Length of negative resection margin does not affect local recurrence and survival in the patients with gastric cancer

Prognostic Relevance of the Proximal Resection Margin Distance in Distal Gastrectomy for Gastric Adenocarcinoma

BACKGROUND

The risk for recurrence in patients with distal gastric cancer can be reduced by surgical radicality. However, dispute exists about the value of the proposed minimum proximal margin distance (PMD). Here, we assess the prognostic value of the safety distance between the proximal resection margin and the tumor.

PATIENTS AND METHODS

This is a single-center cohort study of patients undergoing distal gastrectomy for gastric adenocarcinoma (2001-2021). Cohorts were defined by adequacy of the PMD according to the European Society for Medical Oncology (ESMO) guidelines (≥ 5 cm for intestinal and ≥ 8 cm for diffuse Laurén's subtypes). Overall survival (OS) and time to progression (TTP) were assessed by log-rank and multivariable Cox-regression analyses.

RESULTS

Of 176 patients, 70 (39.8%) had a sufficient PMD. An adequate PMD was associated with cancer of the intestinal subtype (67% vs. 45%, p = 0.010). Estimated 5-year survival was 63% [95% confidence interval (CI) 51-78] and 62% (95% CI 53-73) for adequate and inadequate PMD, respectively. Overall, an adequate PMD was not prognostic for OS (HR 0.81, 95% CI 0.48-1.38) in the multivariable analysis. However, in patients with diffuse subtype, an adequate PMD was associated with improved oncological outcomes (median OS not reached versus 131 months, p = 0.038, median TTP not reached versus 88.0 months, p = 0.003).

CONCLUSION

Patients with diffuse gastric cancer are at greater risk to undergo resection with an inadequate PMD, which in those patients is associated with worse oncological outcomes. For the intestinal subtype, there was no prognostic association with PMD, indicating that a distal gastrectomy with partial preservation of the gastric function may also be feasible in the setting where an extensive PMD is not achievable.

Prognostic effect of microscopically negative but close resection margin in gastric cancer

INTRODUCTION

Microscopically positive resection margin (RM) following curative surgery has been linked to disease recurrence in gastric cancer (GC), but the impact of microscopically negative but close RM (CRM) remains unclear. This study aimed to evaluate the prognostic implications of a CRM of ≤0.5 cm in GC patients.

METHODS

A retrospective review of the institutional GC database identified 1958 patients who underwent curative gastrectomy for pathologically proven GC between January 2011 and December 2015. The patients were categorized into CRM (RM ≤0.5 cm) and sufficient RM (SRM, RM >0.5 cm) groups. The impact of CRM on recurrence-free survival (RFS) and overall survival (OS) was analyzed compared to the SRM group.

RESULTS

The cohort comprised 1264 patients with early GC (EGC, 64.6%) and 694 with advanced GC (AGC, 35.4%). Forty-four patients (2.2%) had RM of ≤0.5 cm. CRM was associated with worse RFS in AGC (5-year RFS in the CRM vs. SRM groups; 41.6% vs. 68.7%, p = 0.011); however, the effect on OS was not significant (p = 0.159). Multivariate analysis revealed that CRM was an independent prognostic factor for RFS (hazard ratio [HR] 2.035, 95% confidence interval [CI] 1.097-3.776). In AGC, the locoregional recurrence rate was significantly higher in the CRM group than in the SRM group (15.4% vs. 4.9%, p = 0.044).

CONCLUSION

CRM of ≤0.5 cm was a significant prognostic factor for RFS in GC patients and was associated with a significant increase in locoregional recurrence in AGC.

Adequate gross resection margin length ensuring pathologically complete resection in gastrectomy for gastric cancer: A systematic review and meta-analysis

Aim

A positive resection margin (RM) is associated with poor survival after gastrectomy for gastric cancer (GC). However, the adequate RM length to avoid a positive RM remains controversial. We performed a systematic review to examine the RM length required to avoid a positive RM in gastrectomy for GC.

