHODS

This study was made up of 272 patients who underwent esophagectomy after NAC at Kobe University Hospital. We evaluated the pathological tumor size and determined the cutoff level for tumor size using receiver operating characteristics analysis to the survival status. Cox proportional hazards regression analyses were performed to identify prognostic factors.

RESULTS

The patients were categorized into two groups: patients with tumor sizes ≥ 36 mm and < 36 mm. Deep pathological tumor invasion and worse histological response to NAC were associated with tumor size ≥ 36 mm. In patients with pT0-1, pT2, and pT4 ESCC, no significant differences in overall survival (OS) rates were observed between the two groups. In patients with pT3, OS of the tumor size ≥ 36 mm group was significantly worse than that of the tumor size < 36 mm group (p < 0.0001). Multivariate analysis in pT3 patients revealed tumor size ≥ 36 mm was an independent risk factor for OS. The 5-year OS rate was 10% in patients with tumor size ≥ 36 mm pT3 ESCC with pathological lymph node metastasis (p < 0.0001).

CONCLUSIONS

Tumor size ≥ 36 mm is an independent risk factor for poorer survival in pT3 patients. Furthermore, tumor size ≥ 36 mm with pathological lymph node metastasis in pT3 patients was associated with very poor survival.

Alb-dNLR Score as a Novel Prognostic Marker for Patients With Locally Advanced Rectal Cancer Undergoing Neoadjuvant Chemoradiotherapy

BACKGROUND/AIM

The albumin and derived neutrophil-to-lymphocyte ratio (Alb-dNLR) score, which combines an inflammation index with a nutritional index, has recently been reported as a useful prognostic marker in various cancers. However, evaluation of the usefulness of Alb-dNLR score in patients with locally advanced rectal cancer (LARC) undergoing neoadjuvant chemoradiotherapy (NACRT) has not been reported yet.

PATIENTS AND METHODS

This retrospective study included 69 patients with LARC undergoing NACRT followed by surgery between November 2005 and July 2020. The cutoff value of the Alb-dNLR score for relapse-free survival (RFS) was determined using a receiver operating characteristic curve. Patients were divided into high and low Alb-dNLR-score groups and analyzed for RFS and overall survival (OS).

RESULTS

A total of 10 patients had high Alb-dNLR scores, and 59 had low Alb-dNLR scores. The high Alb-dNLR-score group had significantly higher rates of open surgery (70.0% vs. 28.8%; p<0.026), greater intraoperative blood loss (2,009 g vs. 421 g; p<0.001), and longer postoperative hospital stays (70 days vs. 42 days, p=0.012) than those of the low-Alb-dNLR-score group. The high Alb-dNLR-score group further demonstrated significantly worse RFS and OS than the low Alb-dNLR-score group (both p<0.001). Multivariate analysis identified the Alb-dNLR score as the most independent prognostic factor for RFS (hazard ratio=5.27; 95% confidence interval=2.09-13.27; p<0.001).

CONCLUSION

The Alb-dNLR score is a valuable prognostic marker for predicting the oncological outcomes in patients with LARC undergoing NACRT.

Significance of Preoperative Tooth Loss in Patients Who Underwent Gastrectomy for Gastric Cancer

Background/Aim

The relationship between gastric cancer and oral health has been reported in several studies. This study aimed to determine the relationship between the postoperative prognosis of gastric cancer and oral health using preoperative tooth loss as a simple index.

Patients and Methods

We conducted a single-center retrospective cohort study. Patients were divided into two groups according to the number of tooth losses. The survival curve was constructed using the Kaplan-Meier method. We also performed univariate and multivariate analyses of overall survival based on Cox proportional hazard regression to determine prognostic factors.

Results

A total of 191 patients were divided into two groups: those with seven or more tooth losses and those with less than seven tooth losses. The three-year overall survival rate was 71.5% in the group with seven or more tooth losses and 87.0% in the group with less than seven tooth losses. The group with seven or more tooth losses had a significantly lower overall survival rate compared to the group with less than seven tooth losses (p=0.0014). However, in multivariate analysis, tooth loss was not identified as an independent prognostic factor whereas age, clinical T stage, CEA level, and serum albumin level were independent poor prognostic factors.

Conclusion

Preoperative tooth loss was not a prognostic factor for gastric cancer after gastrectomy, but tooth loss may be a simple and useful method for evaluating frailty in patients.

Effectiveness of long-term tube feeding intervention in preventing skeletal muscle loss after minimally invasive esophagectomy

PURPOSE

Esophageal cancer is a lethal tumor typically treated by neoadjuvant chemotherapy and surgery. For patients undergoing esophagectomy, postoperative enteral nutrition is important in preventing complications. Sarcopenia is associated with poor postoperative outcomes in esophageal cancer. In this study, we evaluated the benefits of tube feeding intervention and compared its short- and long-term outcomes in patients who underwent esophagectomy.

METHODS

Propensity score matching was performed in 303 patients who underwent esophagectomy at Kobe University Hospital between 2010 and 2020. Patients were divided into feeding and nonfeeding jejunostomy tube groups (n = 70 each). The feeding jejunostomy tube group was further divided into long-term (≥ 60 days) and short-term (< 60 days) subgroups. The groups were then retrospectively compared regarding postoperative albumin levels, body weight, and psoas muscle area and volume.

RESULTS

In the long-term feeding jejunostomy tube group, anastomotic leakage (p = 0.013) and left laryngeal nerve palsy (p = 0.004) occurred frequently. There were no significant between-group differences in postoperative albumin levels, body weight, or psoas muscle area. However, significant psoas muscle volume recovery was confirmed in the long-term jejunostomy tube group at 6 months postoperatively (p = 0.041).

CONCLUSIONS

Tube feeding intervention after minimally invasive esophagectomy may attenuate skeletal muscle mass loss and help prevent sarcopenia.

[Significance of Preoperative Adjuvant Therapy and Subsequent Selective Inguinal Lymph Node Dissection for Rectal or Anal Canal Adenocarcinoma with Inguinal Lymph Node Metastases]

Adenocarcinoma of the rectum and anal canal with inguinal lymph node metastasis(ILNM)is rare and the prognosis is generally poor. The aim of this study was to clarify the clinical significance of selective inguinal lymph node dissection and total mesorectal excision after preoperative therapy for adenocarcinoma of the rectum and anorectal canal with clinically suspected ILNM. Of the 15 patients, 11 received preoperative chemoradiotherapy, 3 received chemotherapy, and 1 received chemotherapy after chemoradiotherapy. 14 patients received preoperative therapy followed by FDG-PET scans were performed in 14 patients after preoperative treatment. 5 patients had negative FDG accumulation in inguinal lymph nodes on FDG-PET scans, and postoperative pathological diagnosis was also negative for metastasis in the inguinal lymph nodes. Of the 9 patients with positive FDG accumulation, 4 had pathologically positive inguinal lymph nodes, 7 had postoperative inguinal seroma, the 5-year survival rate was 77.5%, and the 5-year recurrence-free survival rate was 64.2%. No patient had a recurrence in the inguinal region. Patients with adenocarcinoma of the rectum and anal canal with clinical ILNM had good long-term survival after radical resection with preoperative therapy.

