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.

A nonrandomized controlled trial: long-term outcomes of LATG/LAPG for cStage I gastric cancer: Japan Clinical Oncology Group Study JCOG1401

BACKGROUND

A previous report confirmed the safety of laparoscopy-assisted total and proximal gastrectomies (LATG and LAPG) (JCOG1401). This report demonstrates the 5-year relapse-free survival (RFS) and overall survival (OS) after long-term follow-up to confirm the efficacy of these surgical methods as key secondary endpoints for cStage I gastric cancer.

METHODS

This study enrolled patients who had histologically proven gastric adenocarcinoma and were diagnosed with clinical T1N0, T1N(+), or T2N0 tumors according to the 14th edition of the Japanese Classification of Gastric Carcinoma (3rd English edition).

RESULTS

Between April 2015 and February 2017, 246 patients were enrolled, although one patient was excluded because of misregistration. Meticulous follow-up was continued for > 5 years for each patient, and the data were analyzed in March 2022. The 5-year RFS was 90.0% (95% confidence interval [CI] 85.5-93.2%), and the 5-year OS was 91.2% (95% CI 86.9-94.2%) in all enrolled patients. Grade 3 or 4 late postoperative complications were detected in 12.7% of patients.

CONCLUSIONS

This single-arm study showed that the long-term outcomes of LATG/LAPG for cStage I gastric cancer were acceptable, which is considered one of the standard treatments when performed by experienced surgeons. Trail registration UMIN000017155 ( http://www.umin.ac.jp/ctr/ ).

Acceleration of sarcopenia in elderly patients who develop asymptomatic pneumonia shadow within one year after surgery for early gastric cancer

BACKGROUND

Although early gastric cancer is curable with local treatment, the overall survival in elderly patients did not reach 80% at five years after surgery. The major cause of death in elderly patients with early gastric cancer is not cancer itself but is related to postoperative sarcopenia. Elderly patients frequently develop postoperative asymptomatic pneumonia shadow, which is associated with a poor prognosis. However, why asymptomatic pneumonia shadow worsens the prognosis remains unclear. We investigated whether sarcopenia is accelerated in patients who developed asymptomatic pneumonia shadow.

METHODS

We retrospectively examined patients of > 75 years of age who underwent R0 gastrectomy for gastric cancer and were diagnosed with T1 disease at National Cancer Center Hospital between 2005 and 2012. The diagnosis of asymptomatic pneumonia shadow was defined by diagnostic findings of pneumonia (consolidation type, reticular type, and nodular type) which were newly observed on chest computed tomography performed one year after surgery in comparison to preoperative computed tomography. Postoperative muscle loss was assessed by a computed tomography-based analysis using the L3 skeletal muscle index before and two years after surgery and the rate of decrease was calculated. Patients were classified into two groups according to the rate of decrease (cut-off value: 10%).

RESULTS

Of the 3412 patients who underwent gastrectomy in our hospital during the study period, 142 were included in this study. Asymptomatic pneumonia shadow was found in 26 patients (18%). Patients who developed asymptomatic pneumonia shadow showed a significantly greater loss of muscle volume in comparison to patients who did not develop asymptomatic pneumonia shadow. In the multivariate analysis, total gastrectomy and asymptomatic pneumonia shadow were the independent risk factors for severe muscle loss. However, there was no significant difference in prognosis between the two groups.

CONCLUSIONS

Sarcopenia was accelerated in elderly patients who developed asymptomatic pneumonia shadow after surgery for early gastric cancer. However, the poor prognosis in these patients may not be related to accelerated sarcopenia.

Perioperative TAS-118 plus oxaliplatin in patients with locally advanced gastric cancer: APOLLO-11 study

BACKGROUND

We investigated the feasibility of perioperative chemotherapy with S-1 and leucovorin (TAS-118) plus oxaliplatin in patients with locally advanced gastric cancer.

METHODS

Patients with clinical T3-4N1-3M0 gastric cancer received four courses of TAS-118 (40-60 mg/body, orally, twice daily for seven days) plus oxaliplatin (85 mg/m2, intravenously, day one) every two weeks preoperatively followed by gastrectomy with D2 lymphadenectomy, followed by postoperative chemotherapy with either 12 courses of TAS-118 monotherapy (Step 1) or eight courses of TAS-118 plus oxaliplatin (Step 2). The primary endpoints were completion rates of preoperative chemotherapy with TAS-118 plus oxaliplatin and postoperative chemotherapy with TAS-118 monotherapy (Step 1) or TAS-118 plus oxaliplatin (Step 2).

RESULTS

Among 45 patients enrolled, the preoperative chemotherapy completion rate was 88.9% (90% CI 78.0-95.5). Major grade ≥ 3 adverse events (AEs) were diarrhoea (17.8%) and neutropenia (8.9%). The R0 resection rate was 95.6% (90% CI 86.7-99.2). Complete pathological response was achieved in 6 patients (13.3%). Dose-limiting toxicity was not observed in 31 patients receiving postoperative chemotherapy (Step 1, n = 11; Step 2, n = 20), and completion rates were 90.9% (95% CI 63.6-99.5) for Step 1 and 80.0% (95% CI 59.9-92.9) for Step 2. No more than 10% of grade ≥ 3 AEs were observed in  patients receiving Step 1. Hypokalaemia and neutropenia occurred in 3 and 2 patients, respectively, receiving Step 2. The 3-year recurrence-free and overall survival rates were 66.7% (95% CI 50.9-78.4) and 84.4% (95% CI 70.1-92.3), respectively.

CONCLUSIONS

Perioperative chemotherapy with TAS-118 plus oxaliplatin with D2 gastrectomy is feasible.

Multiancestry genomic and transcriptomic analysis of gastric cancer

Gastric cancer is among the most common malignancies worldwide, characterized by geographical, epidemiological and histological heterogeneity. Here, we report an extensive, multiancestral landscape of driver events in gastric cancer, involving 1,335 cases. Seventy-seven significantly mutated genes (SMGs) were identified, including ARHGAP5 and TRIM49C. We also identified subtype-specific drivers, including PIGR and SOX9, which were enriched in the diffuse subtype of the disease. SMGs also varied according to Epstein-Barr virus infection status and ancestry. Non-protein-truncating CDH1 mutations, which are characterized by in-frame splicing alterations, targeted localized extracellular domains and uniquely occurred in sporadic diffuse-type cases. In patients with gastric cancer with East Asian ancestry, our data suggested a link between alcohol consumption or metabolism and the development of RHOA mutations. Moreover, mutations with potential roles in immune evasion were identified. Overall, these data provide comprehensive insights into the molecular landscape of gastric cancer across various subtypes and ancestries.

Frequency of lymph node metastasis according to tumor location in clinical T1 early gastric cancer: supplementary analysis of the Japan Clinical Oncology Group study (JCOG0912)

BACKGROUND

The frequency of lymph node metastases per lymph node site in early gastric cancer has not been well clarified from the data based on prospective studies. This exploratory analysis aimed to determine the frequency and location of lymph node metastases in clinical T1 gastric cancer using the data from JCOG0912 to investigate the validity of the extent of standard lymph node dissection defined in Japanese guidelines.

METHODS

This analysis included 815 patients with clinical T1 gastric cancer. The proportion of pathological metastasis was identified for each lymph node site per tumor location (middle third and lower third) and four equal parts of the gastric circumference. The secondary aim was identification of the risk factor for lymph node metastasis.

RESULTS

Eighty-nine patients (10.9%) had pathologically positive lymph node metastases. Although the overall frequency of metastases was low (0.3-5.4%), metastases were widely located in each lymph node sites when primary lesion was in the middle third of the stomach. No. 4sb and 9 showed no metastasis when primary lesion was in the lower third of the stomach. Lymph node dissection of metastatic nodes resulted in a 5-year survival in more than 50% of patients. A tumor greater than 3 cm and a T1b tumor were associated with lymph node metastasis.

CONCLUSIONS

This supplementary analysis demonstrated that nodal metastasis from early gastric cancer is widely and disorderly not depending on the location. Thus, systematic lymph node dissection is necessary to cure the early gastric cancer.

Long-term outcomes after laparoscopy-assisted total or proximal gastrectomy with nodal dissection for clinical stage I gastric cancer: Japan Clinical Oncology Group study (JCOG1401)

305

Background: JCOG0912 supports the non-inferiority of laparoscopy-assisted distal gastrectomy (LADG) compared with open distal gastrectomy (ODG) for clinical stage I gastric cancer relapse-free survival (RFS), suggesting that LADG should be considered a standard treatment option when performed by experienced surgeons. No prospective study evaluating laparoscopy-assisted total gastrectomy (LATG) and laparoscopy-assisted proximal gastrectomy (LAPG) has been completed in terms of both safety and long-term survival. Considering that the results of the phase III trial to evaluate the long-term outcome of LADG (JCOG0912) could guarantee that of LATG/LAPG, we conducted a single-arm confirmatory trial (JCOG1401) to evaluate the safety of LATG/LAPG for clinical stage I proximal gastric cancer and JCOG1401 confirmed the safety of LATG/LAPG. Long-term outcomes as the secondary endpoints of this study are reported here after 5-year follow-up period. Methods: Laparoscopic operators were limited to credentialed surgeons. The extent of nodal dissection was selected based on the Gastric Cancer Treatment Guidelines in Japan. The primary endpoint was the proportion of grade 2 (CTCAE ver. 4.0) or greater esophageal anastomotic leak. The sample size was determined to be 245 considering a threshold of 8% and expected value of 3% with a one-sided alpha error of 2.5% and statistical power of 90%. The secondary endpoints were overall survival (OS) and RFS. Results: Between April 2015 and February 2017, 245 patients were enrolled. Among them, 1 patient was excluded from safety analysis due to ineligible. LATG/LAPG was performed in 195/49. 170/47/17/8/2 patients had pStage IA/IB/II/IIIA/IIIB disease and 190/31/15/8 patients had pT1/T2/T3/T4 disease, respectively. Grade 2 or greater esophageal anastomotic leak was 2.5% (6/244) (95% CI 0.9-5.3), as previously reported. 5-year OS was 91.2% (95% CI 86.9-94.2). 5-year RFS was 90.0% (95% CI 85.5-93.2). Among 22 deaths, 14 patients died without recurrence and 8 patients died with recurrence. Twelve recurrences were observed in 5/2/4/1 patients for pT1/T2/T3/T4. The sites of recurrence were peritoneal metastasis in 2 cases, hematogenous metastasis in 9 cases (liver: 6, bone: 2, lung: 1), and other in 1 case. Conclusions: The long-term outcomes of LATG/LAPG for Stage I gastric cancer patients were excellent and seem comparable to those of open procedures. Similar to JCOG0912, JCOG1401 guarantee the long-term survival of LATG/LAPG. Clinical trial information: UMIN000017155 .

