Population-Based Study on Risk Factors for Tumor-Positive Resection Margins in Patients with Gastric Cancer

Effect of Minimally Invasive versus Open Distal Gastrectomy on Long-Term Survival in Patients with Gastric Cancer: Individual Patient Data Meta-analysis

BACKGROUND

Minimally invasive distal gastrectomy (MIDG) has been shown to improve short-term outcomes compared with open distal gastrectomy (ODG) in patients with early (EGC) and locally advanced gastric cancer (LAGC). The impact of MIDG on patient survival remains debated. This study aimed to compare the effect of MIDG versus ODG on long-term survival.

PATIENTS AND METHODS

Randomized clinical trial (RCTs) individual patient data (IPD) meta-analysis with restricted mean survival time difference (RMSTD) estimation. Scopus, MEDLINE, Web of Science, and ClinicalTrials.gov were searched. Primary outcomes were 5-year overall (OS), disease free survival (DFS), and cancer specific survival (CSS). RMSTD and 95% confidence intervals (CI) were used as pooled effect size measures. The certainty of evidence was categorized with the Grading of Recommendations, Assessment, Development, and Evaluation framework.

RESULTS

Overall, ten RCTs (5297 patients) were included; 50.4% of patients underwent MIDG. At 60-months follow-up, the OS and DFS estimates for ODG versus MIDG were 0.41 months (95% CI - 0.17, 0.99; high level of certainty) and 0.42 months (95% CI - 0.38, 1.23; high level of certainty). CSS was specified in two RCTs, hence quantitative analysis was not practicable. The 60-month OS and DFS estimates for LAGC (five studies) were 0.32 months (95% CI - 0.80, 1.44; high level of certainty) and 0.31 months (95% CI - 2.02, 1.33; high level of certainty), respectively. The 36-month DFS appraisal for stage III patients (three studies) was - 0.41 months (95% CI - 26.1, 38.2; low level of certainty).

CONCLUSIONS

This meta-analysis found high-certainty evidence that MIDG and ODG demonstrate similar 5-year OS and DFS in patients with both EGC and LAGC.

Minimally Invasive Versus Open Distal Gastrectomy for Locally Advanced Gastric Cancer: Trial Sequential Analysis of Randomized Trials

BACKGROUND

Minimally invasive distal gastrectomy (MIDG) has been shown to be associated with improved short-term outcomes compared to open distal gastrectomy (ODG) in patients with locally advanced gastric cancer (LAGC). The impact of MIDG on long-term patient survival remains debated. Aim was to compare the MIDG vs. ODG effect on long-term survival.

METHODS

Systematic review and trial sequential analysis (TSA) of randomized controlled trials (RCTs). Web of Science, Scopus, MEDLINE, the Cochrane Central Library, and ClinicalTrials.gov were queried. Hazard ratio (HR) and 95% confidence intervals (CI) were used as pooled effect size measures. Five-year overall (OS) and disease-free survival (DFS) were primary outcomes.

RESULTS

Five RCTs were included (2835 patients). Overall, 1421 (50.1%) patients underwent MIDG and 1414 (49.9%) ODG. The ages ranged from 48 to 70 years and 63.4% were males. The pooled 5-year OS (HR = 0.86; 95% CI 0.70-1.04; I2 = 0.0%) and 5-year DFS (HR = 1.03; 95% CI 0.87-1.23; I2 = 0.0%) were similar for MIDG vs. ODG. The TSA shows a cumulative z-curve without crossing the monitoring boundaries line (Z = 1.96), thus suggesting not conclusive 5-year OS and DFS results because the total information size was not sufficient.

CONCLUSIONS

MIDG and ODG seem to have equivalent 5-year OS and DFS in patients with LAGC. However, the cumulative evidence derived from the TSA showed that the actual information size is not sufficient to provide conclusive data.

