N staging: the role of the pathologist

Gastric remnant cancer and long-term survival in Central Norway 2001 to 2016 - A population-based study

INTRODUCTION

Gastric remnant cancer (GRC) has been defined as a distinct clinical entity and is reported to account for 1-8% of all gastric cancers. We aimed to characterize GRC patients and assess survival in a Western population.

METHODS

Retrospective population-based cohort study including 1217 patients diagnosed with gastric adenocarcinoma in Central Norway 2001-2016. GRCs (n = 78) defined as adenocarcinomas arising in the residual stomach after distal gastrectomy were compared to non-GRC (n = 1139) and to proximal non-GRC (n = 595).

RESULTS

78 (6.4 %) gastric cancers were GRC. The annual number and proportion of GRC declined during the study period (p = 0.003). Median latency from distal gastrectomy to GRC diagnosis was 37.6 years (15.7-68.0) and previous Billroth II reconstruction was most common (87.7%). Compared to controls, GRC patients were more frequently males (83.3%), diagnosed in earlier TNM stages and were older at diagnosis. A smaller proportion of GRC patients received perioperative or palliative chemotherapy, but the R0/R1resection rate of 41.0% was no different from non-GRC patients. Overall median survival for GRC patients irrespective of treatment was 7.0 months, which did not differ from non-GRCs or proximal non-GRC. In multivariate analyses TNM stage and age were independently associated with mortality, whereas GRC per se was not.

CONCLUSIONS

Numbers of GRCs declined during the study period, but the latency between distal gastrectomy and GRC diagnosis was long. GRC patients were more frequently male and older than other gastric cancer patients. GRC was not independently associated with survival after adjusting for TNM stage and tumor location.

Lymph node metastasis in cancer progression: molecular mechanisms, clinical significance and therapeutic interventions

Lymph nodes (LNs) are important hubs for metastatic cell arrest and growth, immune modulation, and secondary dissemination to distant sites through a series of mechanisms, and it has been proved that lymph node metastasis (LNM) is an essential prognostic indicator in many different types of cancer. Therefore, it is important for oncologists to understand the mechanisms of tumor cells to metastasize to LNs, as well as how LNM affects the prognosis and therapy of patients with cancer in order to provide patients with accurate disease assessment and effective treatment strategies. In recent years, with the updates in both basic and clinical studies on LNM and the application of advanced medical technologies, much progress has been made in the understanding of the mechanisms of LNM and the strategies for diagnosis and treatment of LNM. In this review, current knowledge of the anatomical and physiological characteristics of LNs, as well as the molecular mechanisms of LNM, are described. The clinical significance of LNM in different anatomical sites is summarized, including the roles of LNM playing in staging, prognostic prediction, and treatment selection for patients with various types of cancers. And the novel exploration and academic disputes of strategies for recognition, diagnosis, and therapeutic interventions of metastatic LNs are also discussed.

Early-Onset Gastric Cancer from a Geographic Area of High Gastric Cancer Incidence in North-East India: a Retrospective Study

We aim to report about the clinico-pathological characteristics of early-age gastric cancer in North-East India. It is a retrospective and observational study conducted in a tertiary care cancer centre in North-East India. We reviewed physical case records and the hospital electronic medical record system. The study population included all patients of age 40 years or less, with a confirmed diagnosis of gastric adenocarcinoma, who received treatment in the institute. The duration of the study was from 2016 to 2020. Data was collected using a pre-designed proforma, and the results were presented as percentages, ratios, median values and range. A total of 79 patients with early-age gastric cancer were found during the study period. There was female preponderance (45:34). Out of the total, 43% presented in stage IV. Most of them had good performance status (87.3% had ECOG 0-2), and none of them had documented co-morbid illness. Poorly differentiated adenocarcinoma and signet ring cell carcinoma were seen in 36.7% and 25.3% patients, respectively. Only 25 patients (31.6%) underwent definitive surgery, and they had a high nodal burden with a median metastatic lymph nodal ratio of 0.35 (range 0 to 0.91). Out of them, 40% developed systemic recurrence within a short span of time (median time to recurrence being 9.5 months). Peritoneal recurrence was the most common site of failure (80%). Early-age gastric cancer has been associated with aggressive pathological features and poor clinical outcomes in North-East India.

Reassessment of the Optimal Number of Examined Lymph Nodes in Pancreatoduodenectomy for Pancreatic Ductal Adenocarcinoma

OBJECTIVE

The aim of this study was to reappraise the optimal number of examined lymph nodes (ELNs) in pancreatoduodenectomy (PD) for pancreatic ductal adenocarcinoma (PDAC).