[Analysis of Nuclear β-Catenin before Starting Treatment Could Potentially Predict the Therapeutic Response to Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer]

Although a therapeutic response to neoadjuvant chemoradiotherapy(NACRT)is important to improve oncological outcomes after surgery in patients with locally advanced rectal cancer, there is no reliable predictor for this. The Wnt/β-catenin signal is known to be crucial for the tumorigenesis of colorectal cancer. This study aimed to investigate the association between Wnt/β-catenin signal activation and the response to NACRT in patients with locally advanced rectal cancer. We analyzed the expression of nuclear and membranous β-catenin in biopsy samples obtained from 60 patients who underwent curative surgery following NACRT. We found that patients with low nuclear β-catenin expression had a higher rate of good histological responses compared to those with high nuclear β-catenin expression. Additionally, patients with low nuclear/high membranous β-catenin expression tended to have better relapse-free survival. The activation of the Wnt/β- catenin signal pathway, represented by nuclear β-catenin accumulation, was significantly associated with a poor response to NACRT in patients with rectal cancer. The analysis of nuclear β-catenin accumulation before starting treatment could potentially predict the therapeutic response to NACRT.

Safety and Efficacy of Neoadjuvant Chemotherapy for Advanced Gastric Cancer in Elderly Patients

BACKGROUND/AIM

Elderly patients with pathological stage II/III gastric cancer struggle to complete adjuvant chemotherapy. Neoadjuvant chemotherapy (NAC) for treating locally advanced gastric cancer (LAGC) has drawn attention; however, its indication for elderly patients who are vulnerable to chemotherapy is unclear. This study aimed to investigate the feasibility and efficacy of NAC for elderly patients with gastric cancer.

PATIENTS AND METHODS

In this study, patients aged ≥75 years who underwent curative gastrectomy for LAGC or adenocarcinoma of the esophagogastric junction between April 2013 and November 2021 were included. Vulnerable patients, with poor Eastern Cooperative Oncology Group Performance Status (ECOG-PS) of 2-3 were also included. The patients were classified into NAC+ (n=20) and NAC - (n=45) groups. The clinicopathological data of the patients were retrospectively investigated.

RESULTS

The NAC+ group showed a higher R0 resection rate than the NAC- group (100% vs. 89.1%, p=0.3) and pathological downstaging was achieved in 12 (60%) cases, including five (25%) pathological complete responses. The incidence of adverse events during postoperative chemotherapy was 35%, and the rate of postoperative complications greater than Clavien-Dindo Grade II was comparable between the two groups (35% vs. 46.7%, p=0.43). The NAC+ group showed a higher three-year overall survival rate (75% vs. 36%, p=0.015).

CONCLUSION

NAC was feasible and effective for elderly patients including vulnerable patients with LAGC or adenocarcinoma of the esophagogastric junction. It can be considered as treatment option, with a high down staging rate and better survival.

The modified Glasgow prognostic score is a reliable predictor of oncological outcomes in patients with rectal cancer undergoing neoadjuvant chemoradiotherapy

There has been no reliable marker for predicting oncological outcomes in patients with locally advanced rectal cancer (LARC) undergoing neoadjuvant chemoradiotherapy (NACRT). We retrospectively analyzed 73 patients with LARC who underwent curative surgery after NACRT. The modified Glasgow prognostic score (mGPS) was assessed after NACRT, and clinical outcomes were compared between the high (mGPS = 1 or 2; n = 23) and low (mGPS = 0; n = 50) groups. Body mass index was significantly higher in the low mGPS group. The 5-year disease-free survival (DFS) rate was significantly worse in the high mGPS group than that in the low mGPS group (36.7% vs. 76.6%, p = 0.002). Univariate and multivariate analyses of DFS revealed that mGPS was the most significant predictor (p < 0.001). mGPS appears to be a reliable predictor of oncological outcomes in patients with LARC undergoing NACRT.

Evaluation of the Efficiency of a Joystick-Guided Robotic Scope Holder Compared to That of Human Scopists: A Prospective Trial

PURPOSE

This study aimed to compare motions of the laparoscope tip during a laparoscopic task in a training box using a recent joystick-guided robotic scope holder to those manipulated by human scopists. We hypothesized that laparoscopic manipulation could be positively affected by robotic scope holders due to the elimination of unintentional movement.

METHODS

Twelve surgeons participated as operators, and eight medical doctors participated in this study. Among the human scopists, five were trained surgeons and three were novices who had no experience with laparoscopic surgery. A validated laparoscopic task was used to evaluate the path length of the laparoscope tip using an optical position tracker and operative time. The operators performed the designated camera task under three different laparoscopic manipulations: using a joystick-guided robotic scope holder, expert human scopists, and novice scopists.

RESULTS

The median path lengths (cm) of the laparoscopic tip were 94.0, 110.0, and 122.2 in the robotic scope holder, expert, and novice groups, respectively. The path lengths in the robotic scope holder group were significantly shorter than those in the other groups (P < .01). The median operative times (seconds) were 136.6, 66.4, and 62.3 in the robotic scope holder, expert, and novice groups, respectively. The operative time of the robotic scope holder group was significantly longer than that of the other groups (P < .001).

CONCLUSION

A robotic scope holder can provide shorter camera movement owing to the stable holding and intentional scope manipulation by the operator, although it requires a longer operative time than a human assistant.

Deep Learning-based Image Cytometry Using a Bit-pattern Kernel-filtering Algorithm to Avoid Multi-counted Cell Determination

BACKGROUND/AIM

In pathology, the digitization of tissue slide images and the development of image analysis by deep learning have dramatically increased the amount of information obtainable from tissue slides. This advancement is anticipated to not only aid in pathological diagnosis, but also to enhance patient management. Deep learning-based image cytometry (DL-IC) is a technique that plays a pivotal role in this process, enabling cell identification and counting with precision. Accurate cell determination is essential when using this technique. Herein, we aimed to evaluate the performance of our DL-IC in cell identification.

MATERIALS AND METHODS

Cu-Cyto, a DL-IC with a bit-pattern kernel-filtering algorithm designed to help avoid multi-counted cell determination, was developed and evaluated for performance using tumor tissue slide images with immunohistochemical staining (IHC).

