Diagnostic accuracy and utility of intraoperative microscopic margin analysis of gastric and esophageal adenocarcinoma

Advances in Gastric Cancer Surgical Management

The goal of a gastric cancer operation is a microscopically negative resection margin and D2 lymphadenectomy. Minimally invasive techniques (laparoscopic and robotic) have been proven to be equivalent for oncologic care, yet with faster recovery. Endoscopic mucosal resection can be used for T1a N0 tumor resection. Better understanding of hereditary gastric cancer and molecular subtypes has led to specialized recommendations for MSI-high tumors and patients with pathogenic CDH1 mutations. In the future, surgical management will support minimally invasive approaches and personalized cancer care based on subtype.

A YOLOv5-based network for the detection of a diffuse reflectance spectroscopy probe to aid surgical guidance in gastrointestinal cancer surgery

PURPOSE

A positive circumferential resection margin (CRM) for oesophageal and gastric carcinoma is associated with local recurrence and poorer long-term survival. Diffuse reflectance spectroscopy (DRS) is a non-invasive technology able to distinguish tissue type based on spectral data. The aim of this study was to develop a deep learning-based method for DRS probe detection and tracking to aid classification of tumour and non-tumour gastrointestinal (GI) tissue in real time.

METHODS

Data collected from both ex vivo human tissue specimen and sold tissue phantoms were used for the training and retrospective validation of the developed neural network framework. Specifically, a neural network based on the You Only Look Once (YOLO) v5 network was developed to accurately detect and track the tip of the DRS probe on video data acquired during an ex vivo clinical study.

RESULTS

Different metrics were used to analyse the performance of the proposed probe detection and tracking framework, such as precision, recall, mAP 0.5, and Euclidean distance. Overall, the developed framework achieved a 93% precision at 23 FPS for probe detection, while the average Euclidean distance error was 4.90 pixels.

CONCLUSION

The use of a deep learning approach for markerless DRS probe detection and tracking system could pave the way for real-time classification of GI tissue to aid margin assessment in cancer resection surgery and has potential to be applied in routine surgical practice.

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.

Diagnostic accuracy of frozen section biopsy for early gastric cancer extent during endoscopic submucosal dissection: a prospective study

BACKGROUND

Accurate diagnosis of the lateral extent of early gastric cancer during endoscopic submucosal dissection (ESD) is crucial to achieve negative resection margins. Similar to intraoperative consultation with a frozen section in surgery, rapid frozen section diagnosis with endoscopic forceps biopsy may be useful in assessing tumor margins during ESD. This study aimed to evaluate the diagnostic accuracy of frozen section biopsy.

METHODS

We prospectively enrolled 32 patients undergoing ESD for early gastric cancer. Biopsy samples for the frozen sections were randomly collected from fresh resected ESD specimens before formalin fixation. Two different pathologists independently diagnosed 130 frozen sections as "neoplasia," "negative for neoplasia," or "indefinite for neoplasia," and the frozen section diagnosis was compared with the final pathological results of the ESD specimens.

RESULTS

Among the 130 frozen sections, 35 were from cancerous areas, and 95 were from non-cancerous areas. The diagnostic accuracies of the frozen section biopsies by the two pathologists were 98.5 and 94.6%, respectively. Cohen's kappa coefficient of diagnoses by the two pathologists was 0.851 (95% confidence interval: 0.837-0.864). Incorrect diagnoses resulted from freezing artifacts, a small volume of tissue, inflammation, the presence of well-differentiated adenocarcinoma with mild nuclear atypia, and/or tissue damage during ESD.

CONCLUSIONS

Pathological diagnosis of frozen section biopsy is reliable and can be applied as a rapid frozen section diagnosis for evaluating the lateral margins of early gastric cancer during ESD.

Extension of resection after positive intraoperative pathology during surgery for gastric and gastroesophageal junction adenocarcinoma: a retrospective cohort study

BACKGROUND

Residual tumor at the resection margins after surgery for gastric and gastroesophageal junction (GEJ) adenocarcinoma is a known prognostic factor. In this single-center, retrospective cohort study in a tertiary referral center, the authors aimed to evaluate the relevance of intraoperative pathology consultation (IOC) and consecutive extension of surgery on patient survival.

STUDY DESIGN

Of 737 consecutive patients undergoing (sub)total gastrectomy for gastric or GEJ adenocarcinoma, 679 cases with curative intent surgery between 05/1996 and 03/2019 were included. Patients were categorized into: R0 without further resection (direct R0), R0 after positive IOC and extension of resection (converted R0), and R1.

