CAF-associated genes putatively representing distinct prognosis by in silico landscape of stromal components of colon cancer

Comprehensive understanding prognostic relevance of distinct tumor microenvironment (TME) remained elusive in colon cancer. In this study, we performed in silico analysis of the stromal components of primary colon cancer, with a focus on the markers of cancer-associated fibroblasts (CAF) and tumor-associated endothelia (TAE), as well as immunological infiltrates like tumor-associated myeloid cells (TAMC) and cytotoxic T lymphocytes (CTL). The relevant CAF-associated genes (CAFG)(representing R index = 0.9 or beyond with SPARC) were selected based on stroma specificity (cancer stroma/epithelia, cS/E = 10 or beyond) and expression amounts, which were largely exhibited negative prognostic impacts. CAFG were partially shared with TAE-associated genes (TAEG)(PLAT, ANXA1, and PTRF) and TAMC-associated genes (TAMCG)(NNMT), but not with CTL-associated genes (CTLG). Intriguingly, CAFG were prognostically subclassified in order of fibrosis (representing COL5A2, COL5A1, and COL12A1) followed by exclusive TAEG and TAMCG. Prognosis was independently stratified by CD8A, a CTL marker, in the context of low expression of the strongest negative prognostic CAFG, COL8A1. CTLG were comprehensively identified as IFNG, B2M, and TLR4, in the group of low S/E, representing good prognosis. Our current in silico analysis of the micro-dissected stromal gene signatures with prognostic relevance clarified comprehensive understanding of clinical features of the TME and provides deep insights of the landscape.

Short-term outcomes of preoperative chemotherapy with docetaxel, oxaliplatin, and S-1 for gastric cancer with extensive lymph node metastasis (JCOG1704)

BACKGROUND

The prognosis for marginally resectable gastric cancer with extensive lymph node metastasis (ELM) remains unfavorable, even after R0 resection. To assess the safety and efficacy of preoperative docetaxel, oxaliplatin, and S-1 (DOS), we conducted a multicenter phase II trial.

METHODS

Eligibility criteria included histologically proven HER2-negative gastric adenocarcinoma with bulky nodal (bulky N) involvement around major branched arteries or para-aortic node (PAN) metastases. Patients received three cycles of docetaxel (40 mg/m2, day 1), oxaliplatin (100 mg/m2, day 1), and S-1 (80-120 mg/body, days 1-14), followed by gastrectomy with D2 plus PAN dissection. Subsequently, patients underwent postoperative chemotherapy with S-1 for 1 year. The primary endpoint was major (grade ≥ 2a) pathological response rate (pRR) according to the Japanese Classification of Gastric Carcinoma criteria.

RESULTS

Between October 2018 and March 2022, 47 patients (bulky N, 20; PAN, 17; both, 10) were enrolled in the trial. One patient was ineligible. Another declined any protocol treatments before initiation. Among the 45 eligible patients who initiated DOS chemotherapy, 44 (98%) completed 3 cycles and 42 (93%) underwent R0 resection. Major pRR and pathological complete response rates among the 46 eligible patients, including the patient who declined treatment, were 57% (26/46) and 24% (11/46), respectively. Common grade 3 or 4 toxicities were neutropenia (24%), anorexia (16%), febrile neutropenia (9%), and diarrhea (9%). No treatment-related deaths occurred.

CONCLUSIONS

Preoperative chemotherapy with DOS yielded favorable pathological responses with an acceptable toxicity profile. This multimodal approach is highly promising for treating gastric cancer with ELM.

Risk factors for abdominal surgical infectious complications after distal gastrectomy for gastric cancer: A post-hoc analysis of a randomized controlled trial (JCOG0912)

BACKGROUND

Abdominal surgical infectious complications (ASIC) after gastrectomy for gastric cancer impair patients' survival and quality of life. JCOG0912 was conducted to compare laparoscopy-assisted distal gastrectomy with open distal gastrectomy for clinical stage IA or IB gastric cancer. The present study aimed to identify risk factors for ASIC using prospectively collected data.

METHODS

We performed a post-hoc analysis of the risk factors for ASIC using the dataset from JCOG0912. All complications were evaluated according to the Clavien-Dindo classification (CD). ASIC was defined as CD grade I or higher anastomotic leakage, pancreatic fistula, abdominal abscess, and wound infection. Analyses were performed using the logistic regression model for univariable and multivariable analyses.

RESULTS

A total of 910 patients were included (median age, 63 years; male sex, 61 %). Among them, ASIC occurred in 5.8 % of patients. In the univariable analysis, male sex (odds ratio [OR] 2.855, P = 0.003), diabetes (OR 2.565, P = 0.029), and Roux-en-Y (R-Y) reconstruction (vs. Billroth Ⅰ, OR 2.707, P = 0.002) were significant risk factors for ASIC. In the multivariable analysis, male sex (OR 2.364, P = 0.028) and R-Y reconstruction (vs. Billroth Ⅰ, OR 2.310, P = 0.015) were independent risk factors for ASIC.

CONCLUSIONS

Male sex and R-Y reconstruction were risk factors for ASIC after distal gastrectomy. Therefore, when performing surgery on male patients or when R-Y reconstruction is selected after gastrectomy for gastric cancer, surgeons should pay special attention to prevent ASIC.

Low skeletal muscle radiodensity is a risk factor for adjuvant chemotherapy discontinuation in colorectal cancer

BACKGROUND

Previously, we reported SMR (skeletal muscle radiodensity) as a potential prognostic marker for colorectal cancer. However, there have been limited studies on the association between SMR and the continuation of adjuvant chemotherapy in colorectal cancer.

METHODS

In this retrospective study, 143 colorectal cancer patients underwent curative surgery and adjuvant chemotherapy using the CAPOX regimen. Patients' SMRs were measured from preoperative CT images and divided into low (bottom quarter) and high (top three quarters) SMR groups. We compared chemotherapy cycles, capecitabine and oxaliplatin doses, and adverse effects in each group.

RESULTS

The low SMR group had significantly fewer patients completing adjuvant chemotherapy compared to the high SMR group (44% vs. 68%, P < 0.01). Capecitabine and oxaliplatin doses were also lower in the low SMR group. Incidences of Grade 2 or Grade 3 adverse effects did not differ between groups, but treatment discontinuation due to adverse effects was significantly higher in the low SMR group. Logistic regression analysis revealed Stage III disease (odds ratio 18.09, 95% CI 1.41-231.55) and low SMR (odds ratio 3.26, 95% CI 1.11-9.56) as factors associated with unsuccessful treatment completion. Additionally, a higher proportion of low SMR patients received fewer than 2 cycles of chemotherapy (50% vs. 12%).

CONCLUSION

The low SMR group showed higher treatment incompletion rates and received lower drug doses during adjuvant chemotherapy. Low SMR independently contributed to treatment non-completion in colorectal cancer patients.

Early administration of postoperative BCAA-enriched PPN may improve lean body mass loss in gastric cancer patients undergoing gastrectomy

BACKGROUND

It has been reported that weight loss or lean body mass (LBM) loss after gastrectomy for gastric cancer is associated with prognosis and nutritional support alone is insufficient to prevent LBM loss. Branched-chain amino acids (BCAA) play an important role in muscle catabolism, however their clinical effects on suppression of LBM loss in gastric cancer patients undergoing gastrectomy remains elusive. In this current study, we investigated the effect of our original PPN regimen including BCAA (designated to BCAA-regimen) on LBM loss.

METHODS

We conducted a randomized controlled trial (RCT) at a single institution where patients undergoing gastrectomy were assigned to either receive a five-day early postoperative course of the BCAA-regimen (BCAA group) or conventional nutrition. The primary endpoint was the % reduction in LBM at postoperative day 7. The secondary endpoints included the % reduction in LBM at 1 and 3 months postsurgery.

RESULTS

At postoperative day 7, LBM loss in the BCAA group tended to be lower than in the control group (0.16% vs. 1.7%, respectively; P = 0.21), while at 1 month postsurgery, LBM loss in the BCAA group was significantly different to that of the control group (- 0.3% vs. 4.5%, respectively; P = 0.04). At 3 months postgastrectomy, however, LBM loss was similar between the BCAA and the control groups.

CONCLUSION

Our RCT clinical trial clarified that early administration of the postoperative BCAA regimen improved LBM loss at 1 month after surgery in gastric cancer patients undergoing gastrectomy.

Anatomical Position of the Pancreas as a Risk Factor for Pancreatic Fistula after Laparoscopic Gastrectomy for Gastric Cancer

BACKGROUND

Laparoscopic gastrectomy is more frequently associated with postoperative pancreatic fistula than is open gastrectomy. We assumed that compression of the pancreas with various devices to obtain a proper operative view is associated with the higher incidence of PF in LG and that the extent of the compression differs depending on the anatomical position of the pancreas. The present study aimed to elucidate the correlation between the anatomical position of the pancreas and PF after LG for gastric cancer.

METHODS

Patients who underwent LG for gastric cancer from 2005 to 2019 were retrospectively reviewed. Two anatomical parameters representing the height of the slope looking down the celiac artery from the top of the pancreas (P-A length) and the steepness of the slope (UP-CA angle) were measured in computed tomography sagittal projections. The correlation between PF and (1) P-A length, (2) UP-CA angle, and (3) other clinicopathological factors was analyzed using a logistic regression model.

RESULTS

Among 3485 patients, grade ≥ II PF was observed in 140 (4.0%) patients. The UP-CA angle [odds ratio (OR), 2.472; 95% confidence interval (CI), 1.725-3.543; P < 0.001], a high BMI (OR 2.339; 95% CI 1.634-3.348; P < 0.001), and male sex (OR 2.602; 95% CI 1.590-4.257; P < 0.001) were independently correlated with grade ≥ II PF.

CONCLUSIONS

The present study identified a significant correlation between anatomical position of the pancreas and PF after LG. High BMI and male sex were also significantly correlated with PF after LG.