Risk factors and prognostic analysis of microscopic positive esophageal margins after radical surgery for proximal gastric cancer

BACKGROUND

Proximal gastric cancer has been on the rise worldwide in recent years. A positive surgical margin may result in incomplete tumor and affect the prognosis of patients. This study aims to analyse the risk factors for and prognosis associated with microscopic positive esophageal margins (R1 resection) after radical surgery for proximal gastric cancer patients.

METHODS

This was a retrospective analysis of 316 patients with proximal gastric cancer who underwent surgical resection at the Department of Gastrointestinal Surgery of Hengshui People's Hospital from January 2013 to June 2018. Patients were divided into the R1 group (n = 24) and R0 group (n = 292) according to the esophageal margin status. Differences in clinicopathological characteristics and prognosis between the two groups were compared.

RESULTS

Tumor location at the esophagogastric junction, Borrmann type 3/4, Lauren diffuse/mixed type, margin distance < 3 cm, pT4 stage, and vascular invasion were identified as independent risk factors for positive esophageal margins in proximal gastric cancer patients (all P < 0.05). The 5-year overall survival rate was significantly lower in the R1 group than in the R0 group (45.8% vs. 64.2%, P < 0.05). Subgroup analysis revealed that the 5-year overall survival rate was significantly lower in the R1 group in the pT2-3 and pN0 stages (P < 0.05), while there was no significant difference in the pT4 and pN(+) stages (P > 0.05). Multivariate Cox regression analysis revealed that Borrmann type, Lauren type, pT stage, pN stage, and lymphovascular invasion were independent risk factors affecting the prognosis of patients with proximal gastric cancer (all P < 0.05), while esophageal margin status was not an independent risk factor affecting prognosis (P > 0.05).

CONCLUSION

Positive esophageal margins in proximal gastric cancer are associated with various clinicopathological factors and lead to a worse prognosis in patients with pT2-3 and pN0 stages but do not affect the prognosis of patients with pT4 and pN(+) stages.

The correlation between the margin of resection and prognosis in esophagogastric junction adenocarcinoma

Adenocarcinoma of the gastroesophageal junction (AEG) has become increasingly common in Western and Asian populations. Surgical resection is the mainstay of treatment for AEG; however, determining the distance from the upper edge of the tumor to the esophageal margin (PM) is essential for accurate prognosis. Despite the relevance of these studies, most have been retrospective and vary widely in their conclusions. The PM is now widely accepted to have an impact on patient outcomes but can be masked by TNM at later stages. Extended PM is associated with improved outcomes, but the optimal PM is uncertain. Academics continue to debate the surgical route, extent of lymphadenectomy, preoperative tumor size assessment, intraoperative cryosection, neoadjuvant therapy, and other aspects to further ensure a negative margin in patients with gastroesophageal adenocarcinoma. This review summarizes and evaluates the findings from these studies and suggests that the choice of approach for patients with adenocarcinoma of the esophagogastric junction should take into account the extent of esophagectomy and lymphadenectomy. Although several guidelines and reviews recommend the routine use of intraoperative cryosections to evaluate surgical margins, its generalizability is limited. Furthermore, neoadjuvant chemotherapy and radiotherapy are more likely to increase the R0 resection rate. In particular, intraoperative cryosections and neoadjuvant chemoradiotherapy were found to be more effective for achieving negative resection margins in signet ring cell carcinoma.

Current Trends in Volume and Surgical Outcomes in Gastric Cancer

Gastric cancer is ranked as the fifth most frequently diagnosed type of cancer. Complete resection with adequate lymphadenectomy represents the goal of treatment with curative intent. Quality assurance is a crucial factor in the evaluation of oncological surgical care, and centralization of healthcare in referral hospitals has been proposed in several countries. However, an international agreement about the setting of “high-volume hospitals” as well as “minimum volume standards” has not yet been clearly established. Despite the clear postoperative mortality benefits that have been described for gastric cancer surgery conducted by high-volume surgeons in high-volume hospitals, many authors have highlighted the limitations of a non-composite variable to define the ideal postoperative period. The textbook outcome represents a multidimensional measure assessing the quality of care for cancer patients. Transparent and easily available hospital data will increase patients’ awareness, providing suitable elements for a more informed hospital choice.