SUMMARY BACKGROUND DATA

The well-established threshold of 15 ELNs in PD for PDAC is optimized for detecting 1 positive node (PLN) per the previous 7th edition of the American Joint Committee on Cancer (AJCC) staging manual. In the framework of the 8th edition, where at least 4 PLN are needed for an N2 diagnosis, this threshold may be inadequate for accurate staging.

METHODS

Patients who underwent upfront PD at 2 academic institutions between 2000 and 2016 were analyzed. The optimal ELN threshold was defined as the cut-point associated with a 95% probability of identifying at least 4 PLNs in N2 patients. The results were validated addressing the N-status distribution and stage migration.

RESULTS

Overall, 1218 patients were included. The median number of ELN was 26 (IQR 17-37). ELN was independently associated with N2-status (OR 1.27, P < 0.001). The estimated optimal threshold of ELN was 28. This cut-point enabled improved detection of N2 patients and stage III disease (58% vs 37%, P = 0.001). The median survival was 28.6 months. There was an improved survival in N0/N1 patients when ELN exceeded 28, suggesting a stage migration effect (47 vs 29 months, adjusted HR 0.649, P < 0.001). In N2 patients, this threshold was not associated with survival on multivariable analysis.

CONCLUSION

Examining at least 28 LN in PD for PDAC ensures optimal staging through improved detection of N2/stage III disease. This may have relevant implications for benchmarking processes and quality implementation.

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.

Pathologic Lymph Node Staging of Gastric Cancer

OBJECTIVES

The TNM classification is the main tool for lymph node (LN) staging in gastric cancer (GC). However, alternative LN staging systems have been proposed, and the role of features other than the number of metastatic LNs is being investigated. Our aim is to discuss the main challenges of LN assessment in GC.

METHODS

Comprehensive review of the literature on alternative LN staging systems, examined LNs, sentinel LN (SLN) biopsy, LN micrometastases (LNMIs), extracapsular extension (ECE), and tumor deposits (TDs) in GC.

RESULTS

Many controversies exist regarding LN assessment in GC. The TNM classification shows excellent prognostic performance, but alternative prognostic methods such as the LN ratio or log odds of positive LNs have demonstrated to be better than the TNM system in terms of prognostic accuracy. The value of SLN biopsy and LNMIs in GC is still unclear, and several challenges concerning their clinical impact and pathologic analysis must be overcome before their introduction in clinical practice. Most authors have identified ECE and TDs as independent prognostic factors for survival in GC.

CONCLUSIONS

Further studies should be performed to evaluate the impact of these features on the TNM classification and patient outcomes, as well as to standardize alternative LN staging systems.

Retrieval of 30 Lymph Nodes Is Mandatory for Selected Stage II Gastric Cancer Patients

Background

According to the 8th edition AJCC staging manual, a least of 16 lymph nodes retrieval (LNRs) is the minimal requirement for lymph nodes (LNs) dissection of gastric cancer surgery. Previous studies have shown that increasing the number of LNRs (≥30) prolongs survival for selected patients. However, the necessity of retrieving 30 or more LN for stage II gastric cancer patients is still under debate.

Aim

This study aims to explore the impact of retrieving 30 or more lymph nodes on the survival of stage II cancer patients.

Methods

A total of 1,177 patients diagnosed with stage II gastric cancer were enrolled in this study. The clinicopathological parameters and the impact of different LNRs (<30 or ≥30) and positive lymph node ratio (NR) on overall survival (OS) were retrospectively analyzed.

Results

The mean number of LNRs was 34 ± 15. A total of 44% (518/1,177) of patients had an LNRs <30, while 56% (659/1,177) of patients had an LNRs ≥30. The 5-year survival rate was 81% for all patients, 76% for the LNRs <30 group, and 86% for LNRs ≥30 group, respectively (P = 0.003). The survival benefit of retrieving 30 lymph nodes was significant in certain subgroups: age >60 years/male/underwent total gastrectomy/stage IIB. For N+ patients, higher NR was significantly correlated with poor survival.

Conclusion

The survival benefit of retrieving 30 LNs varies in different subgroups. An LNRs of 30 is mandatory for selected stage II gastric cancer patients.