RESULTS

IOC was performed in 242 (35.6%) patients, in 216 (89.3%) at the proximal resection margin. Direct R0-status was achieved in 598 (88.1%), converted R0 in 26 (3.8%) of 38 (5.6%) patients with positive IOC and R1 in 55 (8.1%) patients. The median follow-up was 29 months for surviving patients. 3-year survival rate (3-YSR) was significantly higher for direct R0 compared to converted R0 with 62.3% compared to 21.8% (hazard ratio=0.298; 95% CI=0.186-0.477, P <0.001). 3-YSR was similar between converted R0 and R1 (21.8 vs. 13.3%; hazard ratio =0.928; 95% CI=0.526-1.636, P =0.792). In multivariate analysis, advanced T ( P <0.001), N ( P <0.001), R ( P =0.003), and M1 status ( P <0.001) were associated with worse overall survival.

CONCLUSION

IOC and consecutive extended resection for positive resection margins in gastrectomy for the proximal gastric and GEJ adenocarcinoma does not achieve long-term survival benefits in advanced tumor stages.

Supra-ampullary duodenectomy in a patient with positive distal resection margin after subtotal gastrectomy for gastric cancer: a case report

Resection margin involvement after curative intent resection for gastric cancer results in a poor prognosis and deprives the patient of the chance for a cure. Reoperation to achieve an R0 status should guarantee tolerable morbidity and achievement of negative margins. We performed laparoscopic distal gastrectomy with extracorporeal Billroth II reconstruction in a 56-year-old woman with gastric cancer following neoadjuvant chemotherapy. Scattered cancer cells were observed in the proximal and distal resection margins on immunohistochemical staining for cytokeratin. Two weeks postoperatively, remnant total gastrectomy and supra-ampullary duodenectomy were performed. Before reoperation, percutaneous transhepatic gallbladder drainage and angiocatheter placement outside the ampulla of Vater (AoV) via the cystic duct were performed to avoid pancreaticoduodenectomy and to obtain the maximal distal margin. Duodenal transection was performed 1 cm above the AoV. The resected duodenum was 4 cm in length. The patient had no postoperative complications and received adjuvant chemotherapy 1 month after the reoperation.

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.

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.

Intraoperative frozen section analysis of margin status as a quality indicator in gastric cancer surgery

INTRODUCTION

Positive pathologic margins following gastric cancer (GC) resection carries a poor prognosis. We evaluated intraoperative frozen section (IFS) analysis of resection margins (RMs) as a quality indicator in GC surgery.

METHODS

Patients referred to a provincial cancer agency with surgically resected non-metastatic GC between 2004 and 2012 were included. Associations between IFS analysis, other baseline characteristics, RMs, and overall survival (OS) were assessed using logistic regression, Kaplan-Meier analyses, and Cox proportional hazards modeling.

RESULTS

Among 377 patients, median age was 67 years, 68% were male, and 16% had +RMs. Thirty-four percent of patients underwent IFS analysis, which protected against +RMs (odds ratio [OR]: 0.34, 95% confidence interval [CI]: 0.16-0.73, p = 0.006) and improved OS (hazards ratio [HR]: 0.72, 95% CI: 0.54-0.98, p = 0.037). OS following re-resection of IFS positive patients was similar to IFS negative patients (69 vs. 54 months, p = 0.317). Stage III disease (OR: 12.8, 95% CI: 3.00-55.0, p = 0.001) and gastroesophageal junction tumors (OR: 2.25, 95% CI: 1.05-4.78, p = 0.036) predicted +RMs. Stage III disease led to worse OS (HR: 2.89, 95% CI: 1.92-4.34, p < 0.001) while intestinal histology improved OS (HR: 0.67, 95% CI: 0.50-0.90, p = 0.007).

CONCLUSIONS

IFS analysis reduce +RMs and improve OS and should be incorporated in curative intent GC surgery for patients with locally advanced GC.

Real-time Tracking and Classification of Tumor and Nontumor Tissue in Upper Gastrointestinal Cancers Using Diffuse Reflectance Spectroscopy for Resection Margin Assessment

Importance

Cancers of the upper gastrointestinal tract remain a major contributor to the global cancer burden. The accurate mapping of tumor margins is of particular importance for curative cancer resection and improvement in overall survival. Current mapping techniques preclude a full resection margin assessment in real time.