Risk Factors for Tumor Positive Resection Margins After Neoadjuvant Chemoradiotherapy for Esophageal Cancer: Results From the Dutch Upper GI Cancer Audit: A Nationwide Population-Based Study

OBJECTIVE

To identify risk factors for tumor positive resection margins after neoadjuvant chemoradiotherapy (nCRT) followed by esophagectomy for esophageal cancer.

SUMMARY BACKGROUND DATA

Esophagectomy after nCRT is associated with tumor positive resection margins in 4% to 9% of patients. This study evaluates potential risk factors for positive resection margins after nCRT followed by esophagectomy.

METHODS

All patients who underwent an elective esophagectomy following nCRT in 2011 to 2017 in the Netherlands were included. A multivariable logistic regression was performed to assess the association between potential risk factors and tumor positive resection margins.

RESULTS

In total, 3900 patients were included. Tumor positive resection margins were observed in 150 (4%) patients. Risk factors for tumor positive resection margins included tumor length (in centimeters, OR: 1.1, 95% CI: 1.0-1.1), cT4-stage (OR: 3.0, 95% CI: 1.2-6.7), and an Ivor Lewis esophagectomy (OR: 1.6, 95% CI: 1.0-2.6). Predictors associated with a lower risk of tumor positive resection margins were squamous cell carcinoma (OR: 0.4, 95% CI: 0.2-0.7), distal tumors (OR: 0.5, 95% CI: 0.3-1.0), minimally invasive surgery (OR: 0.6, 95% CI: 0.4-0.9), and a hospital volume of >60 esophagectomies per year (OR: 0.6, 95% CI: 0.4-1.0).

CONCLUSIONS

In this nationwide cohort study, tumor and surgical related factors (tumor length, histology, cT-stage, tumor location, surgical procedure, surgical approach, hospital volume) were identified as risk factors for tumor positive resection margins after nCRT for esophageal cancer. These results can be used to improve the radical resection rate by careful selection of patients and surgical approach and are a plea for centralization of esophageal cancer care.

Prevention and treatment of a positive proximal margin after gastrectomy for cardia cancer

A tumour-positive proximal margin (PPM) after extended gastrectomy for oesophagogastric junction (OGJ) adenocarcinoma is observed in approximately 2-20% of patients. Although a PPM is an unfavourable prognostic factor, the clinical relevance remains unclear as it may reflect poor tumour biology. This narrative review analyses the most relevant literature on PPM after gastrectomy for OGJ cancers. Awareness of the risk factors and possible measures that can be taken to reduce the risk of PPM are important. In patients with a PPM, surgical and non-surgical treatments are available but the effectiveness remains unclear.

Novel multifunctional NIR-II aggregation-induced emission nanoparticles-assisted intraoperative identification and elimination of residual tumor

Incomplete tumor resection is the direct cause of the tumor recurrence and metastasis after surgery. Intraoperative accurate detection and elimination of microscopic residual cancer improve surgery outcomes. In this study, a powerful D1–π–A–D2–R type phototheranostic based on aggregation-induced emission (AIE)-active the second near-infrared window (NIR-II) fluorophore is designed and constructed. The prepared theranostic agent, A1 nanoparticles (NPs), simultaneously shows high absolute quantum yield (1.23%), excellent photothermal conversion efficiency (55.3%), high molar absorption coefficient and moderate singlet oxygen generation performance. In vivo experiments indicate that NIR-II fluorescence imaging of A1 NPs precisely detect microscopic residual tumor (2 mm in diameter) in the tumor bed and metastatic lymph nodes. More notably, a novel integrated strategy that achieves complete tumor eradication (no local recurrence and metastasis after surgery) is proposed. In summary, A1 NPs possess superior imaging and treatment performance, and can detect and eliminate residual tumor lesions intraoperatively. This work provides a promising technique for future clinical applications achieving improved surgical outcomes.