Methods

This systematic review involved all relevant articles identified in PubMed, the Cochrane Library, Web of Science, and ClinicalTrials.gov until August 2023. The incidence of a positive RM related to the RM length and the possible incidence of a positive RM estimated from the discrepancy between the gross and pathological RM length were evaluated. The Newcastle-Ottawa Scale was used to quantify study quality.

Results

Thirteen studies involving 8983 patients were analyzed. Investigation of the incidence of a positive RM in relation to the RM length showed that a proximal RM length of 6 cm guaranteed a negative RM in gastrectomy. Analyses of the possible incidence of a positive RM revealed that a negative RM would be guaranteed if the proximal RM length was 6 cm in distal gastrectomy, if the esophageal resection length was 2 cm in total gastrectomy for GC without esophageal invasion and 2.5 cm in total or proximal gastrectomy for GC with esophageal invasion or esophagogastric junction cancer, and if the distal RM length was 4 cm in proximal gastrectomy for early GC.

Conclusions

The adequate RM lengths to ensure a pathologically negative RM in each type of gastrectomy for GC were herein suggested.

Impact of positive microscopic resection margins (R1) after gastrectomy in diffuse-type gastric cancer

INTRODUCTION

Diffuse-type gastric cancer (DTGC) is associated with poor outcome. Surgical resection margin status (R) is an important prognostic factor, but its exact impact on DTGC patients remains unknown. The aim of this study was to assess the prognostic value of microscopically positive margins (R1) after gastrectomy on survival and tumour recurrence in DTGC patients.

METHODS

All consecutive DTGC patients from two tertiary centers who underwent curative oncologic gastrectomy from 2005 to 2018 were analyzed. The primary endpoint was overall survival (OS) for R0 versus R1 patients. Secondary endpoints included disease-free survival (DFS), recurrence patterns as well as the overall survival benefit of chemotherapy in this DTGC patient cohort.

RESULTS

Overall, 108 patients were analysed, 88 with R0 and 20 with R1 resection. Patients with negative lymph nodes and negative margins (pN0R0) had the best OS (median 102 months, 95% CI 1-207), whereas pN + R0 patients had better median OS than pN + R1 patients (36 months 95% CI 13-59, versus 7 months, 95% CI 1-13, p < 0.001). Similar findings were observed for DFS. Perioperative chemotherapy offered a median OS of 46 months (95% CI 24-68) versus 9 months (95% CI 1-25) after upfront surgery (p = 0.022). R1 patients presented more often early recurrence (< 12 postoperative months, 30% vs 8%, p = 0.002), however, no differences were observed in recurrence location.

CONCLUSION

DTGC patients with microscopically positive margins (R1) presented poorer OS and DFS, and early tumour recurrence in the present series. R0 resection should be obtained whenever possible, even if other adverse biological features are present.

A systematic review of minimal length of lroximal margin in gastric adenocarcinoma resection

For early distal gastric cancers, a proximal margin (PM) > 2-3 cm might probably be sufficient. For advanced tumors, many confounding factors have a prognostic impact on survival and recurrence and negative margin involvement may be more relevant than negative margin length.

INTRODUCTION

In gastric cancer surgery, microscopic positive margin is a poor prognostic factor whereas complete resection with tumor-free margins remains a challenging issue. European guidelines recommended a macroscopic margin of 5 or even 8 cm for diffuse-type cancers to achieve R0 resection. However, it is unclear if the length of negative proximal margin (PM) could have a prognostic impact on survival. We aimed to perform a systematic review of the literature analyzing PM length and its prognostic impact in gastric adenocarcinoma.

MATERIAL AND METHODS

Pubmed and Embase databases were searched for "gastric cancer" or "gastric adenocarcinoma," combined with "proximal margin," between January 1990 and June 2021. English-written studies that specified PM length were included. Survival data, in relation to PM, were extracted.