Objective

To evaluate whether diffuse reflectance spectroscopy (DRS) on gastric and esophageal cancer specimens can differentiate tissue types and provide real-time feedback to the operator.

Design, Setting, and Participants

This was a prospective ex vivo validation study. Patients undergoing esophageal or gastric cancer resection were prospectively recruited into the study between July 2020 and July 2021 at Hammersmith Hospital in London, United Kingdom. Tissue specimens were included for patients undergoing elective surgery for either esophageal carcinoma (adenocarcinoma or squamous cell carcinoma) or gastric adenocarcinoma.

Exposures

A handheld DRS probe and tracking system was used on freshly resected ex vivo tissue to obtain spectral data. Binary classification, following histopathological validation, was performed using 4 supervised machine learning classifiers.

Main Outcomes and Measures

Data were divided into training and testing sets using a stratified 5-fold cross-validation method. Machine learning classifiers were evaluated in terms of sensitivity, specificity, overall accuracy, and the area under the curve.

Results

Of 34 included patients, 22 (65%) were male, and the median (range) age was 68 (35-89) years. A total of 14 097 mean spectra for normal and cancerous tissue were collected. For normal vs cancer tissue, the machine learning classifier achieved a mean (SD) overall diagnostic accuracy of 93.86% (0.66) for stomach tissue and 96.22% (0.50) for esophageal tissue and achieved a mean (SD) sensitivity and specificity of 91.31% (1.5) and 95.13% (0.8), respectively, for stomach tissue and of 94.60% (0.9) and 97.28% (0.6) for esophagus tissue. Real-time tissue tracking and classification was achieved and presented live on screen.

Conclusions and Relevance

This study provides ex vivo validation of the DRS technology for real-time differentiation of gastric and esophageal cancer from healthy tissue using machine learning with high accuracy. As such, it is a step toward the development of a real-time in vivo tumor mapping tool for esophageal and gastric cancers that can aid decision-making of resection margins intraoperatively.

Real-time tracking of a diffuse reflectance spectroscopy probe used to aid histological validation of margin assessment in upper gastrointestinal cancer resection surgery

SIGNIFICANCE

Diffuse reflectance spectroscopy (DRS) allows discrimination of tissue type. Its application is limited by the inability to mark the scanned tissue and the lack of real-time measurements.

AIM

This study aimed to develop a real-time tracking system to enable localization of a DRS probe to aid the classification of tumor and non-tumor tissue.

APPROACH

A green-colored marker attached to the DRS probe was detected using hue-saturation-value (HSV) segmentation. A live, augmented view of tracked optical biopsy sites was recorded in real time. Supervised classifiers were evaluated in terms of sensitivity, specificity, and overall accuracy. A developed software was used for data collection, processing, and statistical analysis.

RESULTS

The measured root mean square error (RMSE) of DRS probe tip tracking was 1.18  ±  0.58  mm and 1.05  ±  0.28  mm for the x and y dimensions, respectively. The diagnostic accuracy of the system to classify tumor and non-tumor tissue in real time was 94% for stomach and 96% for the esophagus.

CONCLUSIONS

We have successfully developed a real-time tracking and classification system for a DRS probe. When used on stomach and esophageal tissue for tumor detection, the accuracy derived demonstrates the strength and clinical value of the technique to aid margin assessment in cancer resection surgery.

Prognostic impact of a microscopic positive margin in patients undergoing gastrectomy for gastric cancer: a propensity score‑matched analysis of a multi‑institutional dataset

PURPOSE

We analyzed the effect of a microscopic positive margin on survival outcomes after gastrectomy for gastric cancer METHODS: We analyzed a multi-institutional dataset to study patients who underwent gastrectomy with curative intent between 2010 and 2014. We used propensity score matching to strictly balance the patients' oncological features, backgrounds, and postoperative treatment to compare the survival outcomes of those with microscopic positive margins and those with negative margins.

RESULTS

Among 3029 patients, 32 (1.1%) had positive margins. After matching, we enrolled 128 patients in this retrospective analysis: 32 with a positive margin and 96 with a negative margin. The recurrence-free survival of the positive-margin group was significantly shorter than that of the negative-margin group (hazard ratio [HR], 1.62, 95% confidence interval, 1.00-2.63, p = 0.0485). Consistent results were observed for patients with pStages I-III disease (HR, 1.65, p = 0.0835), whereas the survival curves overlapped in those with pStage IV disease (HR, 1.29, p = 0.5934). The prevalence of overall recurrence in the positive-margin group was higher than that in the negative-margin group (75% vs 58%, p = 0.0917). This trend was consistent with locoregional recurrence (9% vs 3%) and distant recurrence (69% vs 55%).

