Intestinal-type Tumors Research Articles

Chromosomal copy number based stratification of gastric cancer has added prognostic value to Lauren’s histological classification

BackgroundThe Cancer Genome Atlas (TCGA) recognizes four molecular subgroups of gastric cancer: Epstein-Barr virus (EBV) positive, microsatellite instable (MSI), genomically stable (GS), and chromosomal instable (CIN). Since a GS/CIN classifier is lacking, alternative markers such as Lauren’s histopathology or CDH1/p53 immunohistochemistry are commonly applied. Here we compared survival of gastric cancer subgroups determined by four methods.Methods309 EBV negative and microsatellite stable tumors were included from the Dutch D1/D2 trial and assigned to subgroups by: (i) TCGA’s specific chromosomal copy number aberrations, (ii) genome instability index (GII), (iii) Lauren’s classification, and (iv) CDH1/p53 immunohistochemistry. Subgroups were associated with cancer-related survival (CRS).ResultsFive-year CRS was 42.0% for diffuse and 49.5% for patients with intestinal type tumors, and 57.8% for GS and 41.6% for patients with CIN tumors. Classification by GII or CDH1/p53 IHC did not correlate with CRS. The combination of TCGA and Lauren classifications resulted in four distinct subgroups. Five-year CRS for GS-intestinal (n = 24), GS-diffuse (n = 57), CIN-intestinal (n = 142) and CIN-diffuse (n = 86) was 61.4%, 56.5%, 47.6%, and 31.5%, respectively.ConclusionsTCGA’s GS and CIN subgroups have additional prognostic value to Lauren’s classification in resectable gastric cancer. GS-intestinal, GS-diffuse, CIN-intestinal and CIN-diffuse are suggested stratification variables for future studies.

Abstract 7281: Targeting the YAP/TAZ-TEAD pathway with TEAD inhibitors synergizes with chemotherapy and blocks diffuse gastric cancer progression

Abstract Introduction: Diffuse gastric cancer (DGC) accounts for one third of gastric cancers and is associated with poor differentiation, discohesive growth, chemoresistance, and worse survival compared to intestinal-type tumors. DGC is typically genomically stable, and there are no approved DGC-targeted therapies. Recent studies have identified a potential tumor-promoting role for Yes-associated protein 1 and transcriptional coactivator with PDZ-binding motif (YAP/TAZ), which interact with TEAD transcription factors to regulate gene expression. Therefore, we evaluated the activity and mechanism of TEAD inhibitors in DGC preclinical models. Methods: Gastric cancer patient-derived organoids (PDOs) and cell lines were treated with TEAD inhibitors (K-975, VT103, VT104, VT107) and/or 5-fluorouracil (5-FU) for in vitro assays evaluating cell proliferation or invasion. Additional experiments were conducted to test the in vivo activity of TEAD inhibitors or shRNA-mediated knockdown of YAP in subcutaneous xenograft, orthotopic xenograft, and lung metastasis models using a genetically engineered mouse model of gastric cancer driven by oncogenic KrasG12D and loss of Trp53/Cdh1. Results: TEAD inhibitors K-975, VT103, VT104, and VT107 reduced proliferation, colony formation, and invasion in DGC cell lines and PDOs. We observed no effect of TEAD inhibitors on the viability of normal gastric organoids. Combining the TEAD1-selective inhibitor VT103 with 5-FU chemotherapy resulted in further reduction of DGC PDO viability relative to monotherapy, including in a PDO derived from a patient with locally advanced DGC that demonstrated intrinsic resistance to neoadjuvant chemotherapy. In flank tumors and orthotopic models, inhibition of the YAP/TAZ-TEAD pathway using YAP shRNA and VT103, either alone or in combination with 5-FU, abrogated primary tumor formation, with the strongest inhibition observed with combination treatment. Loss of YAP or VT103 treatment also significantly reduced lung metastasis after tail vein injection of mouse gastric cancer cells. We hypothesized that TEAD inhibition blocks an epithelial-to-mesenchymal transition (EMT) program and generation of cancer stem-like cells (CSCs). Consistent with this hypothesis, TEAD1 inhibition with VT103 or YAP knockdown reduced expression of the CSC marker CD44 in vitro and decreased expression of CD44 and the EMT marker Slug in tumor xenografts. Conclusions: The YAP/TAZ-TEAD pathway is an important driver of gastric cancer growth and metastasis, particularly in DGC where it may promote EMT and cancer stemness. TEAD inhibition reduces gastric cancer growth and invasion in vitro and in vivo in preclinical models and demonstrates synergistic activity with 5-FU chemotherapy. These results suggest a potential role for evaluating the efficacy of TEAD inhibitors in patients with DGC. Citation Format: Anastasiia Bulakhova, Jin Sun Cho, Jack T. Rifkin, Jaewon Kim, Thomas J. Ryan, Tracy T. Tang, Ryan H. Moy. Targeting the YAP/TAZ-TEAD pathway with TEAD inhibitors synergizes with chemotherapy and blocks diffuse gastric cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7281.