RESULTS

Twelve retrospective studies, with a total number of 10,067 patients, met inclusion criteria and were analyzed. Mean length of proximal margin on the whole population varied from 2.6 to 5.29 cm. Three studies found minimal PM cut-off to improve overall survival in univariate analysis. Concerning recurrence-free survival analysis, only 2 series showed better results with PM > 2 or > 3 cm, using Kaplan-Meier method. Multivariate analysis demonstrated an independent impact of PM on overall survival in 2 studies.

CONCLUSION

For early distal gastric cancers, a PM > 2-3 cm might probably be sufficient. For advanced or proximal tumors, many confounding factors have a prognostic impact on survival and recurrence and negative margin involvement may be more relevant than negative margin length.

Current standards of surgical management of gastric cancer: an appraisal

PURPOSE

Gastric cancer (GC) is the fifth most common malignancy worldwide and portends a grim prognosis due to a lack of appreciable improvement in 5-year survival. We aimed to analyze the available literature and summarize the current standards of surgical care for curative and palliative intent treatment of GC.

METHODS

We conducted a systematic search on the PubMed database for studies on the management of GC.

RESULTS

Endoscopic resection is an acceptable treatment option for T1a tumors. The role of optimal resection margin for GC remains unclear. D2 lymph node dissection remains the standard of care with splenectomy needed selectively for splenic hilum involvement. A distal pancreatic resection should be avoided. The advantage of bursectomy and omentectomy in GC surgery is not clear. Multi-visceral resection may be considered for locally advanced GC in carefully selected patients. Minimally invasive approaches are non-inferior to open surgery. Surgery should be abandoned prior even in metastatic GC within the frame of multimodal therapy approach.

CONCLUSION

Various trials have conclusively shown improved patient outcomes when well-established surgical standards are followed.

Korean Practice Guidelines for Gastric Cancer 2022: An Evidence-based, Multidisciplinary Approach

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

The Role of Surgery in the Management of Gastric Cancer: State of the Art

Surgery still represents the mainstay of treatment of all stages of gastric cancer (GC). Surgical resections represent potentially curative options in the case of early GC with a low risk of node metastasis. Sentinel lymph node biopsy and indocyanine green fluorescence are novel techniques which may improve the employment of stomach-sparing procedures, ameliorating quality of life without compromising oncological radicality. Nonetheless, the diffusion of these techniques is limited in Western countries. Conversely, radical gastrectomy with extensive lymphadenectomy and multimodal treatment represents a valid option in the case of advanced GC. Differences between Eastern and Western recommendations still exist, and the optimal multimodal strategy is still a matter of investigation. Recent chemotherapy protocols have made surgery available for patients with oligometastatic disease. In this context, intraperitoneal administration of chemotherapy via HIPEC or PIPAC has emerged as an alternative weapon for patients with peritoneal carcinomatosis. In conclusion, the surgical management of GC is still evolving together with the multimodal strategy. It is mandatory for surgeons to be conscious of the current evolution of the surgical management of GC in the era of multidisciplinary and tailored medicine.

Extent of Surgical Resection for Gastric Cancer: The Safety Distance Between the Tumor and the Proximal Resection Margin

A potentially curative treatment scheme for gastric cancer is considered futile without a proper surgical resection. An oncological, surgical resection for gastric cancer prerequisites a proper resection of the stomach, and a D2 lymph node dissection followed by reconstruction of the gastrointestinal tract continuity. Recently, as the favorable impact of organ preserving surgery on functional outcomes has been increasingly appreciated; distal gastrectomy represents a valid alternative to total gastrectomy provided that the proper oncological principles are not violated. However, the appropriateness of distal gastrectomy as a valid type of resection becomes synonymous with achieving a negative proximal resection margin. The purpose of the present study was to assess the optimal distance between the tumor and the resection margin in a gastrectomy with curative intent, performed for gastric cancer, by reviewing the relevant literature. Having in mind, the well documented discrepancy between the gross and the pathologic boundaries of the tumor, pitfalls might be encountered. Current published guidelines have used a "safety distance" i.e., >4 or 5 cm between the proximal macroscopic tumor border and the proximal resection margin in order to guarantee a negative resection margin on pathology. An increased distance of safety is currently proposed in high-risk tumors such as tumors of the diffuse histological type.

