Liquid biopsy for gastric cancer: Techniques, applications, and future directions.

After the study of circulating tumor cells in blood through liquid biopsy (LB), this technique has evolved to encompass the analysis of multiple materials originating from the tumor, such as nucleic acids, extracellular vesicles, tumor-educated platelets, and other metabolites. Additionally, research has extended to include the examination of samples other than blood or plasma, such as saliva, gastric juice, urine, or stool. LB techniques are diverse, intricate, and variable. They must be highly sensitive, and pre-analytical, patient, and tumor-related factors significantly influence the detection threshold, diagnostic method selection, and potential results. Consequently, the implementation of LB in clinical practice still faces several challenges. The potential applications of LB range from early cancer detection to guiding targeted therapy or immunotherapy in both early and advanced cancer cases, monitoring treatment response, early identification of relapses, or assessing patient risk. On the other hand, gastric cancer (GC) is a disease often diagnosed at advanced stages. Despite recent advances in molecular understanding, the currently available treatment options have not substantially improved the prognosis for many of these patients. The application of LB in GC could be highly valuable as a non-invasive method for early diagnosis and for enhancing the management and outcomes of these patients. In this comprehensive review, from a pathologist's perspective, we provide an overview of the main options available in LB, delve into the fundamental principles of the most studied techniques, explore the potential utility of LB application in the context of GC, and address the obstacles that need to be overcome in the future to make this innovative technique a game-changer in cancer diagnosis and treatment within clinical practice.

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.

DLL3 Is a Prognostic and Potentially Predictive Biomarker for Immunotherapy Linked to PD/PD-L Axis and NOTCH1 in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive neoplasm with very poor patient survival outcomes despite available treatments. There is an urgent need for new potential treatment options and novel biomarkers for these patients. Delta-like canonical Notch ligand 3 (DLL3) interacts with the Notch receptor and causes inhibition of Notch signaling, which confers a survival advantage to PDAC cells. Thus, DLL3 expression could affect cell survival, and its inhibition could increase a patient's survival. To test this hypothesis, a survival analysis was conducted using the progression-free and overall survival from two independent datasets of PDAC patients, with one using mRNA z-score levels and the other using the Hscore protein expression level; both were carried out using a log-rank test and plotted using Kaplan-Meier curves. DLL3 at the mRNA expression level showed an association between high mRNA expression and both a longer progression-free survival (PFS) and overall survival (OS) of patients. Then, we designed a retrospective study with resected PDAC samples. Our primary objective with this dataset was to assess the relationship between PFS and OS and DLL3 protein expression. The secondary assessment was to provide a rationale for the use of anti-DLL3-based treatments in combination with immunotherapy that is supported by the link between DLL3 and other factors that are involved in immune checkpoints. The survival analyses revealed a protective effect of high DLL3 protein expression levels in both PFS and OS. Interestingly, high DLL3 protein expression levels were significantly correlated with PD-L1/2 and negatively correlated with NOTCH1. Therefore, DLL3 could be considered a biomarker for better prognosis in resectable PDAC patients as well as a therapeutic biomarker for immunotherapy response. These facts set a rationale for testing anti-DLL3-based treatments either alone or combined with immunotherapy or other NOTCH1 inhibitors.

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.

Prognostic role of the number of resected and negative lymph nodes in Spanish patients with gastric cancer.

