A Standardized Pathology Report for Gastric Cancer: 2nd Edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

A standardized pathology report for gastric cancer: 2nd edition

The first edition of 'A Standardized Pathology Report for Gastric Cancer' was initiated by the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists and published 17 years ago. Since then, significant advances have been made in the pathologic diagnosis, molecular genetics, and management of gastric cancer (GC). To reflect those changes, a committee for publishing a second edition of the report was formed within the Gastrointestinal Pathology Study Group of the Korean Society of Pathologists. This second edition consists of two parts: standard data elements and conditional data elements. The standard data elements contain the basic pathologic findings and items necessary to predict the prognosis of GC patients, and they are adequate for routine surgical pathology service. Other diagnostic and prognostic factors relevant to adjuvant therapy, including molecular biomarkers, are classified as conditional data elements to allow each pathologist to selectively choose items appropriate to the environment in their institution. We trust that the standardized pathology report will be helpful for GC diagnosis and facilitate large-scale multidisciplinary collaborative studies.

Optimising Multimodality Treatment of Resectable Oesophago-Gastric Adenocarcinoma

Simple Summary

Oesophageal (food pipe) and stomach cancers are amongst the hard-to-treat cancers that result in significant illness and deaths around the globe. Over the last few decades, there has been remarkable progress in the treatment of these cancers as a result of advances in diagnosis, surgical techniques, systemic therapy and radiotherapy. However, even if caught in the early stages, most patients with these cancers will unfortunately have their cancers come back, usually becoming widespread and difficult to treat. Therefore, optimising the early treatment strategy of these cancers is essential to improve the outcome and reduce the risk of recurrence. There are currently various geographically influenced standard of care management practices of early stomach and oesophageal cancers, ranging from using chemotherapy before and after surgery to the use of combined chemoradiotherapy before surgery and more recently the use of immunotherapy after surgery. However, it is not very clear if one strategy is significantly better than the others and there are some ongoing studies aiming to directly compare these treatment options. In addition, our understanding of the molecular and genetic features of these cancers can help improve our clinical practice and inform our choice of the best treatment strategy for the individual patient.

Abstract

Oesophago–gastric adenocarcinoma remains a leading cause of cancer-related morbidity and mortality worldwide. Although there has been an enormous progress in the multimodality management of resectable oesophago–gastric adenocarcinoma, most patients still develop a recurrent disease that eventually becomes resistant to systemic therapy. Currently, there is no global consensus on the optimal multimodality approach and there are variations in accepted standards of care, ranging from preoperative chemoradiation to perioperative chemotherapy and, more recently, adjuvant immune checkpoint inhibitors. Ongoing clinical trials are aimed to directly compare multimodal treatment options as well as the additional benefit of targeted therapies and immunotherapies. Furthermore, our understanding of the molecular and genetic features of oesophago–gastric cancer has improved significantly over the last decade and these data may help inform the best approach for the individual patient, utilising biomarker selection and precision medicine.

Interobserver agreement of a gastric adenocarcinoma tumor regression grading system that incorporates assessment of lymph nodes

Perioperative chemotherapy is increasingly used in combination with surgery for the treatment of patients with locally advanced, resectable gastric cancer. Histologic tumor regression grade (TRG) has emerged as an important prognostic factor; however, a common standard for its evaluation is lacking. Moreover, the clinical significance of regressive changes in metastatic lymph nodes (LNs) remains unclear. We conducted an international study to examine the interobserver agreement of a TRG system that is based on the Becker system for the primary tumors and additionally incorporates regression grading in LNs. Twenty observers at different levels of experience evaluated the TRG in 60 histologic slides (30 primary tumors and 30 LNs) based on the following criteria: for primary tumors, grade 1 represented complete response (no residual tumor), grade 2 represented <10%, grade 3 represented 10-50%, and grade 4 represented >50% residual tumor, as described by Becker et al. For LNs, grade "a" represented complete, grade "b" represented partial, and grade "c" represented no regression. The interobserver agreement was estimated using the Kendall's coefficient of concordance (W). Regarding primary tumors, agreement was good irrespective of the level of experience, reaching a W-value of 0.70 overall, 0.71 among subspecialized, and 0.71 among nonsubspecialized observers. Regarding LNs, interobserver agreement was moderate to good, with W-values of 0.52 overall, 0.64 among subspecialized, and 0.45 among nonsubspecialized observers. These findings indicate that the combination of the Becker TRG system with a three-tiered grading of regression in LNs generates a system that is reproducible. Future studies should investigate whether the additional information of TRG in LNs adds to the prognostic value of histologic regression grading in gastric cancer specimens.