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.

Prediction of tissue-of-origin of early stage cancers using serum miRNomes

BACKGROUND

Noninvasive detection of early stage cancers with accurate prediction of tumor tissue-of-origin could improve patient prognosis. Because miRNA profiles differ between organs, circulating miRNomics represent a promising method for early detection of cancers, but this has not been shown conclusively.

METHODS

A serum miRNA profile (miRNomes)-based classifier was evaluated for its ability to discriminate cancer types using advanced machine learning. The training set comprised 7931 serum samples from patients with 13 types of solid cancers and 5013 noncancer samples. The validation set consisted of 1990 cancer and 1256 noncancer samples. The contribution of each miRNA to the cancer-type classification was evaluated, and those with a high contribution were identified.

RESULTS

Cancer type was predicted with an accuracy of 0.88 (95% confidence interval [CI] = 0.87 to 0.90) in all stages and an accuracy of 0.90 (95% CI = 0.88 to 0.91) in resectable stages (stages 0-II). The F1 score for the discrimination of the 13 cancer types was 0.93. Optimal classification performance was achieved with at least 100 miRNAs that contributed the strongest to accurate prediction of cancer type. Assessment of tissue expression patterns of these miRNAs suggested that miRNAs secreted from the tumor environment could be used to establish cancer type-specific serum miRNomes.

CONCLUSIONS

This study demonstrates that large-scale serum miRNomics in combination with machine learning could lead to the development of a blood-based cancer classification system. Further investigations of the regulating mechanisms of the miRNAs that contributed strongly to accurate prediction of cancer type could pave the way for the clinical use of circulating miRNA diagnostics.

A retrospective 5-year survival analysis of surgically resected gastric cancer cases from the Japanese Gastric Cancer Association nationwide registry (2001-2013)

BACKGROUND

The nationwide registry of the Japanese Gastric Cancer Association collected data of surgically resected cases of gastric cancer between 2001 and 2013. These retrospective analyses aimed to delineate tumor characteristics, surgical history, and survival distribution.

METHODS

Data from 254,706 patients with primary gastric cancer were included. The 5-year survival rates were calculated for various subsets of prognostic factors.

RESULTS

The number of patients over 70 years old increased from 2001 to 2013. The frequency with which laparoscopic gastrectomy was opted for increased dramatically (from 3.5 to 40.8%) in 13 years. We focused on the patients registered between 2010 and 2013, for whom data collection was based on the 3rd edition of the Japanese classification and guidelines. Five-year overall survival (OS) rate among 92,305 patients with resected tumors was 70.6%. The 5-year OS rates of patients with pathological stage IA, IB, IIA, IIB, IIIA, IIIB, IIIC, and IV disease were 89.6%, 83.2%, 77.6%, 68.1%, 59.3%, 45.6%, 29.9%, and 14.0%, respectively.

CONCLUSION

Our detailed analysis highlights the historical changes in outcomes of surgically treated gastric malignancies in Japan, and provides robust dataset for future analysis.

Prognostic Impact of Long-term Postoperative Pneumonia in Elderly Patients with Early Gastric Cancer

Background: Elderly patients with stage I gastric cancer, a disease that is curable by surgery, easily develop long-term postoperative pneumonia (LTPP) within two years after surgery despite showing no active symptoms. The present study assessed whether or not LTPP determines the later prognosis among elderly patients.

Methods: We retrospectively examined patients >75 years old who underwent R0 gastrectomy for gastric cancer and were diagnosed with T1 disease at National Cancer Center Hospital between 2005 and 2012. LTPP was evaluated by chest computed tomography every year until two years after surgery.

Results: Of the 3412 patients who underwent gastrectomy in our hospital during this period, 159 were included in this study. The elderly patients who developed LTPP had a worse prognosis than those who did not. Furthermore, their comorbidities and LTPP were significant independent risk factors for a poor prognosis. Patients who developed LTPP had a significantly higher risk of dying due to respiratory disease or cardiovascular disease than those without pneumonia.

Conclusions: LTPP was significantly related to a poor survival and death from respiratory disease. To improve the prognosis, not only nutritional support but also exercise and rehabilitation program may be required for patients who develop LTPP within two years after surgery.

Long-term postoperative pneumonia in elderly patients with early gastric cancer

Background

Pneumonia is a major cause of death in the elderly population. Considering body weight loss, muscle loss, and reflux after gastrectomy, elderly patients are considered to be at very high risk for pneumonia, which could decrease overall survival because early gastric cancer is mostly curable only by surgery. We aimed to clarify the incidence of pneumonia in the long-term period after gastrectomy in elderly patients who were diagnosed with early gastric cancer and its risk factors.

Methods

We retrospectively examined patients of > 75 years of age who underwent R0 gastrectomy for gastric cancer and who were diagnosed with T1 disease at National Cancer Center Hospital between 2005 and 2012. Long-term postoperative pneumonia was diagnosed by chest computed tomography every year until 2 years after surgery. The presence of preoperative sarcopenia was assessed using preoperative L3 skeletal muscle index.

Results

167 patients were included in this study. Long-term postoperative pneumonia was observed in 44 (26%) patients. Of the 44 people diagnosed with long-term postoperative pneumonia, 33 were diagnosed in the 1st year and 11 in the 2nd year. 117 patients (70%) were diagnosed with sarcopenia which was significantly frequently found in the patients who developed long-term postoperative pneumonia (91%) than those without (63%). Preoperative sarcopenia was the only independent risk factor in multivariate analysis. Type of gastrectomy was not a significant risk factor.

Conclusions

Long-term postoperative pneumonia was frequently observed in the elderly patients. Preoperative sarcopenia was associated with long-term postoperative pneumonia in elderly patients who underwent curative surgery for gastric cancer. After gastrectomy, long-term special care would be required for elderly patients, especially with sarcopenia.

Impact of tumor-related factors and inter-institutional heterogeneity on preoperative T staging for gastric cancer

Background: To improve the diagnostic accuracy of preoperative T staging in gastric cancer, the authors evaluated tumor-related factors that might affect the diagnosis. Materials & methods: The authors analyzed the data of cT2-4b gastric cancer patients enrolled in the prospective, multicenter JCOG1302A study. They used contrast-enhanced computed tomography to analyze the association between tumor-related factors and the diagnostic accuracy of T3-4b staging for gastric cancer. Results: Among 876 cT3-4b tumors, the diagnostic accuracy was relatively low in the lower third of the stomach compared with those in the upper or middle. A multivariable analysis revealed that accuracy was higher in the lesser curvature or entire circumference region than in other areas (p < 0.001), in macroscopic types 3/5 than in types 0/1/2 (p = 0.003) and in the undifferentiated histological type than in the differentiated type (p = 0.011). Conclusion: The authors found tumor-related factors affecting preoperative T staging by enhanced computed tomography.

Management of elderly patients with early gastric cancer in Japan

Management of elderly patients with early gastric cancer is an important issue in an aging society such as Japan. While endoscopic resection is recommended as the standard treatment for early gastric cancers with extremely low risk of lymph node metastasis (<1%), gastrectomy with lymphadenectomy is recommended for the other early gastric cancers as the standard treatment even in elderly patients. Endoscopic submucosal dissection is the most recommended endoscopic resection procedure because of its high ability for 'en bloc' resection. Endoscopic submucosal dissection can reportedly provide favorable short-term outcomes in elderly patients. In terms of patient prognosis, the importance of considering patients' physical and nutritional conditions before endoscopic submucosal dissection has recently attracted attention. With respect to gastrectomy, the nationwide data in Japan have demonstrated relatively low 5-year overall survival and non-negligible post-operative 90-day mortality in men aged ≥75 years and women aged ≥80 years compared with those in younger patients. Among these elderly patients, 20% or more reportedly died within 5 years after gastrectomy mostly due to other diseases. These facts suggested the necessity of a less invasive management option for the elderly patients. Efforts are being made to provide a non-invasive follow-up option without gastrectomy following endoscopic resection in elderly patients. To avoid the increase in gastric cancer-related deaths, the selection of patients with relatively low lymph node metastasis risk is essential, and several tools to estimate the lymph node metastasis risk from early gastric cancers have been developed. To avoid overtreatment with gastrectomy in more elderly early gastric cancer patients, new endoscopic submucosal dissection indications for them are also warranted.

Prediction of tissue origin of adenocarcinomas in the esophagogastric junction by DNA methylation

BACKGROUND

Prediction of tissue origin of esophagogastric junction (EGJ) adenocarcinomas can be important for therapeutic decision, but no molecular marker is available. Here, we aimed to develop such a marker taking advantage of tissue-specific profiles of DNA methylation.