Five-Year Survival Outcomes of Laparoscopy-Assisted vs Open Distal Gastrectomy for Advanced Gastric Cancer: The JLSSG0901 Randomized Clinical Trial

Importance

Evidence of implementation of laparoscopic gastrectomy for locally advanced gastric cancer is currently insufficient, as the primary end point in previous prospective studies was evaluated at a median follow-up time of 3 years. More robust evidence is necessary to verify noninferiority of laparoscopic gastrectomy.

Objective

To compare 5-year survival outcomes between laparoscopy-assisted distal gastrectomy (LADG) and open distal gastrectomy (ODG) with D2 lymph node dissection for locally advanced gastric cancer.

Design, Setting, and Participants

This was a multicenter, open-label, noninferiority, prospective randomized clinical trial. Between November 26, 2009, and July 29, 2016, eligible patients with histologically proven gastric carcinoma from 37 institutes in Japan were enrolled. Two interim analyses and final analysis were performed in October 2014, May 2018, and November 2021, respectively.

Interventions

Patients were randomly assigned (1:1) to either the ODG or LADG group. The procedures were performed exclusively by qualified surgeons.

Main Outcomes and Measures

The primary end point was 5-year relapse-free survival, and the noninferiority margin for the hazard ratio (HR) was set at 1.31. The secondary end points were 5-year overall survival and safety.

Results

A total of 502 patients were included in the full-analysis set: 254 (50.6%) in the ODG group and 248 (49.4%) in the LADG group. Patients in the ODG group had a median (IQR) age of 67 (33-80) years and included 168 males (66.1%). Patients in the LADG group had a median (IQR) age of 64 (34-80) years and included 169 males (68.1%). No significant differences were observed in severe postoperative complications between the 2 groups in the safety analysis (ODG, 4.7% [11 of 233] vs LADG, 3.5% [8 of 227]; P = .64). The median (IQR) follow-up for all patients after randomization was 67.9 (60.3-92.0) months. The 5-year relapse-free survival was 73.9% (95% CI, 68.7%-79.5%) and 75.7% (95% CI, 70.5%-81.2%) for the ODG and LADG groups, respectively, and the HR was 0.96 (90% CI, 0.72-1.26; noninferiority 1-sided P = .03). Further, no significant difference was observed in overall survival time between the 2 groups, and the HR was 0.83 (95% CI, 0.57-1.21; P = .34). The pattern of recurrence was similar between the 2 groups.

Conclusions and Relevance

Results of this study show that on the basis of 5-year follow-up data, LADG with D2 lymph node dissection for locally advanced gastric cancer, when performed by qualified surgeons, was proved noninferior to ODG. This laparoscopic approach could become a standard treatment for locally advanced gastric cancer.

Trial Registration

UMIN Clinical Trial Registry: UMIN000003420.

A phase II study of preoperative chemotherapy with docetaxel, oxaliplatin, and S-1 followed by gastrectomy with D2 plus para-aortic nodal dissection for gastric cancer with extensive lymph node metastasis: JCOG1704

354

Background: Prognosis of gastric cancer (GC) with extensive lymph node metastasis (ELM) is poor due to unresectability even without distant metastases. We conducted a phase II study to evaluate the safety and efficacy of preoperative chemotherapy with docetaxel (D), oxaliplatin (O), and S-1 (S) followed by extended gastrectomy. Methods: Eligibility criteria included histologically proven adenocarcinoma of the stomach; bulky nodal involvement around major branched arteries to the stomach (Bulky N) and/or para-aortic nodal metastases (PAN); cM0 (except para-aortic nodes); negative lavage cytology; not linitis plastica type; PS of 0 or 1; 20-75 years old. Patients received three 21-day cycles of preoperative chemotherapy of D (40 mg/m2 on day 1), O (100 mg/m2 on day 1), and S (80-120 mg /body from day 1 to day 14), and then underwent gastrectomy with D2 plus para-aortic nodal dissection. After surgery, patients received adjuvant chemotherapy with S-1 for 1 year. Primary endpoint was major pathological response rate, defined by the disappearance of more than two-thirds of the primary tumor. Expected and threshold value of major pathological response was set at 40% and 25%, respectively. Sample size was calculated to be 50 based on a one-sided alpha of 0.1, power of 0.8 and single-arm phase II study using a Southwest Oncology Group (SWOG) two-stage design. Results: Between Oct 2018 and Mar 2022, 47 patients were enrolled, of whom 46 were eligible for efficacy analysis. The median age was 67 years. The pathological type was differentiated in 33 patients and undifferentiated in 14. Twenty patients had only bulky N, 17 had only PAN, and 10 had both of bulky N and PAN. Clinical stage was III in 19 and IV in 28 patients. Except one patient refused chemotherapy, 46 patients (45 in three cycles and 1 in one cycle) completed preoperative DOS. Forty-four patients (94%) underwent gastrectomy, including 23 distal gastrectomy and 21 total gastrectomy, and 43 (91%) had an R0 resection. Major pathological response was confirmed in 26 of 46 patients (57% with 80% CI: 46-67), including pCR of 24%, which met the statistical significance (p<0.0001). According to the Becker’s criteria, grade 3 was 13, grade 2 was 12, grade 1b was 7, and grade 1a was 11. DOS-related grade 3/4 toxicities included neutropenia in 11 patients (24%), anorexia in 7 (16%), diarrhea in 4 (9%), and febrile neutropenia in 4 (9%). Surgery-related grade 3/4 toxicities were abdominal abscess in 5 (12%) and pancreatic fistula in 3 (7%). No treatment-related death was observed. Conclusions: Preoperative DOS followed by gastrectomy with D2 plus para-aortic nodal dissection is safe, feasible, and effective for GC with ELM. Clinical trial information: jRCTs031180028 .

Less demand on stem cell marker-positive cancer cells may characterize metastasis of colon cancer

BACKGROUND

CD44 and CD133 are stem cell markers in colorectal cancer (CRC). CD44 has distinctive isoforms with different oncological properties like total CD44 (CD44T) and variant CD44 (CD44V). Clinical significance of such markers remains elusive.

METHODS

Sixty colon cancer were examined for CD44T/CD44V and CD133 at mRNA level in a quantitative PCR, and clarified for their association with clinicopathological factors.

RESULTS

(1) Both CD44T and CD44V showed higher expression in primary colon tumors than in non-cancerous mucosas (p<0.0001), while CD133 was expressed even in non-cancerous mucosa and rather decreased in the tumors (p = 0.048). (2) CD44V expression was significantly associated with CD44T expression (R = 0.62, p<0.0001), while they were not correlated to CD133 at all in the primary tumors. (3) CD44V/CD44T expressions were significantly higher in right colon cancer than in left colon cancer (p = 0.035/p = 0.012, respectively), while CD133 expression were not (p = 0.20). (4) In primary tumors, unexpectedly, CD44V/CD44T/CD133 mRNA expressions were not correlated with aggressive phenotypes, but CD44V/CD44T rather significantly with less aggressive lymph node metastasis/distant metastasis (p = 0.040/p = 0.039, respectively). Moreover, both CD44V and CD133 expressions were significantly decreased in liver metastasis as compared to primary tumors (p = 0.0005 and p = 0.0006, respectively).

CONCLUSION

Our transcript expression analysis of cancer stem cell markers did not conclude that their expression could represent aggressive phenotypes of primary and metastatic tumors, and rather represented less demand on stem cell marker-positive cancer cells.

Late complication after gastrectomy for clinical stage I cancer: supplementary analysis of JCOG0912

BACKGROUND

Late complications following gastric cancer surgery, including postgastrectomy syndromes, are complex problems requiring a solution. Reported risk factors for developing late complications include surgery-related factors, such as the surgical approach and the extent of resection and reconstruction. However, this has not been assessed in a prospective study with a large sample size. Therefore, this study aimed to evaluate associations between surgery-related factors and the development of late complications. Data from the JCOG0912 trial were used. It compared laparoscopy-assisted distal gastrectomy (LADG) to open distal gastrectomy (ODG) in clinical stage I gastric cancer patients.

METHODS

This study included 881/921 patients enrolled in the JCOG0912 trial. The incidence of late complications was compared between the ODG and the LADG arms. In addition, associations between surgery-related factors and the development of late complications were assessed by multivariable analyses using the proportional odds model to identify relevant risk factors.

RESULTS

There was no difference in the type or number of patients with late complications between the LADG and the ODG arms. The multivariable analysis for each late complication revealed that the Billroth-I reconstruction (vs. R-en-Y or Billroth-II) had a lower risk of cholecystitis [odds ratio (OR) 0.187, 95% confidence interval (CI) 0.039-0.905, P = 0.037] or ileus (OR 0.116, 95%CI 0.033-0.406, P < 0.001), and pylorus-preserving gastrectomy (vs. R-en-Y or Billroth-II) had a higher risk of reflux esophagitis (OR 3.348, 95% CI 1.371-8.176, P = 0.008). The surgical approach was not a risk factor for any late complications.

CONCLUSION

Differences in surgical approaches did not constitute a risk for developing late complications after gastrectomy. Billroth-I reconstruction reduced the risk of ileus and cholecystitis, but pylorus-preserving gastrectomy carried a risk for reflux esophagitis.