Clinical assessment of tumor regression grade systems in gastroesophageal adenocarcinoma following neoadjuvant chemotherapy

BACKGROUND

The standard treatment for gastroesophageal cancer is neoadjuvant chemotherapy, followed by surgery, which has been shown to increase survival compared with surgery alone. Evidence is mounting that characterization of the oncologically induced tumor regression is of prognostic importance. However, no consensus regarding the optimal system for describing tumor regression exists. Thus, this study aims to explore three validated/promising tumor regression systems with a focus on their interobserver reliability and usability.

METHODS

We included 100 consecutive patients with gastroesophageal adenocarcinoma who had undergone neoadjuvant oncological treatment followed by surgery. The tumors underwent tumor regression grade (TRG) assessment according to the Standard Mandard-, Modified Mandard-, and Becker systems to assess the interobserver reliability between two consultant pathologists. The interobserver reliability was determined by both Fleiss kappa and weighted kappa metrics. Besides, a semi-quantitative usability questionary was completed and it was expanded with usability comments.

RESULTS

The Fleiss kappa interobserver agreement was 0.67 [95% CI, 0.55-0.79], 0.88 [95% CI, 0.73-1.00], and 0.88 [95% CI, 0.73-1.00] for Standard Mandard-, Modified Mandard-, and the Becker systems, respectively. The weighted kappa (linear) was 0.80 [95% CI, 0.72-0.89], 0.91 [95% CI, 0.84-0.98], and 0.91 [95% CI, 0.84-0.98] for the Standard Mandard-, Modified Mandard-, and the Becker systems, respectively. The usability was scored on a scale of 8-24 by both raters. The systems were scored accordingly: 47 (Modified Mandard system), 43 (Becker system), and 37 (Standard Mandard system).

CONCLUSION

The Modified Mandard- and Becker systems had excellent interobserver reliability and usability. However, the systems could be improved by a better characterization of the different tiers and tumor morphology.

Tumor regression grading after neoadjuvant treatment of esophageal and gastroesophageal junction adenocarcinoma: results of an international Delphi consensus survey

Complete histopathologic tumor regression after neoadjuvant treatment is a well-known prognostic factor for survival among patients with adenocarcinomas of the esophagus and gastroesophageal junction. The aim of this international Delphi survey was to reach a consensus regarding the most useful tumor regression grading (TRG) system that could represent an international standard for histopathologic TRG grading of gastroesophageal carcinomas. Fifteen pathologists with special interest in esophageal and gastric pathology participated in the online survey. The initial questionnaire contained of 43 statements that addressed the following topics: (1) specimen processing, (2) gross examination, (3) cross sectioning, (4) staining, (5) Barrett's esophagus, (6) TRG systems, and (7) TRG in lymph node (LN). Participants rated the items using a 5-point Likert style scale and were encouraged to write comments for each statement. The expert panel recommended a 4-tiered TRG system for assessing the primary tumor: grade 1: No residual tumor (complete histopathologic tumor regression), grade 2: less than 10% residual tumor (near-complete regression), grade 3: 10%-50% residual tumor (partial regression), grade 4: greater than 50% residual tumor (minimal/no regression), combined with a 3-tiered system for grading therapeutic response in metastatic LNs: grade a: no residual tumor (complete histopathologic TRG), grade b: partial regression (tumor cells and regression), grade c: no regression (no sign of tumor response). This TRG grading system can be recommended as an international standard for histopathologic TRG grading in esophageal and gastroesophageal junction adenocarcinoma.

Pathological Tumor Regression Grade Classifications in Gastrointestinal Cancers: Role on Patients' Prognosis

Preoperative chemotherapy or combined radiotherapy and chemotherapy (CRT), followed by surgery, represents the standard approach for locally advanced esophageal, gastric, and rectal carcinomas. To adequately evaluate the effects of neoadjuvant CRT in the resection specimens, several histopathologic tumor regression grade (TRG) scoring systems have been introduced into clinical practice. The primary goal of these TRG systems relies on a correct prognostic stratification of patients in the attempt to help clinical decision-making and influence surgical strategies, postoperative adjuvant therapies, and surveillance intensity. However, most TRG systems suffer from poor reproducibility and low interobserver concordance rates. Many efforts have been made in the identification of alternative, robust, simple, and universally accepted TRG scoring systems, which would help in the comparison of different treatment strategies and in the standardization of multimodal therapies. The aim of this review is to analyze the most commonly used TRG systems in gastrointestinal cancers highlighting their pitfalls and usefulness, depending on the tumor type.