The Histopathological Characteristic of Gastric Carcinoma in the Belgian Tervueren and Groenendael Dog: A Comparison of Two Classification Methods.

Gastric carcinoma is generally considered to be a rare disease in dogs, carrying a grave prognosis. However, in the Tervueren and Groenendael varieties of the Belgian Shepherd dog breed, the disease is highly prevalent. While histopathology is the gold standard for diagnosing gastric carcinoma, there is no general consensus on the methods for histological classification in these cases. Biopsies of a group of 61 dogs with confirmed gastric carcinoma (45 Tervueren and 16 Groenendael) were examined and classified according to World Health Organization (WHO) and Laurén classifications. Kaplan-Meier curves were used to compare survival between the different subtypes and simple and multiple linear regression were used to analyse the association between age of onset and breed variant, sex, neuter status, location of the tumour, inflammation score, and Laurén and WHO classifications. Mean age at diagnosis was significantly different in Groenendael (10.1 ± 2.01) and Tervueren dogs (8.5 ± 1.90). The Laurén classification resulted in 29 (48%) diffuse- and 32 (52%) intestinal-type tumours. Applying the WHO classification resulted in 30 (49%) tubular carcinoma growth patterns and 31 (51%) others. Median survival time was significantly reduced for the diffuse type as compared to the intestinal type according to the Laurén classification, with the same median survival time results for tubular compared to non-tubular subtypes according to the WHO classification (median survival time of 61 vs. 182 days, respectively). Using the WHO and Lauren classification on tumour biopsies may help the practising clinician in the prognostication of gastric carcinoma in Tervueren and Groenendael dogs.

Mucinous tumors arising from ovarian teratomas as another source of pseudomyxoma peritoneii: MR findings comparison with ovarian metastases from appendiceal mucinous tumors.

The origin of pseudomyxoma peritoneii (PMP) has been established as low-grade appendiceal mucinous tumors (AMT). However, intestinal-type ovarian mucinous tumors are known as another source of PMP. Recently, it is advocated that ovarian mucinous tumors causing PMP originates from teratomas. However, AMTs are often too small to detect on imaging; then, differentiating metastatic ovarian tumors of AMT from ovarian teratoma-associated mucinous tumors (OTAMT) is important. Therefore, this study investigates the MR characteristics of OTAMT compared to the ovarian metastasis of AMT. MR findings of six pathologically confirmed OTAMT were retrospectively analyzed compared to ovarian metastases of low-grade appendiceal mucinous neoplasms (LAMN). We studied the existence of PMP, uni- or bilateral disease, the maximum diameter of ovarian masses, the number of loculi, a variety of sizes and signal intensity of each content, the existence of the solid part, fat, calcification within the mass, and appendiceal diameters. All the findings were statistically analyzed using the Mann-Whitney test. Four of the six OTAMT showed PMP. OTAMT showed unilateral disease, had a larger diameter, more frequent intratumoral fat, smaller appendiceal diameter than those in AMT, and they were statistically significant (p < .05). On the other hand, the number, variety of size, signal intensity of loculi, and the solid part, calcification within the mass did not differ from each other. Both OTAMT and ovarian metastasis of AMT appeared as multilocular cystic masses with relatively uniform signal and size of loculi. However, a larger unilateral disease with intratumoral fat and smaller size of the appendix may suggest OTAMT. OTAMT can be another source of PMP, as AMT. MR characteristics of OTAMT were very similar to ovarian metastases of AMT; however, in cases with PMP combined with fat-containing multilocular cystic ovarian mass, we can diagnose them as OTAMT, not PMP caused by AMT.