METHODS

DNA methylation profiles of gastric adenocarcinomas (GACs) were obtained by an Infinium HumanMethylation450 BeadChip array, and those of esophageal adenocarcinoma (EACs) were obtained from the TCGA database. DNA from formalin-fixed paraffin-embedded (FFPE) samples was analyzed by bisulfite pyrosequencing.

RESULTS

In the screening set, 51 of 145,841 CpG sites in CpG islands were methylated at significantly higher levels in 30 GACs compared to those in 30 EACs. Among them, SLC46A3 and cg09177106 were unmethylated in all the 30 EACs. Predictive powers of these two markers were successfully confirmed in an independent validation set (18 GACs and 18 EACs) (SLC46A3, sensitivity = 77.8%, specificity = 100%; cg09177106, sensitivity = 83.3%, specificity = 94.4%), and could be applied to FFPE samples (37 GACs and 18 EACs) (SLC46A3, P = 0.0001; cg09177106, P = 0.0028). On the other hand, EAC-specific markers informative in the FFPE samples could not be isolated. Using these GAC-specific markers, nine of 46 (19.6%) TCGA EGJ adenocarcinomas were predicted to be GACs.

CONCLUSIONS

Two GAC-specific markers, SLC46A3 and cg09177106, had a high specificity for identifying the tissue origin of EGJ adenocarcinoma.

International Retrospective Cohort Study of Conversion Therapy for Stage IV Gastric Cancer 1 (CONVO‐GC‐1)

Aim

Much attention has been paid to conversion therapy for stage IV gastric cancer, however, its operative comorbidities and survival benefit have not yet been clarified. CONVO‐GC‐1, an international retrospective cohort study, was designed to investigate the role of conversion surgery in Japan, Korea, and China.

Methods

The rate of operative complications was the primary endpoint and the overall survival (OS), according to the four‐category criteria previously published (Gastric Cancer:19; 2016), was analyzed as the secondary endpoint.

Results

A total of 1206 patients underwent surgery after chemotherapy with curative intent. Operative complications were observed in 290 (24.0%) patients in all grades, including pancreatic fistula and surgical site infection. The median survival time (MST) of all resected patients was 36.7 mo (M) and those of R0, R1, and R2 resection were 56.6 M, 25.8 M, and 21.7 M, respectively. Moreover, the MST of R0 patients were 47.8 M, 116.7 M, 44.8 M in categories 1, 2, and 3, respectively, and not reached in category 4. Interestingly, the MST of P1 patients was as favorable as that of P0CY1 patients if R0 resection was achieved. The MST of patients with liver metastasis was also favorable regardless of the number of lesions, and the MST of patients with para‐aortic lymph node (LN) No 16a1/b2 metastasis was not inferior to that of patients with para‐aortic LN No 16a2/b1 metastasis.

Conclusion

Conversion therapy for stage IV gastric cancer is safe and could be a new therapeutic strategy to improve the survival of patients, especially those with R0 resection.

The prognostic impact of macroscopic serosal change on resectable advanced gastric cancer

BACKGROUND

Advanced gastric cancer sometimes causes macroscopic serosal change (MSC) due to direct invasion or inflammation. However, the prognostic significance of MSC remains unclear.

METHODS

A total of 1410 patients who had been diagnosed with deeper-than-pathological-T2 gastric cancer and undergone R0 gastrectomy with lymph node dissection at the National Cancer Center Hospital during January 2000 and December 2012 were restrospectively reviewed.

RESULTS

MSC was not found in 108 of the 506 patients with pathological T4a (21.3%), whereas it was detected in 250 of the 904 patients with pathological T2-T3 (27.7%). The sensitivity, specificity and accuracy for diagnosing pathological serosa exposed (SE) by MSC were 78.7, 72.3 and 74.6%, respectively. The MSC-positive cases had a worse 5-year overall survival (OS) than the MSC-negative cases in pT3 (72.9% vs. 84.3%, p = 0.001), pT4a (56.2% vs. 73.4%, p = 0.001), pStageIIB (76.0% vs. 88.4%, p = 0.005), pStageIIIA (63.4% vs. 75.6%, p = 0.019), pStageIIIB (53.6% vs. 69.2%, p = 0.029) and pStage IIIC (27.6% vs. 50.0%, p = 0.062). A multivariate analysis showed that MSC was a significant independent predictor for the OS (hazard ratio [HR]: 1.587, 95%CI 1.209-2.083, p = 0.001) along with the tumor depth (HR: 7.742, 95%CI: 2.935-20.421, p < 0.001), nodal status (HR:5.783, 95% CI 3.985-8.391, p < 0.001) and age (HR:2.382, 95%CI: 1.918-2.957, p < 0.001). Peritoneal recurrence rates were higher in the MSC-positive cases than in the MSC-negative cases at each pT stage.

CONCLUSIONS

In this study, the MSC was one of the independent prognostic factors in patients with resectable locally advanced gastric cancer.

Optimal surgery and lymph node metastasis of duodenal bulbar neuroendocrine neoplasms

BACKGROUND

There is no consensus on the extent of nodal dissection for duodenal bulbar NENs (neuroendocrine neoplasms).

MATERIALS AND METHODS

We constructed and analyzed a combined dataset consisting of the patients who received surgery in our hospital and the patients from the literature based on a systematic review. The incidence, risk factors and location of nodal metastases were examined.

RESULTS

Fifty-nine cases including 11 cases managed at our hospital and 48 cases identified from the literature search were examined. Nodal metastasis was observed in 24 patients (40.7%). The 5-year overall survival rate was 100%, regardless of nodal metastasis. Risk factors for lymph node metastasis were tumor size ≥15 mm and muscularis propria or deeper invasion. Stomach-related lymph node metastasis was found in >20% of patients who were positive for at least one risk factor and 15.4% when patients were negative for both risk factors, while pancreas-related lymph node metastasis was observed in 45.5% of patients who were positive for both risk factors, 7.7% who were only positive for one risk factor, and 0% who were negative for both risk factors.

CONCLUSIONS

Tumor size and depth of invasion would determine whether the optimal surgery for duodenal bulbar NENs is distal gastrectomy or pancreatico-duodenectomy.

Pathological complete response at the para-aortic nodes as a possible surrogate endpoint in gastric cancer surgery with para-aortic node dissection after neoadjuvant chemotherapy

PURPOSE

Gastric cancer with para-aortic node (PAN) metastasis has a chance to be cured with multidisciplinary treatment of D2 and PAN dissection (PAND) following neoadjuvant chemotherapy (NAC), but its prognosis remains unsatisfactory. To establish a better multidisciplinary treatment, a better surrogate endpoint is needed. The present study focused on a pathological complete response at the PANs alone as a new surrogate endpoint and evaluated its prognostic value.

METHODS

The study examined patients who received radical gastrectomy with D2 and PAND after NAC for gastric cancer with PAN metastasis from 2004 to 2015. The study compared five methods of evaluating the response to NAC: RECIST, clinical disappearance of PANs (cPAN), histological response of the primary tumor defined by Japanese Classification of Gastric Carcinoma (JCGC histological criteria) and Becker's criteria, and pathological disappearance of PANs (pPAN). The efficacy of these methods was compared using the hazard ratio (HR) for death between responders and non-responders.

RESULTS

Thirty-two patients were analyzed. The respective HR and 5-year overall survival rates of responders and non-responders were 1.316 and 49.1% vs. 60.0% by RECIST, 1.106 and 52.9% vs. 52.5% by cPAN, 0.246 and 71.3% vs. 28.6% by JCGC histological criteria, 0.239 and 76.2% vs. 36.8% by Becker's criteria, and 0.074 and 81.0% vs. 0.0% by pPAN.

CONCLUSIONS

A pathological complete response at the PANs had the lowest HR and clearly differentiated the survival, suggesting it might be a good surrogate endpoint for identifying future candidates for NAC in multidisciplinary treatment for gastric cancer with PAN metastasis.

Cooperative participation of epigenomic and genomic alterations in the clinicopathological diversity of gastric adenocarcinomas: significance of cell adhesion and epithelial-mesenchymal transition-related signaling pathways

The present study was conducted to clarify the cooperative significance of epigenomic and genomic abnormalities during gastric carcinogenesis. Using 21 samples of normal control gastric mucosa (C), 109 samples of non-cancerous gastric mucosa (N) and 105 samples of cancerous tissue (T) from 109 patients with primary gastric adenocarcinomas, genome-wide DNA methylation analysis was performed using Infinium assay. Among these samples, 66 paired N and corresponding T samples were subjected to whole-exome and single nucleotide polymorphism array analyses. As had been shown in our previous study, 109 patients were clustered clinicopathologically into least aggressive Cluster A (n = 20), most aggressive Cluster B1 (n = 20) and Cluster B2 (n = 69). Most DNA methylation alterations in each cluster had already occurred even in N samples compared with C samples, and DNA methylation alterations at the precancerous N stage were inherited by the established cancers themselves. Recurrent single nucleotide variants and insertions/deletions resulting in functional disruption of the proteins encoded by the ABCA10, BNC2, CDH1, CTNNB1, SMAD4 and VAV2 genes were specific to Cluster B1, whereas those of the APC, EGFR, ERBB2, ERBB3, MLH1 and MUC6 genes were specific to Cluster A. MetaCore pathway analysis revealed that the epigenomically affected TWIST1 gene and genomically affected CDH1, CTNNB1, MMP9, TLN2, ROCK1 and SMAD4 genes were accumulated in signaling pathways related to cell adhesion, cytoskeleton remodeling and epithelial–mesenchymal transition in Cluster B1. These data indicate that epigenomic alterations at the precancerous stage are important in gastric carcinogenesis and that epigenomic and genomic alterations cooperatively underlie the aggressiveness of gastric adenocarcinomas.