Perioperative Treatment in Resectable Gastric Cancer: Current Perspectives and Future Directions

Gastric cancer (GC) is the fifth-most common cancer worldwide and an important cause of cancer-related-death. The growing knowledge of its molecular pathogenesis has shown that GC is not a single entity, but a constellation of different diseases, each with its own molecular and clinical characteristics. Currently, surgery represents the only curative approach for localized GC, but only 20% of patients (pts) showed resectable disease at diagnosis and, even in case of curative resection, the prognosis remains poor due to the high rate of disease relapse. In this context, multimodal perioperative approaches were developed in western and eastern countries in order to decrease relapse rates and improve survival. However, there is little consensus about the optimal treatment for non-metastatic GC. In this review, we summarize the current status and future developments of perioperative chemotherapy in resectable GC, attempting to find clear answers to the real problems in clinical practice.

Pathology assessment of pancreatic cancer following neoadjuvant treatment: Time to move on

Neoadjuvant treatment has increasingly become an integral part of the multimodal management of patients with pancreatic cancer. In patients who are able to undergo surgery following preoperative therapy, tumour regression grading remains the diagnostic gold standard for the histomorphological assessment of the effect of neoadjuvant treatment. In recent years, however, there has been growing concern about inherent flaws of tumour regression grading systems as well as their imprecise and impractical criteria that result in divergence of practice and lack of interobserver agreement. Furthermore, existing tumour regression systems differ in their defining criteria and thresholds, leading to incomparability of data. In this review, the principles and limitations of the main existing tumour regression systems are discussed, and potential alternative assessment approaches and novel markers are presented.

Prospective cohort study of neoadjuvant therapy toxicity in the treatment of oesophageal adenocarcinoma

BACKGROUND

Early studies investigating the benefits of neoadjuvant therapy in oesophageal cancer showed conflicting results, taking many years before a survival advantage was demonstrated in randomised trials. Gains are modest, limited by progressive disease and toxicity. This study aimed to investigate the relationship between neoadjuvant therapy-associated toxicity and clinical outcomes including survival in patients with potentially curable oesophageal adenocarcinoma.

MATERIALS AND METHODS

A cohort of 286 patients undergoing neoadjuvant therapy followed by surgical resection at a single institution was identified from a prospective database. Adverse events from neoadjuvant therapy were recorded and graded. Patients were divided into two groups according to whether they suffered toxicity or not. Clinical outcomes including whether patients completed the neoadjuvant course, whether they proceeded to resection and overall survival, were compared between the groups.

RESULTS

Neoadjuvant therapy-related toxicity was identified in 67/286 patients. 46 patients suffered severe, life-threatening or fatal adverse events. In patients with toxicity, 47% did not complete the chemotherapy course compared to 17% without toxicity, RR 2.7 (95%CI 1.7-4.4), (P < 0.001). In patients suffering toxicity, 17.9% failed to proceed to resection compared with 7.8% in those without toxicity, RR 2.3 (95%CI 1.2-4.6) P = 0.02. Median overall survival was shorter in patients suffering toxicity (20.7 months) compared to those without toxicity (37.8 months), P = 0.008. When patients failing to proceed to resection were excluded, median overall survival was shorter in patients suffering toxicity (26.2 months) compared with those without toxicity (47.8), P = 0.039.

CONCLUSION

Neoadjuvant therapy-related toxicity is common and can have serious consequences including failure to complete chemotherapy cycles, a higher risk of not proceeding to surgical resection and poorer overall survival. Efforts should be made to reduce toxicity and research should aim to identify responders and factors predictive of toxicity.

Tumor regression grading of gastrointestinal cancers after neoadjuvant therapy

Neoadjuvant therapy has been successfully introduced in the treatment of locally advanced gastrointestinal malignancies, particularly esophageal, gastric, and rectal cancers. The effects of preoperative chemo- or radiochemotherapy can be determined by histopathological investigation of the resection specimen following this treatment. Frequent histological findings after neoadjuvant therapy include various amounts of residual tumor, inflammation, resorptive changes with infiltrates of foamy histiocytes, foreign body reactions, and scarry fibrosis. Several tumor regression grading (TRG) systems, which aim to categorize the amount of regressive changes after cytotoxic treatment in primary tumor sites, have been proposed for gastroesophageal and rectal carcinomas. These systems primarily refer to the amount of therapy-induced fibrosis in relation to the residual tumor (e.g., the Mandard, Dworak, or AJCC systems) or the estimated percentage of residual tumor in relation to the previous tumor site (e.g., the Becker, Rödel, or Rectal Cancer Regression Grading systems). TRGs provide valuable prognostic information, as in most cases, complete or subtotal tumor regression after neoadjuvant treatment is associated with better patient outcomes. This review describes the typical histopathological findings after neoadjuvant treatment, discusses the most commonly used TRG systems for gastroesophageal and rectal carcinomas, addresses the limitations and critical issues of tumor regression grading in these tumors, and describes the clinical impact of TRG.