Abstract 134: Lymph node metastases are seeded via two distinct ways in phylogenetic study of gastric cancer

Abstract Backgrounds: Gastric cancer (GC) ranked 5th and 8th on the list of cancer related deaths worldwide and in Taiwan, respectively. Due to its high frequency of lymph node spread, lymph node dissection has become a standard procedure in surgical treatment. A randomized trial showed that patients who underwent D2 lymphadenectomy had a better 5-year survival outcome than ones who had D1 dissection in advanced gastric cancer, implying the D2 lymph node might serve as an outpost before tumor cells spread to distant organs. This clinical observation raises a possibility that the regional lymphatic spread could be under strict selection but not a passive process. Materials and Methods: To understand the evolutionary relationship between primary tumors, perigastric lymph nodes, and second tier of lymph nodes in the extra-perigastric area, we reconstruct their phylogeny using genetic variants in hypermutable DNA regions where the mutation rate is 102~104-fold than unique sequence. We have assembled a cohort of 10 gastric cancer patients, including intestinal-, diffuse- and mixed type GC. For each case, we collected all workable lymph node metastases and intensely sampled primary tumors. On average, we have over fifteen samples per case on the phylogenetic tree. Results: Preliminary data of the first two patients show high heterogeneity within primary tumors as well as between different lesions of lymph nodes or peritoneal metastases in gastric cancer. Interestingly, in stark contrast to all other lymph node metastases which intermingle with primary tumors, a clade consisting of one proximal and one distal lymph node with a bootstrap value above 90% is observed in each phylogeny, and it is worth noting that samples on these clades are from intestinal type tumor. Conclusion: Our results indicate that most tumor cells arrive both regional and distal lymph nodes passively via lymphatic drainage in GC while a selective process also exists which coincides with clinical observation. Whether the existence of tumor cells under a relatively stricter selection process would lead to different clinical outcomes is under investigation. Citation Format: Pei-Chi Cheng, Wei-Ting Hung, Yung-Ming Jeng, I-Rue Lai. Lymph node metastases are seeded via two distinct ways in phylogenetic study of gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 134.

The prognostic role of epidermal growth factor receptor mutation in completely resected ampullary adenocarcinoma.

Theaim ofthis study is to make adifferential diagnosis and prognosis oftheampullary adenocarcinoma subtypes. We also investigated therole ofprognostic markers PD-1 and PD-L1, and epidermal growth factor receptor (EGFR). Local or locally advanced stage ampullary adenocarcinoma patients who had undergone pancreaticoduodenectomy at thetime ofdiagnosis were included. MUC1, MUC2, MUC5AC, CDX2, CK7, CK20, PD-1, and PDL-1 were analysed immunohistochemically, and EGFR was analysed by real-time polymerase chain reaction. According to histopathological and immunohistochemical evaluation, we found 27 patients as pancreatobiliary type and 56 patients as intestinal type adenocarcinoma. Themedian survival ofpatients with intestinal and pancreatobiliary type adenocarcinoma was 23 months and 76 months ( p = 0.201), respectively. When thesurvival ofPD1-positive ( n = 23) and PD-L1-positive ( n = 18) patients were compared with thepatients with negative staining ( n = 60, n = 65), no significant difference was found. Epidermal growth factor receptor mutation was detected in atotal of6 patients, and 5 ofthese 6 mutations were shown in intestinal type tumours and one in apancreatobiliary type tumour. Asignificant difference was determined in terms ofoverall survival for thepatients with EGFR mutations compared to those without ( p = 0.008). In conclusion, we could reveal theprognostic significance ofEGFR mutation, which is also atarget molecule.

Specifics of Young Gastric Cancer Patients: A Population-Based Analysis of 46,110 Patients with Gastric Cancer from the German Clinical Cancer Registry Group.