Clinical Relevance of the Tumor Location-Modified Laurén Classification System for Gastric Cancer in a Western Population

Background

The Tumor Location-Modified Laurén Classification (MLC) system combines Laurén histologic subtype and anatomic tumor location. It divides gastric tumors into proximal non-diffuse (PND), distal non-diffuse (DND), and diffuse (D) types. The optimum classification of patients with Laurén mixed tumors in this system is not clear due to its grouping with both diffuse and non-diffuse types in previous studies. The clinical relevance of the MLC in a Western population has not been examined.

Methods

A cohort study investigated 404 patients who underwent gastrectomy for gastric adenocarcinoma between 2005 and 2020. The classification of Laurén mixed tumors was evaluated using receiver operating characteristic (ROC) curve analysis and comparison of clinicopathologic characteristics (chi-square). Survival analysis was performed using multivariable Cox regression.

Results

The ROC curve analysis demonstrated a slightly higher area under the curve value for predicting survival when Laurén mixed tumors were grouped with intestinal-type rather than diffuse-type tumors (0.58 vs 0.57). Survival, tumor recurrence, and resection margin positivity in mixed tumors also was more similar to intestinal type. Distal non-diffuse tumors had the best 5-year survival (DND 64.7 % vs PND 56.1 % vs diffuse 45.1 %; p = 0.006) and were least likely to have recurrence (DND 27.0 % vs PND 34.3 % vs diffuse 48.3 %; p = 0.001). Multivariable analysis demonstrated that MLC was an independent prognostic factor for survival (PND: hazard ratio [HR], 1.64; 95 % confidence interval [CI], 1.16–2.32 vs diffuse: HR, 2.20; 95 % CI, 1.56–3.09)

Conclusions

The MLC was an independent prognostic marker in this Western cohort of patients with gastric adenocarcinoma. The patients with PND and D tumors had worse survival than those with DND tumors.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-11252-y.

Sex differences in tumor characteristics, treatment, and outcomes of gastric and esophageal cancer surgery: nationwide cohort data from the Dutch Upper GI Cancer Audit

BACKGROUND

Sex differences in clinicopathological characteristics, treatment, and postoperative outcomes of gastric and esophageal cancer are largely undefined. This study aimed to compare tumor and treatment characteristics and outcomes of gastric and esophageal cancer surgery between male and female patients.

METHODS

Patients after elective surgery for primary esophageal (EAC) or gastric adenocarcinoma (GAC) registered in the Dutch Upper GI Cancer Audit between 2011 and 2016 were included. The primary endpoint, 5-year relative survival with relative excess risk (RER), i.e., adjusted for the normal life expectancy, was compared between male and female patients with EAC and GAC.

RESULTS

In total, 4937 patients were included (75% male) with a mean age of 66 years. cT and cN-stages showed a similar distribution in male and female patients. In females, antrum GAC was more frequent (47% vs. 38%, p < 0.001). Female patients with EAC less frequently received neo-adjuvant treatment (OR = 0.60, 95% CI 0.38-0.96, p = 0.033). For GAC, less postoperative morbidity (33% vs. 38% p = 0.017) and less re-interventions (12% vs. 16%, p = 0.008) were observed in females, although they had inferior 5-year relative survival (49% vs. 56%, RER = 1.31, 95% CI 1.09-1.58, p = 0.004). No differences in relative survival of EAC were observed.

CONCLUSIONS

In addition to significant sex differences in tumor location, female patients with esophageal adenocarcinoma less frequently received neo-adjuvant therapy, and female patients with gastric adenocarcinoma had inferior relative survival. Further consideration and exploration of sex differences in surgical treatment and outcomes are necessary to improve tailored treatment and outcomes.

Outcomes of Esophagogastric Cancer Surgery During Eight Years of Surgical Auditing by the Dutch Upper Gastrointestinal Cancer Audit (DUCA)

OBJECTIVE

To evaluate changes in treatment and outcomes of esophagogastric cancer surgery after introduction of the DUCA. In addition, the presence of risk-averse behavior was assessed.