RESULTS

The performances of three versions of Cu-Cyto were evaluated according to their learning stages. In the early stage of learning, the F1 score for immunostained CD8⁺ T cells (0.343) was higher than the scores for non-immunostained cells [adenocarcinoma cells (0.040) and lymphocytes (0.002)]. As training and validation progressed, the F1 scores for all cells improved. In the latest stage of learning, the F1 scores for adenocarcinoma cells, lymphocytes, and CD8⁺ T cells were 0.589, 0.889, and 0.911, respectively.

CONCLUSION

Cu-Cyto demonstrated good performance in cell determination. IHC can boost learning efficiencies in the early stages of learning. Its performance is expected to improve even further with continuous learning, and the DL-IC can contribute to the implementation of precision oncology.

Patients younger than 40 years with colorectal cancer have a similar prognosis to older patients

PURPOSE

Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. In recent years, the proportion of patients diagnosed with CRC at younger ages has increased. The clinicopathological features and oncological outcomes in younger patients with CRC remain controversial. We aimed to analyze the clinicopathological features and oncological outcomes in younger patients with CRC.

METHODS

We examined 980 patients who underwent surgery for primary colorectal adenocarcinoma between 2006 and 2020. Patients were divided into two cohorts: younger (< 40 years old) and older (≥ 40 years old).

RESULTS

Of the 980 patients, 26 (2.7%) were under the age of 40 years. The younger group had more advanced disease (57.7% vs. 36.6%, p = 0.031) and more cases beyond the transverse colon (84.6% vs. 65.3%, p = 0.029) than the older group. Adjuvant chemotherapy was administered more frequently in the younger group (50% vs. 25.8%, p < 0.01). Relapse-free survival and overall survival were similar between the groups at all stages. Moreover, in stages II and III they were also comparable, regardless of the administration of adjuvant chemotherapy.

CONCLUSIONS

Younger patients with CRC have a prognosis equivalent to that of older patients. Further studies are needed to establish the optimal treatment strategies for these patients.

Safety of Laparoscopic Gastrectomy for Advanced Gastric Cancer With Greater than Serosal Invasion Depth

BACKGROUND/AIM

There are several concerns about oncological contamination and technical difficulty in the laparoscopic approach for locally advanced gastric cancer. We aimed to determine the safety and usefulness of laparoscopic gastrectomy for patients with advanced gastric cancer with tumor depth greater than serosal invasion.

PATIENTS AND METHODS

Sixty-two laparoscopic and 82 laparotomy gastric cancer cases surgically diagnosed as serosal or other organ invasions intraoperatively between 2011 and 2021 were included. The laparoscopic and open gastrectomy results were compared by propensity score matching using stage, preoperative chemotherapy, curative resection, surgical technique, and age as explanatory variables and laparoscopy and open resection as outcome variables.

RESULTS

No difference in median operative time (341 vs. 386 minutes, p=0.24) was observed, but median blood loss (0 vs. 510 ml, p<0.001) and blood transfusion requirement (9.5 vs. 43%, p<0.001) were lower in the laparoscopic group. No difference was observed between the two groups regarding complications. Furthermore, 3-year overall survival was also similar (43 vs. 42%, p=0.74).

CONCLUSION

The laparoscopic surgery results are comparable to those of open surgery in treating gastric cancer with T4a or greater depth. In addition, it is minimally invasive with less blood loss, making it a standard approach.

Efficacy and Postoperative Outcomes of Laparoscopic Retrosternal Route Creation for the Gastric Conduit: Propensity Score-Matched Comparison to Posterior Mediastinal Reconstruction

BACKGROUND

Retrosternal reconstruction has lower risks for severe postoperative morbidities, such as gastro-tracheal fistula or esophageal hiatal hernia. We have previously reported the laparoscopic retrosternal route creation (LRRC) method, but its safety and efficacy remain unclear.

METHODS

In total, 374 patients with esophageal carcinoma who underwent minimally invasive McKeown esophagectomy in the prone position between 2010 and 2021 were retrospectively reviewed. We performed a propensity score-matched analysis with the simple, nearest-neighbor method and no calipers to compare postoperative outcomes and reconstructed gastric conduit functionality between patients who underwent LRRC and counterparts who underwent posterior mediastinal reconstruction.

RESULTS

After matching, 62 patients were included in the laparoscopic retrosternal group (LR group) or posterior mediastinal group (PM group). No significant differences were observed between the groups, apart from the number of robot-assisted surgeries, the extent of lymph node dissection, and the method of cervical anastomosis. There were no significant differences in the incidence of Clavien-Dindo grade ≥ 2 complications. Gastro-tracheal fistula (n = 1) and esophageal hiatal hernia (n = 2) occurred in the PM group but not in the LR group. There were no differences in the incidence of pulmonary embolism between the groups (5% vs. 5%). The postoperative anastomotic stenosis rate was similar (16% vs. 27%, p = 0.192). Endoscopic findings of reflux esophagitis (modified Los Angeles classification ≥ M) at 1 year after surgery were significantly better in the LR group (p = 0.037).

CONCLUSIONS

LRRC for gastric conduit reconstruction is safe and valuable. It is associated with good reconstructed gastric conduit function.

Learning Curve for Transanal Total Mesorectal Excision for Low Rectal Malignancy

BACKGROUND

Although transanal total mesorectal excision (TaTME) is a promising treatment for low rectal cancer, it is considered technically demanding, and the number of cases required to become proficient in TaTME remains unknown. The purpose of this study was to assess the TaTME learning curve based on the total mesorectal excision completion time.

STUDY DESIGN

This retrospective analysis comprised 128 individuals who received TaTME between September 2016 and December 2021. The cumulative sum method was used to generate the learning curve. The duration of the procedure from the beginning to the end of the circumferential rendezvous was used to define the total mesorectal excision completion time.

RESULTS

The learning curve consists of 3 phases: phase I (learning phase: cases 1 to 38), phase II (consolidation phase: cases 39 to 70), and phase III (maturing phase: cases 71 to 128). As the phases varied, both the overall operative time and total mesorectal excision completion time decreased considerably. Through the 3 phases of TaTME, intraoperative adverse events decreased, and in phase III, none occurred. Only 1 instance of local recurrence occurred during phase III, and none occurred during phase I or II.

CONCLUSIONS

After 70 operations, the surgeon could join the mastery phase of TaTME based on the total mesorectal excision completion time. After the mastering phase began, there were no intraoperative negative occurrences. From the beginning, the oncological safety could be guaranteed.

The Influence of Preoperative Smoking Status on Postoperative Complications and Long-Term Outcome Following Thoracoscopic Esophagectomy in Prone Position for Esophageal Carcinoma

BACKGROUND

Esophagectomy for esophageal carcinoma is associated with higher morbidity and mortality rates than other gastrointestinal surgeries. Smoking is an established risk factor for postoperative complications after esophagectomy. This study aimed retrospectively to investigate the impact of smoking status on short- and long-term outcomes for patients undergoing thoracoscopic esophagectomy in the prone position (TEP) for esophageal carcinoma.