INTRODUCTION: Lymph node (LN) involvement is one of the most critical prognostic factors in resected gastric cancer (GC). Some analyses, mainly conducted in Asian populations, have found that patients with a higher number of total lymph nodes (NTLN) and/or negative lymph nodes (NNLN) have a better prognosis, although other authors have failed to confirm these results. MATERIALS AND METHODS: Retrospective study including all patients with GC resected in a tertiary hospital in Spain between 2001 and 2019 (n = 315). Clinicopathological features were collected and patients were categorized according to the NTLN and the NNLN. Statistical analyses were performed. RESULTS: Mean NNLN was 17. The NNLN was significantly related to multiple clinicopathological variables, including recurrence and tumor-related death. The classification based on the NNLN (N1: ≥16, N2: 8-15, N3: ≤7) effectively stratified the entire cohort into three distinct prognostic groups and maintained its prognostic value within both the pN0 and pN+ patient subsets. Furthermore, it was an independent prognostic indicator for both overall and disease-free survival. Conversely, the mean NTLN was 21.9. Patients with ≤16 LN retrieved exhibited distinct clinicopathological features compared to those with >16 LN, but no significant differences were observed in terms of recurrence or disease-associated death. The application of alternative cut-off points for NTLN (10, 20, 25, 30, and 40) showed no prognostic significance. CONCLUSIONS: In Spanish patients with resected GC the NNLN hold prognostic significance, while the NTLN does not appear to be prognostically significant. Incorporating the NNLN into GC staging may enhance the accuracy of the TNM system.

Estudio piloto comparativo del test VPH con genotipado parcial en primera línea frente a otras estrategias de cribado poblacional del cáncer de cérvix. Estudio CRYGEN 16/18 / Comparative pilot study about HPV test with partial genotyping in primary screening versus other strategies for cervical cancer population screening, CRYGEN 16/18 study

Introducción: La detección precoz del cáncer de cérvix requiere la implementación de programas de cribado del virus del papiloma humano (VPH). Sin embargo, existen discrepancias en la optimización de esas estrategias. Se evalúa el rendimiento de 10 protocolos basados en técnicas moleculares, citológicas o combinadas en cribado primario. Material y métodos: Se diseña un estudio ciego, prospectivo e intervencionista en 1.977 mujeres de 35 años. La determinación molecular se realizó por la plataforma Cobas 4800HPV. Los análisis citológicos se realizaron en las mismas muestras sin conocimiento del resultado molecular. Todas las mujeres en las que se detectaba VPH-16/VPH-18 o presentaban alteración citológica y detección de otros genotipos de alto riesgo (VPHar) eran derivadas a colposcopia. Resultados: El ensayo molecular detectó presencia de VPHar en el 12,5% de las mujeres, mientras solo el 8,1% de las citologías fueron patológicas. El 19,5% de las pacientes derivadas a colposcopia revelaron lesiones de alto grado, estando VPH-16 presente en el 65,3% de ellas. En 6 de esas ocasiones (VPH-16 siempre presente) la citología había sido informada como normal. El seguimiento al año de las mujeres con citología normal y detección de VPHar identificó una lesión HSIL/CIN2+(asociada a VPH-33). En el estudio comparativo con otras estrategias el protocolo denominado CRYGEN 16/18 rindió el mejor equilibrio de sensibilidad y especificidad con la menor derivación a colposcopia. Conclusiones. La realización de detección molecular de VPH con genotipado parcial en primera línea, al menos VPH-16, con derivación directa a colposcopia, aumenta la tasa de detección de lesiones HSIL/CIN2+.(AU)

Introduction: The early detection of cervical cancer requires the implementation of molecular screening programs for human papillomavirus (HPV). However, there are discrepancies in the optimization of screening protocols. The performance of 10 primary screening strategies based on molecular, cytological or combined techniques is now evaluated. Material and methods: A blind, prospective, and interventional study was designed in 1977 35-year-old women. The molecular determination was carried out by the Cobas 4800 HPV platform. Cytological analysis was performed on the same samples without knowledge of the result of the molecular assay. All women in whom HPV-16/HPV-18 was detected or presented cytological alteration together with detection of other high-risk genotypes (HPVhr) were referred to colposcopy. Results: The molecular assay detected the presence of HPVhr genotypes in 12.5% of the women, while only 8.1% of the cytologies were pathological. Among the patients referred to colposcopy, in 19.5% high-grade lesions were observed, being HPV-16 present in 65.3% of them. In six of these high-grade lesions (associated with HPV-16 in all cases), cytology was reported as normal. The follow-up one year later, of women with normal cytology and HPVhr detection a HSIL/CIN2+ lesion was detected (associated to HPV-33). In the comparative study with other strategies, the protocol called CRYGEN 16/18 yielded the best balance of sensitivity and specificity with the least referral to colposcopy. Conclusions: Performing molecular detection of HPVhr with partial first-line genotyping of at least HPV-16, with direct referral to colposcopy, increases the detection rate of HSIL/CIN2+ lesions.(AU)

Comparative pilot study about HPV test with partial genotyping in primary screening versus other strategies for cervical cancer population screening, CRYGEN 16/18 study.

