A comparative study on two different pathological methods to retrieve lymph nodes following gastrectomy

Treatment of Gastric Cancer Means Surgery, but Not Surgery Alone

Despite numerous studies, gastric cancer (GC) still presents a high mortality rate in Eastern and Western countries, increasing attention for new therapeutic strategies [...].

The Association of Race With Adequate Lymph Node Evaluation for Gastric Cancer

BACKGROUND

National studies have reported racial and socioeconomic disparities in gastric cancer (GC) care. The current study evaluated adequate lymph node (LN) assessment (≥16 LNs) during resection for GC within a healthcare system servicing a socioeconomically disparate, mostly non-White population in the Southeast United States.

METHODS

A retrospective cohort study of patients undergoing resection for GC between 2003-2019 was performed. Factors associated with adequate LN assessment including patient and tumor characteristics were analyzed.

RESULTS

Among 202 patients, adequate LN assessment was performed in 97 (48%) patients. On univariable analysis, younger age, non-White race, lower Charlson Comorbidity Index (CCI), Medicaid or no insurance, D1+/D2 lymphadenectomy, clinical evidence of regional LN metastases, total gastrectomy, and receipt of neoadjuvant therapy were associated with adequate LN assessment. On multivariable analysis, non-White race (OR 2.79, 95% CI 1.38-5.65), CCI <4 (OR 2.14, 95% CI 1.15-3.96), and D1+/D2 lymphadenectomy (OR 3.63, 95% CI 1.96-6.74) were the only factors independently associated with adequate LN evaluation.

CONCLUSIONS

In the current study, non-White race, independent of socioeconomics, was significantly associated with adequate LN assessment. Future work is necessary to improve standardization and achieve higher rates of adequate LN assessment for all patients during resection for GC.

Surgeon-Pathologist Team Approach Dramatically Affects Lymph Nodes Detection and Improves Patients' Short-Term Outcome

Simple Summary

Appropriate lymph node harvesting for patients with gastric cancer is fundamental for a correct staging and is strongly related to survival. In this study, we present a new protocol for on-site macroscopic evaluation and sampling of lymph nodes for gastric cancer patients. With the joint collaboration of surgeons and pathologists, our method aims to provide the largest possible number of analyzed lymph nodes per patient, allowing for a better staging. We are convinced that this approach is routinely feasible, and our preliminary results seem to confirm better patient stratification compared to other lymph node dissection methods.

Abstract

The downstaging of gastric cancer has recently gained particular attention in the field of gastric cancer surgery. The phenomenon is mainly due to an inappropriate sampling of lymph nodes during standard lymphadenectomy. Hence, collection of the maximum number of lymph nodes is a critical factor affecting the outcome of patients. None of the techniques proposed so far have demonstrated a real efficiency in increasing the number of identified lymph nodes. To harvest the maximum number of lymph nodes, we designed a protocol for on-site macroscopic evaluation and sampling of lymph nodes according to the Japanese Gastric Cancer Association protocol. The procedure was carried out by a surgeon/pathologist team in the operating room. We enrolled one hundred patients, 50 of whom belonged to the study group and 50 to a control group. The study group included patients who underwent lymph node dissection following the proposed protocol; the control group encompassed patients undergoing standard procedures for sampling. We compared the number and maximum diameter of lymph nodes collected in both groups, as well as some postoperative variables, the 30-day mortality and the overall survival. In the study group, the mean number of lymph nodes harvested was higher than the control one (p = 0.001). Moreover, by applying the proposed technique, we sampled lymph nodes with a very small diameter, some of which were metastatic. Noticeably, no difference in terms of postoperative course was identified between the two groups, again supporting the feasibility of an extended lymphadenectomy. By comparing the prognosis of patients, a better overall survival (p = 0.03) was detected in the study group; however, to date, no long-term follow-up is available. Interestingly, patients with metastasis in node stations number 8, 9, 11 or with skip metastasis, experienced a worse outcome and died. Based on our preliminary results, the pathologist/surgeon team approach seems to be a reliable option, despite of a slight increase in sfaff workload and technical cost. It allows for the harvesting of a larger number of lymph nodes and improves the outcome of the patients thanks to more precise staging and therapy. Nevertheless, since a higher number of patients are necessary to confirm our findings and assess the impact of this technique on oncological outcome, our study could serve as a proof-of-concept for a larger, multicentric collaboration.