METHODS

In this study, 234 patients with esophageal carcinoma who underwent TEP between 2012 and 2020 were divided into two groups based on smoking status (current or non-current smokers and the Brinkman index) by patients' declarations. Postoperative complications (Clavien-Dindo classification grade ≥2), overall survival (OS), and disease-free survival (DFS) were compared between smoking statuses.

RESULTS

The rates of postoperative complications did not differ significantly between the two groups (current smoker vs non-current smoker; Brinkman index ≥800 vs <800). The rate of postoperative pneumonia was higher in the combination group of current and higher Brinkman index (≥800) smokers than in the other group (25.0 % vs 11.8 %; P = 0.036). Multivariate analysis showed that smoking status was an independent risk factor for postoperative pneumonia (hazard ratio, 0.41; 95 % confidence interval, 0.18-0.93; P = 0.037). According to the long-term outcomes, no significant differences in OS and DFS were observed between the smoking statuses.

CONCLUSIONS

The combination of current smoking and heavy smoking history is a risk factor for postoperative pneumonia in patients who have esophageal carcinoma treated with TEP, although no correlation was observed between the long-term outcomes and smoking status.

Feasibility and safety of robotic surgery for low rectal cancer combined with transanal total mesorectal excision

PURPOSE

Laparoscopic surgery for low rectal cancer is often challenging. Transanal total mesorectal excision (TaTME) and robotic surgery have been introduced to overcome the technical difficulties in laparoscopic surgery and achieve more favorable outcomes. Hybrid robotic surgery, which combines TaTME with the abdominal robotic approach, incorporates the advantages of each of these surgical techniques and might achieve less invasive and safer surgery. This study evaluated the safety and feasibility of hybrid robotic surgery with TaTME (hybrid TaTME).

METHODS

We retrospectively reviewed 162 TaTME cases performed at our department from September 2016 to May 2022. Among them, 92 cases of conventional TaTME and 30 of hybrid TaTME were eligible. We used propensity score matching analysis (PSM) to adjust for patients' characteristics and compared the short-term outcomes of the two treatment groups.

RESULTS

Twenty-seven cases in each group were extracted using PSM. The operation time in hybrid TaTME was comparable to that in conventional TaTME. There was no significant difference in the postoperative hospital stay between the two groups. Other intra- and post-operative outcomes were also comparable between the two groups. Furthermore, no significant differences were observed between the two groups in the curative resection and recurrence rates.

CONCLUSION

Hybrid TaTME for low rectal cancer was as favorable as conventional TaTME in producing satisfactory short-term outcomes. However, furthermore, larger-scale studies conducted over longer study periods are needed to evaluate the validity of the findings.

Significance of Wnt/β-Catenin Signal Activation for Resistance to Neoadjuvant Chemoradiotherapy in Rectal Cancer

Although a therapeutic response to neoadjuvant chemoradiotherapy (NACRT) is important to improve oncological outcomes after surgery in patients with locally advanced rectal cancer, there is no reliable predictor for this. The Wnt/β-catenin signal is known to be crucial for the tumorigenesis of colorectal cancer. This study aimed to investigate the association of Wnt/β-catenin signal activation with a pathological response to NACRT. The immunohistochemical expression of nuclear and membranous β-catenin was analyzed in biopsy samples obtained from 60 patients with locally advanced rectal cancer who received curative surgery following NACRT. The association of Wnt/β-catenin signal activation with their clinical outcomes was investigated. Notably, the body mass index of these patients was significantly higher in the low nuclear β-catenin expression group. Moreover, patients in the high nuclear β-catenin expression group tended to have more advanced disease and a higher rate of positive vascular invasion than those in the low expression group. Furthermore, the rate of good histological responses was significantly higher in the low nuclear β-catenin expression group (72% vs. 37.1%, p < 0.01). Overall, relapse-free survival tended to be better in patients with low nuclear/high membranous β-catenin expression (n = 9) than in other individuals (n = 51) (p = 0.093 and p = 0.214, respectively). Activation of the Wnt/β-catenin signal pathway represented by nuclear β-catenin accumulation was significantly associated with a poor response to NACRT in patients with rectal cancer. Analysis of nuclear β-catenin accumulation before starting treatment might help predict the therapeutic response to NACRT.

Clinical outcomes of neoadjuvant therapy followed by selective inguinal lymph node dissection and total mesorectal excision for metastasized low rectal cancer

PURPOSE

Rectal or anal canal adenocarcinoma with inguinal lymph node metastasis (ILNM) is rare and is associated with poor prognostic outcomes. This study aimed to elucidate the clinical significance of neoadjuvant therapy followed by selective inguinal lymph node dissection and total mesorectal excision for rectal or anal canal adenocarcinoma with clinically suspected ILNM.

METHODS

This study enrolled 15 consecutive patients who underwent neoadjuvant therapy and curative resection for rectal or anal canal adenocarcinoma with clinically suspected ILNM between 2005 and 2019 at a single institution. Inguinal lymph node dissection was selectively performed on the side of suspected metastasis before neoadjuvant therapy. Short- and long-term outcomes were retrospectively reviewed.

RESULTS

Out of the15 patients, 11 were treated with neoadjuvant chemoradiation, three with chemotherapy, and one with chemoradiation followed by chemotherapy. Fluorodeoxyglucose (FDG)-positron emission tomography (PET) scans were performed after neoadjuvant therapy in 14 patients. Five patients had negative FDG accumulation in inguinal lymph nodes on FDG-PET scan, and their inguinal lymph nodes were also pathologically negative for metastasis. Of the nine patients who had positive FDG accumulation, four had pathologically positive inguinal lymph nodes. Seven patients (46.7%) had inguinal seroma postoperatively. Five-year-overall survival was 77.5%, and 5-year-relapse-free survival was 64.2%. No patient had a recurrence in the inguinal region.

CONCLUSION

In patients with rectal or anal canal adenocarcinoma associated with clinical ILNM, radical resection with neoadjuvant therapy provides a good long-term survival.

Reduced Number and Immune Dysfunction of CD4+ T Cells in Obesity Accelerate Colorectal Cancer Progression

Obesity, a known risk factor for various types of cancer, reduces the number and function of cytotoxic immune cells in the tumor immune microenvironment (TIME). However, the impact of obesity on CD4+ T cells remains unclear. Therefore, this study aimed to clarify the impact of obesity on CD4+ T cells in the TIME. A tumor-bearing obese mouse model was established by feeding with 45% high-fat diet (HFD), followed by inoculation with a colon cancer cell line MC38. Tumor growth was significantly accelerated compared to that in mice fed a control diet. Tumor CD4+ T cells showed a significant reduction in number and an increased expression of programmed death-1 (PD-1), and decreased CD107a expression and cytokine such as IFN-γ and TNF-α production, indicating dysfunction. We further established CD4+ T cell-depleted HFD-fed model mice, which showed reduced tumor infiltration, increased PD-1 expression in CD8+ T cells, and obesity-induced acceleration of tumor growth in a CD4+ T cell-dependent manner. These findings suggest that the reduced number and dysfunction of CD4+ T cells due to obesity led to a decreased anti-tumor response of both CD4+ and CD8+ T cells to ultimately accelerate the progression of colorectal cancer. Our findings may elucidate the pathogenesis for poor outcomes of colorectal cancer associated with obesity.