CONCLUSIONS

The survival of patients after curative gastrectomy for gastric cancer was worse in those with microscopic positive margins than in those with negative margins.

Analysis of Esophagectomy Margin Practice and Survival Implications

BACKGROUND

The objective of this study was to determine how thoracic surgeons manage intraoperative esophagectomy positive margins and how these decisions may relate to overall survival and progression-free survival in esophageal cancer.

METHODS

A survey was sent to thoracic surgeons to understand the management of intraoperative positive esophagectomy margins. Primary data at two high-volume esophageal cancer institutions from 1994 to 2017 were retrospectively reviewed to identify patients who had intraoperative positive frozen section margins during esophagectomy. Patient characteristics and survival data were collected and analyzed. Overall survival and progression-free survival were assessed using a Cox model.

RESULTS

Eighty-five percent of thoracic surgeons responding to a survey reported the utilization of frozen pathologic evaluation during esophagectomy with attempts at re-resection to achieve negative margin. Our esophagectomy database identified 94 patients with intraoperative positive margins. Of those re-resected (n = 67, 63%), 44 patients (46.8%) were converted to R0 resections. overall survival was improved for patients in the R0 group (13 months) vs R+ group (3.4 months, P = .04). Progression-free survival was also improved between the R0 group (8.6 months) and the R+ group (2.2 months, P = .03). In a multivariable analysis for progression-free survival, margin status was an independent predictor of survival (hazard ratio 3.13, P = .03).

CONCLUSIONS

From a thoracic surgery survey, 85% of surgeons use intraoperative frozen section margin analysis to guide surgical decision making during an esophagectomy. Analyzing patients with a positive margin discovered during esophagectomy suggests that esophageal cancer patients who can undergo re-resection to a negative margin have increased progression-free survival. The final margin appears to be related to progression-free survival.

Diagnostic challenges of intra-operative frozen consultation for gastrointestinal signet ring cell carcinoma†

AIMS

Signet ring cell carcinoma (SRCC) is challenging to recognise on intra-operative frozen sections, with known high false-negative rates. The objective of this study was to investigate common factors contributing to discrepancies between intra-operative frozen diagnoses and those made upon review of permanent sections, and summarise our experiences gained and lessons learned on minimising errors on intra-operative frozen diagnoses of gastrointestinal SRCC.

METHODS AND RESULTS

We retrospectively examined our pathology database from 25 May 2000 to 1 January 2018 and re-reviewed intra-operative frozen sections and permanent haematoxylin and eosin (H&E) slides for specimens confirmed with SRCC on permanent sections. This study includes 83 specimens taken from 50 patients, with an accuracy of 85.5%. Main common factors causing discordance or deferral in recognising SRCC between intra-operative frozen procedures and permanent sections include: (i) resemblance of clusters of SRCC cells with a myxoid background; (ii) disguise as normal or reactive cells (histiocytes, macrophages, large reactive lymphocytes, plasma cells or adipocytes) due to their relatively clear or depleted cytoplasmic mucin; and (iii) histological sampling errors, leading to misses of small foci of SRCC on frozen section slides.

CONCLUSIONS

An accurate diagnosis of SRCC during intra-operative frozen consultations remains challenging. Based on our experiences and lessons, the most important strategies to reduce diagnostic errors are: (i) understanding the unusual histomorphological features of SRCC cells on frozen sections including, but not limited to, intracellular mucin depletion, absence of desmoplasia and no adjacent pre-cancer changes; and (ii) close attention to abrupt transition from normal architecture (e.g. glandular or submucosal loose connective tissue) to myxoid and/or inflammatory-like appearance, which potentially harbours SRCC.

Risk factors analysis and stratification for microscopically positive resection margin in gastric cancer patients

Background

Cancer cells are often found postoperatively at surgical resection margins (RM) in patients with gastric cancer because of submucosal infiltration or hesitation to secure adequate RM. This study was designed to evaluate risk factors for microscopic positive RM and to clarify which patients should undergo intraoperative frozen section diagnosis (IFSD).

Methods

Patients who underwent R0/1 gastrectomy for gastric adenocarcinoma between 2000 and 2018 in a single cancer center in Japan were studied. We divided the patients into a positive RM group and negative RM group according to the results of definitive histopathological examinations. We performed multivariate analysis to analyze risk factors for positive RM by and used the identified risk factors to risk stratify the patients.