Short-term outcomes of robot-assisted versus conventional laparoscopic surgery for mid and low rectal cancer after neoadjuvant chemoradiotherapy: a propensity score-matched analysis

The benefits of robot-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. Only a few studies have evaluated the safety and feasibility of RALS following neoadjuvant chemoradiotherapy (NCRT). This study aimed to compare the short-term outcomes of RALS versus conventional laparoscopic surgery (CLS) after NCRT for rectal cancer. Propensity score matching of 111 consecutive patients who underwent RALS or CLS after NCRT for rectal adenocarcinoma between February 2014 and February 2022 was performed. Among them, 60 matched patients were enrolled and their short-term outcomes were compared. Although operative time, conversion rate to open laparotomy and blood loss were comparable, the incidence of postoperative complications, including anastomotic leakage, was significantly lower, urinary retention tended to be lower, and the days to soft diet intake and postoperative hospital stay were significantly shorter in the RALS than the CLS group. No postoperative mortality was observed in either group, and there were no significant differences in terms of resection margins and number of lymph nodes dissected. RALS after NCRT for rectal cancer is safe and technically feasible, and has acceptable short-term outcomes. Further studies are required for validation of the long-term oncological outcomes.

Short- and long-term outcomes of robotic-assisted laparoscopic surgery for rectal cancer: A single-center retrospective cohort study

INTRODUCTION

Whether rectal cancer surgery by robotic-assisted laparoscopic surgery provides beneficial advantages remains controversial. Although favorable outcomes in terms of the safety and technical feasibility of robotic-assisted laparoscopic surgery have been demonstrated for rectal cancer, long-term oncological outcomes for robotic-assisted laparoscopic surgery have only been examined in a few studies. This retrospective study of subjects who underwent robotic-assisted laparoscopic surgery evaluated short- and long-term outcomes of consecutive rectal cancer patients.

METHODS

Between November 2016 and January 2020, we analyzed the records of 62 consecutive patients who underwent robotic-assisted laparoscopic surgery for rectal adenocarcinoma without distant metastasis to evaluate short- and long-term outcomes.

RESULTS

Tumors were located in the lower or mid-rectum (88.7%) in most patients. The median operative time was 357 min. No patient received transfusions, and the median blood loss was 10.5 ml. Open laparotomy was not required in any patient. A Clavien-Dindo classification of all grades was observed in 12 patients (19.4%). Positive radial margin was not observed in any patient. Duration of median follow-up was 40.5 mo, while 3-y overall survival and 3-y relapse-free survival rates were 96.8% and 85.0%, respectively. The local recurrence rate was 3.4%.

CONCLUSION

Favorable short- and long-term outcomes demonstrated robotic-assisted laparoscopic surgery was safe and technically feasible for rectal cancer.

Comparison of short-term outcomes of robotic-assisted and conventional laparoscopic surgery for rectal cancer: A propensity score-matched analysis

INTRODUCTION

The advantages of robotic-assisted laparoscopic surgery (RALS) for rectal cancer remain controversial. This study clarified and compared the short-term outcomes of RALS for rectal cancer with those of conventional laparoscopic surgery (CLS).

METHODS

The records of 303 consecutive patients who underwent RALS or CLS for rectal adenocarcinoma between November 2016 and November 2021 were analyzed using propensity score-matched analysis. After matching, 188 patients were enrolled in our study to compare short-term outcomes, such as operative results, postoperative complications, and pathological findings, in each group.

RESULTS

After matching, baseline characteristics were comparable between groups. Although operative time in the RALS group was significantly longer than in the CLS group (p < 0.0001), the conversion rate to open laparotomy and the postoperative complication rate in the RALS group were significantly lower than in the CLS group (p = 0.0240 and p = 0.0109, respectively). Blood loss was comparable between groups. In the RALS group, postoperative hospital stay and days to soft diet were significantly shorter than those in the CLS group (p = 0.0464 and p < 0.0001, respectively). No postoperative mortality was observed in either group and significant differences were observed in resection margins and number of lymph nodes harvested.

CONCLUSION

Robotic-assisted laparoscopic surgery for rectal cancer was safe, technically feasible, and had acceptable short-term outcomes. Further studies are required to validate long-term oncological outcomes.

Excellent oncological outcomes besides short-term safety of laparoscopic and endoscopic cooperative surgery for gastric gastrointestinal stromal tumor

Background and study aims  Laparoscopic and endoscopic cooperative surgery (LECS) for gastric submucosal tumor was developed as a type of minimal local resection and is now widely used in Asian countries. However, the oncological safety of LECS for gastric gastrointestinal stromal tumor (GIST) remains unclear. LECS has potential oncology-related problems that may influence survival outcomes. Furthermore, the feasibility and safety of LECS have not yet been fully established. Patients and methods  Patients who were intended to undergo LECS for gastric GIST from 2006 to 2020 were retrospectively selected. The indication for LECS was determined according to the guidelines. The completion of LECS, complications, and survival outcomes of the patients were analyzed. Results  Two hundred fifty-nine patients were eligible in this study. According to intraoperative findings, 44 patients underwent local resection without luminal endoscopic procedures. Of the remaining 215 patients, 213 completely underwent LECS, which corresponds to a completion rate of 99.1 %. Six patients (2.8 %) had postoperative complications of Clavien-Dindo classification grade II or higher. Delayed gastric emptying was most commonly found in four patients (1.9 %). Old age ( P  = 0.0349), female sex ( P  = 0.0095), tumor located in the lesser curvature ( P  = 0.0015), and large tumor diameter ( P  = 0.0232) were significantly more common in patients with complications. The 3-year overall and disease-specific survival rates were 99 % and 100 %, respectively, in 215 patients who were intended to undergo LECS. Conclusions  Despite several oncological concerns, LECS for gastric GIST is oncologically safe besides a feasible and safe procedure in the short-term.

Skeletal Muscle Changes Assessed by Preoperative Computed Tomography Images Can Predict the Long-Term Prognosis of Stage III Colorectal Cancer

Background

Myopenia and myosteatosis are reported to be long-term prognostic factors in patients with colorectal cancer (CRC). However, the established parameters are unsuitable for the Japanese population because their body composition is different from that of the Western population.

Objective

We aimed to elucidate the effect of skeletal muscle changes among Japanese adults, measured using preoperative computed tomography (CT) as a prognostic factor in patients with stage III CRC.

Patients

We retrospectively analyzed 341 patients diagnosed with stage III CRC. The cross-sectional area (skeletal muscle index: SMI) and mean radiodensity of skeletal muscle (skeletal muscle radiodensity: SMR) were measured using preoperative CT. The optimal sex-specific cutoff value, which was used to divide the patients according to the risk of recurrence, was set for SMI and SMR. Univariate and multivariate analysis were performed to determine the prognostic factors for recurrence-free survival (RFS).

Results

The cutoff values of SMI for men and women were set as 48.5 and 41.4, respectively, and those of SMR were 35.0 and 21.7, respectively. Univariate analysis identified low SMI and SMR in men and low SMR in women as the worst prognostic factors for RFS. Multivariate analysis identified low SMI in men and low SMR in women as independent poor prognostic factors for RFS (hazard ratio [HR] = 1.87, 95% confidence interval [CI], 1.08-3.47, P = .03 and HR = 2.49, CI, 1.21-4.95, P = .01).

Conclusion

Low SMI in men and low SMR in women were the independent prognostic factors for patients with stage III CRC.

Effects of perioperative eicosapentaenoic acid‑enriched oral nutritional supplement on the long‑term oncological outcomes after total gastrectomy for gastric cancer

Basic and clinical reports have suggested that eicosapentaenoic acid (EPA) exhibits anti-tumor activity. The present study evaluated whether perioperative EPA could improve the survival of patients with localized gastric cancer as a key secondary endpoint of a randomized clinical study. The present study was designed as multicenter, open-label, superiority, randomized trial to confirm the preventive effect of EPA on body weight loss after total gastrectomy for gastric cancer. Eligible patients were randomized to either the standard-diet group (EPA-off group) or EPA-on group by a centralized dynamic method. An EPA-enriched supplement (ProSure^®) was given to the EPA-on group in addition to their standard diet. This supplement included 600 kcal with 2.2 g/day of EPA. Among the 126 patients who were randomized, 123 patients (EPA-off group, n=60; EPA-on group, n=63) were examined in the survival analyses. All background factors were well balanced between the two groups. The 3-year and 5-year overall survival rates were 74.6 and 67.8%, respectively, in the EPA-off group, and 77.8 and 76.2% in the EPA-on group. There was no significant difference between the EPA-off and EPA-on groups (hazard ratio, 0.77; P=0.424). In the subgroup analysis, the hazard ratio was 0.39 in patients who received neoadjuvant chemotherapy and 0.57 in patients with nodal metastasis. In conclusion, a clear survival benefit of perioperative EPA was not observed in localized gastric cancer. The value of EPA should be further tested in a future study in patients with unfavorable advanced gastric cancer. Clinical trial number: UMIN000006380; date of registration, September 21, 2011.

Improved anastomotic technique for esophagojejunal anastomosis using circular stapler

PURPOSE

In total gastrectomy, Roux-en-Y reconstruction with esophagojejunal anastomosis has been widely used in gastrointestinal reconstruction. In the case of anastomotic leakage of RY reconstruction, esophagojejunal anastomosis should be paid attention, and esophageal fragility is considered the reason for the leakage. Here, we introduce an atraumatic and innovative technique for esophagojejunostomy.

METHODS

We prospectively performed routine novel esophagojejunal anastomosis using circular stapler device and reviewed the records of 14 consecutive patients with gastric cancer who underwent open total gastrectomy at Kitasato University Hospital from April 2019 to March 2020. By placing about 10 stay sutures around the entire esophageal stump, the esophageal stump can be opened to the maximum diameter. The forceps grasping the tissue was not necessary for these procedures, consequently preventing either tears the esophageal stump tissue or narrowing the esophageal lumen.

RESULTS

These 14 cases were far advanced cases of gastric cancer, 6 cases of splenectomy and 3 cases of distal pancreatectomy. No technical problems such as esophageal tear were observed in all cases. Postoperative complications were observed in 6 patients (42.9%), and their contents varied. However, they all improved conservatively. Regarding anastomotic complications, anastomotic leakage of Clavien-Dindo-II was observed in one case, but it improved conservatively.