Introduction: 2−8% of all gastric cancer occurs at a younger age, also known as early-onset gastric cancer (EOGC). The aim of the present work was to use clinical registry data to classify and characterize the young cohort of patients with gastric cancer more precisely. Methods: German Cancer Registry Group of the Society of German Tumor Centers—Network for Care, Quality and Research in Oncology (ADT)was queried for patients with gastric cancer from 2000−2016. An approach that stratified relative distributions of histological subtypes of gastric adenocarcinoma according to age percentiles was used to define and characterize EOGC. Demographics, tumor characteristics, treatment and survival were analyzed. Results: A total of 46,110 patients were included. Comparison of different groups of age with incidences of histological subtypes showed that incidence of signet ring cell carcinoma (SRCC) increased with decreasing age and exceeded pooled incidences of diffuse and intestinal type tumors in the youngest 20% of patients. We selected this group with median age of 53 as EOGC. The proportion of female patients was lower in EOGC than that of elderly patients (43% versus 45%; p < 0.001). EOGC presented more advanced and undifferentiated tumors with G3/4 stages in 77% versus 62%, T3/4 stages in 51% versus 48%, nodal positive tumors in 57% versus 53% and metastasis in 35% versus 30% (p < 0.001) and received less curative treatment (42% versus 52%; p < 0.001). Survival of EOGC was significantly better (five-years survival: 44% versus 31% (p < 0.0001), with age as independent predictor of better survival (HR 0.61; p < 0.0001). Conclusion: With this population-based registry study we were able to objectively define a cohort of patients referred to as EOGC. Despite more aggressive/advanced tumors and less curative treatment, survival was significantly better compared to elderly patients, and age was identified as an independent predictor for better survival.

Tubulovillous adenoma with high-grade dysplasia of the vulva harboring high tumor mutational burden and cancer-associated mutations: a case report

BackgroundVulvar cancer is a rare disease, accounting for approximately 5% of gynecological malignancies. Primary adenocarcinoma of intestinal-type of the vulva or its precancerous lesion is extremely rare, and details regarding its origin, evolution and related genetic mutations are unknown. Treatment options for this cancer have not been defined.Case presentationA 63-year-old Japanese woman came to the hospital because she was aware of a vulvar mass. There was a 1 cm mass on the dorsal side of the vulva, just outside the remains of the hymen. Biopsy revealed suspected adenocarcinoma, and wide local excision was performed. From histopathology and immunohistochemistry, the specimen was diagnosed as tubulovillous adenoma with high-grade dysplasia of the vulva. No other primary lesions were found, and the vulva was considered the primary site. A gene panel test (FoundationOneCDx assay) showed a high tumor mutational burden and mutations in TP53, KEL, RB1, RNF43, PTEN, GNAS, and PIK3CA.ConclusionsThe current case of tubulovillous adenoma with high-grade dysplasia of the vulva had a variety of cancer-associated mutations, despite being a precancerous lesion. In cases of intestinal-type neoplasms of the vulva, it may be helpful to check tumor mutational burden and gene mutations for treatment selection.

Deep learning captures selective features for discrimination of microsatellite instability from pathologic tissue slides of gastric cancer.

Microsatellite instability (MSI) status is an important prognostic marker for various cancers. Furthermore, because immune checkpoint inhibitors are much more effective in tumors with high level of MSI (MSI-H), MSI status is routinely tested in multiple cancer types. Therefore, many studies have tested the feasibility of deep learning (DL)-based prediction of MSI status from hematoxylin and eosin (H&E)-stained tissue slides. In the present study, we attempted a fully automated classification of MSI status in gastric cancer (GC) tissue slides. For frozen and formalin-fixed paraffin-embedded (FFPE) GC tissues from The Cancer Genome Atlas (TCGA), the areas under the curves (AUCs) for the receiver operating characteristic (ROC) curves were 0.893 and 0.902, respectively. The classifier trained with the TCGA FFPE tissues performed well on an external validation Asian FFPE cohort, with an AUC of 0.874. However, the DL-based classifier seems incompatible with cancers from different organs because morphologic features of MSI-H tissues are different. Analysis of histomorphologic features of MSI-H GC tissues suggested that MSI-H GC could largely be divided into two groups: intestinal type tumors with moderate to poor differentiation and diffuse type mucinous tumors. However, the recognizable morphologic features cannot completely explain the good performance of the DL-based classifier. These results indicate that DL could automatically learn the optimal features for discrimination of MSI status in GC tissue slides. This study demonstrated the potential of a DL-based MSI classifier as a screening tool for definitive cases.