[A Case of Pathological Complete Response after Conversion Surgery for HER2-Positive Advanced Gastric Cancer with Multiple Distant Metastases]

The patient is a 70's man. Esophagogastroduodenoscopy and contrast-enhanced CT scan of the abdomen revealed gastric cancer, 2 liver metastases, and peritoneal dissemination. He was diagnosed with unresectable advanced gastric cancer and received 5 courses of chemotherapy(CapeOX plus T-mab). The primary tumor size had reduced, and liver metastases and peritoneal dissemination were not detectable, so laparoscopic distal gastrectomy and partial hepatectomy were performed. Histopathological findings revealed no viable cancer cells in either the primary tumor or the hepatic resection site, and the histological response was Grade 3. The patient has been recurrence-free for 6 months since the surgery. Even in Stage Ⅳ gastric cancer with multiple distant metastases, long-term survival may be expected by conversion surgery after response to chemotherapy.

Short- and long-term outcomes of thoracoscopic esophagectomy in the prone position for esophageal squamous cell carcinoma in patients with obstructive ventilatory disorder: a propensity score-matched study

BACKGROUND

Many patients with esophageal squamous cell carcinoma (ESCC) have obstructive ventilatory disorder (OVD), which is considered a risk factor for postoperative pneumonia. It has been reported that thoracoscopic esophagectomy in the prone position (TEP) is less invasive and is associated with fewer postoperative respiratory complications compared with open esophagectomy. This matched-cohort study aimed to elucidate the safety and oncologic outcomes of ESCC patients with OVD who undergo TEP.

METHODS

In this matched-cohort study, 237 patients with ESCC who underwent TEP between 2010 and 2018 were divided into two groups based on forced expiratory volume in 1 s/forced vital capacity. Postoperative complications (Clavien-Dindo classification grade II or higher), overall survival (OS), and disease-free survival (DFS) were compared between the two groups.

RESULTS

Based on their propensity scores, 75 patients with normal respiratory function (NRF) and 75 with OVD were selected. The rates of postoperative pneumonia were not significantly different between the two groups (NRF group vs OVD group: 18.7% vs 18.7%; P = 1.000). The rates of recurrent laryngeal nerve palsy and anastomotic leakage were also not significantly different (NRF group vs OVD group: 12.0% vs 18.7%, P = 0.365; 18.7% vs 18.7%, P = 1.000). The 5-year OS and DFS rates in the NRF vs OVD groups were 66.2% vs 54.9% and 63.5% vs 52.9%, respectively, with no significant differences (P = 0.421, 0.197).

CONCLUSIONS

TEP can be safely performed on ESCC patients with OVD and can result in an oncological efficiency equal to that of the NRF group.

Laparoscopic Endoscopic Cooperative Surgery Using Open-Window Suturing Technique for Treating Non-ampullary Superficial Duodenal Neoplasms Located on the Pancreatic Side

PURPOSE

No study has focused on the safety and feasibility of our previously developed open-window suturing technique to close mucosal defects on the pancreatic side after endoscopic submucosal dissection from the opened duodenal wall. This study aimed to evaluate the safety and usefulness of laparoscopic endoscopic cooperative surgery for duodenal tumors for treating superficial non-ampullary duodenal epithelial tumors on the pancreatic side of the duodenum.

METHODS

This retrospective study included 61 consecutive patients who underwent surgery during August 2014-November 2021. After dissection when the tumor was on the pancreatic side, we sutured the mucosal defect from the opened duodenal wall. A preoperative endoscopic pancreatic stent was placed for tumors within 1 cm of the ampulla of Vater. The surgical outcomes were compared between tumors on the pancreatic and non-pancreatic sides.

RESULTS

There were 27 and 34 patients with tumors on the pancreatic and non-pancreatic sides, respectively. The patient characteristics were similar. Preoperative pancreatic stents were placed in four patients in the pancreatic side group. The median operative time was significantly longer on the pancreatic side than in the non-pancreatic side group (241 vs. 209 min, P = 0.02). In one patient in the pancreatic side group, an intraoperative injury of the ampulla of Vater was successfully treated with intraoperative management. There were no significant differences in the incidence of postoperative grade II or higher complications between the groups.

CONCLUSIONS

Laparoscopic endoscopic cooperative surgery for duodenal tumors for treating superficial non-ampullary duodenal epithelial tumors on the pancreatic side is safe and feasible.

Obesity and narrow pelvis prolong the operative time in conventional laparoscopic rectal cancer surgery, but not in a two-team transanal total mesorectal excision approach

PURPOSE

Narrow pelvis, tumor diameter, and obesity have been reported as clinical variables correlated with the difficulty of conventional laparoscopic low anterior resection (Lap-LAR). A two-team transanal total mesorectal excision (TaTME) approach where the transabdominal and TaTME are performed simultaneously might reduce the difficulty associated with these factors. This study aimed to clarify the factors associated with the longer time required for TME (TME time) in conventional Lap-LAR and a two-team approach for TaTME.

METHODS

We analyzed 52 patients with rectal carcinoma treated with Lap-LAR and 35 patients treated with TaTME. We performed simple linear regression analysis to assess the association between TME time and bony pelvic size using 3D pelvimetry, longest tumor diameter, and body mass index (BMI).

RESULTS

Linear regression analysis demonstrated a highly significant association between TME time and obstetric conjugate (R²  = 0.098, P = .024) and BMI (R²  = 0.307, P < .001) in the Lap-LAR group, while no significant association was observed in the TaTME group. Male patients, who had a narrower bony pelvis and higher BMI than female patients, had longer TME time than female patients in the Lap-LAR group (213 minutes vs 172 minutes, P = .021), while the TME time of male and female patients did not differ in the TaTME group (122 minutes vs 108 minutes, P = .451). The TME time in the TaTME group was significantly shorter than that in the Lap-LAR group (121 minutes vs 197 minutes, P < .001).

CONCLUSION

A two-team TaTME approach provided a shorter TME time compared to conventional Lap-LAR, regardless of pelvic size and BMI.