CONCLUSION

Our new atraumatic anastomosis technique could abolish problems such as tear of esophagus wall due to introduce a larger-sized anvil, trauma of esophageal wall by grasping with forceps such as Alice or Babcock. Consequently, the atraumatic and innovative technique might make the esophagojejunostomy safe. This method might prevent anastomotic leakage and other complications effectively.

Pancreas-contactless gastrectomy for gastric cancer prevents postoperative inflammation

BACKGROUND

Pancreas-related complications after laparoscopic gastrectomy (LG) for gastric cancer can be fatal. We developed a gastrectomy procedure with no pancreas contact to prevent such complications and herein report the surgical outcomes.

METHODS

We retrospectively reviewed 182 consecutive patients with gastric cancer who underwent LG at Kitasato University Hospital from January 2017 to January 2020. These patients were divided into a pancreas-contact group (C group) and pancreas-contactless group (CL group) for comparison of postoperative complications, and inflammatory parameters such as body temperature (BT) and C-reactive protein (CRP).

RESULTS

Postoperative complications of CDc grade ≧ IIIa were significantly fewer in the CL group than in the C group [0/76 (0%) vs. 6/106 (5.7%), P = 0.035]. The median drain amylase (drain-AMY) on postoperative day 1 (POD1) was significantly lower in the CL group than in the C group (641 vs. 1162 IU/L, P = 0.02), as was BT at POD1 (37.4 °C vs. 37.7 °C, P = 0.04), the patient group with a BT above 37.5 °C at POD3 [5/76 (6.5%) vs. 18/106 (17%), P = 0.037], and those showing a CRP above 20.0 mg/dL at POD3 [5/76 (6.5%) vs. 20/106 (19%), P = 0.018].

CONCLUSIONS

Our technique to prevent pancreas contact during supra-pancreatic lymph node dissection during LG could minimize the inflammatory response and prevent further postoperative complications. Further large-scale, prospective studies are now required.

Haploinsufficiency by minute MutL homolog 1 promoter DNA methylation may represent unique phenotypes of microsatellite instability-gastric carcinogenesis

Promoter DNA methylation of MutL homolog 1 (MLH1) is considered to play a causative role in microsatellite instability (MSI) carcinogenesis in primary gastric cancer, and a high MSI status is associated with treatment sensitivity to human cancers. Nevertheless, clinicopathological analysis is defective for MLH1 methylation status in a quantitative manner. We newly developed quantitative methylation specific PCR using a TaqMan probe and applied it to 138 patients with primary gastric cancer who underwent gastrectomy in addition to basic molecular features such as MSI, Epstein Barr virus, and other DNA methylation status. (1) In primary gastric cancer, median methylation value was 0.055, ranging from 0 to 124.3. First, MLH1 hypermethylation was strongly correlated with MSI-High/MSI-Low status and suppressed immunostaining (P < 0.0001). (2) The MLH1 hypermethylation was associated with advanced age (P = 0.0048), antral location (P = 0.0486), synchronous multiple gastric cancer (P = 0.0001), and differentiated histology (P = 0.028). (3) Log-rank plot analysis identified the most relevant cut-off value (0.23) to reflect gentle phenotypes in MLH1 hypermethylation cases (P = 0.0019), especially in advanced gastric cancer (P = 0.0132), which are designated as haploinsufficiency of MSI (MSI-haplo) phenotype in this study. (4) In synchronous multiple gastric cancer, MLH1 hypermethylation was not necessarily confirmed as field cancerization. (5) MSI-haplo defined by MLH1 methylation status represented distinct prognostic phenotype even after molecular classifications. MLH1 hypermethylation designated as MSI-haplo may represent unique prognostic phenotype during gastric carcinogenesis.

Laparoscopic and endoscopic cooperative surgery for advanced gastric cancer as palliative surgery in elderly patients: a case report

Background

The number of elderly patients with gastric cancer is increasing, with the very elderly often refusing radical gastrectomy with lymph node dissection. Such a patient presented to us and we proposed a palliative surgery involving gastric local resection using laparoscopy endoscopy cooperative surgery (LECS).

Case presentation

An 89-year-old woman presented to our hospital with progressing anemia. She had an aortic arch replacement for aortic dissection 6 months previously and was taking antithrombotic drugs for atrial fibrillation. She was diagnosed with advanced gastric cancer, and we presented a radical resection treatment plan involving distal gastrectomy with lymph node dissection. However, she strongly refused undergoing radical gastric cancer resection. We believed that at least local control of the tumor could be effective in preventing future bleeding or stenosis due to tumor progression. Therefore, we proposed a local gastrectomy with LECS as an optional treatment, and she agreed to this treatment. The surgery was performed with minimal blood loss, and no postoperative complications were observed. Histopathological examination revealed a 45 × 31-mm, Type 2, poorly differentiated adenocarcinoma (pT4a, ly0, v1a), and the resected margin was negative. The patient was alive 2 years after surgery without apparent recurrence or other illness. In addition, her weight was maintained, together with her daily activity.

Conclusion

Local resection of gastric cancer with LECS might be an option for the palliative treatment of patients who refuse radical resection of gastric cancer.

Activation of iNKT Cells Facilitates Liver Repair After Hepatic Ischemia Reperfusion Injury Through Acceleration of Macrophage Polarization

Macrophage polarization is critical for liver tissue repair following acute liver injury. However, the underlying mechanisms of macrophage phenotype switching are not well defined. Invariant natural killer T (iNKT) cells orchestrate tissue inflammation and tissue repair by regulating cytokine production. Herein, we examined whether iNKT cells played an important role in liver repair after hepatic ischemia-reperfusion (I/R) injury by affecting macrophage polarization. To this end, we subjected male C57BL/6 mice to hepatic I/R injury, and mice received an intraperitoneal (ip) injection of α-galactosylceramide (α-GalCer) or vehicle. Compared with that of the vehicle, α-GalCer administration resulted in the promotion of liver repair accompanied by acceleration of macrophage differentiation and by increases in the numbers of Ly6C^high pro-inflammatory macrophages and Ly6C^low reparative macrophages. iNKT cells activated with α-GalCer produced interleukin (IL)-4 and interferon (IFN)-γ. Treatment with anti-IL-4 antibodies delayed liver repair, which was associated with an increased number of Ly6C^high macrophages and a decreased number of Ly6C^low macrophages. Treatment with anti-IFN-γ antibodies promoted liver repair, associated with reduced the number of Ly6C^high macrophages, but did not change the number of Ly6C^low macrophages. Bone marrow-derived macrophages up-regulated the expression of genes related to both a pro-inflammatory and a reparative phenotype when co-cultured with activated iNKT cells. Anti-IL-4 antibodies increased the levels of pro-inflammatory macrophage-related genes and decreased those of reparative macrophage-related genes in cultured macrophages, while anti-IFN-γ antibodies reversed the polarization of macrophages. Cd1d-deficient mice showed delayed liver repair and suppressed macrophage switching, compared with that in wild-type mice. These results suggest that the activation of iNKT cells by α-GalCer facilitated liver repair after hepatic I/R injury by both IL-4-and IFN-γ-mediated acceleration of macrophage polarization. Therefore, the activation of iNKT cells may represent a therapeutic tool for liver repair after hepatic I/R injury.

Safety and feasibility of laparoscopic and endoscopic cooperative surgery for duodenal neoplasm: a retrospective multicenter study

BACKGROUND

A delayed perforation can often occur after endoscopic treatment for duodenal neoplasms and may be fatal due to leakage of pancreatic and bile juices. We aimed to evaluate the feasibility and safety of laparoscopic and endoscopic cooperative surgery for duodenal neoplasms (D-LECS) in a multicenter, retrospective study.

METHODS

The clinical characteristics and surgical outcomes of 206 patients with duodenal neoplasms in whom D-LECS had initially been attempted at one of 14 institutions were reviewed retrospectively.

RESULTS

Of the 206 patients, 63 (30.6 %), 128 (62.1 %), and 15 patients (7.3 %) had lesions at the bulb, second portion, and third portion of the duodenum, respectively. The rates of en bloc and R0 resections during D-LECS were 96.1 % and 95.1 %, respectively. Intraoperative and delayed perforations occurred in 10 (4.9 %) and 5 patients (2.4 %), respectively. No cases of recurrence were observed. Surgical duration of ≥ 180 minutes was an independent risk factor for postoperative complications.

CONCLUSIONS

The results revealed that D-LECS was performed with oncological safety and technical feasibility.

Surgical outcomes in gastroenterological surgery in Japan: Report of the National Clinical Database 2011-2019

BACKGROUND

We aimed to present the 2019 annual report of the gastroenterological section of the National Clinical Database (NCD).

METHODS

We reviewed 609,589 cases recorded in 2019 and 5,029,764 cases registered from 2011 to 2019 for the 115 selected gastroenterological surgical procedures.

RESULTS

The main features of gastroenterological surgery in Japan were similar to those described in the 2018 annual report, namely, that 1) operative numbers gradually increased in all procedures, except gastrectomy and hepatectomy, which decreased in these years; 2) in all eight major gastroenterological surgeries, the age distribution tended toward older patients; 3) the morbidity of esophagectomy, hepatectomy, and pancreaticoduodenectomy increased, but mortality was minimized in all procedures; 4) all eight major gastroenterological procedures have increasingly been performed under laparoscopy; and 5) board-certified surgeons were increasingly involved. These trends in recent years were more prominent in 2019.

CONCLUSIONS

Thanks to the continuous cooperation and dedication of the surgeons, medical staff, and surgical clinical reviewers who registered the clinical data into the NCD, it is possible to understand the comprehensive landscape of surgery in Japan and to disclose new evidence in this field. The Japanese Society of Gastroenterological Surgery will continue to promote the value of this database and encourage the use of feedback and clinical studies using the NCD, now and in the future. Generating further approaches to surgical quality improvement are important directions for future research.

