Molecular Classifications in Gastric Cancer: A Call for Interdisciplinary Collaboration

Gastric cancer (GC) is a heterogeneous disease, often diagnosed at advanced stages, with a 5-year survival rate of approximately 20%. Despite notable technological advancements in cancer research over the past decades, their impact on GC management and outcomes has been limited. Numerous molecular alterations have been identified in GC, leading to various molecular classifications, such as those developed by The Cancer Genome Atlas (TCGA) and the Asian Cancer Research Group (ACRG). Other authors have proposed alternative perspectives, including immune, proteomic, or epigenetic-based classifications. However, molecular stratification has not yet transitioned into clinical practice for GC, and little attention has been paid to alternative molecular classifications. In this review, we explore diverse molecular classifications in GC from a practical point of view, emphasizing their relationships with clinicopathological factors, prognosis, and therapeutic approaches. We have focused on classifications beyond those of TCGA and the ACRG, which have been less extensively reviewed previously. Additionally, we discuss the challenges that must be overcome to ensure their impact on patient treatment and prognosis. This review aims to serve as a practical framework to understand the molecular landscape of GC, facilitate the development of consensus molecular categories, and guide the design of innovative molecular studies in the field.

Prognostic role of the log odds of positive lymph nodes in Western patients with resected gastric cancer: A comparison with the 8th edition of the TNM staging system

OBJECTIVES

Several alternative lymph node staging systems have recently been described for gastric cancer. The log odds of positive lymph nodes (LODDS) system may be superior to the pN stage (American Joint Committee on Cancer) and lymph node ratio systems in predicting outcomes for patients with gastric cancers, as indicated by some researchers. Most studies, however, have been conducted in Asian countries, and conflicting results have been reported by other investigators.

METHODS

We conducted a retrospective study of all 377 cases of gastric cancer resected at a tertiary hospital in Spain between 2000 and 2019. Clinicopathologic features were collected, LODDS were calculated and categorized into 5 groups (S1-S5), and statistical analysis was performed.

RESULTS

The cases included (n = 315) were classified as S1 (25.6%), S2 (18.4%), S3 (21.3%), S4 (20.3%), and S5 (14.4%). The LODDS classification was significantly associated with tumor size, Laurén subtype, presence of signet ring cells, tumor grade, perineural infiltration, lymphovascular invasion, growth pattern, pT, tumor recurrence, and death. Kaplan-Meier analysis based on the LODDS classification demonstrated improved patient stratification compared with the pN stage for both overall survival (OS) and disease-free survival (DFS). Area under the curve values for recurrence and death were superior for the LODDS classification, and this classification was independently related to OS and DFS. In addition, the LODDS classification successfully divided patients without lymph node metastases (pN0) into subgroups with distinct prognoses.

CONCLUSIONS

For our cohort, the LODDS system showed better prognostic performance than pN stage; it was an independent predictor of OS and DFS, and it provided valuable prognostic information in cases without lymph node metastases. Its prognostic accuracy, however, decreased in cases with fewer than 16 lymph nodes resected.

Impact of Age at Diagnosis on Clinicopathological Features, Prognosis, and Management of Gastric Cancer: A Retrospective Single-Center Experience from Spain

The impact of age on various aspects of gastric cancer (GC) remains controversial. Clarifying this issue can improve our understanding of the disease, refine risk stratification models, and aid in personalized therapeutic approaches. This study aimed to evaluate the influence of age at diagnosis on the clinicopathological features, prognosis, and management of a specific cohort of Spanish patients with resected GC. The study encompassed 315 patients treated at a single tertiary hospital in Spain, divided into two age-based subgroups: ≤65 years and >65 years. The mean and median ages at diagnosis were 72 and 76 years. Most tumors were diagnosed at pT3 stage (49.2%), and 59.6% of patients had lymph node metastases. 21.3% of cases were diagnosed with GC at age ≤ 65 years. Younger patients showed a significantly higher prevalence of flat, diffuse, high-grade tumors, signet-ring cells, perineural infiltration, D2 lymphadenectomies, and adjuvant therapy. They also exhibited a higher rate of recurrences, but had a significantly longer follow-up. Kaplan-Meier curves indicated no significant prognostic differences based on age. Finally, age did not independently predict overall survival or disease-free survival. Our results suggest that younger patients may require more aggressive treatment due to adverse clinicopathologic features, but the lack of prognostic differences among age groups in our cohort indicates the need for further investigation into the complex interplay between age, clinicopathologic factors, and long-term outcomes in GC.