Comprehensive complication index as a prognostic factor in minimally invasive esophagectomy for esophageal squamous cell carcinoma

BACKGROUND

Postoperative complications affect long-term prognosis in patients with esophageal squamous cell carcinoma (ESCC). Although a comprehensive estimator can predict long-term prognosis, the Clavien-Dindo classification system, a widely used approach to evaluate complications, assesses each complication individually. We aimed to clarify the utility of the comprehensive complication index (CCI) on predicting the overall survival (OS) of patients with ESCC following minimally invasive esophagectomy (MIE).

METHODS

This was a retrospective study of patients undergoing MIE for ESCC in the prone position between January 2011 and December 2018. Multivariate analyses using the Cox proportional hazards model were performed to determine independent risk factors for OS.

RESULTS

The study cohort included 229 patients who were categorized into patients with CCI values of ≥ 33.7 (CCI high) and < 33.7 (CCI low) by receiver-operating characteristic (ROC) curve analysis. There were no significant differences between the two groups according to clinicopathological factors, such as sex, age, tumor location, tumor depth, lymph node metastasis, and neoadjuvant chemotherapy. The intraoperative transfusion rate in the CCI high group was significantly higher than in the CCI low group. The 5 year OS rate was significantly lower in the CCI high group than in the CCI low group (49.5% vs. 65.7%, p = 0.030). By multivariate analyses, age, tumor depth, lymph node metastasis, and the CCI were independent predictors of OS.

CONCLUSIONS

Comprehensive assessment of postoperative complications using the CCI was useful in predicting OS of patients undergoing MIE for the ESCC.

Actual Sarcopenia Reflects Poor Prognosis in Patients with Esophageal Cancer

BACKGROUND

Minimally invasive esophagectomy (MIE) for esophageal cancer patients with sarcopenia is associated with a high risk of perioperative complications; however, the relationship between sarcopenia and the survival of esophageal cancer patients remains controversial. In this study, we aimed to develop a stratifying marker for sarcopenia to precisely predict patients' prognosis.

METHODS

We retrospectively studied 135 patients who underwent thoracoscopic esophagectomy at Kobe University Hospital from 2011 to 2015 and who were preoperatively diagnosed with or without sarcopenia based on the Asian Working Group for Sarcopenia index. Creatinine levels and albumin as measures of skeletal muscle volume and nutritional status, respectively, were used to develop a marker to be used for stratifying sarcopenic patients based on prognosis.

RESULTS

Of the 135 patients, 35 were diagnosed with sarcopenia and 100 were not. We combined the creatinine and albumin levels (Cr × Alb) as a stratifying marker for sarcopenia, and extracted sarcopenic patients with values below the Cr × Alb cut-off as the actual sarcopenic group. The 5-year overall survival (OS) rates of the actual and non-actual sarcopenic groups were 28.9% and 58.9%, respectively (p = 0.0005), and the 5-year disease-free survival rate of the actual sarcopenic group was 34.1%, and 62.8% (p = 0.0106) for the non-actual sarcopenic group. This stratified sarcopenia model was an independent prognostic factor and was superior to sarcopenia alone for OS.

CONCLUSIONS

In patients undergoing MIE, preoperative measurement of Cr × Alb may be a prognostic stratification marker for patients with sarcopenia.

Albumin and Derived Neutrophil-to-Lymphocyte Ratio is a Novel Prognostic Factor for Patients with Esophageal Squamous Cell Carcinoma

BACKGROUND

Multidisciplinary treatment combining neoadjuvant treatment (NAT) and surgery has slightly improved the prognosis of patients with esophageal squamous cell carcinoma (ESCC). Although various biomarkers targeting nutrition and inflammation are associated with cancer prognosis, most studies have focused on conditions prior to NAT. Developing real-time and sensitive biomarkers that monitor changes in systemic conditions during NAT is important. We established a novel nutritional and inflammatory index, represented as the albumin to derived neutrophil-to-lymphocyte ratio (Alb-dNLR), and calculated the change in Alb-dNLR (ΔAlb-dNLR) during neoadjuvant chemotherapy (nCT). In this study, we aimed to evaluate whether ΔAlb-dNLR is associated with prognosis in patients with ESCC.

METHODS

We investigated 172 patients who underwent nCT before esophagectomy between April 2010 and March 2018. The dNLR was calculated as the ratio of neutrophil count to (white blood cell count - neutrophil count), Alb-dNLR was calculated by dividing the serum albumin level by the dNLR, and ΔAlb-dNLR was evaluated by dividing the post-Alb-dNLR by the pre-Alb-dNLR. Patients were divided into 'high' and 'low' groups according to the ΔAlb-dNLR.

RESULTS

Thirty-nine patients (22.7%) had a low ΔAlb-dNLR (≤ 0.8), and the 5-year overall survival (OS) rates in patients with low and high ΔAlb-dNLR were 38.1% and 53.6%, respectively (p = 0.0072). Multivariate analyses demonstrated that estimated blood loss (p = 0.044), pathological T stage (p = 0.0005), pathological N stage (p = 0.017), and ΔAlb-dNLR (p = 0.005) were independent prognostic factors for OS.

CONCLUSIONS

ΔAlb-dNLR is a useful prognostic factor for OS in patients with ESCC receiving nCT.

Impact of the Platelet-to-Lymphocyte Ratio as a Biomarker for Esophageal Squamous Cell Carcinoma

BACKGROUND/AIM

Esophageal squamous cell carcinoma (ESCC) is a deadly malignant disease. This study examined whether the platelet-to-lymphocyte ratio (PLR) can be used as a biomarker to evaluate prognosis in patients with advanced ESCC following neoadjuvant chemotherapy (NAC) and undergoing minimally invasive esophagectomy (MIE).

PATIENTS AND METHODS

We examined 174 patients between January 2010 and December 2015 at the Kobe University. Of these, 121 were treated with NAC. The PLR cutoff was determined through receiver-operating characteristic curve analysis. Univariate and multivariate analyses were conducted to identify prognostic factors for overall survival (OS).

RESULTS

The PLR cutoff for OS in 121 patients was 169.6. Patients with PLR ≥169.6 had worse 5-year OS rates (31.1%) than those with a PLR <169.6 (61.1%, p=0.001). Multivariate analysis revealed that a PLR of ≥169.6 was an independent factor for poor prognosis.

CONCLUSION

PLR is an independent prognostic factor for patients with ESCC after NAC and MIE.

Perioperative Safety of Gastrectomy for Patients Receiving Antithrombotic Treatment

BACKGROUND/AIM

The safety of gastrectomy for patients receiving antithrombotic agents remains unclear. This retrospective cohort study sought to compare outcomes between patients who did and did not receive antithrombotic agents.

PATIENTS AND METHODS

This single-center retrospective cohort study included 548 patients who underwent gastrectomy for primary gastric adenocarcinoma from January 2011 to December 2019. The surgical outcomes were compared between two groups according to whether they received antithrombotic therapy (n=121) or not (n=427).