Approaches and genetic determinants in predicting response to neoadjuvant chemotherapy in locally advanced gastric cancer

Gastric cancer remains a major health burden worldwide. There is near-universal agreement that neoadjuvant chemotherapy (NAC) is a preferred management for locally advanced gastric cancer (LAGC). However, the optimal approach for an individual patient is still not clear and remains controversial, which could be at least partly explained by the lack of predictive tools. The ability to predict chemosensitivity from NAC in routine clinical practice is difficult and is an area of intense investigation, especially in the Precision-Medicine Era. Available consistent evidence suggests that a favorable tumor histopathological response to NAC may be a useful positive prognostic marker in gastric cancer. Hence, it is reasonable to speculate that making the histopathological response from NAC predictable will dramatically facility the NAC and improve patients' outcome. This review provides an overview on the current status of predictive biomarkers for histopathological response from NAC in LAGC, including clinicopathological variables, imaging and molecular testing. Furthermore, limitations and future perspectives are also discussed.

Association between the thoroughness of the histopathological examination and survival in patients with esophageal squamous cell carcinoma who achieve pathological complete response after chemoradiotherapy

The College of American Pathologists guidelines recommend examining at least four representative tumor blocks for determining pathological T stage in patients with primarily resected esophageal cancer. Whether the same pathological requirements are adequate in patients undergoing esophagectomy following neoadjuvant chemoradiotherapy (nCRT) remains unclear. We hypothesized that current examination protocols may underestimate the presence of microscopical residual disease after nCRT, potentially leading to under-staging. We retrospectively reviewed the records of patients with esophageal squamous cancer (ESCC) who were diagnosed as having pathological complete response (pCR) following nCRT. The thoroughness of the pathological examination in pCR patients was examined using (i) the number of blocks examined in suspicious tumor area (≤4 vs. >4), and (ii) the block quotient (calculated as the pretreatment tumor length divided by the number of blocks examined in suspicious tumor area). A total of 91 patients were enrolled. The mean number of blocks used to confirm pCR was 4.8 (range: 2-14). The 5-year overall survival (OS) and disease-free survival (DFS) in the entire cohort were 55% and 65%, respectively. Multivariate analyses identified the block quotient as the only independent predictor of OS and DFS. Receiver operating characteristic curve analysis indicated an optimal cutoff value of 1.4 for the block quotient. Among the patients who achieved pCR, the 5-year DFS differed significantly between subjects with a low (≤1.4) or high (>1.4) block quotient (76% vs. 47%, respectively, P = 0.03). The block quotient (calculated by the pretreatment tumor length divided by the number of blocks) - which reflects the meticulousness of the histopathological examination for confirming pCR - is associated with survival in ESCC patients.

Is surgery in the elderly for oesophageal cancer justifiable? Results from a single centre

Aims. Advanced age is an identified risk factor for patients undergoing oncological surgical resection. The surgery for oesophageal cancer is associated with significant morbidity and mortality. Our aim was to study the operative management of elderly patients (≥70 years) at a single institute. Methods. The data was collected from 206 patients who have undergone operative resection of oesophageal cancer. The demographic, operative, histological, and postoperative follow-up of all patients were analysed. Results. A total of 46 patients of ≥70 years who had surgical resection for oesophageal cancer were identified. Patients ≥70 years had poor overall survival (P = 0.00). Also elderly patients with nodal involvement had poor survival (P = 0.04). Age at the time of surgery had no impact on the incidence of postoperative complication and inpatient mortality. Both the univariate and multivariate analyses showed age, nodal stage, and positive resection margins as independent prognostic factors for patients undergoing surgery for oesophageal cancer. Conclusions. Advanced age is associated with poor outcome following oesophageal resection. However, the optimisation of both preoperative and postoperative care can significantly improve outcomes. The decision of operative management should be individualised. Age should be considered as one of the factors in surgical resection of oesophageal cancer in the elderly patients.