Surgically treated gastric cancer in Japan: 2011 annual report of the national clinical database gastric cancer registry

BACKGROUND

The National Clinical Database (NCD) nationwide registry program of gastric cancer started in 2018. The purpose of this study was to report the treatment results of the NCD registry in the form of treatment results of the real world in Japan.

METHODS

Patients' characteristics, tumor features, treatments, and outcomes were collected using a web-based data entry system. We analyzed the initial NCD database for data on surgically treated gastric cancer patients in 2011.

RESULTS

A total of 30,257 patients with malignant gastric tumors were enrolled by the NCD registry program from 501 hospitals in all 47 prefectures. Of these, the status of data entry was not approved in 8.8% of the registered data, and follow-up information was missing in 1.2% of the approved cases. Excluding 1777 cases, which were not resected for primary gastric cancer, 25,306 resected cases included 44.4% of stomach surgeries recorded in the NCD. The 5 year survival rate of the resected cases was 71.3% and the operative mortality rate was 0.41%. The stage-specific 5 year survival rates were as follows: 89.6% for stage IA, 83.8% for stage IB, 77.3% for stage IIA, 69.1% for stage IIB, 58.7% for stage IIIA, 44.1% for stage IIIB, 30.1% for stage IIIC, and 13.4% for stage IV.

CONCLUSIONS

The NCD gastric cancer registry program demonstrated validity for database construction. The gastric cancer registry is expected to become a nationwide registry with the dissemination of data entry system and method in the NCD.

Impact of preoperative chemotherapy as initial treatment for advanced gastric cancer with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) or localized peritoneal metastasis (P1a): a multi-institutional retrospective study

BACKGROUND

Gastric cancer (GC) patients with peritoneal metastasis are defined as stage IV in the Japanese classification of GC. For patients with peritoneal metastasis limited to positive peritoneal lavage cytology (CY1) and/or localized peritoneal metastasis (P1a), gastrectomy followed by S1 monotherapy is one of the most widely accepted therapeutic strategy in Japan. This study investigated the efficacy of preoperative chemotherapy as initial treatment in GC patients with CY1 and/or P1a.

METHODS

We retrospectively reviewed GC patients diagnosed with CY1 and/or P1a at 34 institutions in Japan between 2008 and 2012. Selection criteria were: adenocarcinoma, no distant metastasis except CY1 or P1a, and no prior treatment. The subjects were divided into an Initial-Chemotherapy group and an Initial-Surgery group, according to the initial treatment.

RESULTS

A total of 824 patients were collected and 713 eligible patients were identified for this study. As the initial treatment, 150 patients received chemotherapy (Initial-Cx), and 563 patients underwent surgery (Initial-Sx). Initial-Cx regimens were cisplatin plus S1/docetaxel plus cisplatin plus S1/others (n = 90/37/23). Both overall survival (OS) and progression-free survival (PFS) were similar between the Initial-Cx and Initial-Sx groups (median OS 24.8 and 24.0 months, HR 1.07, 95% CI 0.87-1.3; median PFS 14.9 and 13.9 months, HR 1.04, 95% CI 0.85-1.27). The 5-year OS rates were 22.3% in the Initial-Cx group and 21.5% in the Initial-Sx group.

CONCLUSIONS

Although, the preoperative chemotherapy did not show a survival benefit for GC patients with CY1 and/or P1a, initial-Cx showed favorable survival in patients who converted to P0 and CY0.

Risk for lymph node metastasis in Epstein-Barr virus-associated gastric carcinoma with submucosal invasion

OBJECTIVES

Epstein-Barr virus-associated gastric cancer (EBVGC) has been reported to be associated with a low risk for lymph node metastasis (LNM). However, the curative criteria for endoscopic submucosal dissection (ESD) for submucosal EBVGC (pT1b-EBVGC) remain unclear. Our study aimed to investigate the risk factors for LNM in pT1b-EBVGC.

METHODS

This was a retrospective multicenter study at five institutes in Japan. We reviewed medical records and extracted all pT1b-EBVGC cases that met the following criteria: (i) histologically proven submucosal gastric cancer; (ii) surgical or endoscopic resection between January 2000 and December 2016; and (iii) presence of Epstein-Barr virus (EBV) in tumor cells verified by EBV-encoded small RNA in situ hybridization (EBER-ISH). The association between clinicopathological factors and LNM were assessed using multivariable logistic regression analysis.

RESULTS

A total of 185 pT1b-EBVGC cases were included in the analysis. LNM was found in nine cases (4.9%). Multivariable logistic regression analysis demonstrated that lymphatic invasion (OR 9.1; 95% CI 2.1-46.1) and submucosal invasion ≥4000 μm (OR 9.2; 95% CI 1.3-110.3) were significant risk factors for LNM. When we focused on pT1b-EBVGC without lymphatic invasion and with submucosal invasion <2000 μm, the rate of LNM was 0% (0/96, 95% CI 0-3.8%).

CONCLUSIONS

Our findings indicated that lymphatic invasion and submucosal invasion ≥4000 μm were significant risk factors for LNM. ESD could be an appropriate option for pT1b-EBVGC without lymphatic invasion and with submucosal invasion <2000 μm.

Gastrectomy with or without neoadjuvant S-1 plus cisplatin for type 4 or large type 3 gastric cancer (JCOG0501): an open-label, phase 3, randomized controlled trial

BACKGROUND

Specific treatment strategies are sorely needed for scirrhous-type gastric cancer still, which has poor prognosis. Based on the promising results of our previous phase II study (JCOG0210), we initiated a phase III study to confirm the efficacy of neoadjuvant chemotherapy (NAC) in type 4 or large type 3 gastric cancer.

METHODS

Patients aged 20-75 years without a macroscopic unresectable factor as confirmed via staging laparoscopy were randomly assigned to surgery followed by adjuvant chemotherapy with S-1 (Arm A) or NAC (S-1plus cisplatin) followed by D2 gastrectomy plus adjuvant chemotherapy with S-1 (Arm B). The primary endpoint was overall survival (OS).

RESULTS

Between October 2005 and July 2013, 316 patients were enrolled, allocating 158 patients to each arm. In Arm B, in which NAC was completed in 88% of patients. Significant downstaging based on tumor depth, lymph node metastasis, and peritoneal cytology was observed using NAC. Excluding the initial 16 patients randomized before the first revision of the protocol, 149 and 151 patients in arms A and B, respectively, were included in the primary analysis. The 3-year OS rates were 62.4% [95% confidence interval (CI)  54.1-69.6] in Arm A and 60.9% (95% CI  52.7-68.2) in Arm B. The hazard ratio of Arm B against Arm A was 0.916 (95% CI  0.679-1.236).

CONCLUSIONS

For type 4 or large type 3 gastric cancer, NAC with S-1 plus cisplatin failed to demonstrate a survival benefit. D2 surgery followed by adjuvant chemotherapy remains the standard treatment.

Feasibility study of TAS-118 plus oxaliplatin as perioperative chemotherapy for patients with locally advanced gastric cancer (APOLLO-11)

205

Background:TAS-118 (S-1 and leucovorin) + oxaliplatin (L-OHP) improved overall survival (OS) compared to S-1 + cisplatin for patients (pts) with advanced gastric cancer (GC) (Kang, Lancet Oncol. 2020). This study investigated the feasibility of peri (pre and post)-operative (op) chemotherapy (chemo) with TAS-118 ± L-OHP in pts with locally advanced resectable GC. While it was reported that pre-op TAS-118 + L-OHP followed by D2 gastrectomy was well tolerated and showed promising efficay (Takahari, ASCO-GI. 2020), the recommended post-op chemo regimen, TAS-118 or TAS-118 + L-OHP, has yet to be determined. Methods:Eligible pts with GC of clinical T3-4N1-3M0 were enrolled. The protocol treatment consisted of pre-op chemo with 4 courses of TAS-118 (40-60 mg/body, orally, twice daily, 7 days) + L-OHP (85 mg/m2, intravenously, day 1) in a 2-week cycle, and gastrectomy with D2 lymphadenectomy, followed by post-op chemo with 12 courses of TAS-118 (step 1) and 8 courses of TAS-118 + L-OHP (step 2). Step 2 was started if the dose-limiting toxicity (DLT) occurred in < 6 of 10 pts in step 1. Up to 20 pts were included in the analysis of feasibility after a recommended regimen was determined. Results:Between December 2016 and February 2019, 45 pts were enrolled. The numbers of pts with cT3/4a and cN1/2/3 were 13/32 and 25/17/3, respectively. Excluding 14 pts (4 achieving pathological complete response, 4 not satisfying the criteria for post-op chemo, 3 physician judgement or pt withdrawal, 2 progressive disease, 1 adverse event [AE]), 31 pts (11/20 in step 1/2) received the post-op chemo. No DLT was observed in either step. The post-op chemo completion rate was 90.9% (95% CI, 63.6-99.5) in step 1 and 80.0% (95% CI, 59.9-92.9) in step 2. The median relative dose intensity of TAS-118 in step 1 was 83.3%, and those of TAS-118 and L-OHP in step 2 were 69.9% and 74.3%, respectively. One pt in step 2 discontinued post-op chemo due to AE. Grade ³ 3 AEs observed in ≥ 10% of pts were weight loss in both step 1 and step 2 (2 in each), and hypokalemia (n = 3) and neutropenia (n = 2) in step 2. At 1-year follow-up after the last pt was enrolled, recurrence-free survival and OS rates were 91.1% (95% CI, 78.0-96.6) and 100%, respectively at 12 months, and 69.1% (95% CI, 49.6-82.3) and 95.5% (95% CI, 71.9-99.3), respectively at 24 months. Conclusions:Taken together with the feasibility and efficacy of pre-op chemo, peri-op chemo with TAS-118 + L-OHP with D2 gastrectomy was well tolerated and showed promising efficacy. Clinical trial information: UMIN000024688.