Alterations in p53, Microsatellite Stability and Lack of MUC5AC Expression as Molecular Features of Colorectal Carcinoma Associated with Inflammatory Bowel Disease

Colitis-associated colorectal carcinoma (CAC) occurs in inflammatory bowel disease (IBD) because of the "chronic inflammation-dysplasia-cancer" carcinogenesis pathway characterized by p53 alterations in the early stages. Recently, gastric metaplasia (GM) has been described as the initial event of the serrated colorectal cancer (CRC) process, resulting from chronic stress on the colon mucosa. The aim of the study is to characterize CAC analyzing p53 alterations and microsatellite instability (MSI) to explore their relationship with GM using a series of CRC and the adjacent intestinal mucosa. Immunohistochemistry was performed to assess p53 alterations, MSI and MUC5AC expression as a surrogate for GM. The p53 mut-pattern was found in more than half of the CAC, most frequently stable (MSS) and MUC5AC negative. Only six tumors were unstable (MSI-H), being with p53 wt-pattern (p = 0.010) and MUC5AC positive (p = 0.005). MUC5AC staining was more frequently observed in intestinal mucosa, inflamed or with chronic changes, than in CAC, especially in those with p53 wt-pattern and MSS. Based on our results, we conclude that, as in the serrated pathway of CRC, in IBD GM occurs in inflamed mucosa, persists in those with chronic changes and disappears with the acquisition of p53 mutations.

Overview and update on molecular testing in non-small cell lung carcinoma utilizing endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) samples

Lung carcinoma remains one of the most frequent and aggressive human neoplasms. Fortunately, in the last decades, the increasing knowledge of the molecular mechanisms leading to cancer development has allowed the use of targeted therapies with improvement of prognosis in many patients. Clinical management has also changed after the introduction of endobronchialultrasonographic bronchoscopy that allows a conservative staging of lung tumors, avoiding the need of mediastinoscopy for lymph node staging. Lung pathologists and cytopathologists are facing the challenge of giving the more comprehensive prognostic and predictive information with ever smaller tissue or cytological samples. The aim of this review is to summarize the molecular testing for non-small cell lung carcinoma and how pathologists can contribute to the patient's outcome with a conscious management of biological samples.

Prognostic influence of CDX2 expression in gastric carcinoma after surgery with a curative intent

INTRODUCTION AND OBJECTIVES

CDX2 is a specific transcription factor with a significant role in the early differentiation and maintenance of intestinal epithelial cells during gastrointestinal development and also as a tumor suppressor. The aim of this study was to assess the potential role of CDX2 expression as a prognostic predictor.

MATERIAL AND METHODS

ninety-two of 206 (44.6%) patients with gastric carcinoma that underwent a curative surgery and had immunohistochemical staining for CDX2 were enrolled into the study; 51.1% were female and the average age was 74.07 years. Overall, 56.5% of tumors were of the intestinal type, 33.7% were diffuse and 9.8% were mixed; 23.9% were T1/T2, 76.1% were T3/T4 and lymph node metastases (N+) were identified in 69.6% of cases; 13% (12) were clinical stage I, 40.2% (37) were stage II and 46.7% (43) were stage III.

RESULTS

a total of 68.5% (63) expressed CDX2. Our study suggests that CDX2 expression (HR = 0.339, p = 0.024) represents an independent risk marker together with the Lauren type (HR = 3.471, p = 0.022). There was association between a milder clinical stage and CDX2 expression (stage I) (p = 0.046). A significant difference was found in overall survival that favored patients with positive CDX2 expression (85.7% vs 65.5%, p = 0.012).

CONCLUSION

our results confirm that CDX2 expression in gastric carcinoma is associated with improved prognosis, although further studies are needed to draw definitive conclusions.

Strong Antitumor Activity of Bevacizumab and Aflibercept in Neuroendocrine Carcinomas: In-Depth Preclinical Study

BACKGROUND

Neuroendocrine carcinoma (NEC) is a rare and very aggressive tumor. It has been greatly understudied, and very little is known about optimal treatment strategy for patients with this disease. The purpose of this study was to evaluate in vivo whether anti-vascular endothelial growth factor (VEGF) drugs could be a therapeutic alternative for these tumors with a poor prognosis.