Impact of Surgical Margins on Overall Survival after Gastrectomy for Gastric Cancer: A Validation of Japanese Gastric Cancer Association Guidelines on a Western Series

Purpose

No consensus exists on the resection extent needed to ensure oncological safety in gastrectomy for gastric adenocarcinoma (GAC). This study aims to assess the impact of margin adequacy according to Japanese Gastric Cancer Association (JGCA) guidelines on overall survival (OS).

Patients and Methods

Patients who underwent surgery for stage I–III GAC at our institution between 2010 and 2017 were included. Margin adequacy according to JGCA, National Comprehensive Cancer Network (NCCN), and European Society for Medical Oncology (ESMO) guidelines was assessed, and their predictive value on OS was evaluated with Harrell’s C-index. Patients were analyzed according to their margins’ adherence to JGCA guidelines, and a propensity score matching (PSM) was run. Indication to either total gastrectomy (TG) or distal gastrectomy (DG) according to each guideline was also assessed.

Results

A total of 279 patients were included, of whom 220 (79%) underwent DG. Adequate margins according to JGCA were obtained in 209 patients (75%). On multivariate analysis, JGCA margin adequacy was independently associated with OS, together with American Society of Anesthesiologist class, neoadjuvant chemotherapy, lymphadenectomy extent, R0 resection, and postoperative N stage. After PSM, patients with JGCA adequate margins showed better OS, recurrence-free survival (RFS), and local RFS than patients with JGCA inadequate margins. For 220 DG, JGCA guidelines would have recommended TG in 25 patients (11%), NCCN in 30 (14%), and ESMO in 90 (41%) (p < 0.001).

Conclusion

Adequacy of surgical resection margins to JGCA guidelines leads to improved survival outcomes and allows for a more organ-preserving approach than Western guidelines.

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

Objective

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

Summary background data

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

Methods

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

Results

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

Conclusion

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

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

Introduction

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

Methods

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

Results

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

Conclusions

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

Prognostic value and nomograms of proximal margin distance in gastric cancer with radical distal gastrectomy

Objective

The proximal margin (PM) distance for distal gastrectomy (DG) of gastric cancer (GC) remains controversial. This study investigated the prognostic value of PM distance for survival outcomes, and aimed to combine clinicopathologic variables associated with survival outcomes after DG with different PM distance for GC into a prediction nomogram.

Methods

Patients who underwent radical DG from June 2004 to June 2014 at Department of General Surgery, Nanfang Hospital, Southern Medical University were included. The first endpoints of the prognostic value of PM distance (assessed in 0.5 cm increments) for disease-free survival (DFS) and overall survival (OS) were assessed. Multivariate analysis by Cox proportional hazards regression was performed using the training set, and the nomogram was constructed, patients were chronologically assigned to the training set for dates from June 1, 2004 to January 30, 2012 (n=493) and to the validation set from February 1, 2012 to June 30, 2014 (n=211).

Results

Among 704 patients with pTNM stage I, pTNM stage II, T1−2, T3−4, N0, differentiated type, tumor size ≤5.0 cm, a PM of (2.1−5.0) cmvs. PM≤2.0 cm showed a statistically significant difference in DFS and OS, while a PM>5.0 cm was not associated with any further improvement in DFS and OSvs. a PM of 2.1−5.0 cm. In patients with pTNM stage III, N1, N2−3, undifferentiated type, tumor size >5.0 cm, the PM distance was not significantly correlated with DFS and OS between patients with a PM of (2.1−5.0) cm and a PM≤2 cm, or between patients with a PM >5.0 cm and a PM of (2.1−5.0) cm, so there were no significant differences across the three PM groups. In the training set, the C-indexes of DFS and OS, were 0.721 and 0.735, respectively, and in the validation set, the C-indexes of DFS and OS, were 0.752 and 0.751, respectively.