Results

A total of 2757 patients were studied, including 49 (1.8%) in the positive RM group. The risk factors significantly associated with positive RM were remnant gastric cancer (odds ratio [OR] 4.7), esophageal invasion (OR 6.3), tumor size ≥80 mm (OR 3.9), and a histopathological diagnosis of undifferentiated type (OR 3.6), macroscopic type 4 (OR 3.7), or pT4 disease (OR 4.6). On risk stratification analysis, the incidence of positive RM was 0.1% without any risk factors, increasing to 0.4% with one risk factor, 3.1% with two risk factors, 5.3% with three risk factors, 21.3% with four risk factors, and 85.7% with five risk factors.

Conclusions

The risk of macroscopically positive RM increased in patients who have risk factors. IFSD should be performed in patients who have four or more risk factors.

Frozen section diagnosis of gastrointestinal poorly cohesive and signet-ring cell adenocarcinoma: useful morphologic features to avoid misdiagnosis

Frozen section examination of adenocarcinomas with poorly cohesive growth, including signet-ring cell carcinoma, is challenging. Due to their diffuse morphology, the tumor cells may be indistinct and difficult to distinguish from inflammatory or stromal cells. Misdiagnosis may result in significant adverse clinical outcome. We performed a detailed retrospective analysis of such cases to identify features that are helpful to avoid misdiagnosis at the time of frozen section. We reviewed the original frozen section slides from 50 patients with poorly cohesive carcinoma (PCC) including 32 with positive and 18 with negative frozen section slides. Tumor cells and inflammatory cells were evaluated for 17 distinct cytologic and nine architectural or stromal features. Features with 100% specificity and positive predictive value (PPV) for carcinoma included the presence of cells with a single distinct cytoplasmic mucin vacuole, focal gland formation, and perineural invasion. Features with high specificity, sensitivity, PPV, and negative predictive value (NPV) (all > 75%) included irregular nuclear contours, large nuclear size with many nuclei > 4× the size of a small lymphocyte, and disruption/obliteration of normal structures. Other features with high specificity and PPV (both ≥ 85%) but relatively low sensitivity and NPV-included crescent-shaped/indented nuclei, prominent nucleoli, anisonucleosis (> 4:1 difference in nuclear size), multinucleation, and the presence of mitotic figures. We characterized useful histologic features of poorly cohesive carcinoma that may serve to distinguish carcinoma cells from benign inflammatory or stroma cells. Knowledge of the relatively specific features in particular may help surgical pathologists avoid false-negative interpretation resulting in significant clinical morbidity.

Prevalence of False-Negative Results of Intraoperative Consultation on Surgical Margins During Resection of Gastric and Gastroesophageal Adenocarcinoma

Importance

Intraoperative consultation (IOC) on surgical margins during curative intent resection of gastric and gastroesophageal adenocarcinoma presents sampling and interpretive challenges. A false-negative (FN) IOC result can affect clinical care. Many factors may be associated with higher risk for an FN result of IOC on surgical margins.

Objective

To assess the prevalence and clinical implications of FN results of IOC on surgical margins during resection of gastric and gastroesophageal adenocarcinoma.

Design, Setting, and Participants

This retrospective study assessed the results of IOC on surgical margins to determine the prevalence of FN results and the accuracy and clinical implications of the results for patients undergoing curative intent resection for gastric or gastroesophageal adenocarcinoma. The study examined patients with gastric or gastroesophageal adenocarcinoma who underwent resection with curative intent at a single-institution referral center from January 1, 1992, to December 31, 2015.

Interventions

Curative intent gastric and/or esophageal resection.

Main Outcomes and Measures

False-negative results of IOC on surgical margins, accuracy of the results, factors associated with decreased accuracy of the results, and clinical implications of FN results.