RESULTS

Among the entire cohort, the patients in the antithrombotic therapy group were significantly older than those who did not receive this therapy and had significantly higher postoperative complication rates than those who did not (33.1% vs. 23.9%; p=0.046). However, after propensity score matching, no significant difference in the postoperative complication rate was observed between the two groups.

CONCLUSION

Despite having a high risk for postoperative complications, patients receiving antithrombotic therapy can safely undergo gastric resection.

Semi-in vitro detection of Mg2+-dependent DNase that specifically digest mitochondrial nucleoids in the zygote of Physarum polycephalum

The maternal/uniparental inheritance of mitochondria is controlled by the selective elimination of paternal/uniparental mitochondria and digestion of their mitochondrial DNA (mtDNA). In isogamy, the selective digestion of mtDNA in uniparental mitochondria is initiated after mating and is completed prior to the elimination of mitochondria, but the molecular mechanism of the digestion of uniparental mtDNA remains unknown. In this study, we developed a semi-in vitro assay for DNase, wherein the digestion of mitochondrial nucleoids (mt-nucleoids) was microscopically observed using isolated mitochondria from Physarum polycephalum and the DNase involved in uniparental inheritance was characterized. When myxamoebae of AI35 and DP246 are crossed, mtDNA and mt-nucleoid from only the DP246 parent are digested. The digestion of mt-nucleoids was observed in zygotes 3 h after plating for mating. During the digestion of mt-nucleoids, mitochondrial membrane integrity was maintained. In the semi-in vitro assay, the digestion of mt-nucleoids was only observed in the presence of Mg²⁺ at pH 7.5-9.0. Moreover, such Mg²⁺-dependent DNase activity was specifically detected in mitochondria isolated from zygotes 3 h after plating for mating. Therefore, Mg²⁺-dependent DNase is potentially involved in uniparental inheritance. Our findings provide insights into the DNase involved in uniparental inheritance and its regulatory mechanism.

Laparoscopic sigmoidectomy with splenic flexure mobilization for colon cancer in situs inversus totalis: Preoperative assessment and preparation

Situs inversus totalis (SIT) is a rare condition in which the internal organ's position is a mirror image of normal anatomy. Although several investigators reported laparoscopic surgery for colorectal cancer in patients with SIT, it is considered difficult even for an experienced surgeon because of the mirror position. We show a case report of laparoscopic sigmoidectomy with the splenic flexure mobilization (SFM) procedure in SIT. A 79-year-old woman with SIT was referred to our hospital for a locally advanced sigmoid cancer (cT3N1M0, cStageIIIB). We safely performed the laparoscopic sigmoidectomy with SFM, as shown in detail below. No postoperative complication occurred, and the patient is in good health with no recurrences 30 months after surgery, as of the writing this report. We propose three critical points; checking the CT angiography to understand the anatomy; using flip-horizontal video of "normal" laparoscopic sigmoidectomy to confirm an unfamiliar situation; adding the epigastric trocar to make SFM procedures safe and comfortable.

Two-Team Lateral Pelvic Lymph Node Dissection Assisted By the Transanal Approach

INTRODUCTION

Although lateral pelvic lymph node dissection is considered as a treatment option for advanced rectal cancer, it is technically demanding. Recently, the transanal approach for total mesorectal excision has become increasingly used. In this Technical Note, we describe lateral pelvic lymph node dissection using a 2-team method that was assisted by the transanal approach.

TECHNIQUE

First, the lateral pelvic area was entered from the anal side by dissection between the S4 sacral splanchnic nerve and levator ani muscle. Then, the fatty tissues including the obturator compartment and the distal part of the internal iliac compartment were separated from the inferior and superior vesical vessels and the bladder wall. Next, the fatty tissues were separated from the lateral pelvic wall. The obturator nerve was isolated and preserved, whereas the obturator vessels were resected at their peripheral end. Then, the fatty tissues were dissected from the bottom plane. Finally, the fatty tissues were dissected from the ventral bladder wall and were completely isolated from the obturator nerve in cooperation with the transabdominal team.

RESULTS

The 2-team method shortened the operative time dramatically and decreased mental and physical burden on the operators during lateral dissection. Assistance with the transanal approach helped with a secure and effective dissection, especially of the most distal parts, such as around the internal pudendal and inferior vesical arteries, because substantial skill is required for the transabdominal approach alone.

CONCLUSIONS

This procedure is useful for the safe and effective performance of lateral pelvic lymph node dissection for patients with rectal cancer.

Albumin-Derived NLR Score is a Novel Prognostic Marker for Esophageal Squamous Cell Carcinoma

BACKGROUND

Multidisciplinary treatment for esophageal squamous cell carcinoma (ESCC) has improved outcomes, but the prognosis for ESCC remains poor. Nutritional and inflammatory indicators are reported to be associated with cancer prognosis. The combination of albumin and the derived neutrophil-to-lymphocyte ratio (Alb-dNLR) score was established to measure the immune system and nutritional status. The authors hypothesized that the Alb-dNLR score could be a new reliable prognostic factor for ESCC patients.

METHODS

The study evaluated 269 patients who underwent esophagectomy between April 2010 and March 2018, including 185 patients who received neoadjuvant chemotherapy. The Alb-dNLR score was calculated using serum albumin and the dNLR. The dNLR was calculated as neutrophils to (leukocyte-neutrophil count). The cutoff values of the albumin and dNLR for overall survival (OS) were determined using the receiver operating characteristic curve. Patients were divided into "high" and "low" groups according to the Alb-dNLR score.

RESULTS

A high Alb-dNLR score was found in 61 cases (22.7%). The 5-year OS was 34% in the high Alb-dNLR group and 66.2% in the low Alb-dNLR group (p < 0.0001). The 5-year cause-specific survival (CSS) was 51.5% in the high Alb-dNLR group and 74.7% in the low Alb-dNLR group (p < 0.0001). Multivariate analyses demonstrated that the Alb-dNLR score was an independent prognostic factor for OS (hazard ratio [HR], 2.198; 95% confidence interval [CI], 1.460-3.263; p = 0.0002) and CSS (HR, 1.733; 95% CI, 1.035-2.835; p = 0.0371).

CONCLUSIONS

The Alb-dNLR score is an extremely useful, easy-to-use parameter to predict OS and CSS for ESCC patients.

Risk Factors for Complications Following Lateral Pelvic Lymph Node Dissection for Rectal Cancer

BACKGROUND

Lateral pelvic lymph node metastasis impairs the oncological outcomes of patients with rectal cancer. Although lateral pelvic lymph node dissection (LLND) might be an effective procedure for such patients, the associated risk factors for postoperative complications are unknown.

PATIENTS AND METHODS

The operative outcomes of 21 patients undergoing unilateral LLND and 26 patients undergoing bilateral LLND for rectal cancer were compared. The risk factors for complications were evaluated using a logistic regression model.