Conclusions

It is necessary to obtain not less than 2.0 cm of PM distance in early-stage disease, while PM distance was not associated with long-term survival in later and more aggressive stages of disease because more advanced GC is a systemic disease. Different types of patients should be considered for removal of an individualized PM distance intra-operatively. We developed a universally applicable prediction model for accurately determining the 1-year, 3-year and 5-year DFS and OS of GC patients according to their preoperative clinicopathologic characteristics and PM distance.

Optimal proximal resection margin distance for gastrectomy in advanced gastric cancer

BACKGROUND

The conventional guidelines to obtain a safe proximal resection margin (PRM) of 5-6 cm during advanced gastric cancer (AGC) surgery are still applied by many surgeons across the world. Several recent studies have raised questions regarding the need for such extensive resection, but without reaching consensus. This study was designed to prove that the PRM distance does not affect the prognosis of patients who undergo gastrectomy for AGC.

AIM

To investigate the influence of the PRM distance on the prognosis of patients who underwent gastrectomy for AGC.

METHODS

Electronic medical records of 1518 patients who underwent curative gastrectomy for AGC between June 2004 and December 2007 at Asan Medical Center, a tertiary care center in Korea, were reviewed retrospectively for the study. The demographics and clinicopathologic outcomes were compared between patients who underwent surgery with different PRM distances using one-way ANOVA and Fisher’s exact test for continuous and categorical variables, respectively. The influence of PRM on recurrence-free survival and overall survival were analyzed using Kaplan-Meier survival analysis and Cox proportional hazard analysis.

RESULTS

The median PRM distance was 4.8 cm and 3.5 cm in the distal gastrectomy (DG) and total gastrectomy (TG) groups, respectively. Patient cohorts in the DG and TG groups were subdivided into different groups according to the PRM distance; ≤ 1.0 cm, 1.1-3.0 cm, 3.1-5.0 cm and > 5.0 cm. The DG and TG groups showed no statistical difference in recurrence rate (23.5% vs 30.6% vs 24.0% vs 24.7%, P = 0.765) or local recurrence rate (5.9% vs 6.5% vs 8.4% vs 6.2%, P = 0.727) according to the distance of PRM. In both groups, Kalpan-Meier analysis showed no statistical difference in recurrence-free survival (P = 0.467 in DG group; P = 0.155 in TG group) or overall survival (P = 0.503 in DG group; P = 0.155 in TG group) according to the PRM distance. Multivariate analysis using Cox proportional hazard model revealed that in both groups, there was no significant difference in recurrence-free survival according to the PRM distance.

CONCLUSION

The distance of PRM is not a prognostic factor for patients who undergo curative gastrectomy for AGC.

Surgical margins in gastric cancer T2 and T3 and its relationship with recurrence and overall survival at 5 years

INTRODUCTION

Surgical resection is the potentially curative treatment in gastric cancer. However, definitive surgical margins are controversial.

MATERIAL AND METHODS

We conducted a retrospective, observational study. All patients with gastric cancer treated with surgery of T2 and T3, tumors without involvement of the esophagogastric junction and without neoadjuvant treatment were included.

RESULTS

A total of 70 patients were included. 44 men (62.9%) and 26 women (37.1%). In multivariate analysis, depth of the invasion (T2 vs T3), lymphadenectomy and more than 5 positive nodes were independent factors for recurrence at 5 years. Depth of the invasion (T2 vs T3), intra-abdominal metastases and recurrence were independent factors of overall survival at 5 years. ROC analysis did not show a definitive surgical margin with better 5-year overall survival and lower recurrence.