History and emerging trends in chemotherapy for gastric cancer

Chemotherapy is indispensable for gastric cancer. For unresectable and/or recurrent gastric cancer, first-line chemotherapy consists of multidrug regimens including oral 5-FU agents such as S1/Xeloda and platinum preparations, as well as Trastuzumab, which is effective in HER2-positive cases. Second- and third-line chemotherapy regimens include taxanes, Ramucirumab (R-mab), and Nivolumab (N-mab), which have different mechanisms of action from first-line chemotherapy. R-mab is molecularly targeted to vascular endothelial growth factor receptor 2 in the host cells, but its indication is not conditional. For resectable gastric cancer, in Eastern countries, postoperative adjuvant chemotherapy has been successful, including S1, Docetaxel/S1 (DS), and Xeloda/Oxaliplatin (Xelox) regimens, whereas, in Western countries, the 5-FU/Leucovorin/Oxaliplatin/Docetaxel (FLOT) regimen was recently shown to be effective in the perioperative chemotherapy setting. Most recently, however, in Eastern countries, perioperative SOX was demonstrated to be effective in specific advanced gastric cancer. For stage IV gastric cancer, new therapeutic strategies have been proposed such as neoadjuvant chemotherapy and conversion surgery, and cures can be conditionally obtained. Recent genomic understanding of gastric cancer proposed a diversity of molecular targets by molecular profiling. Such optimized chemotherapy regimens, according to the specific clinical situations, have been rigorously established for the best survival of advanced gastric cancer.

Comparison of effects of six main gastrectomy procedures on patients’ quality of life assessed by Postgastrectomy Syndrome Assessment Scale-45

BACKGROUND

The effects of various gastrectomy procedures on the patient’s quality of life (QOL) are not well understood. Thus, this nationwide multi-institutional cross-sectional study using the Postgastrectomy Syndrome Assessment Scale-45 (PGSAS-45), a well-established questionnaire designed to clarify the severity and characteristics of the postgastrectomy syndrome, was conducted.

AIM

To compare the effects of six main gastrectomy procedures on the postoperative QOL.

METHODS

Eligible questionnaires retrieved from 2368 patients who underwent either of six gastrectomy procedures [total gastrectomy with Roux-en-Y reconstruction (TGRY; n = 393), proximal gastrectomy (PG; n = 193), distal gastrectomy with Roux-en-Y reconstruction (DGRY; n = 475), distal gastrectomy with Billroth-I reconstruction (DGBI; n = 909), pylorus-preserving gastrectomy (PPG; n = 313), and local resection of the stomach (LR; n = 85)] were analyzed. Among the 19 main outcome measures of PGSAS-45, the severity and characteristics of postgastrectomy syndrome were compared for the aforementioned six gastrectomy procedures using analysis of means.

RESULTS

TGRY and PG significantly impaired the QOL of postoperative patients. Postoperative QOL was excellent in LR (cardia and pylorus were preserved with minimal resection). In procedures removing the distal stomach, diarrhea subscale (SS) and dumping SS were less frequent in PPG than in DGBI and DGRY. However, there was no difference in the postoperative QOL between DGBI and DGRY. The most noticeable adverse effects caused by gastrectomy were meal-related distress SS, dissatisfaction at the meal, and weight loss, with significant differences among the surgical procedures.

CONCLUSION

Postoperative QOL greatly differed among six gastrectomy procedures. The severity and characteristics of postgastrectomy syndrome should be considered to select gastrectomy procedures, overcome surgical shortcomings, and enhance postoperative care.

Randomized study of prevention of gastrointestinal toxicities by nutritional support using an amino acid-rich elemental diet during chemotherapy in patients with esophageal cancer (KDOG 1101)

BACKGROUND

This randomized study was designed to evaluate the clinical effect of an elemental diet during chemotherapy in patients with esophageal cancer.

METHODS

The inclusion criteria were as follows: (1) esophageal squamous cell carcinoma, (2) stage IB-IV, (3) schedule to receive docetaxel, cisplatin, and 5-fluorouracil (DCF chemotherapy), (4) 20-80 years old, (5) performance status of 0-2, (6) oral intake ability, and (7) written informed consent. Patients were divided into two groups: the elemental supplementary group and the non-supplementary group. Patients received ELENTAL^® (160 g/day) orally 9 weeks after the start of chemotherapy. Primary endpoint was the incidence of grade 2 or higher gastrointestinal toxicity according to the Common Terminology Criteria for Adverse Events, version 4.0. Secondary endpoints were the incidence of all adverse events and the evaluation of nutritional status.

RESULTS

Thirty-six patients in the elemental supplementary group and 35 patients in the non-supplementary group were included in the analysis. The incidence of grade 2 or higher gastrointestinal toxicity and all grade 3 or 4 adverse events did not differ significantly between the groups. In the elemental supplementary group, the body weight (p = 0.057), muscle mass (p = 0.056), and blood levels of transferrin (p = 0.009), total amino acids (p = 0.019), and essential amino acids (p = 0.006) tended to be maintained after chemotherapy.

CONCLUSION

Nutritional support provided by an amino acid-rich elemental diet was ineffective for reducing the incidence of adverse events caused by DCF chemotherapy in patients with esophageal cancer.

Comparison of Postoperative Quality of Life among Three Different Reconstruction Methods After Proximal Gastrectomy: Insights From the PGSAS Study

BACKGROUND

Proximal gastrectomy (PG) has become an increasingly preferred procedure for early cancer in the upper third of the stomach, owing to reportedly superior quality of life (QOL) after PG when compared with total gastrectomy. However, various methods of reconstruction have currently been proposed. We compared the postoperative QOL among the three different reconstruction methods after PG using the Postgastrectomy Syndrome Assessment Scale-45 (PGSAS-45) questionnaire.

METHODS

Post Gastrectomy Syndrome Assessment Study (PGSAS), a nationwide multi-institutional survey, was conducted to evaluate QOL using the PGSAS-45 among various types of gastrectomy. Of the 2,368 eligible data from the PGSAS survey, data from 193 patients who underwent PG were retrieved and used in the current study. The PGSAS-45 consists of 45 items including 22 original gastrectomy specific items in addition to the SF-8 and GSRS. These were consolidated into 19 main outcome measures pertaining postgastrectomy symptoms, amount of food ingested, quality of ingestion, work, and level of satisfaction for daily work, and the three reconstruction methods (n = 193; 115 esophago-gastrostomy [PGEG], 34 jejunal interposition [PGJI], and 44 jejunal pouch interposition [PGJPI]) were compared using PGSAS-45.

RESULTS

Size of the remnant stomach was significantly larger in PGEG, and significantly smaller in PGJI and PGJPI (P < 0.05). There was no difference in other patient background factors among the groups. EGJPI tended to be superior to PGEG in several of the 19 main outcome with marginal significance (P = 0.047-0.076).

CONCLUSION

PGJPI appears to be the most favorable of the three reconstruction methods after PG especially when the size of remnant stomach is rather small.

TRIAL REGISTRATION NUMBER

UMIN-CTR #000002116 entitled as "A study to observe correlation between resection and reconstruction procedures employed for gastric neoplasms and development of postgastrectomy syndrome".

Oncological Impact of Gross Proximal Margin Length in Distal Gastrectomy for Gastric Cancer: Is the Japanese Recommendation Valid?

Objective

To identify an oncological impact of gross proximal margin (PM) length in distal gastrectomy for cancer.

Summary background data

In Japan, to obtain pathologically negative PMs in gastrectomy for cancer, the Gastric Cancer Treatment Guidelines (GCTGs) recommend maintaining the PM length to at least 2 cm for cT1, 3 cm for the expansive growth type (Exp), and 5 cm for the infiltrative growth type (Inf) of cT2-4. The GCTGs also recommend confirming pathologically negative PMs by intraoperative frozen section analyses when the gross PMs are shorter than the recommendations. However, whether they are valid is unknown.

Methods

Patients who intended to undergo curative distal gastrectomy were included. They were divided into groups A (adherence to the GCTGs) and NA (nonadherence) according to the PM length. The incidence of pathologically positive PMs and survival outcomes were compared between the groups. Propensity scores (PSs) were used in comparisons of survival outcomes to eliminate potential confounders.

Results

A total of 1036 patients were eligible. Pathologically positive PMs were identified in group NA with cT1 and Inf, and the incidence was 1.6% and 3.1%, respectively. Adjusted analysis using the PSs showed comparable survival outcomes between the groups. However, the hazard ratios according to the PSs presented a possible survival advantage in maintaining the recommended gross PM lengths except for cT1 and Exp located in the lower stomach.

Conclusion

Surgeons should maintain the gross PM lengths recommended in the GCTGs to both obtain pathologically negative PMs and avoid survival disadvantages.

Prospective study to validate the clinical utility of DNA diagnosis of peritoneal fluid cytology test in gastric cancer

The clinical efficacy of DNA cytology test (CY) in gastric cancer (GC) has been retrospectively proposed using cancer‐specific methylation of cysteine dioxygenase type 1 (CDO1). We confirmed the clinical utility of DNA CY in a prospective cohort. Four hundred GC samples were prospectively collected for washing cytology (UMIN000026191), and detection of the DNA methylation of CDO1 was assessed by quantitative methylation‐specific PCR in the sediments. Endpoint was defined as the match rate between conventional CY1 and DNA CY1 (diagnostic sensitivity), and the DNA CY0 rate (diagnostic specificity) in pStage IA. DNA CY1 was detected in 45 cases (12.5%), while CY1 was seen in 31 cases (8.6%) of 361 chemotherapy‐naïve samples, where the sensitivity and specificity of the DNA CY in the peritoneal solutions were 74.2% and 96.5%, respectively. The DNA CY was positive for 3.5/0/4.9/11.4/58.8% in pStage IA/IB/II/III/IV, respectively (P < .01). In the multivariate analysis, DNA CY1 was independently correlated with pathological tumor depth (pT) (P = .0012), female gender (P = .0099), CY1 (P = .0135), P1 (P = .019), and carcinoembryonic antigen (CEA) (P = .036). The combination of DNA CY1 and P factor nearly all covered the potential peritoneal dissemination (P1 and/or CY1 and/or DNA CY1) (58/61:95.1%). DNA CY1 had a significantly poorer prognosis than DNA CY0 in GC patients (P < .0001). DNA CY1 detected by CDO1 promoter DNA methylation has a great value to detect minimal residual disease of the peritoneum in GC clinics, representing poor prognosis as a novel single DNA marker.