Final results of a phase III trial to evaluate bursectomy for patients with subserosal/serosal gastric cancer (JCOG1001)

206

Background: We previously reported that the superiority of bursectomy was not demonstrated for subserosal(SS)/serosal(SE) gastric cancer by the second interim analysis performed with 54% of the expected events observed. We report the final 5-year follow-up data. Methods: Eligibility criteria included histologically proven adenocarcinoma of the stomach, cT3(SS) or cT4a(SE). Patients were intraoperatively randomized to non-bursectomy arm or bursectomy arm. Primary endpoint was overall survival (OS), and secondary endpoint was relapse-free survival (RFS). A total of 1,200 patients were required to detect a hazard ratio of 0.77 with a one-sided alpha of 5% and 80% power. Results: A total of 1204 eligible patients with cT3 / cT4a gastric cancer were randomized (602 in non-bursectomy arm, 602 in bursectomy arm, respectively). Patients’ background and operative procedures were well balanced between the arms. The 5y-OS were 76.5% (95% CI, 72.8 to 79.7) in non-bursectomy arm and 74.9% (71.2 to 78.2) in bursectomy arm. Hazard ratio (HR) for bursectomy was 1.03 (0.83-1.27, one-sided p = 0.598). The 5y-RFS were 70.7% (66.9 to 74.2) in non-bursectomy arm and 66.8% (62.9 to 70.5) in bursectomy arm [HR: 1.131 (0.93-1.38)]. HR for death was almost similar in all sub-categories (0.73-1.29) except cN2 (13th edition of Japanese Classification of Gastric Carcinoma); HR classified by cN was 1.06 (95% CI: 0.75-1.49) for cN0 (n = 521), 1.25 (0.92-1.71) for cN1 (n = 525), and 0.59 (0.32-1.06) for cN2 (n = 158) (p = 0.048 for interaction). The most frequent site of recurrence was the peritoneum [74 (12.3%) in non-bursectomy arm, 73 (12.1%) in bursectomy arm], and bursectomy arm showed a trend of increasing liver metastasis (n = 45, 7.5%) as compared with non-bursectomy arm (n = 33, 5.5%). Six independent poor prognostic factors were identified by multivariable analysis for OS: age ≥ 66 (vs. ≤ 65) (HR, 1.30; 95% CI, 1.04-1.62), macroscopic type 3/5 (vs. type 0/1/2) (1.43; 1.15-1.79), total gastrectomy (vs. distal gastrectomy) (1.44; 1.03-2.02), pT3 (vs. pT1-2) (1.77; 1.17-2.676), pT4 (vs. pT1-2) (3.00; 1.99-4.53), pN1 (vs. pN0) (2.34; 1.52-3.59), pN2-3b (vs. pN0)(4.02; 2.82-5.74) and adjuvant chemotherapy (vs. without chemotherapy) (0.53; 0.42-0.67), but bursectomy was not significant (1.10 0.89-1.36). Conclusions: In the final analysis as well as in the interim analysis, bursectomy was not recommended as a standard treatment for cT3 or cT4 gastric cancer. Clinical trial information: UMIN000003688.

Risk factors for the continuation of S-1 adjuvant chemotherapy for gastric cancer analyzed from the JCOG1104 phase III trial

196

Background: The phase III trial (JCOG1104), comparing between 4- (6 months) and 8-course (1 year) of S-1 as the adjuvant chemotherapy for pathological stage II gastric cancer, registered a total of 590 patients between Feb. 2012 and Mar. 2017 until the study was terminated due to futility at the interim analysis (relapse-free survival at 3 years: 93.1% in the 8-course group and 89.8% in the 4-course group). Non-inferiority of the 4-course to the 8-course was not shown, highlighting a continuation of S-1 adjuvant chemotherapy for one year. This preplanned exploratory study investigated the risk factors for time to treatment failure (TTF). Methods: TTF was defined as the time from randomization to the date of termination of S-1 before the planned treatment period, relapse, or any cause of death, whichever came first, and censored on the last date of contact for a surviving patient after completing the planned treatment or the last date of S-1 in the patients under the protocol treatment when the trial was closed. The risk factor of TTF was analyzed by Cox proportional hazard model using the variables of the planned treatment period, PS, age, sex, body weight loss (percentile of the body weight loss at the registration compared with that before surgery: BWL), albumin, lymphocyte count, creatinine clearance (Ccr), extent of gastrectomy (total gastrectomy vs. others), surgical approach (open vs. laparoscopic approach), and blood loss during surgery. As TTF did not reach 50%, proportion of treatment completion was compared. Results: Among 590 registered patients, this study included 530 patients (273 in the 8-course group and 257 in the 4-course group) by excluding 24 ineligible patients, 7 patients who did not start the protocol treatment, and 29 patients with unavailable data for variables. Proportion of treatment completion at 6 months estimated by Kaplan-Meier method were 89.2% in the 4-course group and 84.6% in the 8-course group ( P=0.1204), and that at 1 year was 73.6% in the 8-course group. Risk factors of TTF before 6M identified by multivariable analysis with stepwise selection method including both groups, in which all patients completed treatment were censored at 6 months, were the planned treatment period (4-courses vs. 8-course, HR 0.611, 95% Confidence interval (CI) 0.375-0.996, P=0.0482), age (continuous value, HR 1.039, 95% CI 1.004-1.074, P=0.0266), and Ccr (<80 vs. >80 ml/min, HR 1.943, 95% CI 1.105-3.415, P=0.0211). As for the TTF in the 8-course group, BWL (>10% vs <10%, HR 2.167, 95% CI 1.269-3.703, P=0.0046) and Ccr (<80 vs. >80 ml/min, HR 1.900, 95% CI 1.186-3.045, P=0.0076) were independent risk factors. Conclusions: Compared to 8-course, 4-course of S-1 adjuvant chemotherapy was associated with a higher 6-month proportion of treatment completion. When planning the adjuvant chemotherapy with S-1 for one year, BWL (>10%) and low Ccr (<80 ml/min) were risk factors for treatment failure. Clinical trial information: UMIN000007306.

Recurrence after ESD curative resection for early gastric cancer

BACKGROUND

Endoscopic submucosal dissection (ESD) is gaining ground as a minimally invasive treatment for early gastric cancer (EGC) that has a negligible risk of lymph node metastasis. According to the 5th edition of Japanese gastric cancer treatment guidelines, annual or biannual follow-up with endoscopy is recommended, but follow-up with abdominal ultrasonography or computed tomography (CT) for surveillance of metastases is not recommended after the eCuraA resection. However, we experienced a case of lymph node recurrence following ESD resulting in eCuraA.

CASE PRESENTATION

A 76-year-old female received ESD for EGC in a previous hospital 4 years ago. Pathological findings were tub1, 30 mm, T1a (M), UL0, Ly0, V0, pHM-, pVM- (eCuraA) according to the 15th edition of Japanese Classification of Gastric Carcinoma. Follow-up esophagogastroduodenoscopy revealed submucosal tumor, which was suspected as a swollen lymph node by CT and endoscopic ultrasound fine-needle aspiration revealed the recurrence of gastric cancer. We performed total gastrectomy with D2 lymph node dissection. Postoperative pathological examination revealed no local recurrent tumor at the ESD site in the stomach. Swollen lymph node was diagnosed as metastasis and lymph node metastasis was limited near the cardia.

CONCLUSION

This case provides valuable information about tumor with a minimum poorly differentiated adenocarcinoma component may develop lymph node metastasis even satisfying the guidelines criteria for curative resection.

A novel combination of serum microRNAs for the detection of early gastric cancer

BACKGROUND

The aim of this study was to identify serum miRNAs that discriminate early gastric cancer (EGC) samples from non-cancer controls using a large cohort.

METHODS

This retrospective case-control study included 1417 serum samples from patients with EGC (seen at the National Cancer Center Hospital in Tokyo between 2008 and 2012) and 1417 age- and gender-matched non-cancer controls. The samples were randomly assigned to discovery and validation sets and the miRNA expression profiles of whole serum samples were comprehensively evaluated using a highly sensitive DNA chip (3D-Gene^®) designed to detect 2565 miRNA sequences. Diagnostic models were constructed using the levels of several miRNAs in the discovery set, and the diagnostic performance of the model was evaluated in the validation set.

RESULTS

The discovery set consisted of 708 samples from EGC patients and 709 samples from non-cancer controls, and the validation set consisted of 709 samples from EGC patients and 708 samples from non-cancer controls. The diagnostic EGC index was constructed using four miRNAs (miR-4257, miR-6785-5p, miR-187-5p, and miR-5739). In the discovery set, a receiver operating characteristic curve analysis of the EGC index revealed that the area under the curve (AUC) was 0.996 with a sensitivity of 0.983 and a specificity of 0.977. In the validation set, the AUC for the EGC index was 0.998 with a sensitivity of 0.996 and a specificity of 0.953.

CONCLUSIONS

A novel combination of four serum miRNAs could be a useful non-invasive diagnostic biomarker to detect EGC with high accuracy. A multicenter prospective study is ongoing to confirm the present observations.

Is lymph node dissection for neuroendocrine carcinoma of the stomach effective as it is for adenocarcinoma?