Clinical and pathological staging of gastric cancer: Current perspectives and implications

Accurate categorization of invasive depth and lymph node metastasis or optimization of TNM categories is fundamentally critical for prognostic assessment and decision making regarding subsequent therapies after surgery for gastric cancer. Improving the precision of the TNM staging is the ongoing goal. The evolution of the staging system indicates that there is no "ideal staging". Every update has criticized the lack of a standard approach for the stages to date. T staging depends on the accurate determination of the depth of infiltration based on pathological continuous sections. N staging is susceptible to the influence of lymph node detection, and insufficient lymph node detection can lead to N staging migration. M staging is required to improve the detection rate of peritoneal positive free cancer cells to determine the high risk factors of peritoneal metastasis. At present, the quality of standardized pathological diagnosis of gastric cancer requires improvement. Based on a review of the literature and experience from multiple gastric cancer centers, we present a new development in TNM staging and a way to improve clinical and pathological quality control of gastric cancer.

Lymph Node Yield Following Packet Submission After Isolation By Surgeon During Gastrectomy

Purpose

To compare the lymph node yields of lymph node packet submission (PS), packet submission after isolation by surgeons (PSI), and en bloc lymph node submission (EBS) after gastrectomy.

Methods

We conducted a prospective study including 118 gastric cancer patients who underwent gastrectomy between June 2016 and August 2016. We also retrospectively reviewed 607 patients who underwent gastrectomy from May 2015 to May 2016. Following gastrectomy, lymph node specimens were either submitted en bloc (EBS group), divided into packets with accompanying adipose tissue according to the lymph node stations (PS group), or isolated individually based on the surgeon’s visualization and palpation before submission to the Pathology Department (PSI group).

Results

The average lymph node yield was significantly higher in the PSI compared with the PS group in the prospective study (46.5±19.4 vs 31.8±11.1), and significantly higher in the PS compared with the EBS group in the retrospective study (31.5±12.6 vs 23.9±8.9) (both P<0.001). There was no significant difference in positive lymph node yields in either of these comparisons (prospective study, P=0.581; retrospective study, P=0.489). The survival curve indicated no significant difference between the PS and PSI groups (log rank P=0.957); however, these three groups share different lymph node ratio (LNR).

Conclusion

PSI could yield more lymph nodes than PS or EBS with a lower LNR at pathological examination. However, the difference in lymph nodes harvested had no impact on survival, which may need further investigation.

Clinical update on head and neck cancer: molecular biology and ongoing challenges

Head and neck squamous cell carcinomas (HNSCCs) are an aggressive, genetically complex and difficult to treat group of cancers. In lieu of truly effective targeted therapies, surgery and radiotherapy represent the primary treatment options for most patients. But these treatments are associated with significant morbidity and a reduction in quality of life. Resistance to both radiotherapy and the only available targeted therapy, and subsequent relapse are common. Research has therefore focussed on identifying biomarkers to stratify patients into clinically meaningful groups and to develop more effective targeted therapies. However, as we are now discovering, the poor response to therapy and aggressive nature of HNSCCs is not only affected by the complex alterations in intracellular signalling pathways but is also heavily influenced by the behaviour of the extracellular microenvironment. The HNSCC tumour landscape is an environment permissive of these tumours' aggressive nature, fostered by the actions of the immune system, the response to tumour hypoxia and the influence of the microbiome. Solving these challenges now rests on expanding our knowledge of these areas, in parallel with a greater understanding of the molecular biology of HNSCC subtypes. This update aims to build on our earlier 2014 review by bringing up to date our understanding of the molecular biology of HNSCCs and provide insights into areas of ongoing research and perspectives for the future.

The prognosis role of AJCC/UICC 8th edition staging system in gastric cancer, a retrospective analysis

OBJECTIVE

The present study was designed to investigate whether AJCC/UICC 8^th edition staging system precisely differentiated patients with different prognosis of gastric cancer (GC).

METHODS

There were 540 GC cases included in this study. Stratification was done according to the 7^th and 8^th AJCC/UICC tumor-node-metastasis (TNM) staging systems. Detailed comparison was conducted between two editions in terms of the sub-classification of pN3 stage, redefinitions of stage III, homogeneity, discrimination power, predictive accuracy, and complexity.

RESULTS

Compared to the 7^th edition, the 8^th TNM staging system performed better by incorporating pN3a and pN3b into the final stage of GC (P<0.001), had better stage grouping homogeneity (P<0.001), prognostic value (area under the curve, AUC-value was 0.809), and comparable discrimination power.

CONCLUSIONS

AJCC 8^th TNM staging system showed improved efficiency in GC prognosis.