SUMMARY OF BACKGROUND DATA

Clinical auditing is seen as an important quality improvement tool; however, its long-term efficacy remains largely unknown. In addition, critics claim that enhancements result from risk-averse behavior rather than positive effects of auditing.

METHODS

DUCA data were used from registration start (1-1-2011) until 31-12-2018. Trends in patient, tumor, hospital and treatment characteristics were univariably assessed. Trends in short-term outcomes were investigated using multilevel multivariable logistic regression. Presence of risk aversion was described by the corrected proportion of patients undergoing surgery, using data from the Netherlands Cancer Registry. To evaluate the impact of centralization on time trends identified, the association between hospital volume and outcomes was investigated.

RESULTS

This study included 6172 patients with esophageal and 3,690 with gastric cancer who underwent surgery. Pathological outcomes (lymph node yield, radicality) improved and futile surgery decreased over the years. In-hospital/30-day mortality decreased for esophagectomy (4.2% to 2.5%) and for gastrectomy (7.1% to 4.3%). Reinterventions, (minor) complications and readmissions increased. Risk aversion appeared absent. Between 2011-2018, annual median hospital volumes increased from 38 to 53 for esophagectomy and from 14 to 29 for gastrectomy. Higher hospital volumes were associated with several improved outcomes measures.

CONCLUSIONS

During 8 years of auditing, outcomes improved, with no signs of risk-averse behavior. These improvements occurred in parallel with centralization. Feedback on postoperative complications remains the focus of the DUCA.

Long-Wave Infrared Imaging for Intraoperative Cancer Detection-What is the True Temperature of a Cancer?

BACKGROUND

During cancer operations, the cancer itself is often hard to delineate-buried beneath healthy tissue and lacking discernable differences from the surrounding healthy organ. Long-wave infrared, or thermal, imaging poses a unique solution to this problem, allowing for the real-time label-free visualization of temperature deviations within the depth of tissues. The current study evaluated this technology for intraoperative cancer detection.

METHODS

In this diagnostic study, patients with gastrointestinal, hepatobiliary, and renal cancers underwent long-wave infrared imaging of the malignancy during routine operations.

RESULTS

It was found that 74% were clearly identifiable as hypothermic anomalies. The average temperature difference was 2.4°C (range 0.7 to 5.0) relative to the surrounding tissue. Cancers as deep as 3.3 cm from the surgical surface were visualized. Yet, 79% of the images had clinically relevant false positive signals [median 3 per image (range 0 to 10)] establishing an accuracy of 47%. Analysis suggests that the degree of temperature difference was primarily determined by features within the cancer and not peritumoral changes in the surrounding tissue.

CONCLUSION

These findings provide important information on the unexpected hypothermal properties of intra-abdominal cancers, directions for future use of intraoperative long-wave infrared imaging, and new knowledge about the in vivo thermal energy expenditure of cancers and peritumoral tissue.

Assessing the hospital volume-outcome relationship in surgery: a scoping review

INTRODUCTION

Many recent studies have investigated the hospital volume-outcome relationship in surgery. In some cases, the results have prompted the centralization of surgical activity. However, the methodologies and interpretations differ markedly from one study to another. The objective of the present scoping review was to describe the various features used to assess the volume-outcome relationship: the analyzed datasets, study population, outcome, covariates, confounders, volume modalities, and statistical methods.

METHODS AND ANALYSIS

The review was conducted according to a study protocol published in BMJ Open in 2020. Two authors (both of whom had helped to design the study protocol) screened publications independently according to the title, the abstract and then the full text. To ensure exhaustivity, all the papers included by each reviewer went through to the next step.

INTERPRETATION

The 403 included studies covered 90 types of surgery, 61 types of outcome, and 72 covariates or potential confounders. 191 (47.5%) studies focussed on oncological surgery and 37.8% focussed visceral or digestive tract surgery. Overall, 86.6% of the studies found a statistically significant volume-outcome relationship, although the findings differed from one type of surgery to another. Furthermore, the types of outcome and the covariates were highly diverse. The majority of studies were performed in Western countries, and oncological and visceral surgical procedures were over-represented; this might limit the generalizability and comparability of the studies' results.