METHODS

We have developed 2 xenograft models using either human cell line derived from lung (H460) or from colon (COLO320) NEC to assess the effect of 2 antiangiogenic drugs, aflibercept and bevacizumab, on tumor growth and their pathological characteristics. Additionally, tumors were subjected to immunohistochemistry staining and proteins were measured with Western blot and ELISA.

RESULTS

Both aflibercept and bevacizumab showed significant antitumor activity (p < 0.001). In the H460 model, aflibercept resulted in 94% tumor growth inhibition (TGI) and bevacizumab treatment resulted in 72.2% TGI. Similarly, in the COLO320 model, aflibercept and bevacizumab resulted in 89.3 and 84% TGI, respectively. Moreover, antitumor activity occurs early after treatment initiation. Using Tumor Control Index score, which address the kinetics of tumor growth in a way comparable to the methods used in human clinical studies, we confirmed that both drugs inhibit significantly tumor growth. When tumor stabilization was evaluated, aflibercept shows higher ability to stabilize NEC tumors than bevacizumab.

CONCLUSION

Results derived from this study strongly support anti-VEGF therapies, especially aflibercept, as a novel therapeutic option in NECs. Further studies are necessary, but our observations encourage the evaluation of antiangiogenics in clinical trials combined with standard chemotherapy.

CDX2 expression can predict response to neoadjuvant therapy in gastric carcinoma

PURPOSE

Caudal-related homeobox transcription factor 2 (CDX2) has recently been proposed as a prognostic factor for gastric carcinoma. However and to the best of our knowledge, no previous report has analyzed CDX2 expression in patients with gastric adenocarcinoma receiving neoadjuvant therapy (NAT).

PATIENTS, MATERIALS AND METHODS

This is a retrospective cohort study to analyze the potential role of CDX2 expression to predict response to NAT and prognosis. This study has enrolled 57 patients receiving chemotherapy for locally advanced gastric carcinoma.

RESULTS

59.6% of the patients were men; mean age was 64.96 years. Only 8% of the patients showed a complete response to therapy, 10% had grade 1, 28% grade 2, and 54% grade 3 regression, respectively, according to modified Ryan's criteria. On follow-up, 38.6% of the patients showed recurrence of disease (50% distant metastasis) and 28.1% eventually died of it. Twenty-three (40.4%) patients showed intense CDX2 expression. We found a statistically significant association between CDX2 expression and poor regression with NAT, but we found no association with outcome.

DISCUSSION

Our study indicates that CDX2 expression can predict lack of response to NAT. Our results have not confirmed the association with prognosis shown in previous reports.

CONCLUSIONS

Despite these preliminary results, furthermore studies are necessary to define the potential use of CDX2 in gastric carcinoma.

Eosinophilic colitis: experience in a large tertiary hospital

BACKGROUND

Eosinophilic colitis (EC) is a rare and ill-defined entity with an unknown pathogenesis and an unsatisfactory treatment response. The standard histopathological criteria for EC diagnosis lack specificity and not all the cases fulfilling those criteria are considered clinically as EC and treated. The objective of this study is to refine diagnostic criteria for EC.

METHODS

Retrospective study of all the cases with a histopathological diagnosis of EC in Hospital Clinico San Carlos (Madrid, Spain) from 2006 to 2016. We have reviewed their clinical and pathological features and tried to define the features differentiating cases considered EC on clinical grounds.

RESULTS

We identified 106 EC cases. In 22 cases, a clinical EC diagnosis was established. Confirmed EC was associated with younger age, female gender, diarrhea, higher maximum number of eosinophils÷HPF (high-power field), intraepithelial eosinophils, architectural distortion and absence of acute inflammation. We chose a cut-off point of 40 for both mean and maximum number of eosinophils÷HPF. A mean number of eosinophils÷HPF higher than 40 was related to architectural distortion, mucosal atrophy, signs of eosinophil activation and submucosal infiltration. Cases with a maximum number of eosinophils÷HPF higher than 40 showed more architectural distortion, intraepithelial eosinophils, submucosal infiltration and lack of lymphoplasmacytic infiltration.

CONCLUSIONS

Histopathological diagnosis of EC is not well correlated with clinical EC. An increase in specificity can be achieved by raising the cut-off point to 40 eosinophils÷HPF and by combining mean and maximum number of eosinophils with other microscopic and clinical features suggestive of EC.