BACKGROUND

We evaluated the significance of lymph node dissection for gastric neuroendocrine carcinoma (NEC) by calculating the therapeutic value index for each station.

METHODS

This study included 2164 advanced gastric cancer patients (common-type [Common-GC], n = 2125; and gastric NEC [NEC-GC], n = 39). Clinicopathological data were collected, and survival, type of recurrence, and the index for each type of gastrectomy were determined.

RESULTS

NEC-GC was characterized by an older population (P = 0.009), upper tumor location (P = 0.021), frequent venous invasion (P < 0.001), and less neural invasion (P = 0.043). NEC-GC tended to be more frequent in men (P = 0.152), and to be associated with total gastrectomy (P = 0.177) and M1 cases (P = 0.167). The five-year overall survival rates of the Common-GC and NEC-GC groups were 73.8% (95% confidence interval: 71.8-75.6) and 54.7% (37.5-68.9), respectively (P = 0.016). Both groups showed similar index values in each station. Regarding the index of the peri-gastric nodal station (D1 station)/stations away from the stomach (D2 station), although the index of the D1 station was similar in the two groups (41.3 and 43.1), the index of the D2 station in the NEC-GC group was approximately half that of the Common-GC group (10.0 and 5.3). The total recurrence rates of the two groups were similar (P = 0.871). However, the rates of hematogenous and lymphatic recurrence tended to be higher in the NEC-GC group (P = 0.132 and P = 0.152).

CONCLUSIONS

The therapeutic efficacy of the D1 station was similar in Common-GC and NEC-GC but that of the D2 station was worse in NEC-GC. Gastrectomy with D2 dissection would be less effective for NEC-GC.

Laparoscopic resection of a primary diaphragmatic schwannoma: a case report and literature review

Background

Schwannomas are nerve sheath tumors that commonly originate from the stomach and small intestine. A primary schwannoma of the diaphragm is rare and does not show any symptoms until it grows to a certain size. Hence, it is extremely rare that it was found at a size that allowed resection under videoscopic surgery.

Case presentation

A 77-year-old woman was referred to our department for surgical treatment of a tumor located near the gastric fornix. She underwent a routine esophagogastroduodenoscopy 2 years and 7 months prior to the referral. It was suspected that she had a submucosal tumor measuring 10 mm, located in the fornix, and was then referred to her previous physician. During her follow-up, endoscopic ultrasonography (EUS) revealed that the cystic structure had continued to grow toward the gastric wall, and she was then referred to the endoscopy division of our hospital. She continued to be followed-up, and it was noted that the tumor was gradually increasing in size. Therefore, she requested surgical resection, and was finally referred to our division. Since the tumor was rather small, we planned a laparoscopic surgery. An initial examination during the operation revealed that the tumor was located on the left diaphragm. Since the tumor was relatively small and visibility was good, we decided to continue with the laparoscopic surgery. Partial diaphragmectomy with complete inclusion of the tumor was performed, and the defect of the diaphragm was directly closed by a running suture. Pathological examination revealed a benign schwannoma that had originated from the diaphragm. To support our findings, we also reviewed the scientific literature on diaphragmatic schwannoma cases reported up to April 2020.

Conclusions

In this extremely rare case, we successfully resected the diaphragmatic schwannoma using laparoscopic surgery.

Optimal extent of lymph node dissection for remnant advanced gastric carcinoma after distal gastrectomy: a retrospective analysis of more than 3000 patients from the nationwide registry of the Japanese Gastric Cancer Association

BACKGROUND

No guidelines are available for defining the extent of lymph node (LN) dissection in patients with remnant gastric carcinoma (RGC). Hence, this retrospective study aimed to determine the optimal extent of LN dissection in patients with RGC.

METHODS

We retrospectively evaluated the therapeutic outcomes of node dissection for RGC from a nationwide registry. When the metastatic rate or 5-year survival rate exceeded 10%, dissection was recommended. We calculated the dissection index by multiplying the incidence of metastasis at that nodal station by the 5-year survival rate of patients with metastasis at the station. A dissection index of > 1.0 was considered significant.

RESULTS

We included 1133 patients with RGC (T2-T4 tumor) who had undergone distal gastrectomy as the primary surgery for the evaluation of the survival benefit of nodal dissection. Any regional node station was considered significant. When the primary surgery was for malignant disease, the index was high for Nos. 3 (10.2), 7 (9.5), 1 (7.1), and 9 (8.0) nodes. For nodes at the splenic hilum, the index value was 4.4, which was higher than that for the perigastric nodes (Nos. 4sa and 4sb). The index for No. 10 nodes was the highest (10.5) when tumors involved a greater curvature.

CONCLUSIONS

The therapeutic strategy for RGC remains the same, regardless of the histology of the primary disease during the initial surgery. Total gastrectomy and dissection of the perigastric LNs (Nos. 1-4), suprapancreatic LNs (Nos. 7-9 and 11), and LNs at the splenic hilum (No. 10) are justified.

Does staged surgical training for minimally invasive esophagectomy have an impact on short-term outcomes?

BACKGROUND

sophageal cancer has a low incidence, and the anatomy is difficult to understand during esophagectomy. This necessitates a precise and lengthy operation. Therefore, the establishment of a training system in esophageal surgery is of critical importance. In this study, we compared the short-term outcomes of minimally invasive esophagectomy (MIE) performed by consultants versus trainees and explored the factors that impacted the thoracic operation time for each group.

METHODS

We have introduced standardized MIE surgical techniques to our trainees in 2016. Our procedure consists of a laparoscopic phase and a thoracoscopic phase and is systematically designed to be learned in a step-by-step manner in each phase. We retrospectively identified 308 patients who underwent MIE from April 2016 to April 2018. The patients were divided into those who underwent MIE by consultants and those who underwent MIE by trainees. The preoperative background factors, operation-related factors, and postoperative complications were compared between the two groups. We also assessed the association between a prolonged thoracic operation time and tumor-and patient-related factors in each of the consults and trainees.

RESULTS

Significantly more patients had stage ≥ III cancer in the consultant than trainee group. However, the postoperative complications were comparable, specifically pneumonia (11% vs. 18%), anastomotic leakage (11% vs. 13%), and mortality (0.6% vs. 1.3%). There was no significant difference in the lymph node yield (20 vs. 17) or R0 resection rate (94% vs. 91%) between the two groups. However, the trainees had a significantly longer thoracic operation time (143 ± 34 vs. 190 ± 28 min) and significantly greater blood loss (93 vs. 183 ml). Oncological factors were correlated with a prolonged thoracic operation time in the consultants, but not in the trainees.

CONCLUSIONS

Under standardized surgical management using a stepwise educational program, performance of MIE by trainees has no impact on short-term outcomes.

Endoscopic Ultrasonography Miniature Probe Performance for Depth Diagnosis of Early Gastric Cancer with Suspected Submucosal Invasion

Background/Aims

The accurate assessment of the depth of invasion of early gastric cancer (EGC) is critical to determine the most appropriate treatment option. However, it is difficult to distinguish shallow submucosal (SM1) invasion from deeper submucosal (SM2) invasion. We investigated the diagnostic performance of endoscopic ultrasonography (EUS) using a miniature probe for EGC with suspected SM invasion.

Methods

From April 2008 to June 2018, EGCs with suspected SM invasion were analyzed retrospectively. The EGCs examined by a 20 MHz high-frequency miniature probe was included in our study. Esophago-gastric junction cancers and patients treated by chemotherapy before resection were excluded. The sensitivity and specificity for the detection of SM2 invasion by EUS were compared with those of white light imaging (WLI). Additionally, factors related to depth underestimation or overestimation were investigated using multivariate analysis.

Results

A total of 278 EGCs in 259 patients were included in the final analysis. The sensitivity and specificity for SM2 or deeper by EUS were 73.7% (87/118) and 74.4% (119/160), respectively. The sensitivity and specificity by WLI were 47.5% (56/118) and 68.1% (109/160), respectively. The sensitivity of EUS was significantly superior to that of conventional endoscopy (p<0.01). Multivariate analysis revealed that an anterior location of the EGC was an independent risk factor for underestimation by EUS (odds ratio, 3.3; 95% confidence interval, 1.1 to 9.8; p=0.03).

Conclusions

The depth diagnostic performance for EGCs with suspected SM invasion using EUS was satisfactory and superior to that of conventional endoscopy. Additionally, it is important to recognize factors that may lead to misdiagnosis in those lesions.

Extra-gastrointestinal stromal tumor arising in the lesser omentum with a platelet-derived growth factor receptor alpha (PDGFRA) mutation: a case report and literature review

BACKGROUND

Gastrointestinal stromal tumors (GIST) arising from sites other than the gastrointestinal (GI) tract, termed extra-gastrointestinal stromal tumors (EGIST), are rare. Among EGIST, those with platelet-derived growth factor receptor alpha (PDGFRA) mutations are even rarer, with only a few cases reported. About 80% of GIST has KIT mutations, and 10% of GIST have PDGFRA mutations, which commonly affect the TK2 domain (exon 18). Among the exon 18 mutations, the D842V substitution is limited to gastric GIST. In EGIST, the degree of KIT and PDGFRA mutations varies on where the location of the tumor is, and it is suggested that omental EGIST is similar to gastric GIST. Adjuvant imatinib therapy is recommended for high-risk GIST; however, it is known that imatinib is less effective against GIST with a PDGFRA D842V mutation.