INTRODUCTION: The early detection of cervical cancer requires the implementation of molecular screening programmes for human papillomavirus (HPV). However, there are discrepancies in the optimization of screening protocols. The performance of 10 primary screening strategies based on molecular, cytological or combined techniques is now evaluated. MATERIAL AND METHODS: A blind, prospective, and interventional study was designed in 1.977 35-year-old women. The molecular determination was carried out by the Cobas 4800 HPV platform. Cytological analysis were performed on the same samples without knowledge of the result of the molecular assay. All women in whom HPV-16/HPV-18 was detected or presented cytological alteration together with detection of other high-risk genotypes (HPVhr) were referred to colposcopy. RESULTS: The molecular assay detected the presence of HPVhr genotypes in 12.5% of the women, while only 8.1% of the cytologies were pathological. Among the patients referred to colposcopy, in 19.5% high-grade lesions were observed, being HPV-16 present in 65.3% of them. In six of these high-grade lesions (associated with HPV-16 in all cases), cytology was reported as normal. The follow-up one year later, of women with normal cytology and HPVhr detection a HSIL/CIN2+ lesion was detected (associated to HPV-33). In the comparative study with other strategies, the protocol called CRYGEN 16/18 yielded the best balance of sensitivity and specificity with the least referral to colposcopy. CONCLUSIONS: Performing molecular detection of HPVhr with partial first-line genotyping of at least HPV-16, with direct referral to colposcopy, increases the detection rate of HSIL/CIN2+ lesions.

Clinicopathological differences, risk factors and prognostic scores for western patients with intestinal and diffuse-type gastric cancer.

BACKGROUND: In the molecular era, the Laurén system is still a cost-effective and widely implemented classification for gastric cancer (GC) and it has been recently associated with clinical, histological and molecular features of these tumors. Despite recent advances in the understanding of the molecular biology of GC, there is a need to develop new prognostic tools for patient stratification in clinical practice. Thus, the identification of easily available prognostic factors in patients with intestinal and diffuse-type tumors can significantly improve risk assessment and patient stratification in GC. AIM: To identify clinicopathological differences, risk factors, and to develop cost-effective prognostic scores for patients with intestinal and diffuse-type GC. METHODS: Retrospective study of all patients undergoing surgery for GC at a tertiary referral center from 2001 to 2019. 286 cases met inclusion criteria (intestinal: 190, diffuse: 96). Clinical data and gross findings were collected. All specimens were reviewed by two independent pathologists and a detailed protocol for histologic evaluation was followed. Five tissue microarrays (TMAs) were constructed and sections of the TMA block were immunostained for HERCEPTEST, MSH2, MSH6, MLH1 and PMS2. Statistical analyses were performed and prognostic scores were developed based on hazard ratios. RESULTS: Intestinal and diffuse-type GC showed different epidemiological, clinicopathological and prognostic features. Diffuse tumors were significantly associated with younger age, less symptomatology, flat morphology, deeper invasion, perineural infiltration, advanced stage at diagnosis, administration of adjuvant therapy and poorer prognosis. Intestinal lesions were fungoid or polypoid, showed necrosis, desmoplasia, microsatellite instability and HERCEPTEST positivity and were diagnosed at earlier stages. Tumor depth, desmoplasia, macroscopic type and lymph node involvement were independently related to the Laurén subtype. Furthermore, intestinal and diffuse GC were associated with different risk factors for progression and death. Vascular invasion, perineural infiltration and growth pattern were important prognostic factors in intestinal-type GC. On the contrary, tumor size and necrosis were significant prognosticators in diffuse-type GC. Our recurrence and cancer-specific death scores for patients with intestinal and diffuse-type GC showed an excellent patient stratification into three (diffuse GC) or four (intestinal) prognostic groups. CONCLUSION: Our findings support that Laurén subtypes represent different clinicopathological and biological entities. The development of specific prognostic scores is a useful and cost-effective strategy to improve risk assessment in GC.