[Laparoscopic Partial Hepatectomy for the Liver Metastasis of Gastric Cancer after Nab-Paclitaxel plus Ramucirumab Combination Therapy-A Case Report]

We report a case of laparoscopic partial hepatectomy after nab-paclitaxel plus ramucirumab(nab-PTX plus RAM)combination therapy for postoperative liver recurrence of gastric cancer. The patient was a 50's man who underwent laparoscopic distal gastrectomy, D2 lymph node dissection, and Billroth-I reconstruction for gastric cancer. The pathological findings were L, Gre, Post, Type 3, por>tub2, pT3N3a, M1(CY1), fStage Ⅳ. Postoperative chemotherapy with S-1 was performed. The CT examination 6 months after the operation revealed a total of 3 tumors(maximum diameter of 5×4 cm)in liver segments S6, 7, and 8. We started nab-PTX plus RAM combination therapy for liver metastases and performed laparoscopic partial hepatectomy when 12 courses of the treatment were completed. The postoperative course was uneventful, and the patient was discharged on postoperative day 7. Pathological results suggested that the tumor was exposed on the cut surface, and 6 courses of nab-PTX plus RAM combination therapy were administered postoperatively. The patient has been recurrence-free 12 months after the operation.

A "Just Enough" Gross Proximal Margin Length Ensuring Pathologically Complete Resection in Distal Gastrectomy for Gastric Cancer

Introduction

The objective of this study is to determine a "just enough" gross proximal margin (PM) length to ensure a pathologically negative PM in distal gastrectomy for gastric cancer. There is a discrepancy between the gross and pathological proximal boundaries of gastric cancer. We must transect the stomach maintaining some safety margins to obtain a pathologically negative PM. However, we have no standard to indicate where to transect the stomach.

Methods

Patients undergoing distal gastrectomy for gastric cancer were enrolled. A new parameter named ΔPM, which corresponded to the pathological extension proximal to the gross tumor boundary toward the resection stump, was evaluated. The number of patients was counted in each ΔPM range of 1-cm increments. The maximum ΔPM was defined as the first value at which the number of patients became 0, and it was determined as the recommended gross PM length for each disease type.

Results

In cT1, 259 and 330 patients were assigned to differentiated (Dif) and undifferentiated types (Und), respectively. The maximum ΔPM was 20 mm for Dif and 40 mm for Und. In cT2-4, 194 and 490 patients were assigned to the expansive (Exp) and infiltrative (Inf) growth types. The maximum ΔPM was 30 mm for Exp. The maximum ΔPM was 50 mm for Inf of less than 80 mm and 60 mm for Inf of 80 mm or more.

Conclusions

A newly recommended gross PM length to ensure pathologically negative PMs in distal gastrectomy for each gastric cancer type was determined.

Robot-assisted minimally invasive esophagectomy for esophageal cancer: Meticulous surgery minimizing postoperative complications

Minimally invasive esophagectomy (MIE) has been reported to reduce postoperative complications especially pulmonary complications and have equivalent long-term survival outcomes as compared to open esophagectomy. Robot-assisted minimally invasive esophagectomy (RAMIE) using da Vinci surgical system (Intuitive Surgical, Sunnyvale, USA) is rapidly gaining attention because it helps surgeons to perform meticulous surgical procedures. McKeown RAMIE has been preferably performed in East Asia where squamous cell carcinoma which lies in more proximal esophagus than adenocarcinoma is a predominant histological type of esophageal cancer. On the other hand, Ivor Lewis RAMIE has been preferably performed in the Western countries where adenocarcinoma including Barrett esophageal cancer is the most frequent histology. Average rates of postoperative complications have been reported to be lower in Ivor Lewis RAMIE than those in McKeown RAMIE. Ivor Lewis RAMIE may get more attention for thoracic esophageal cancer. The studies comparing RAMIE and MIE where recurrent nerve lymphadenectomy was thoroughly performed reported that the rate of recurrent nerve injury is lower in RAMIE than in MIE. Recurrent nerve injury leads to serious complications such as aspiration pneumonia. It seems highly probable that RAMIE is beneficial in performing recurrent nerve lymphadenectomy. Surgery for esophageal cancer will probably be more centralized in hospitals with surgical robots, which enable accurate lymph node dissection with less complications, leading to improved outcomes for patients with esophageal cancer. RAMIE might occupy an important position in surgery for esophageal cancer.

Postoperative pancreatic fistula after gastrectomy for gastric cancer

Postoperative pancreatic fistula is one of the most severe complications after gastric cancer surgery, and can cause critical patient conditions leading to surgery-related death. Fortunately, the incidence of postoperative pancreatic fistula after gastrectomy seems to be decreasing with changes in operative procedures. The rate was reported at about 30% after open gastrectomy with Appleby's method in 1997, but lately has improved below 1% for robotic gastrectomy in 2019. For the diagnosis of postoperative pancreatic fistula, drain amylase concentration has been demonstrated to be beneficial and some reports have proposed the optimal cut-off values of drain amylase to predict major postoperative pancreatic fistula. There have been many reports identifying risk factors for postoperative pancreatic fistula, including overweight patients, pancreatic anatomy, blunt trauma from compression of the pancreas, and thermal injuries caused by the continuous use of energy devices. And importantly, laparoscopic gastrectomy has been shown to be more often associated with postoperative pancreatic fistula than open gastrectomy in the prospective national clinical database in Japan. Hence, further sophistication of surgical techniques to reduce pancreas compression would have great promise in reducing postoperative pancreatic fistula after laparoscopic gastrectomy.

Clinical outcomes of radical gastrectomy following trastuzumab-based chemotherapy for stage IV HER2-positive gastric or gastroesophageal junction cancer

PURPOSE

Patients who receive trastuzumab (T-mab) plus chemotherapy for stage IV HER2-positive gastric or gastroesophageal junction cancer sometimes respond remarkably well and can undergo radical surgery. However, the clinical outcomes of preoperative T-mab combined chemotherapy with radical gastrectomy remain unclear. We conducted this study to investigate the clinical outcomes of this multimodal treatment.

METHODS

From among a total of 199 patients who received T-mab-based chemotherapy for stage IV HER2-positive gastric or gastroesophageal junction cancer between 2011 and 2018, the subjects of this retrospective analysis were 20 patients who subsequently underwent radical gastrectomy.

RESULTS

Seven patients had gastroesophageal junction cancer and 13 had gastric cancer. Eleven patients had unresectable stage IV cancer and 9 had resectable metastatic disease. Chemotherapy regimens included capecitabine, cisplatin + T-mab (11 patients), and S-1, oxaliplatin + T-mab (nine patients). The median number of chemotherapy cycles before surgery was three (range, 2-62). During preoperative chemotherapy, grade 3/4 adverse events developed in six patients. None suffered grade ≥ 3b postoperative complications. The 3-year relapse-free survival (RFS) and overall survival (OS) rates were 58.9% and 89.5%, respectively.

CONCLUSION

Combined preoperative T-mab-based chemotherapy and surgery appears to be safe and effective for stage IV HER2-positive gastric or gastroesophageal junction cancer, with a clinically meaningful impact on RFS and OS.

Perirenal fat thickness as a predictor of postoperative complications after laparoscopic distal gastrectomy for gastric cancer

Background

Laparoscopic distal gastrectomy is used widely in surgery for gastric cancer. Excess visceral fat can limit the ability to dissect the suprapancreatic region, potentially increasing the risk of local complications, particularly pancreatic fistula. This study evaluated perirenal fat thickness as a surrogate for visceral fat to see whether this was related to complications after laparoscopic distal gastrectomy.

Methods

Perirenal fat thickness was measured dorsal to the left kidney as an indicator of visceral fat in patients with gastric cancer who underwent laparoscopic distal gastrectomy. Patients were divided into two groups: those with and those without complications. The relationship between perirenal fat thickness and postoperative complications was evaluated.

Results

The optimal cut‐off value for predicting morbidity using adipose tissue thickness was 10·7 mm; a distance equal to or greater than this was considered a positive perirenal fat thickness sign (PTS). A positive PTS showed a significant correlation with visceral fat area. Multivariable analysis found that a positive PTS was an independent risk factor for complications (hazard ratio 4·42, 95 per cent c.i. 2·31 to 8·86; P < 0·001).

Conclusion

Perirenal fat thickness as an indicator of visceral fat was an independent predictor of postoperative complications after laparoscopic distal gastrectomy for gastric cancer.

Therapeutic value of splenectomy to dissect splenic hilar lymph nodes for type 4 gastric cancer involving the greater curvature, compared with other types

BACKGROUND

Whether splenectomy for splenic hilar lymph node (No. 10) dissection in type 4 gastric cancer involving the greater curvature is necessary is not established. Patients with type 4 gastric cancer often experience peritoneal relapse, despite curative surgery, and total gastrectomy with splenectomy is frequently associated with infectious complications.

METHOD

Patients with cT2-T4 gastric cancer in the upper or middle third of the stomach, or both, involving the greater curvature who underwent R0 total gastrectomy with splenectomy between 2006 and 2016 were selected. Clinicopathological findings, postoperative complications, the incidence of lymph node metastasis, and the therapeutic value index of each station were compared between type 4 and non-type 4 gastric cancer.