Short- and long-term oncological outcomes of totally laparoscopic gastrectomy versus laparoscopy-assisted gastrectomy for clinical stage I gastric cancer

BACKGROUND

Totally laparoscopic gastrectomy (TLG), which involves a complete intracorporeal gastric transection and the creation of an anastomosis, has been gradually adopted. However, a potential limitation of intracorporeal transection is the lack of tactile feedback, and whether this limitation influences oncological outcomes is unclear. The aim of this study is to evaluate the short- and long-term oncological safety of TLG using endoscopy-guided intracorporeal gastric transection for clinical stage (cStage) I gastric cancer.

METHODS

A total of 1875 consecutive patients who underwent laparoscopic gastrectomy for cStage I gastric cancer between January 2007 and March 2015 were enrolled in this study. Marking clips were preoperatively placed and a transection line was determined by perceiving it tactually in laparoscopy-assisted gastrectomy (LAG) or endoscopically in TLG. After propensity score matching, 1366 patients (683 each for LAG and TLG groups) were selected to primarily test the non-inferiority of TLG to that of LAG for relapse-free survival (RFS).

RESULTS

In the propensity-matched population, the 5-year RFS rates of the LAG and TLG groups were 94.3% (95% confidence interval (CI) 92.2-95.8%), and 95.6% (95% CI 93.8-96.9%), respectively. The hazard ratio (TLG/LAG) was 0.77 (95% CI 0.48-1.24, P for non-inferiority < 0.01). There were no significant differences in the recurrence profiles. The incidence of the remnant of marking clips or tumor tissue did not differ (LAG: 1.0% vs. TLG: 1.9%, P = 0.177).

CONCLUSIONS

TLG using preoperative markings and intraoperative endoscopic guidance provides cStage I gastric cancer patients with comparable oncological outcomes to the conventional method.

Minimally Invasive Oncologic Upper Gastrointestinal Surgery can be Performed Safely on all Weekdays: A Nationwide Cohort Study

Background

Existing literature suggests deteriorating surgical outcome of esophagogastric surgery as the week progresses. However, these studies were conducted in the pre-centralization and pre-minimally invasive era. In addition, they failed to correct for fixed weekdays of esophagogastric cancer surgery among hospitals. This study aimed to describe the impact of weekday of minimally invasive upper gastrointestinal surgery on short-term surgical outcomes.

Methods

All patients registered in the Dutch Upper Gastrointestinal Cancer Audit who underwent curative minimally invasive esophageal or gastric carcinoma surgery in 2015–2019, were included in this nationwide cohort study. Using multilevel multivariable logistic regression, the impact of weekday of surgery on 14 short-term surgical outcomes was investigated. To correct for interhospital variance in fixed weekday(s) of surgery multilevel analyses was used. Results were adjusted for patient, tumor, and treatment characteristics using multivariable logistic regression analyses.

Results

This study included 4,102 patients undergoing minimally invasive upper gastrointestinal surgery (2,968 esophageal cancer and 1,134 gastric cancer patients). Weekday of surgery did not impact postoperative complications, severe postoperative complications, surgical/technical complications, medical complications, anastomotic leakage, complicated postoperative course, failure to rescue, surgical radicality, lymph node yield, 30-day/in-hospital mortality, reinterventions, length of ICU stay, 30-day readmission, and textbook outcome after neither esophageal cancer nor gastric cancer surgery.

Conclusions

Minimally invasive esophagogastric surgery can be performed safely on all weekdays with respect to short-term surgical outcomes, which is important information for operation room scheduling.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00268-021-06160-x.

Failure to Cure in Patients Undergoing Surgery for Gastric Cancer: A Nationwide Cohort Study

Background

This study aimed to describe the incidence of failure to cure (a composite outcome measure defined as surgery not meeting its initial aim), and the impact of hospital variation in the administration of neoadjuvant therapy on this outcome measure.