Mitochondrial Oxidative Stress Promotes Cardiac Remodeling in Myocardial Infarction through the Activation of Endoplasmic Reticulum Stress.

We have evaluated cardiac function and fibrosis in infarcted male Wistar rats treated with MitoQ (50 mg/kg/day) or vehicle for 4 weeks. A cohort of patients admitted with a first episode of acute MI were also analyzed with cardiac magnetic resonance and T1 mapping during admission and at a 12-month follow-up. Infarcted animals presented cardiac hypertrophy and a reduction in the left ventricular ejection fraction (LVEF) and E- and A-waves (E/A) ratio when compared to controls. Myocardial infarction (MI) rats also showed cardiac fibrosis and endoplasmic reticulum (ER) stress activation. Binding immunoglobulin protein (BiP) levels, a marker of ER stress, were correlated with collagen I levels. MitoQ reduced oxidative stress and prevented all these changes without affecting the infarct size. The LVEF and E/A ratio in patients with MI were 57.6 ± 7.9% and 0.96 ± 0.34, respectively. No major changes in cardiac function, extracellular volume fraction (ECV), or LV mass were observed at follow-up. Interestingly, the myeloperoxidase (MPO) levels were associated with the ECV in basal conditions. BiP staining and collagen content were also higher in cardiac samples from autopsies of patients who had suffered an MI than in those who had died from other causes. These results show the interactions between mitochondrial oxidative stress and ER stress, which can result in the development of diffuse fibrosis in the context of MI.

Analysis of the Effects of Melanin Depigmentation on Immunohistochemical Staining.

Heavily pigmented lesions are difficult to evaluate histologically, as melanin obscures cellular details. Several classic laboratory techniques aim to clear melanin and allow evaluation. Most of them are old and appeared before immunohistochemistry (IHC) use. Many laboratories perform IHC with aminoethylcarbazole instead of diaminobenzidine (DAB) in heavily pigmented lesions, as red-stained is easy to interpret despite pigmentation. Nevertheless, many laboratories lack alternatives to DAB. The aim of this study is to compare 6 different tissue bleaching techniques and evaluate which is the best for immunohistochemical staining with DAB. In the present study we have selected a case with gross pigmentation because of the high grade of melanin deposition. We have performed 6 different bleaching techniques and subsequently performed 2 different IHC stains, frequently used in melanoma: SOX10 (nuclear) and Melan-A (cytoplasmic). Five different pathologists, 2 of them with expertise in dermatopathology, have blindly reviewed and scored the staining quality. Our results indicate a high grade of interobserver concordance in the evaluation of IHC results between pathologists. All the bleaching techniques that included a sulfuric acid led to tissue detachment from the slide. The best method for SOX10 was that based in potassium permanganate, with a high quality of staining (4 over 5), while the best method for Melan-A was the 1 based in peroxide hydrogen (4 over 5). We consider this study can be quite useful for those laboratories lacking aminoethylcarbazole for IHC techniques, allowing the use of DAB for IHC of heavily pigmented lesions.

Comparative pilot study about HPV test with partial genotyping in primary screening versus other strategies for cervical cancer population screening, CRYGEN 16/18 study. / Estudio piloto comparativo del test VPH con genotipado parcial en primera línea frente a otras estrategias de cribado poblacional del cáncer de cérvix. Estudio CRYGEN 16/18.