RESULTS

We enrolled 50 patients with type 4 and 60 with non-type 4. The former had a significantly higher proportion of the undifferentiated type and larger and deeper tumors. The overall incidence of Grade III or higher complications was 20.9%. The incidence of No. 10 metastasis was 26.0% in type 4 and 31.7% in non-type 4. Although the therapeutic value index of the No. 10 was 13.7 in type 4 and 15.0 in non-type 4, the index of type 4 ranked just below several peri-gastric stations and seventh, while that in non-type 4 ranked second.

CONCLUSION

Splenectomy for No. 10 dissection may be oncologically valid for type 4 gastric cancer involving the greater curvature. A safer procedure for No. 10 dissection should be established.

Prediction of Efficacy of Postoperative Chemotherapy by DNA Methylation of CDO1 in Gastric Cancer

BACKGROUND

CDO1 is a presumed tumor suppressor gene in human cancers, the expression of which is silenced by promoter DNA methylation. Moreover, CDO1 harbors functionally oncogenic aspects through modification of mitochondrial membrane potential. We recently proposed that this oncogenic feature allows for the prediction of the efficacy of postoperative chemotherapy in colon cancer. The present study aims to elucidate the efficacy of prediction of success of postoperative chemotherapy in advanced gastric cancer to improve the treatment strategy of patients.

MATERIALS AND METHODS

Forced expression of CDO1 in gastric cancer cell lines was assessed using the JC-1 assay. Promoter DNA methylation was investigated in quantitative TaqMan methylation-specific polymerase chain reaction in 321 pathological stage II/III advanced gastric cancer cases treated by curative gastrectomy with or without postoperative chemotherapy.

RESULTS

(1) Forced expression of CDO1 led to increased mitochondrial membrane potential, accompanied by augmented survival in gastric cancer cells under anaerobic conditions. These results suggest that CDO1-expressing cancer cells survive more easily in anaerobic lesions which are inaccessible to anticancer drugs. (2) Intriguingly, in cases with the highest CDO1 methylation (ranging from 15% to 40%), patients with postoperative chemotherapy showed significantly better survival than those with no postoperative chemotherapy. (3) A robust prognostic difference was observed that was explained by differential recurrences of distant metastasis (P = 0.0031), followed by lymph node (P = 0.0142) and peritoneal dissemination (P = 0.0472).

CONCLUSIONS

The oncogenic aspects of CDO1 can be of use to determine patients with gastric cancer who will likely respond to treatment of invisible systemic dissemination by postoperative adjuvant chemotherapy.

Neoadjuvant chemotherapy plus surgery for high-risk advanced gastric cancer: long-term results of KDOG1001 trial

PURPOSE

The purpose of this study is to evaluate the long-term survival outcomes of KDOG1001 trial after a minimum follow-up of 3 years.

METHODS

Patients with bulky N2 lymph nodes, linitis plastica (type 4), or large ulcero-invasive-type tumors (type 3) received up to four 28-day cycles of DCS neoadjuvant chemotherapy (docetaxel at 40 mg/m², cisplatin at 60 mg/m² on day 1, and S-1 at 40 mg/m² twice daily for 2 weeks) followed by gastrectomy with D2 lymphadenectomy plus adjuvant S-1 therapy for 1 year. The final preplanned analysis of long-term outcomes including overall survival and relapse-free survival was conducted after minimum follow-up of 3 years. This trial is registered with the University Hospital Medical Information Network Clinical Trials Registry, number UMIN 000003642, and has been completed.

RESULTS

From May 2010 through January 2017, 40 patients were enrolled. All included patients underwent neoadjuvant chemotherapy with DCS followed by gastrectomy with D2 lymphadenectomy, and 32 (80%) completed adjuvant S-1 therapy for 1 year. After a median follow-up for surviving patients of 68 months at the last follow-up in January 2020, 3-year overall survival rate was 77.5% (95% confidence interval 62.1-87.9%), while 3-year relapse-free survival rate was 62.5% (95% confidence interval 46.8-76.0%).

CONCLUSION

Neoadjuvant chemotherapy with 4 cycles of DCS followed by D2 gastrectomy plus adjuvant S-1 was associated with relatively good long-term oncologic outcomes for patients with the high-risk gastric cancer.

Delta-shaped anastomosis vs circular stapler anastomosis after laparoscopic distal gastrectomy with Billroth I reconstruction: A randomized controlled trial

INTRODUCTION

The aim of this study is to evaluate the efficacy of delta-shaped anastomosis compared to circular stapler anastomosis in laparoscopic distal gastrectomy with Billroth I reconstruction.

METHODS

This is a single-center randomized controlled study. Eligibility criteria included histologically proven gastric adenocarcinoma in the lower third of the stomach, clinical stage I tumor. Patients were preoperatively randomized to circular stapler anastomosis or delta-shaped anastomosis. The primary endpoint is the number of analgesics used during three days after surgery. We compared the surgical outcomes of the two groups. Postoperative quality of life was evaluated using the Postgastrectomy Syndrome Assessment Scale-45. This trial was registered at the UMIN Clinical Trials Registry as UMIN000025160.

RESULTS

Between December 2016 and September 2018, 39 patients (delta-shaped anastomosis 18, circular stapler anastomosis 21) were enrolled. There was no difference in the number of analgesics used during three days after surgery (median nine: delta-shaped anastomosis vs nine: circular stapler anastomosis, P = .91). There was no difference in the overall proportion with in-hospital grade II-IIIB surgical complications (11%: delta-shaped anastomosis, 14%: circular stapler anastomosis). There was no operation-related death in either arm. Regarding postoperative quality of life evaluated one month after surgery, diarrhea subscale was significantly worse in delta-shaped anastomosis than in circular stapler anastomosis.

CONCLUSION

We did not demonstrate the advantage of delta-shaped anastomosis in terms of postoperative pain. Since delta-shaped anastomosis tended to cause postoperative abdominal symptoms related to diarrhea, we should carefully apply the delta-shaped anastomosis to laparoscopic distal gastrectomy with Billroth I reconstruction.

Treatment option of endoscopic stent insertion or gastrojejunostomy for gastric outlet obstruction due to gastric cancer: a propensity score-matched analysis

BACKGROUND

There are currently two treatment options for gastric outlet obstruction (GOO) due to gastric cancer, endoscopic stenting and surgical gastrojejunostomy. However, their therapeutic effects have not yet been established. Therefore, the present study was undertaken to examine these effects.

METHODS

The Japanese Gastric Cancer Association invited its delegates to participate in a retrospective multicenter cohort study on patients with GOO due to gastric cancer who underwent stent therapy or gastrojejunostomy in 2015.

RESULTS

We obtained data from 85 patients undergoing stent therapy and 94 undergoing gastrojejunostomy from 42 hospitals. Baseline data revealed that stent patients had lower food intake, poorer performance status, and worse prognostic indices than gastrojejunostomy patients. Postoperative food intake and survival times were worse in stent patients than in gastrojejunostomy patients. We performed propensity score matching to select pairs of patients with similar baseline characteristics in the two treatment groups. After matching, the frequency of postoperative complications was significantly less in stent patients (3%, 1/33) than in gastrojejunostomy patients (21%, 7/34; p = 0.03). A low residue or full diet was achieved by 97% of stent patients (32/33) and 97% of gastrojejunostomy patients (33/34) (p = 0.98). Median survival times were 7.8 months in stent patients and 4.0 months in gastrojejunostomy patients (p = 0.38).

CONCLUSIONS

Propensity score matching demonstrated that endoscopic stent placement resulted in less postoperative morbidity than and a similar food intake and equivalent survival times to gastrojejunostomy. These results suggest the utility of stent therapy.

Risk factors and prognosis of gastric stasis, a crucial problem after laparoscopic pylorus-preserving gastrectomy for early middle-third gastric cancer

BACKGROUND

Pylorus-preserving gastrectomy (PPG) is a function-preserving procedure for cT1N0 gastric cancer located in the middle-third of stomach, which is currently performed through a laparoscopic approach (LPPG). PPG is sometimes associated with a crucial problem during the early postoperative course, designated gastric stasis. However, information regarding gastric stasis remains to be fully elucidated.

METHODS

The study included 897 patients who underwent LPPG between 2005 and 2017. Early postoperative gastric stasis (E-stasis) was defined when the following conditions were fulfilled: upper abdominal distension, remnant stomach fullness on radiography image, and period of starvation exceeding 72 h within 1 month postoperatively. To evaluate long-term outcomes of E-stasis, late postoperative food residue (L-residue) was defined as grade 2 or higher food residue endoscopically according to the RGB (residue, gastritis, bile) classification at 1 year postoperatively. Risk factors and long-term outcomes of E-stasis were retrospectively analyzed.

RESULTS

E-stasis was the most common complication during the early postoperative course. E-stasis occurred in 68 (7.6%) patients. Multivariate analysis identified age (≥ 61 years), DM, and postoperative intraabdominal infection as risk factors. At 1 year postoperatively, relative body weight ratio and postoperative serum albumin in the patients who experienced E-stasis was significantly lower than those in the other patients (P = 0.042 and 0.011, respectively). Of the patients who suffered from E-stasis, 42.5% experienced L-residue.

CONCLUSIONS

E-stasis after LPPG occurs in 7.6% of patients. Age, DM, and intraabdominal infection are significantly related to E-stasis. E-stasis is associated with poorer nutritional and functional outcomes even at 1 year postoperatively.