CONCLUSIONS

In patients with gastric cancer T2 and T3, surgical margin did not affect 5-year overall survival or recurrence rate. Other factors are associated with recurrence and 5-year overall survival at 5 years, regardless of the distance from the tumor to the margin.

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.

Clinicopathologic features of remnant gastric cancer after curative distal gastrectomy according to previous reconstruction method: a retrospective cohort study

BACKGROUND

Survival rate of patients treated for gastric cancer has increased due to early detection and improvements of surgical technique and chemotherapy. Increase in survival rate has led to an increase in the risk for remnant gastric cancer (RGC). The purpose of this study was to investigate clinicopathologic features of RGC according to previous reconstruction method and factors affecting the interval from previous curative distal gastrectomy for gastric cancer to RGC occurrence.

METHODS

Medical records of patients diagnosed with RGC at Yeungnam University Medical Center from January 2000 to December 2017 who had a history of distal gastrectomy with D2 LN dissection due to gastric cancer were reviewed retrospectively.

RESULTS

Forty-eight patients were enrolled in this study. The mean interval of 48 RGC patients was 105.6 months (8.8 years). RGC after Billroth II reconstruction recurred more often at anastomosis site than RGC after Billroth I reconstruction (p = 0.001). The mean interval of RGC after Billroth I reconstruction was 67 months, shorter than 119 months of RGC after Billroth II reconstruction (p = 0.003). On the contrary, interval showed no difference according to stage of previous gastric cancer, remnant gastric cancer, or sex (p = 0.810, 0.145, and 0.372, respectively).

CONCLUSIONS

RGC after Billroth I reconstruction tends to arise earlier at non-anastomosis site than RGC after Billroth II. Therefore, we should examine non-anastomosis site carefully from the beginning of surveillance after gastric cancer surgery with Billroth I reconstruction for better outcome.

Long-term Outcomes of Laparoscopic Versus Open Transhiatal Approach for the Treatment of Esophagogastric Junction Cancer

Purpose

The laparoscopic transhiatal approach (LA) for adenocarcinoma of the esophagogastric junction (AEJ) is advantageous since it allows better visualization of the surgical field than the open approach (OA). We compared the surgical outcomes of the 2 approaches.

Materials and Methods

We analyzed 108 patients with AEJ who underwent transhiatal distal esophagectomy and gastrectomy with curative intent between 2003 and 2015. Surgical outcomes were reviewed using electronic medical records.

Results

The LA and OA were performed in 37 and 71 patients, respectively. Compared to the OA, the LA was associated with significantly shorter duration of postoperative hospital stay (9 vs. 11 days, P=0.001), shorter proximal resection margins (3 vs. 7 mm, P=0.004), and extended operative times (240 vs. 191 min, P=0.001). No significant difference was observed between the LA and OA for intraoperative blood loss (100 vs. 100 mL, P=0.392) or surgical morbidity rate (grade≥II) for complications (8.1% vs. 23.9%, P=0.080). Two cases of anastomotic leakage occurred in the OA group. The number of harvested lymph nodes was not significantly different between the LA and OA groups (54 vs. 51, P=0.889). The 5-year overall and 3-year relapse-free survival rates were 81.8% and 50.7% (P=0.024) and 77.3% and 46.4% (P=0.009) for the LA and OA groups, respectively. Multivariable analyses revealed no independent factors associated with overall survival.

Conclusions

The LA is feasible and safe with short- and long-term oncologic outcomes similar to those of the OA.

Tumor localization using radio-frequency identification clip marker: experimental results of an ex vivo porcine model

PURPOSE

With the widespread use of minimally invasive surgery, tumor detection is becoming more difficult. We present the experimental results of a radio-frequency identification (RFID) lesion detection system in an ex vivo porcine model.

METHODS

The efficacy and feasibility of a newly developed RFID lesion detection system were examined. It was applied to the stomach and colon of pigs weighing 40 kg. The RFID clip was attached to the upper and lower mucosal sides of the stomach. Colon specimens with thin and thick walls were used. The clipped sites were marked on the serosa by a pin. The longest distance from the pin the RFID tag could be detected was measured 25 times in each direction.