Regional Draining Lymph Nodes: Considerations for Medical Device Studies

Lymph nodes and associated lymphatics filter extracellular fluid and lymph to maintain tissue-fluid balance and detect distant tissue injury. Examination of regional draining lymph nodes (RDLs; lymph nodes that drain the route of article dosing) is an important step in detecting immunotoxicity and other associated changes during general toxicology studies. Similarly, evaluation of RDLs is often a key component of evaluating medical devices. Nonclinical medical device studies can present challenges for RDL evaluation, due to the wide variety of tissues and organs that are implanted with devices, the potential for wear debris/degradation products, and the likely disruption of normal lymphatic drainage by surgical procedures. This article discusses concepts for consideration when designing a nonclinical medical device study that includes the macroscopic evaluation, collection, histologic processing, microscopic assessment, and documentation of findings within RDLs. References describing RDLs for common implantation sites are reported, as are considerations for specific tissues and species commonly used in medical device biocompatibility and functional testing.

Surgeon Assessment of Gastric Cancer Lymph Node Specimens with a Video of Technique

INTRODUCTION

In the majority of US institutions, gastrectomy specimens are sent for pathologic examination without surgeon assessment or standardized technique of lymph node (LN) assessment for gastric cancer. We conducted a quality improvement project at a US cancer center utilizing surgeon assessment of gastric LNs, and created a video to illustrate a technique of standardized lymph node assessment.

METHODS

Convenience sampling was employed among patients with gastric adenocarcinomas who underwent curative-intent D2 gastrectomy between July 2016 and June 2017. For each patient, a surgeon assessed gastric LNs by harvesting individual LNs, followed by conventional evaluation by a pathologist.

RESULTS

We enrolled 17 patients for this quality improvement project. Eight patients underwent total gastrectomy, and nine patients underwent subtotal gastrectomy. Twelve patients underwent preoperative chemoradiation therapy, three underwent preoperative chemotherapy alone, and two underwent upfront surgery. The median number of examined LNs was 43. All patients had ≥ 16 LNs examined, and 88% of patients had ≥ 30 LNs examined.

CONCLUSION

Surgeon assessment of gastric LN specimens was feasible and effective to provide high-quality pathologic LN assessment after gastrectomy in gastric adenocarcinoma patients. Standardization of the technical methods for gastric LN evaluation is needed to improve the accuracy and quality of gastric cancer staging in the US. The provided video can help inform standardization of gastric LN assessment.

N staging: the role of the pathologist

Gastric cancer is the second cause of cancer-related mortality worldwide. Metastases, including lymph nodes ones, heavily influence the prognosis of this disease. The pathological detection of positive lymph nodes is pivotal for an optimal prognostication and clinical management of affected individuals. Several factors influence the pathological investigation of surgical specimens, ultimately affecting the number of retrieved lymph nodes and, with it, the reliability of N staging. The pathologist plays a central role in optimizing this process. Factors influencing lymph node retrieval and analysis will be herein reviewed, together with the procedures adopted for an optimal pathological analysis of lymph nodes in gastric cancer.

Ex Vivo Lymphadenectomy During Gastrectomy for Adenocarcinoma Optimizes Lymph Node Yield

INTRODUCTION

Variability in surgical and pathological techniques in Western centers may lead to inconsistency in lymph node staging in patients with gastric adenocarcinoma. We hypothesize that ex vivo dissection (EVD) after gastrectomy for adenocarcinoma increases lymph node yield.

METHODS

We retrospectively reviewed 222 consecutive patients who underwent gastrectomy with curative intent for adenocarcinoma between November 2010 and June 2014. In August of 2012, we began performing EVD of nodes in surgical specimens (EVD group, N = 111), as opposed to submitting specimens en bloc with lymph node basins attached to the specimen (No EVD group, N = 111). Primary end point was lymph node yield.

RESULTS

The median number of lymph nodes procured was significantly higher in the EVD compared to that in the No EVD group (30 vs. 21 lymph nodes, respectively; P < 0.0001). Moreover, 28% of the No EVD group were not adequately staged (defined by ≤15 nodes), compared to 5% of the EVD group (P < 0.0001). Stage-for-stage overall survival was not significantly different.

CONCLUSION

EVD may be a useful tool to maximize lymph node yield. However, this had no impact on staging or survival. This is an interesting finding that warrants further investigation.

Labeling of active proteases in fresh-frozen tissues by topical application of quenched activity-based probes

Active enzymes, such as proteases, often serve as valuable biomarkers for various disease pathologies. Therefore, methods to detect specific enzyme activities in biological samples can provide information to guide disease detection and diagnosis and to increase our understanding of the biological roles of specific enzyme targets. In this protocol, we outline methods for the topical application of fluorescently quenched activity-based probes (qABPs) to fresh-frozen tissue samples. This technique enables rapid imaging of enzyme activity at cellular resolution, and it can be combined with antibody labeling for immunodiagnosis. In this method, fresh-frozen tissue sections are fixed, incubated with the probe and imaged using fluorescence microscopy. This provides an advance over classical immunohistochemistry (IHC) in that it is rapid (4-8 h) and inexpensive, and it provides information on enzyme activity. Furthermore, it can be used with any of the growing number of fluorescent ABPs to provide data for more effective disease monitoring and diagnosis.