CASE PRESENTATION

A 75-year-old man was referred to our hospital with an extrinsic tumor of the lesser curvature of the gastric body. Intraoperative findings showed a tumor located outside of the lesser omentum with no connection between the tumor and the gastric wall. The tumor was subsequently resected. Pathological examination indicated a GIST arising in the lesser omentum measuring 70 mm in its longer dimension. Because the tumor had a PDGFRA mutation (D842V substitution), imatinib was suspected to lack efficacy to the tumor. Thus, although the tumor was considered clinically to have a high risk of recurrence, adjuvant imatinib therapy was not indicated. The patient has been free of recurrence for 29 months since the surgery.

CONCLUSION

We described a case of EGIST with a PDGFRA mutation arising in the lesser omentum. And we reviewed 57 cases of omental EGIST and showed that the clinicopathological characteristics and mutation status in omental EGIST were very similar to gastric GIST. In particular, PDGFAR D842V mutation rate in omental EGIST seemed as high as that in gastric GIST. These results suggested that omental EGIST is strongly related to gastric GIST, so the behavior of omental EGIST might be akin to gastric GIST. However, further studies are required to determine the prognosis and the necessity of adjuvant therapy for EGIST with a PDGFRA mutation.

Predictive value of the surgical Apgar score on postoperative complications in advanced gastric cancer patients treated with neoadjuvant chemotherapy followed by radical gastrectomy: a single-center retrospective study

Background

The surgical Apgar score (SAS) or modified SAS (mSAS) has been reported as a simple and easy risk assessment system for predicting postoperative complications in primary surgery for gastric cancer. However, few studies have described the SAS’s utility in gastric surgery after neoadjuvant chemotherapy (NAC).

Methods

One hundred and fifteen patients who received NAC and radical gastrectomy from 2008 and 2015 were included in this study. The SAS was determined by the estimated blood loss (EBL), lowest intraoperative mean arterial pressure, and lowest heart rate. The mSAS was determined by the EBL reassessed using the interquartile values. The predictive values of the SAS/mSAS for postoperative complications were assessed with univariate and multiple logistic regression analyses.

Results

Among the 115 patients, 41 (35.7%) developed postoperative complications. According to analyses with receiver operating characteristic curves of the SAS and mSAS for predicting postoperative complications, the cut-off value of the mSAS was set at 8. The rates of anastomotic leakage, pancreatic fistula, and arrhythmia in patients with high mSAS (> 8) values were higher than in those with low (0–3) and moderate [1–4] mSAS values. A multiple logistic regression analysis showed that the operation time, body mass index, and diabetes mellitus were independent risk factors for postoperative complications. The mSAS was not a significant predictor.

Conclusion

The predictive value of SAS or mSAS for morbidity may be limited in patients who undergo gastric cancer surgery after NAC. Future prospective studies with a large sample size will be needed to confirm the present results.

Health-related quality-of-life assessment in accordance with reconstruction procedures for distal gastrectomy for stage I gastric cancer using data from JCOG0912

4562

Background: There are three major reconstruction methods after gastrectomy for distal gastric cancer; Billroth-I (B-I), Roux-en-Y (RY) and pylorus-preserving gastrectomy (PPG). These procedures can affect postoperative health-related quality-of-life (HRQoL), but the method is often selected due to physician’s preference or each institutional policy without solid evidence. We aimed to explore differences in HRQoL after each reconstruction procedure selected in JCOG0912, a phase III noninferiority trial comparing open and laparoscopic distal gastrectomies for stage I gastric cancer. Methods: Among 33 institutions participated in JCOG0912, 4 major cancer centers were selected for HRQoL assessment. HRQoL was assessed using the EORTC QLQ-C30 and STO22 before (baseline) and at 1, 3, 12, and 36 months after surgery as preplanned exploratory analysis. Results: Excluding 2 patients who didn’t answer the questionnaire, 590 patients were analyzed in this study. For reconstruction, B-I was performed for 222 patients (37.7%), RY for 178 (30.2%) and PPG for 189 (32.1%). Proportion of the opted reconstruction procedures was not different in open and laparoscopic gastrectomies. Global health status (GHS) scores of QLQ-C30 were not different among 3 groups at any time point. In comparison of B-I and RY, B-I was better than RY in constipation, while RY was better than B-I in diarrhea and reflux symptoms. In comparison of B-I and PPG, B-I was better than PPG in constipation and reflux symptoms, while PPG was better than B-I in diarrhea. When comparing RY and PPG, RY was better than PPG in constipation and reflux symptoms, while PPG was better than RY in taste (table). Conclusions: GHS scores were similar regardless of the reconstruction procedure, however postoperative symptoms including reflux, constipation, and diarrhea were various according to reconstruction methods. [Table: see text]

Usefulness of carbon-11-labeled methionine positron-emission tomography for assessing the treatment response of primary central nervous system lymphoma

BACKGROUND

Primary central nervous system lymphoma (PCNSL) responds relatively quickly to chemotherapy or radiotherapy. However, determination of a complete response after treatment is often difficult because of extremely light residual contrast enhancement on magnetic resonance images due to the effects of microhemorrhages and scar tissue formation. These small enhancing lesions define an unconfirmed complete response. The aim of this study was to investigate the usefulness of carbon-11-labeled methionine (11C-Met) positron-emission tomography (PET) for determining the treatment response of PCNSL.

METHODS

Data for 36 patients who were treated for PCNSL between 2011 and 2015 and underwent magnetic resonance imaging and 11C-Met PET were reviewed. Magnetic resonance imaging findings were classified as complete response, unconfirmed complete response, and tumor mass (a composite of partial response, stable disease and progressive disease). PET images were evaluated, standardized uptake values were quantified, and the tumor-to-normal tissue count ratio (TNR) was calculated. Receiver operating characteristic curves were generated to determine the optimal cutoff TNRs.

RESULTS

The optimal TNRs for differentiating complete response and unconfirmed complete response from tumor mass were 1.83 (area under the curve, 0.951) and 1.80 (area under the curve, 0.932), respectively. The corresponding sensitivity and specificity values for the diagnosis of tumor mass were 82.4 and 100%, respectively, in the complete response group and 85.3 and 85%, respectively, in the unconfirmed complete response group.

CONCLUSIONS

A TNR of ≥1.80 can aid in the detection of active PCNSL using 11C-Met PET. Thus, 11C-Met-PET may be a useful tool for accurate evaluation of the treatment efficacy in PCNSL.

Determinant Factors on Differences in Survival for Gastric Cancer Between the United States and Japan Using Nationwide Databases

Background

Although the incidence and mortality have decreased, gastric cancer (GC) is still a public health issue globally. An international study reported higher survival in Korea and Japan than other countries, including the United States. We examined the determinant factors of the high survival in Japan compared with the United States.

Methods

We analysed data on 78,648 cases from the nationwide GC registration project, the Japanese Gastric Cancer Association (JGCA), from 2004–2007 and compared them with 16,722 cases from the Surveillance, Epidemiology, and End Results Program (SEER), a United States population-based cancer registry data from 2004–2010. We estimated 5-year relative survival and applied a multivariate excess hazard model to compare the two countries, considering the effect of number of lymph nodes (LNs) examined.

Results

Five-year relative survival in Japan was 81.0%, compared with 45.0% in the United States. After controlling for confounding factors, we still observed significantly higher survival in Japan. Among N2 patients, a higher number of LNs examined showed better survival in both countries. Among N3 patients, the relationship between number of LNs examined and differences in survival between the two countries disappeared.

Conclusion

Although the wide differences in GC survival between Japan and United States can be largely explained by differences in the stage at diagnosis, the number of LNs examined may also help to explain the gaps between two countries, which is related to stage migration.

A nodal diagnosis by computed tomography is unreliable for patients who need additional gastrectomy after endoscopic submucosal dissection

PURPOSE

T1 gastric cancer is treated by endoscopic submucosal dissection (ESD) or surgery, considering the risk of lymph node metastasis. Additional gastrectomy is necessary when the pathological specimens after ESD show some risk of lymph node metastasis. Preoperative computed tomography (CT) after ESD sometimes reveals enlarged lymph nodes, which should prompt surgeons to select D2 over D1/D1+. However, whether or not CT after ESD is reliable remains unclear.

METHODS

Patients who underwent radical gastrectomy for clinical T1 between April 2015 and June 2019 were enrolled. The patients were classified into those who underwent CT after ESD (group A) and those who underwent CT before primary surgery or ESD (group B). The accuracy of the nodal diagnosis was compared between groups.

RESULTS

A total of 650 patients (group A; 81, group B; 569) were examined. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value (group A vs. group B) were 77.8% vs. 84.2%, 0.0% vs. 15.9%, 84.0% vs. 95.7%, 0.0% vs. 38.2%, and 91.3% vs. 87.1%, respectively. The false-positive rate was 100% in group A and 61.8% in group B (p = 0.011).

CONCLUSIONS

A nodal diagnosis by CT is unreliable for patients who need additional gastrectomy after ESD.

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1-3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10-18.

Is D2 surgery necessary for clinical T1 gastric cancer with nodal swelling?

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Background: D2 surgery is required for clinical T1 gastric cancer with nodal swelling, however, D2 has a higher risk for morbidity than D1/D1+. Moreover, previous study demonstrated that the false positive rate for nodal diagnosis in clinical T1 was very high. To select optimal surgery with high probability, we explored risk factors for false positivity in clinical T1 disease. Methods: Patients who underwent radical gastrectomy for clinical T1 gastric cancer between April 2015 and June 2019 were enrolled. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive values for nodal diagnosis were retrospectively investigated. The risk factors for false positivity were also analyzed by the following factors; age, sex, histological type, tumor size, tumor depth, location, tumor type, presence of ulcer, and timing of CT that is (1) the patients who underwent primary endoscopic mucosal dissection (ESD) but resulted in non-curative resection, then received CT to proceed to surgery (delayed CT group) or (2) the other patients who had received CT before primary surgery or before non-curative ESD (primary CT group). Results: A total of 679 patients were examined in the present study. The accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were 83.5% (567/679), 14.3% (13/91), 94.2% (554/588), 27.7% (13/47), and 87.7% (554/632), respectively. The false positive rate was 72.3% (34/47). In univariate analysis, differentiated tumor ( p= 0.012) and delayed CT (p < 0.001) were associated with the false positivity. Multivariate analysis revealed that delayed CT (OR, 4.534; p < 0.001) was a sole significant risk factor for false positivity. False positive rate was 100% (13/13) in the delayed CT group and 61.8% (21/34) in the primary CT group ( p= 0.009). Conclusions: False positive rate was high in clinical T1 disease, especially when the patients received delayed CT after non-curative ESD. D2 surgery would be unnecessary even though nodal swelling was detected in CT after non-curative ESD.