RESULTS

Univariate and multivariate analyses revealed that a longer operative time (≥480 min) was the most important risk factor for grade II or more postoperative complications according to the Clavien-Dindo classification (odds ratio=6.58; 95% confidence interval=1.35-32.1; p=0.020). A bilateral procedure was not a significant risk factor for postoperative complications.

CONCLUSION

Surgeons should make efforts to shorten the operative time to reduce the risk of postoperative complications.

Short-term and long-term outcomes after laparoscopic surgery for elderly patients with colorectal cancer aged over 80 years: a propensity score matching analysis

PURPOSE

There has been an increase in the percentage of elderly patients with colorectal cancer (CRC). However, few studies have reported the short- and long-term outcomes of laparoscopic surgery for elderly patients with CRC aged over 80 years.

METHODS

This study included 529 patients who underwent laparoscopic resection for clinical stage 0-III CRC at Kobe University Hospital between January 2010 and December 2018. Propensity score matching (PSM) was used to create balanced cohorts of the elderly (aged ≥ 80, n = 113) and the non-elderly (aged < 80, n = 113). Their clinical outcomes were compared after PSM.

RESULTS

After matching, carcinoembryonic antigen (CEA) level was higher in the non-elderly group, and adjuvant chemotherapy was less frequently employed in the elderly group. D3 dissection was performed more frequently and the number of the harvested lymph nodes tended to be larger in the non-elderly group. There was no significant difference in the rates of postoperative complications, reoperation within 30 days, and 30-day mortality between the groups. The 5-year relapse-free survival rate was not statistically different between the two groups (77.3% for the non-elderly vs. 62.7% for the elderly, p = 0.13). The multivariate analyses for the whole cohort showed that the factors of sex, tumor location, operation time, and conversion to open surgery, but not the age, were significant predictors of postoperative complications.

CONCLUSION

Laparoscopic surgery for colorectal cancer patients aged over 80 years is technically and oncologically safe.

Sarcopenia assessed by skeletal muscle mass volume is a prognostic factor for oncological outcomes of rectal cancer patients undergoing neoadjuvant chemoradiotherapy followed by surgery

INTRODUCTION

Recently, sarcopenia has been reported to be associated with poor postoperative outcomes in various cancers. However, its clinical significance for rectal cancer patients undergoing neoadjuvant chemoradiotherapy (NACRT) followed by surgery remains unknown.

MATERIALS AND METHODS

This study included 46 patients with locally advanced rectal cancer who underwent curative surgery after NACRT. Sarcopenia was assessed by measuring the cross-sectional psoas muscle area (PA) at L3 and total bilateral psoas muscle volume (PV). Patients with a lower PV or PA value than the median were assigned to the sarcopenia group while others were assigned to the non-sarcopenia group. Clinical outcomes were then compared between groups.

RESULTS

The sarcopenia group included 22 patients. The rate of overall postoperative complications did not differ between groups. Five-year relapse-free survival (RFS) was significantly lower in the sarcopenia group when sarcopenia was assessed by PV after NACRT (44.0% vs. 82.6%, P = 0.00494). In contrast, RFS did not differ between groups when sarcopenia was assessed by PA. Multivariable analysis identified PV after NACRT as the most significant risk factor for RFS (hazard ratio 4.00; 95% CI 1.27-12.66, P = 0.018).

CONCLUSION

Sarcopenia assessed by total PV after NACRT may be an accurate and reliable predictor of poor oncological outcomes in rectal cancer patients.

Preoperative neutrophil-to-lymphocyte ratio predicts the prognosis of esophageal squamous cell cancer patients undergoing minimally invasive esophagectomy after neoadjuvant chemotherapy

BACKGROUND

One of the primary treatment for resectable advanced esophageal squamous cell cancer (ESCC) is neoadjuvant chemotherapy (NAC) followed by minimally invasive esophagectomy (MIE). Because the neutrophil-to-lymphocyte ratio (NLR) is a widely reported prognostic factor in several cancers, we investigated whether the preoperative NLR is a biomarker in ESCC patients treated with NAC and MIE.

METHODS

In this study, we investigated 174 ESCC patients who underwent MIE from January 2010 to December 2015, including 121 patients who received NAC. The cutoff value of the NLR was analyzed using the receiver operating characteristic curve. Multivariate analyses were performed to clarify independent prognostic factors for overall survival (OS).

RESULTS

The cutoff value of the NLR for OS in 121 patients who received NAC was 2.5 ng/ml, and the area under the curve was 0.63026 (p = 0.0127). The 5-year OS rate was 64% in those with an NLR <2.5 and 39% in those with an NLR ≥2.5. According to multivariate analysis, NLR ≥2.5, pathological T, pathological N, and intraoperative blood loss of >415 ml were independent poor prognostic factors.

CONCLUSIONS

NLR is a biomarker of prognosis in ESCC patients who undergo MIE after NAC.

Comparison of laparoscopic gastrectomy with 3-D/HD and 2-D/4 K camera system for gastric cancer: a prospective randomized control study

PURPOSE

We conducted a prospective clinical control study to identify the best imaging technology among three-dimensional (3-D) high-definition (HD) stereovision and two-dimensional (2-D) ultra-high-resolution (4 K) technology and confirm their effects on surgical outcomes of laparoscopic gastrectomy for gastric cancer.

METHODS

From April 2018 to August 2019, 50 patients were randomly classified into two groups based on the imaging technology (3-D/HD group = 25, 2-D/4 K = 25). After excluding eight patients based on laparoscopic findings, 42 patients were analyzed (3-D/HD group = 21, 2-D/4 K = 21). The primary endpoint was the operative time; the secondary endpoints were blood loss, postoperative infectious complications, and postoperative hospital stay.

RESULTS

The patients' backgrounds were similar (sex, age, body mass index [BMI], stage, procedure, and extent of lymph node dissection). There were no significant differences in operative time (252 vs. 238 min, P = 0.70), total blood loss, postoperative infectious complications, and postoperative hospital stay between the two groups. However, video analysis of surgeries revealed a significantly shortened median operative time (18 vs. 25 min, P = 0.04) in the suturing step with 3-D/HD; the median number of camera cleaning procedures during suprapancreatic lymph node dissection was significantly lower with 2-D/4 K than with 3-D/HD (n = 4.4 vs. 2.8, P = 0.02).

CONCLUSION

3-D/HD and 2-D/4 K laparoscopic radical gastrectomies provide similar surgical outcomes. However, the 3-D monitor reduces suturing time during reconstruction, while the 4 K monitor reduces the number of camera cleaning procedures during lymphadenectomy.

TRIAL REGISTRATION

Registered in the University Hospital Medical Information Network Clinical Trials Registry (identification number 000029227).