Results

This study included 2002 patients (median age, 65 years; 1343 [67.1%] male; 1638 [81.8%] white) who received 3171 IOCs on surgical margins. Of the 3171 IOCs, the prevalence of FN results was 1.7%, with an accuracy of 98.1%. The prevalence of an FN IOC result was 1.2% for esophageal margins, 2.0% for gastric margins, and 2.5% for duodenal margins (P = .04). The prevalence of an FN IOC result was higher for patients with diffuse or signet ring disease compared with those without (2.6% vs 1.2%, P = .002) and for those not receiving neoadjuvant radiotherapy compared with those receiving neoadjuvant radiotherapy (1.4% vs 0.7%, P < .001). The prevalence of FN results of IOCs performed by nongastrointestinal pathologists was similar to that of IOCs performed by gastrointestinal pathologists (2.3% vs 1.9%, P = .60). The disease-specific survival was 34 months (95% CI, 20.7-47.2 months) for those with an FN result and 26.9 months (95% CI, 18.3-35.4; P = .72) for those with a true-positive result. Half of the patients with FN IOC results received further margin-directed therapy, including subsequent resection or radiotherapy.

Conclusions and Relevance

This study found that IOC on surgical margins was accurate at a specialty center. Signet ring or diffuse disease, duodenal margins, and not receiving neoadjuvant radiotherapy were challenging scenarios for IOC on surgical margins. The use of IOC on surgical margins may be optimal when it will affect intraoperative decision making framed by the stage of disease, tumor location, and surgical fitness of the patient.

Outcomes after completion total gastrectomy for gastric remnant cancer: experience from a Canadian tertiary centre

BACKGROUND

There is controversy about the safety and outcomes of completion total gastrectomy (CTG) for gastric adenocarcinoma. We compared a cohort of patients who underwent CTG for gastric remnant cancer (GRC) after partial gastrectomy for benign disease with patients who underwent primary total gastrectomy (PTG) for sporadic gastric cancer.

METHODS

We retrospectively reviewed a single-institution, prospectively maintained clinical database of patients who had undergone gastrectomy from 2005 to 2016 for demographic, surgical, clinical and tumour pathology data, as well as postoperative, pathologic and oncologic outcomes including complications, length of stay, disease-free survival and overall survival. We used the χ² and Wilcoxon rank-sum tests to compare groups and performed the Mantel-Cox log-rank test for Kaplan-Meier survival estimates. We compared the CTG group to all patients in the PTG group and to a 5:1 propensity-matched PTG cohort.

RESULTS

We analyzed data for 64 patients (9 CTG, 55 PTG). The groups were equivalent at baseline and had similar operative, perioperative treatment and pathologic characteristics. After propensity matching, the reoperation rate for complications was higher after CTG than PTG (22% v. 0%, p = 0.03), but there was no significant difference in the overall complication rate or length of stay. At 5 years, there was no difference in disease-free survival (28% v. 58%, p = 0.4) or overall survival (33% v. 44%, p = 0.7).

CONCLUSION

Our findings suggest that CTG for gastric adenocarcinoma can be undertaken safely a priori with no additional risk of recurrence or death compared to PTG for sporadic gastric cancer.

Optimal Intraoperative Assessment of Gastric Margins

OBJECTIVES

Intraoperative pathology consultation (IOC) to assess margins is frequently requested during surgery of the stomach and gastroesophageal junction.

METHODS

We studied 110 consecutive patients undergoing gastrectomy with IOC margin assessment.

RESULTS

Gastric margins at IOC utilized the most blocks but were least often positive. In 64% of patients, the entire gastric margin was examined using average six blocks; representative sections were examined in 25% of patients using two blocks. There was no difference in patient outcome between those who had entire vs representative sections of margin examined. Gross variables showing strongest associations with positive margins were tumor size and tumor distance to margin. Tumors sized greater than 2.3 cm had significantly increased risk of positive margin, and tumor distance greater than 4.5 cm to margin was associated with negative margins.

CONCLUSIONS

We conclude representative sections of the closest gastric margin are sufficient to ensure R0 resection in the majority of cases.

Surgical Considerations in the Management of Gastric Adenocarcinoma

Since Theodor Billroth and César Roux perfected the methods of postgastrectomy reconstruction in as early as the late nineteenth century, surgical management of gastric cancer has made incremental progress. The longstanding and contentious debate on the optimal extent of lymph node dissection for gastric cancer seems to have settled in favor of D2 dissection. Pylorus-preserving distal (central) gastrectomy has emerged as a less invasive, function-preserving option for T1N0 middle-third gastric cancers. Frozen section analysis of margins seems partially helpful in this direction. Last, the role of palliative gastrectomy in patients with metastatic seems less important than initially thought.