RESULTS

In the upper gastric wall, the RFID tag detection distance was 4.5 ± 0.9 mm, 5.6 ± 0.7 mm, 12.5 ± 0.7 mm, and 5.3 ± 0.5 mm in the four directions, respectively (right, left, upper, and lower). In the antrum, the RFID tag detection distance was 5.8 ± 0.7 mm, 6.9 ± 0.5 mm, 5.6 ± 0.5 mm, and 3.7 ± 0.5 mm in the four directions. In the thin colon, the RFID tag detection distance was 6.3 ± 0.5 mm, 5.0 ± 0.5 mm, 9.7 ± 0.7 mm, and 6.4 ± 0.4 mm in the four directions. In the thick colon, the RFID tag detection distance was 3.5 ± 0.8 mm, 6.6 ± 0.5 mm, 8.4 ± 0.6 mm, and 9.8 ± 0.5 mm in the four directions. The area of detection was smallest for the antrum (83.7 mm²) and similar for the other sites (150.6, 154.7 and 157.7 mm² for the upper body, thin colon, and thick colon, respectively).

CONCLUSIONS

The distance at which the RFID tag was detected was usually within 10 mm. These results indicate the feasibility of the clinical application of the add-on clip and RFID tag as a marker for identifying the location of various gastrointestinal tumors.

[Laparoscopic Proximal Gastrectomy as a Surgical Treatment for Upper Third Early Gastric Cancer]

Recently, the incidence of upper third gastric cancer has increased, and with it the number of endoscopic submucosal dissection (ESD) procedures performed has been increasing. However, if ESD is not indicated or non-curable, surgical treatment may be necessary. In the case of lower third gastric cancer, it is possible to preserve the upper part of the stomach; however, in the case of upper third gastric cancer, total gastrectomy is still the standard treatment option, regardless of the stage. This is due to the complications associated with upper third gastric cancer, such as gastroesophageal reflux after proximal gastrectomy rather than oncologic problems. Recently, the introduction of the double tract reconstruction method after proximal gastrectomy has become one of the surgical treatment methods for upper third early gastric cancer. However, since there has not been a prospective comparative study evaluating its efficacy, the ongoing multicenter prospective randomized controlled trial (KLASS-05) comparing laparoscopic proximal gastrectomy with double tract reconstruction and laparoscopic total gastrectomy is expected to be important for determining the future of treatment of upper third early gastric cancer.

Staging and surgical approaches in gastric cancer: a clinical practice guideline

BACKGROUND

Resection is the cornerstone of cure for gastric adenocarcinoma; however, several aspects of surgical intervention remain controversial or are suboptimally applied at a population level, including staging, extent of lymphadenectomy (lnd), minimum number of lymph nodes that have to be assessed, gross resection margins, use of minimally invasive surgery, and relationship of surgical volumes with patient outcomes and resection in stage iv gastric cancer.

METHODS

Literature searches were conducted in databases including medline (up to 10 June 2016), embase (up to week 24 of 2016), the Cochrane Library and various other practice guideline sites and guideline developer Web sites. A practice guideline was developed.

RESULTS

One guideline, seven systematic reviews, and forty-eight primary studies were included in the evidence base for this guidance document. Seven recommendations are presented.

CONCLUSIONS

All patients should be discussed at a multidisciplinary team meeting, and computed tomography (ct) imaging of chest and abdomen should always be performed when staging patients. Diagnostic laparoscopy is useful in the determination of M1 disease not visible on ct images. A D2 lnd is preferred for curative-intent resection of gastric cancer. At least 16 lymph nodes should be assessed for adequate staging of curative-resected gastric cancer. Gastric cancer surgery should aim to achieve an R0 resection margin. In the metastatic setting, surgery should be considered only for palliation of symptoms. Patients should be referred to higher-volume centres and those that have adequate support to manage potential complications. Laparoscopic resections should be performed to the same standards as those for open resections, by surgeons who are experienced in both advanced laparoscopic surgery and gastric cancer management.