Methods

All patients in the Dutch Upper Gastrointestinal Cancer Audit undergoing curatively intended gastric cancer surgery in 2011–2019 were included. Failure to cure was defined as (1) ‘open-close’ surgery; (2) irradical surgery (R1/R2); or (3) 30-day/in-hospital mortality. Case-mix-corrected funnel plots, based on multivariable logistic regression analyses, investigated hospital variation. The impact of a hospital’s tendency to administer neoadjuvant chemotherapy on the heterogeneity in failure to cure between hospitals was assessed based on median odds ratios and multilevel logistic regression analyses.

Results

Some 3862 patients from 28 hospitals were included. Failure to cure was noted in 22.3% (hospital variation: 14.5–34.8%). After case-mix correction, two hospitals had significantly higher-than-expected failure to cure rates, and one hospital had a lower-than-expected rate. The failure to cure rate was significantly higher in hospitals with a low tendency to administer neoadjuvant chemotherapy. Approximately 29% of hospital variation in failure to cure could be attributed to different hospital policies regarding neoadjuvant therapy.

Conclusions

Failure to cure has an incidence of 22% in patients undergoing gastric cancer surgery. Higher failure to cure rates were seen in centers administering less neoadjuvant chemotherapy, which confirms the Dutch guideline recommendation on the administration of neoadjuvant chemotherapy. Failure to cure provides short loop feedback and can be used as a quality indicator in surgical audits.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-020-09510-6.

Assessing the hospital volume-outcome relationship in surgery: a scoping review protocol

INTRODUCTION

Even if a positive volume-outcome correlation in surgery is mostly admitted in many surgical fields, the various ways to assess this relationship make it difficult for researchers and policymakers to use it. Our aim is therefore to provide an overview of the way hospital volume-outcome relationship was assessed. Through this overview, our goal is to identify potential gaps in the assessment of this relationship, to help researchers who want to pursue work in this field and, ultimately, to help policy makers interpret such analyses.

METHODS AND ANALYSIS

This review will be conducted using the six stages of the scoping review method: identifying the research question, searching for relevant studies, selecting studies, data extraction, collating, summarising and reporting the results and concluding. This review will address all the key questions used to assess the volume-outcome relationship in surgery.Primary research papers investigating the hospital volume-outcome relationship from 2009 will be included. Studies only looking at surgeons' volume-outcome relationship or studies were the volume variable is not individualisable will be excluded.Both MEDLINE and Scopus will be searched along with grey literature. Two researchers will perform all the stages of the review: screen the titles and abstracts, review the full text of selected articles to determine final inclusions and extract the data. The results will be summarised quantitatively using numerical counts.

ETHICAL CONSIDERATIONS AND DISSEMINATION

Reviews of published articles are considered secondary analysis and do not need ethical approval. The findings will be disseminated through multiple channels like conferences and peer-reviewed journals.

What are the important prognostic factors in gastric cancer with positive duodenal margins? A multi-institutional analysis

PURPOSE

Positive margins are reported in from 4.8 to 9.5% of all gastric cancer surgeries and they have a negative impact on the overall survival. Few cases with positive duodenal margins have been included in previous studies regarding the prognosis.

METHODS

This multi-institutional retrospective study included 115 gastric cancer patients with positive duodenal margins following gastrectomy between January 2002 and December 2017. The association between clinicopathological factors and the overall survival was evaluated by univariate and multivariate analyses.

RESULTS

The three-year overall survival was 22% and the median survival was 13 months. A multivariate analysis found that distant metastasis, no postoperative chemotherapy, and non-Type 4 disease were significantly associated with a poor survival. Patients without distant metastasis who received postoperative chemotherapy had a 3-year overall survival of 56% and a median survival of 44 months.