Novel Method for Differentiating Histological Types of Gastric Adenocarcinoma by Using Confocal Raman Microspectroscopy

Gastric adenocarcinoma, a single heterogeneous disease with multiple epidemiological and histopathological characteristics, accounts for approximately 10% of cancers worldwide. It is categorized into four histological types: papillary adenocarcinoma (PAC), tubular adenocarcinoma (TAC), mucinous adenocarcinoma (MAC), and signet ring cell adenocarcinoma (SRC). Effective differentiation of the four types of adenocarcinoma will greatly improve the treatment of gastric adenocarcinoma to increase its five-year survival rate. We reported here the differentiation of the four histological types of gastric adenocarcinoma from the molecularly structural viewpoint of confocal Raman microspectroscopy. In total, 79 patients underwent laparoscopic or open radical gastrectomy during 2008-2011: 21 for signet ring cell carcinoma, 21 for tubular adenocarcinoma, 14 for papillary adenocarcinoma, 6 for mucinous carcinoma, and 17 for normal gastric mucosas obtained from patients underwent operation for other benign lesions. Clinical data were retrospectively reviewed from medical charts, and Raman data were processed and analyzed by using principal component analysis (PCA) and linear discriminant analysis (LDA). Two-dimensional plots of PCA and LDA clearly demonstrated that the four histological types of gastric adenocarcinoma could be differentiated, and confocal Raman microspectroscopy provides potentially a rapid and effective method for differentiating SRC and MAC from TAC or PAC.

Differentiating gastrointestinal stromal tumors from gastric adenocarcinomas and normal mucosae using confocal Raman microspectroscopy

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract, and gastric adenocarcinomas are a common cancer worldwide. To differentiate GISTs from adenocarcinomas is important because the surgical processes for both are different; the former excises the tumor with negative margins, while the latter requires radical gastrectomy with lymph node dissection. Endoscopy with biopsy is used to distinguish GISTs from adenocarcinomas; however, it may cause tumor bleeding in GISTs. We reported here the confocal Raman microspectroscopy as an effective tool to differentiate GISTs, adenocarcinomas, and normal mucosae. Of 119 patients enrolled in this study, 102 patients underwent gastrectomy (40 GISTs and 62 adenocarcinomas), and 17 patients with benign lesions were obtained as normal mucosae. Raman signals were integrated for 100 s for each spot on the specimen, and 5 to 10 spots, depending on the sample size, were chosen for each specimen. There were significant differences among those tissues as evidenced by different Raman signal responding to phospholipids and protein structures. The spectral data were further processed and analyzed by using principal component analysis. A two-dimensional plot demonstrated that GISTs, adenocarcinomas, and normal gastric mucosae could be effectively differentiated from each other.

What to do after R1-resection of adenocarcinomas of the esophagogastric junction?

BACKGROUND AND OBJECTIVES

The management of R1-resected adenocarcinoma of the esophagogastric junction (AEG) is unclear. We aimed to identify risk factors and prevalence of R1 resections, their recurrence and prognosis, and efficacy of postoperative therapy.

METHODS

A single center cohort of 766 consecutive patients undergoing curative intent resection for AEG was analyzed retrospectively.

RESULTS

R1-resection rate was 13%. Poorer tumor differentiation, higher T-, N-, and UICC/AJCC-stages were associated with R1-resections. Compared to R0-resected patients, R1-resected patients had a higher incidence of tumor recurrence (77% vs. 32%; P < 0.001) and worse overall survival (5-year overall survival 43% vs. 10%; P < 0.001). The pattern of recurrence did not differ between R0- and R1-resections with distant metastases in 90% and 87% of patients with tumor recurrence. We found a trend towards better overall survival for R1-resected patients receiving postoperative therapy compared to R1-resected patients without postoperative therapy (median 17.4 vs. 14.6 months, P = 0.056).

CONCLUSIONS

The association of R1-resections with poor tumor characteristics allows for identification of patients at risk for R1-resection. As in R0-resections, tumor recurrence in R1-resections is mainly systemic, not local. The potential benefit of additive local postoperative therapies in R1-resected patients must be balanced against overall prognosis and therapy-specific morbidity and mortality. J. Surg. Oncol. 2016;114:428-433. © 2016 Wiley Periodicals, Inc.