INTRODUCTION: The early detection of cervical cancer requires the implementation of molecular screening programs for human papillomavirus (HPV). However, there are discrepancies in the optimization of screening protocols. The performance of 10 primary screening strategies based on molecular, cytological or combined techniques is now evaluated. MATERIAL AND METHODS: A blind, prospective, and interventional study was designed in 1977 35-year-old women. The molecular determination was carried out by the Cobas 4800 HPV platform. Cytological analysis was performed on the same samples without knowledge of the result of the molecular assay. All women in whom HPV-16/HPV-18 was detected or presented cytological alteration together with detection of other high-risk genotypes (HPVhr) were referred to colposcopy. RESULTS: The molecular assay detected the presence of HPVhr genotypes in 12.5% of the women, while only 8.1% of the cytologies were pathological. Among the patients referred to colposcopy, in 19.5% high-grade lesions were observed, being HPV-16 present in 65.3% of them. In six of these high-grade lesions (associated with HPV-16 in all cases), cytology was reported as normal. The follow-up one year later, of women with normal cytology and HPVhr detection a HSIL/CIN2+ lesion was detected (associated to HPV-33). In the comparative study with other strategies, the protocol called CRYGEN 16/18 yielded the best balance of sensitivity and specificity with the least referral to colposcopy. CONCLUSIONS: Performing molecular detection of HPVhr with partial first-line genotyping of at least HPV-16, with direct referral to colposcopy, increases the detection rate of HSIL/CIN2+ lesions.

Are Borrmann's Types of Advanced Gastric Cancer Distinct Clinicopathological and Molecular Entities? A Western Study.

Most studies on the clinicopathological impact of Borrmann classification for gastric cancer (GC) have been performed in Asian patients with type IV tumors, and immunohistochemical features of Borrmann types have scarcely been analyzed. We assessed the clinicopathological, molecular features and prognostic value of Borrmann types in all patients with advanced GC resected in a Western institution (n = 260). We observed a significant relationship between Borrmann types and age, systemic symptoms, tumor size, Laurén subtype, presence of signet-ring cells, infiltrative growth, high grade, tumor necrosis, HERCEPTEST positivity, microsatellite instability (MSI) and molecular subtypes. Polypoid GC showed systemic symptoms, intestinal-type histology, low grade, expansive growth and HERCEPTEST positivity. Fungating GC occurred in symptomatic older patients. It presented intestinal-type histology, infiltrative growth and necrosis. Ulcerated GC showed smaller size, intestinal-type histology, high grade and infiltrative growth. Most polypoid and ulcerated tumors were stable-p53-not overexpressed or microsatellite unstable. Flat lesions were high-grade diffuse tumors with no MSI, and occurred in younger and less symptomatic patients. No association was found between Borrmann classification and prognosis. According to our results, Borrmann types may represent distinct clinicopathological and biological entities. Further research should be conducted to confirm the role of Borrmann classification in the stratification of patients with advanced GC.

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.

[Post mortem core needle biopsy of Covid-19 fatalities]. / Punción post mortem con aguja gruesa a cadáveres fallecidos por COVID-19.

The difficulties involved in performing autopsies of patients who had died due to COVID-19 required the use of alternative methods in order to obtain tissue samples of affected organs. We describe the technique of core needle aspiration, without ultrasonographic guidance, which we used in 19 cadavers and which produced a high yield in lungs, heart (>94%) and liver (>89%), thus enabling the study of the morphological changes produced by SARS-CoV-2.

A DNA damage repair gene-associated signature predicts responses of patients with advanced soft-tissue sarcoma to treatment with trabectedin.

Predictive biomarkers of trabectedin represent an unmet need in advanced soft-tissue sarcomas (STS). DNA damage repair (DDR) genes, involved in homologous recombination or nucleotide excision repair, had been previously described as biomarkers of trabectedin resistance or sensitivity, respectively. The majority of these studies only focused on specific factors (ERCC1, ERCC5, and BRCA1) and did not evaluate several other DDR-related genes that could have a relevant role for trabectedin efficacy. In this retrospective translational study, 118 genes involved in DDR were evaluated to determine, by transcriptomics, a predictive gene signature of trabectedin efficacy. A six-gene predictive signature of trabectedin efficacy was built in a series of 139 tumor samples from patients with advanced STS. Patients in the high-risk gene signature group showed a significantly worse progression-free survival compared with patients in the low-risk group (2.1 vs 6.0 months, respectively). Differential gene expression analysis defined new potential predictive biomarkers of trabectedin sensitivity (PARP3 and CCNH) or resistance (DNAJB11 and PARP1). Our study identified a new gene signature that significantly predicts patients with higher probability to respond to treatment with trabectedin. Targeting some genes of this signature emerges as a potential strategy to enhance trabectedin efficacy.