[Pathology of the R1 classification in visceral cancer surgery]

The completeness of tumor removal is described in the residual tumor classification (R classification). The R category of a surgical specimen reflects the effects of treatment, influences further treatment decisions and is associated with patient survival. Thorough pathological examination of all resection planes, including the circumferential margin, is necessary for accurate classification.

Evaluation of the recurrence pattern of gastric cancer after laparoscopic gastrectomy with D2 lymphadenectomy

Background

The aim of this study was to analyze the oncological aspects of gastric cancer following laparoscopic gastrectomy with D2 lymphadenectomy (LG-D2).

Methods

We retrospectively evaluated the long-term outcomes of 354 patients who underwent LG-D2 for primary gastric cancer. Recurrence patterns and predictors of peritoneal metastasis were analyzed.

Results

Median follow-up time was 43.8 months. Five-year overall survival rates for yp/pStages I, II, and III gastric cancer were 93.7, 78.5, and 42.2 %, respectively. Recurrence was observed in 86 patients. Peritoneal metastasis was the most frequent recurrence pattern (n = 51), followed by hepatic metastasis (n = 17). Lymphatic recurrence at distant sites was observed in 10 patients. No locoregional lymph node metastasis or local recurrence was seen. Nine of 51 cases of peritoneal recurrence were detected by probe laparoscopy. Peritoneal recurrence rates were significantly higher in yp/pT4 and yp/pN3 diseases compared with yp/pT ≤ 3 and yp/pN ≤ 2 diseases. Multivariate analyses demonstrated that yp/pT4, yp/pN3, tumor size ≥70 mm, vascular invasion, and undifferentiated tumors were predictors of peritoneal recurrence following LG-D2.

Conclusion

Long-term outcomes of gastric cancer following LG-D2, including recurrence patterns and predictors of peritoneal metastasis, were comparable to those following open D2 gastrectomy. LG-D2 showed good local control. Probe laparoscopy after LG may be effective in detecting peritoneal recurrence, which is not determined with less invasive examinations, including a CT scan. Future large-scale prospective studies are desirable to evaluate not only surgical but also oncological benefits and safety of LG-D2 for advanced gastric cancer.

The importance of the proximal resection margin distance for proximal gastric adenocarcinoma: A multi-institutional study of the US Gastric Cancer Collaborative

BACKGROUND

A 5 cm margin is advocated for distal gastric adenocarcinoma (GAC). The optimal proximal resection margin (PM) length for proximal GAC is not established.

METHODS

Patients who underwent curative-intent resection for proximal GAC from 2000 to 2012 at 7 centers in the US Gastric Cancer Collaborative were included. PM length was sequentially dichotomized and analyzed at 0.5 cm increments (0.5-6.5 cm). Outcomes after negative margin (R0) and positive microscopic margin (R1) resections were compared. Primary endpoints were local recurrence (LR) and overall survival (OS).

RESULTS

All patients (n = 162) had R0 distal margins. 151 (93.2%) had an R0-PM with mean length of 2.6 cm (median:1.7 cm; range:0.1-15 cm). A greater PM distance was not associated with LR or OS. An R1-PM was associated with higher N-stage (N3:73% vs. 26%; P = 0.007) and increased LR (HR6.1; P = 0.009) but not associated with decreased OS. On multivariate analysis, an R1-PM was also not independently associated with LR.

CONCLUSIONS

For resection of proximal gastric adenocarcinoma, proximal margin length is not associated with local recurrence or overall survival. An R1 margin is associated with advanced N-stage but is not independently associated with recurrence or survival. When performing resection of proximal gastric adenocarcinoma, efforts to achieve a specific margin distance, especially if it necessitates an esophagectomy, should be abandoned.