Profiling of adrenocorticotropic hormone and arginine vasopressin in human pituitary gland and tumor thin tissue sections using droplet-based liquid-microjunction surface-sampling-HPLC-ESI-MS-MS

Described here are the results from the profiling of the proteins arginine vasopressin (AVP) and adrenocorticotropic hormone (ACTH) from normal human pituitary gland and pituitary adenoma tissue sections, using a fully automated droplet-based liquid-microjunction surface-sampling-HPLC-ESI-MS-MS system for spatially resolved sampling, HPLC separation, and mass spectrometric detection. Excellent correlation was found between the protein distribution data obtained with this method and data obtained with matrix-assisted laser desorption/ionization (MALDI) chemical imaging analyses of serial sections of the same tissue. The protein distributions correlated with the visible anatomic pattern of the pituitary gland. AVP was most abundant in the posterior pituitary gland region (neurohypophysis), and ATCH was dominant in the anterior pituitary gland region (adenohypophysis). The relative amounts of AVP and ACTH sampled from a series of ACTH-secreting and non-secreting pituitary adenomas correlated with histopathological evaluation. ACTH was readily detected at significantly higher levels in regions of ACTH-secreting adenomas and in normal anterior adenohypophysis compared with non-secreting adenoma and neurohypophysis. AVP was mostly detected in normal neurohypophysis, as expected. This work reveals that a fully automated droplet-based liquid-microjunction surface-sampling system coupled to HPLC-ESI-MS-MS can be readily used for spatially resolved sampling, separation, detection, and semi-quantitation of physiologically-relevant peptide and protein hormones, including AVP and ACTH, directly from human tissue. In addition, the relative simplicity, rapidity, and specificity of this method support the potential of this basic technology, with further advancement, for assisting surgical decision-making. Graphical Abstract Mass spectrometry based profiling of hormones in human pituitary gland and tumor thin tissue sections.

Frozen section: guiding the hands of surgeons?

Frozen section (FS) analysis is a powerful tool that can provide a rapid diagnosis, directing operative management. However, FSs can also be misused. We consider an FS to be "inappropriate" when it does not influence operative management or immediate patient care. Not only can inappropriate FSs compromise diagnostic material, they can impact turnaround time of other FSs. We evaluated the utilization of FSs at our institution and assessed influence on intraoperative management. Frozen sections performed at the University of Alabama at Birmingham Hospital in 2013 were stratified by surgical subspecialty. Operative, clinical, and pathology notes were reviewed to determine the rationale for sending each FS and to determine impact on intraoperative management. Cases lacking operative notes were excluded. A total of 4104 FSs were performed in 1896 cases. Surgical subspecialties included cardiothoracic, otolaryngology, breast, surgical oncology, gynecology, gastrointestinal, hepatobiliary, urology, transplant, and orthopedics. 42.5% of FSs evaluated margin status, 34.8% confirmed or excluded malignancy, 9.5% were for tumor classification, 6.7% assessed adequacy for diagnosis, 1.9% were to confirm or exclude infection, 2.8% were for transplant, and 1.8% were for lymphoma workup. Twelve percent (491/4104) of FSs did not influence operative management. This was most common among cardiothoracic surgeries (34%). No inappropriate FSs were sent for any transplant surgeries. Otolaryngology used the most FSs and had less than 1% that were inappropriate. Most FSs influence operative management. The rationale for sending an FS and its influence on operative management was subspecialty dependent. Interdepartmental discussions of FS utilization might be helpful in the elimination of unnecessary FSs.

Current status of management of malignant disease: current management of esophageal cancer

OBJECTIVE

The objective of this study is to outline the evidence regarding the surgical management of esophageal cancer and provide a single institutional outline regarding its implementation.

BACKGROUND

Esophageal cancer is a major cause of cancer-related morbidity and mortality worldwide. Surgery continues to play an important role in its management and offers the best chance for cure in localized and locally advanced disease. However, considerable controversy exists regarding the optimum treatment strategy in this patient population. Furthermore, despite advances in operative and perioperative care and the advent of minimally invasive approaches, the majority of patients succumb to distant metastases after curative intent resection. This failure highlights the importance of multimodal, stage-directed therapy in the management of patients with newly diagnosed esophageal tumors.

METHODS

Herein, we provide a comprehensive, evidence-based review of the diagnostic workup and locoregional and systemic treatment options available to esophageal cancer patients. The evidence supporting perioperative chemotherapy versus chemoradiotherapy is outlined and discussed. In addition, we highlight our institutional approach to the diagnostic evaluation, operative selection strategy, and perioperative treatment regimen selection based on the stage of presentation. Finally, we discuss the role of enhanced recovery in the postoperative management of this complex group of patients.

CONCLUSIONS

Esophageal cancer remains a devastating disease with high mortality. Favorable outcomes mandate a multimodal, stage-directed treatment approach.