Towards standardization of lymph-node ratio classifications: Validation and comparison of different lymph node ratio classifications for predicting prognosis of patients with resected gastric cancer.

INTRODUCTION: The TNM staging system is the main prognostic tool for GC, but the number of metastatic lymph nodes (LN) can be affected by surgical, pathological, tumor or host factors. Several authors have shown that lymph node ratio (LNR) may be superior to TNM staging in GC. However, cut-off values vary between studies and LNR assessment is not standardized. MATERIAL AND METHODS: Retrospective study of all GC resected in a western tertiary center (N = 377). Clinical features were collected and pathological features were assessed by two independent pathologists. Eight LNR classifications were selected and applied to our patients. Statistical analyses were performed. RESULTS: 315 patients were included. Most tumors were T3 (49.2%) N+ (59.3%). During follow-up, 36.7% of patients progressed and 27.4% died due to tumor. All LNR classifications were significantly associated with clinicopathological features such as Laurén subtype, lymphovascular invasion, perineural infiltration, T stage, tumor progression or death. All LNR classifications were independent prognostic factors for OS and DFS, and ROC analyses calculated similar AUC values for all staging systems. Kaplan-Meier curves showed that Pedrazzani, Wang, Liu and Huang classifications stratified patients better into three (Pedrazzani) or four categories. These classifications tended to downstage TNM N2 and N3 tumors. In cases with less than 16 LNs resected, Pedrazzani and Wang classifications showed the best prognostic performance. CONCLUSIONS: Pedrazzani, Wang, Liu and Huang classifications showed good prognostic performance in western GC patients. Larger studies in other cohorts are needed to identify the most consistent LNR classification for GC.

Ber-EP4 staining in effusion cytology: A potential source of false positives.

The distinction between reactive mesothelium and carcinoma in serous effusions can be very difficult. Immunocytochemistry (ICC) is the most widely used tool to improve the diagnostic accuracy of body fluid cytology, with several ICC markers being proposed. Ber-EP4 antibody has shown high sensitivity and specificity rates for diagnosing metastatic carcinoma. In our department, we have detected Ber-EP4 positivity in mesothelium in some cytological specimens. We reviewed all articles on Ber-EP4 staining in effusion cytology, summarized current findings and analyzed the staining pattern of all cases expressing Ber-EP4. Some cases showing Ber-EP4 positivity in mesothelium have been reported, most of which showed only weak Ber-EP4 staining or staining of less than 50% of mesothelial cells. However, some cases may show strong positivity both in cytological and histological specimens. Clinicians and pathologists should be aware of this source of misdiagnosis, and ICC results in mesothelium should be always interpreted cautiously and correlated with clinical tests, other ICC markers and patient's previous history.

[Update on gastric cancer. New molecular classifications]. / Actualización en cáncer gástrico. Nuevas clasificaciones moleculares.

Gastric cancer (GC) is an aggressive tumor, which is usually diagnosed at an advanced stage and shows high mortality rates. Several GC classifications have been published, based on features such as tumor location, endoscopic features or microscopic architecture. However, TNM stage remains the mainstay of GC management and treatment. In the last years, technical advances have allowed us to investigate the biological heterogeneity of GC and develop new molecular classifications. This knowledge may enhance current classifications, and has the potential to refine GC management and aid in the identification of new molecular targets. In this literature review we have summarized the main findings in epidemiology, screening, classification systems and treatment of GC, focusing on the molecular alterations and new molecular classifications published in the last years.