Multiple gastrointestinal metastasis after endoscopic submucosal dissection for poorly differentiated gastric adenocarcinoma

A 76-year-old man had a diagnosis of double primary cancers consisting of poorly differentiated esophageal squamous cell carcinoma (ESCC) invading the submucosa and poorly differentiated gastric adenocarcinoma (GAC) invading the submucosa. The clinical stage of both ESCC and GAC was T1N0M0 stage I. The tumor diameter of ESCC and GAC was 20 mm and 25 mm, respectively. We performed chemoradiotherapy for ESCC. Chemotherapy consisted of nedaplatin in an intravenous dose of 90 mg/m² on day 1 and 5-fluorouracil in an intravenous dose of 800 mg/m² on days 1-5, repeated every 4 weeks for two cycles. Radiotherapy consisted of 50.4 Gy in 28 fractions for ESCC. GAC was down-staged after chemoradiotherapy for ESCC and was treated by endoscopic submucosal dissection (ESD). The tumor was histopathologically confirmed to be down-staged to intramucosal cancer with a diameter of 18 mm and no evidence of lymphovascular invasion and ulceration. Multiple metastasis occurred in the stomach, the small intestine and the colorectum after ESD. ESD is not a curative treatment even if chemotherapy is effective for poorly differentiated GAC invading the submucosa. Multiple gastrointestinal metastasis may be a unique recurrence pattern after ESD for such a lesion.

Neoadjuvant chemotherapy plus surgery for high-risk advanced gastric cancer: Long-term results of KDOG1001 trial

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Background: In the phase 2, open-label, KDOG1001 (UMIN000003642) study, neoadjuvant chemotherapy (NAC) with docetaxel, cisplatin, and S-1 (DCS), followed by gastrectomy with D2 lymph node dissection for high-risk advanced gastric cancer showed feasibility of DCS therapy with an enough R0 resection rate of 90%. Here we present long-term results after a minimum follow-up of 3 years. Methods: Patients with bulky node metastasis (bulky N), linitis plastica (type 4), or large ulcero-invasive-type tumors (type 3) received up to four 28-day cycles of DCS neoadjuvant chemotherapy (docetaxel at 40 mg/m2, cisplatin at 60 mg/m2 on day 1, and S-1 at 40 mg/m2 twice daily for 2 weeks) followed by gastrectomy with D2 lymphadenectomy. This analysis presents the final preplanned assessment of outcomes after 3 years. Primary endpoint was R0 resection rate. Secondary endpoints included overall survival (OS), progression free survival (PFS), completion rate of the protocol treatment, and pathological response rate (pRR) of DCS NAC. Results: Of 40 patients enrolled from May 2010 through January 2017, 7 (17.5%) had bulky N, 18 (45.0%) had type 4, and 16 (40%) had large type 3 with 1 (2.5%) having both large type 3 and bulky N2. All included patients underwent preoperative DCS chemotherapy followed by surgery with D2 lymphadenectomy with 32 (80%) completed postoperative S-1 therapy for 1 year. After a median follow-up for surviving patients of 67 mo (range, 36 mo to 110 mo) at the last follow-up in January 2020, 3-year OS was 78% [95% confidence interval (CI) 62–88%], while 3-year PFS was 63% (95% CI 47–76%). Completion rate of the protocol treatment was 62.5% (25/40) with pRR of 57.5% (23/40). In bulky N2, 3-y OS was 86% and 3-y PFS was 71% with pRR of 100%. In type 4, 3-y OS was 67% and 3-y PFS was 50% with pRR of 44%. In large type 3, 3-y OS was 88% and 3-y PFS was 75% with pRR of 56%. Patients with type 4 had significantly worse OS and PFS than those with the other types [HR 7.20 (95% CI 2.23–32.21) and HR 3.00 (95% CI 1.21–8.19)]. Conclusions: Preoperative chemotherapy with up to four cycles of DCS followed by gastrectomy plus adjuvant S-1 therapy is a promising treatment strategy for patients with bulky node metastasis, type 4 and large type 3 gastric cancers. For type 4 cancer, further improvement of treatment strategy is needed. Clinical trial information: 000003642 .

Intraoperative conversion from laparoscopic gastrectomy to an open procedure: a decade of experience in a Japanese high-volume center

BACKGROUND

Although laparoscopic gastrectomy (LG) is a widely accepted treatment for gastric cancer, conversion to laparotomy is sometimes required. The current study aimed to review the time trends of intraoperative conversions to open procedures during the decade in which the LG procedure was being developed.

METHODS

Cases in which LG was attempted at the Cancer Institute Hospital from 2005 to 2018 were retrospectively reviewed, and the details regarding conversions to open surgery were examined.

RESULTS

Twenty-two (0.63%) of 3,498 patients required conversion to open surgery due to technical difficulties. The major reasons for conversions were difficulties in reconstruction (seven patients; 0.20%) and intraoperative bleeding (six patients; 0.17%). All conversions due to difficulties in reconstruction occurred in the introduction period of LG during the performance of esophagojejunostomy or esophagogastrostomy in laparoscopic total gastrectomy or proximal gastrectomy using a circular stapler. Five (71.4%) of the seven patients in whom conversion was performed due to difficulties in reconstruction developed postoperative severe complications. No conversions due to difficulties in reconstruction have been experienced since 2011, possibly due to the decrease in the number of laparoscopic total gastrectomy procedures and the introduction of the use of a linear stapler in esophagojejunostomy. To manage intraoperative bleeding in LG, hemostatic procedures were systematized and conversions were considered if visualization was not maintained following the procedures. None of the six patients who required laparotomy due to intraoperative bleeding required surgical or radiological intervention postoperatively.

CONCLUSION

Over a decade of experience and procedural changes have markedly decreased the incidence of conversion to open surgery in LG. The main causes of conversion during the early period of LG introduction were difficulties in reconstruction and intraoperative bleeding; the incidences of these complications have been decreased by employing the appropriate procedures for LG.

Facilitated completion of 1-year adjuvant S-1 monotherapy for pathological stage II or III gastric cancer by medical oncologists

PURPOSE

Several factors are known to be significantly associated with a low completion rate of 1-year adjuvant S-1 monotherapy for gastric cancer. The present study investigated whether or not the specialties of physicians conducting adjuvant S-1 monotherapy affect the completion rate.

METHODS

A total of 437 patients who underwent curative gastrectomy followed by adjuvant S-1 monotherapy for pathological stage II or III gastric cancer between 2008 and 2013 were retrospectively analyzed. Factors affecting completion of adjuvant S-1 monotherapy, including the physicians (medical oncologists or surgeons) administering S-1, were evaluated by a multivariate analysis. The relationship between patient factors and physicians was analyzed regarding the cumulative incidence of discontinuation. The number of times the dose was reduced, the schedule changed, or administration was suspended or delayed in patients completing adjuvant S-1 monotherapy was also counted.

RESULTS

The multivariate analysis showed that old age (≥ 65 years old), excess body weight loss (≥ 15%), and surgeons were independently associated with discontinuation. In older patients, the cumulative incidence of discontinuation by medical oncologists was significantly lower than that by surgeons. Medical oncologists ensured that older patients continued S-1 by frequent suspension or a delay in each course.

CONCLUSIONS

Medical oncologists may facilitate completion of adjuvant S-1 monotherapy.

An Unmodulated Very-Low-Voltage Electrosurgical Technology Creates Predictable and Ultimate Tissue Coagulation: From Experimental Data to Clinical Use

Objective. We analyzed the underlying principles of an unmodulated very-low-voltage (VLV) mode, designated as “soft coagulation” in hemostasis, and demonstrate its clinical applications. Summary Background Data. While the advantage of the VLV mode has been reported across surgical specialties, the basic principle has not been well described and remains ambiguous. Methods. Characteristics of major electrosurgical modes were measured in different settings. For the VLV mode, the tissue effect and electrical parameters were assessed in simulated environments. Results. The VLV mode achieved tissue coagulation with the lowest voltage compared with the other modes in any settings. With increasing impedance, the voltage of the VLV mode stayed very low at under 200 V compared with other modes. The VLV mode constantly produced effective tissue coagulation without carbonization. We have demonstrated the clinical applications of the method. Conclusions. The voltage of the VLV mode consistently stays under 200 V, resulting in tissue coagulation with minimal vaporization or carbonization. Therefore, the VLV mode produces more predictable tissue coagulation and minimizes undesirable collateral thermal tissue effects, enabling nerve- and function-preserving surgery. The use of VLV mode through better understanding of minimally invasive way of using electrosurgery may lead to better surgical outcomes.

A phase I study of docetaxel/oxaliplatin/S-1 (DOS) combination neoadjuvant chemotherapy for patients with locally advanced adenocarcinoma of the esophagogastric junction

BACKGROUND

The optimal dose of each drug used in the docetaxel, oxaliplatin, and S-1 (DOS) chemotherapy remains to be clarified for the Japanese population. The purpose of this study was to determine a recommended dose for a combination neoadjuvant DOS chemotherapy for Japanese patients with locally advanced adenocarcinoma of the esophagogastric junction (AEG).

METHODS

Patients with cT3 or more advanced AEG without distant metastasis were eligible for this study. The planned dosages of docetaxel (mg/m², day 1), oxaliplatin (mg/m², day 1), and S-1 (mg/day, days 1-14) were: 50/100/80-120 at level 1, and 60/100/80-120 at level 2, respectively. The treatment cycle was repeated every 3 weeks, and patients were assessed for response to the treatment after 2 and 3 cycles. This study was registered in the UMIN Clinical Trial Registry (UMIN 000022210).

RESULTS

We enrolled 12 patients with locally advanced AEG in this study. At dose level 1, one of the six patients experienced dose-limiting toxicity (DLT) of grade 3 diarrhea and grade 3 febrile neutropenia. Two of the next six patients also experienced DLT of need for more than 2-week delay of the start of the second cycle due to adverse events at dose level 2. Based on these results, level 2 was considered the recommended dose for this regimen.

CONCLUSION

Recommended doses of docetaxel (mg/m²), oxaliplatin (mg/m²), and S-1 (mg/day) were 60/100/80-120. This chemotherapy scheme showed good preliminary efficacy with acceptable toxicity warranting a further phase II trial to investigate the efficacy of this regimen.