CONCLUSION

The patients who underwent post-operative chemotherapy showed a significantly better OS compared with those who did not undergo post-operative chemotherapy, regardless of the existence of distant metastasis. Postoperative chemotherapy may, therefore, improve the prognosis of surgically treated gastric cancer patients with positive duodenal margins.

Margin Positivity in Resectable Esophageal Cancer: Are there Modifiable Risk Factors?

BACKGROUND

Patients with esophageal cancer have poor overall survival, with positive resection margins worsening survival. Margin positivity rates are used as quality measures in other malignancies, but modifiable risk factors are necessary to develop actionable targets for improvement. Our objectives were to (1) evaluate trends in esophageal cancer margin positivity, and (2) identify modifiable patient/hospital factors associated with margin positivity.

METHODS

Patients who underwent esophagectomy from 2004 to 2015 were identified from the National Cancer Database. Trends in margin positivity by time and hospital volume were evaluated using Cochrane-Armitage tests. Associations between patient/hospital factors and margin positivity were assessed by multivariable logistic regression.

RESULTS

Among 29,706 patients who underwent esophagectomy for cancer, 9.37% had positive margins. Margin positivity rates decreased over time (10.62% in 2004 to 8.61% in 2015; p < 0.001). Older patients (≥ 75 years) were more likely to have positive margins [odds ratio (OR) 2.04, 95% confidence interval (CI) 1.42-2.92], as were patients with a Charlson-Deyo Index ≥ 3 (OR 1.84, 95% CI 1.08-3.12). Patients who received neoadjuvant therapy were less likely to have positive margins (OR 0.37, 95% CI 0.29-0.47), while laparoscopic surgical approach was associated with increased margin positivity (OR 1.70, 95% CI 1.40-2.06). As the hospital annual esophagectomy volume increased, margin positivity rates decreased (7.76% in the fourth quartile vs. 11.39% in the first quartile; OR 0.70, 95% CI 0.49-0.99).

CONCLUSIONS

Use of neoadjuvant therapy, surgical approach, and hospital volume are modifiable risk factors for margin positivity in esophageal cancer. These factors should be considered in treatment planning, and margin positivity rates could be considered as a quality measure in esophageal cancer.

Impact of proximal resection margin involvement on survival outcome in patients with proximal gastric cancer

AIM

The aim of this study was to evaluate the risk factors for proximal resection margin involvement and its impact on survival outcome in patients with proximal gastric cancer.

METHODS

A total of 488 patients who underwent potentially curative resection for proximal gastric cancer were retrospectively reviewed. Clinicopathological characteristics and survival differences between patients with positive and negative resection margins were compared and prognostic factors were determined by Cox multivariate analysis.

RESULTS

In this study, 7.6% (37/488) of patients with proximal gastric cancer had a positive proximal resection margin after postoperative histopathological examination. Positive resection margins were significantly associated with advanced tumour stage and more aggressive biological features including larger tumour size, serosal invasion and lymphovascular invasion. Serosal invasion (OR 4.543, 95% CI 2.201 to 9.380, p<0.001) and lymphovascular invasion (OR 2.279, 95% CI 1.129 to 4.600, p<0.05) were independent risk factors for positive proximal resection margins. In terms of survival outcome, positive resection margins had an adverse impact on the prognosis of patients with proximal gastric cancer (median DFS: 20.7 vs 30.2 months, p<0.001). The multivariate analysis indicated that positive resection margins (HR 1.494, 95% CI 1.042 to 2.142, p=0.029), T stage (T3-T4, HR 2.264, 95% CI 1.484 to 3.454, p<0.001) and N stage (N1-N2 stage, HR 1.696, 95% CI 1.279 to 2.248, p<0.001; N3 stage, HR 2.691, 95% CI 1.967 to 3.681, p<0.001) were independent prognostic factors for patients with proximal gastric cancer.

CONCLUSION

Proximal resection margin involvement was an indicator of more aggressive tumours and an independent prognostic factor for patients with proximal gastric cancer. Aggressive efforts should be made to achieve a negative resection margin if gastric cancer was deemed to be potentially resectable.