Is splenectomy for dissecting splenic hilar lymph nodes justified in scirrhous type of gastric cancer?

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Background: Splenectomy for dissecting splenic hilar nodes (#10) should be avoided for most gastric cancer considering high morbidity and no survival benefit, while that is often selected in scirrhous type of gastric cancer because this special type frequently invades the whole stomach and the #10 nodes. Splenectomy is necessary for dissecting #10, however, survival benefit of dissecting #10 is unclear. Methods: Patients who had scirrhous gastric cancer and underwent D2 total gastrectomy with splenectomy in National Cancer Center Hospital, Japan, between 2000 to 2011 were retrospectively analyzed. The therapeutic value index was calculated by multiplying the metastatic rate of each nodal station and the 5-year survival of patients who had metastasis to each node. Results: In total, 144 patients were eligible for the present study. The most frequent metastatic site was the nodes along the lessar curvature (#3, 57%), followed by the nodes along the right gastro-epiploic artery (#4d, 45%), the right nodes located at the cardia (#1, 34%), the nodes along the left gastro-epiploic artery (#4sb, 23%), the inferior nodes at the pyloric ring (#6, 22%), the nodes along the left gastric artery (#7, 21%), the nodes along the short gastric artery (#4sa, 18%), the nodes along the cardiac branched artery (#2, 15%), the nodes around the spleen (#10, 15%), the distal nodes along the splenic artery (#11d, 15%), the proximal nodes along the splenic artery (#11p, 13%), the nodes around the celiac artery (#9, 13%), and the nodes along the common hepatic artery (#8a, 10%). These lymph nodes had a metastatic rate of more than 10%. The node with the highest index was #3(18), followed by #4d(13.4), #1(9.59), #4sa(5.85), #4sb(5.75), #10(4.86), #7(4.16), #11d(4.16), #11p(3.87), #2(3.07), #8a(2.08), and #9(1.39). The index of #10 was exceeded that of #2, #7, #8a, and #9 which are the key nodes dissected in D2. Conclusions: The metastatic rate of splenic hilar nodes was relatively high, and the therapeutic index was the sixth highest in the fifteen regional lymph nodes included in D2 dissection. Splenectomy for dissecting splenic hilar nodes would be justified in scirrhous type of gastric cancer considering its survival benefit.

Health-related quality-of-life results from JCOG0912: A phase III noninferiority trial comparing open and laparoscopy-assisted distal gastrectomy for stage I gastric cancer

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Background: Laparoscopy-assisted distal gastrectomy (LADG) was non-inferior to open (ODG) in patients with stage I gastric cancer in randomized phase 3 non-inferiority trial (JCOG0912). Here, we present the results of health-related quality of life (HRQoL) which was a secondary endpoint in JCOG0912. Methods: Among 33 institutions participated in JCOG0912, 4 major cancer centers were selected for HRQOL assessment. HRQoL was assessed using EORTC QLQ-C30 and the EORTC-STO22 before (baseline) and at 1, 3, 12, and 36 months after surgery. The primary HRQOL scale was QLQ-C30 global health status. We defined clinically meaningful decrease of HRQoL as decrease in 10 points or more from the baseline. Missing data were regarded as decrease. Assuming that expected %decrease of global health status at 3 months was 61% in ODG and 45% in LADG with 80% power and two-sided alpha of 0.05, sample size for HRQOL assessment was calculated to be 304. When this hypothesis at 3 months was confirmed, statistical comparison was tested in turn at 12 and 36 months. Results: Among 921 enrolled patients in JCOG0912 from Mar 2010 to Nov 2013, 592 were enrolled from the 4 centers in this HRQoL study. The %decrease of global health status at 3 months was different between ODG and LADG (37.2% (109/293) in ODG vs 29.2% (86/295) in LADG, odds ratio [OR] 0.65 (95% CI: 0.45-0.93, p = 0.020)), but was not different in 1 month (56.0% (164/293) vs 55.3% (163/295), OR 0.92 (0.61-1.32)), 12 months (26.3% (77/293) vs 27.8% (82/295) (OR 1.07 (0.73-1.56))and 36 months (31.4% (91/293)vs 30.8% (91/295) (odds ratio, 0.96 (0.67-1.37))). Among the other subscales, LADG had significantly better symptom scores for pain at 1 and 3 months, constipation at 3 and 12 months, and eating restrictions at 3 months. Conclusions: Decrease of HRQoL was less frequently observed in LADG than ODG especially in the early phase after surgery. Considering non-inferiority and better HRQoL of LADG, LADG is strongly recommended for stage I gastric cancer. However, we have to be careful to expand the indication of LADG for advanced gastric cancer until a solid evidence is obtained. Clinical trial information: UMIN000003319.

Cancer cell niche factors secreted from cancer-associated fibroblast by loss of H3K27me3

OBJECTIVE

Cancer-associated fibroblasts (CAFs), a major component of cancer stroma, can confer aggressive properties to cancer cells by secreting multiple factors. Their phenotypes are stably maintained, but the mechanisms are not fully understood. We aimed to show the critical role of epigenetic changes in CAFs in maintaining their tumour-promoting capacity and to show the validity of the epigenomic approach in identifying therapeutic targets from CAFs to starve cancer cells.

DESIGN

Twelve pairs of primary gastric CAFs and their corresponding non-CAFs (NCAFs) were established from surgical specimens. Genome-wide DNA methylation and H3K27me3 analyses were conducted by BeadArray 450K and ChIP-on-Chip, respectively. Functions of potential a therapeutic target were analysed by inhibiting it, and prognostic impact was assessed in a database.

RESULTS

CAFs had diverse and distinct DNA methylation and H3K27me3 patterns compared with NCAFs. Loss of H3K27me3, but not DNA methylation, in CAFs was enriched for genes involved in stem cell niche, cell growth, tissue development and stromal-epithelial interactions, such as WNT5A, GREM1, NOG and IGF2. Among these, we revealed that WNT5A, which had been considered to be derived from cancer cells, was highly expressed in cancer stromal fibroblasts, and was associated with poor prognosis. Inhibition of secreted WNT5A from CAFs suppressed cancer cell growth and migration.

CONCLUSIONS

H3K27me3 plays a crucial role in defining tumour-promoting capacities of CAFs, and multiple stem cell niche factors were secreted from CAFs due to loss of H3K27me3. The validity of the epigenetic approach to uncover therapeutic targets for cancer-starving therapy was demonstrated.

Feasibility and pathological response of TAS-118 + oxaliplatin as perioperative chemotherapy for patients with locally advanced gastric cancer (APOLLO-11)

351

Background: TAS-118 is a novel oral agent, containing S-1 and leucovorin. In the SOLAR study (NCT02322593), TAS-118 + oxaliplatin (OHP) significantly improved overall survival compared to S-1 + cisplatin for patients (pts) with advanced gastric cancer (GC). We conducted this open-label study to assess feasibility of perioperative adjuvant chemotherapy with TAS-118 + OHP in pts with locally advanced resectable GC with lymph node metastasis. (Clinical trial information: UMIN000024688). Methods: Eligible pts who had histopathologically confirmed GC with clinical T3-4N1-3M0 on image findings (14th Japanese classification of gastric carcinoma), age 20 to 79 years, were enrolled in this study. The protocol treatment consisted of preoperative 4 courses of TAS-118 (80-120 mg/body, days 1-7) + OHP (85 mg/m2, day 1) every 2 weeks, and gastrectomy with D2 lymphadenectomy, followed by postoperative 12 courses of TAS-118 alone (step1) or 8 cycles of TAS-118 + OHP (step2). The primary endpoints were tolerability of preoperative chemotherapy, gastrectomy and postoperative chemotherapy with TAS-118 plus OHP. Here, we report the feasibility of preoperative chemotherapy and gastrectomy, and pathological response. Results: Between December 2016 and April 2018, 45 pts with a median age of 61 years were enrolled. The numbers of pts with T stage (cT3/4a) and those with N stage (cN1/2/3) were 13/32 and 25/17/3, respectively. The completion rate of preoperative chemotherapy and gastrectomy was 88.9% ( 95% CI 78.0-95.5) and 95.6% (95% CI 86.7-99.2). The relative dose intensity of TAS-118 and OHP was 86.0% and 90.6%. During the 4 cycles of preoperative TAS-118 + OHP, 2 pts discontinued the treatment due to adverse event (AE). Major grade 3-4 AEs were diarrhea (17.8%) and neutropenia (8.9%). R0 resection rate was as high as 95.6%. One pts experienced grade 4 postoperative bleeding, but no treatment-related death was reported. pCR was achieved in 6/45 pts (13.3%) and other 7 pts (28.9%) showed near complete regression (<10 % residual tumor cells). Conclusions: Preoperative TAS-118 + OHP followed by D2 gastorectomy was well tolerated and showed promising efficacy. Clinical trial information: 000024688.