Genetic and Transcriptional Analysis of 8q24.21 Cluster in Gastric Cancer.

Previous studies from our research group have shown that trisomy 8 and the amplification of the 8q24.21 region is very frequent in gastric cancer (GC). Little is known about the role of most genes located in this region. Thus, the aim of this study was to understand the possible impact of transcriptional alterations and copy number variation (CNV) of four genes located in the 8q24.21 region - FAM49B, FAM84B, GSDMC and miR-5194 - in GC. Fifty-one to 85 matched pairs of tumoral and adjacent non-tumoral gastric tissues, from patients with primary GC, were used to analyze gene expression and CNV of the selected genes. We also included 29 H. pylori negative and gastritis negative gastric mucosa tissues from individuals without cancer obtained by endoscopy, as control samples. The expression of FAM49B, GSDMC and miR-5194 was higher in both tumoral and adjacent non-tumoral samples compared to the negative control. The expression of FAM84B showed no significant difference between tumoral samples and negative controls. However, the expression of FAM84B in the adjacent non-tumoral samples was higher compared to negative control and tumoral samples. Moreover, the higher expression of GSDMC was associated with T3 and T4 tumors, with tumors on stage III and IV and with advanced tumors. Higher copy numbers of FAM49B and GSDMC were associated with intestinal tumor type and with moderately or well-differentiated tumors. Higher copy number of FAM84B was associated with moderately or well-differentiated tumors. Furthermore, the expression of all four genes was positively correlated. All four genes are upregulated in GC and may play an important role in these neoplasms. GSDMC expression was associated with more aggressive tumors.

Expression of cartilage oligomeric matrix protein in periampullary adenocarcinoma is associated with pancreatobiliary-type morphology, higher levels of fibrosis and immune cell exclusion

ABSTRACT Cartilage oligomeric matrix protein (COMP) is an emerging regulator of tumor progression. The aim of this study was to evaluate the expression of COMP in periampullary adenocarcinoma with respect to prognostic value for survival and relapse, levels of fibrosis and infiltrating immune cells. COMP expression was evaluated using immunohistochemistry in primary tumors and subsets of paired lymph node metastases in tissue microarrays including 175 patients with periampullary adenocarcinoma. Collagen content was assessed with Sirius Red-Fast Green staining. High COMP levels were detected in cancer cells and in stroma, in 46% and 57% of the patients, respectively. High COMP expression was strongly associated with more aggressive pancreatobiliary-type (PB-type) compared to intestinal-type tumors (p < .0001). Importantly, high expression of COMP correlated with the exclusion of cytotoxic T-cells from the cancer cell compartment of the tumors, particularly in PB-type tumors. Higher levels of fibrosis measured by the density of collagen fibers correlated with high COMP levels in both cancer cells and stroma. This in turn could lead to exclusion of cytotoxic T-cells from accessing the cancer cells, a recognized immunotherapy resistance mechanism. Targeting COMP could therefore be considered as a novel therapeutic strategy in PB-type periampullary adenocarcinoma.

Immunohistochemical expression of E-Cadherin in gastric carcinoma in Erbil city, Kurdistan Region

Background and objectives: Gastric carcinoma is at fourth position incidence-wise and holds a second place for deaths due to cancer. The Cadherins represent an important class of the adhesiveness molecules, which play an essential role in the homotypical cell-cell adhesion and in the complex process of invasion and metastasis. The point of this study is to identify the rate of the E-Cadherin immunoexpression in gastric carcinoma in Erbil locality and investigate its association with the clinico pathological parameters. Methods: A retrospective study was carried out in Rizgary teaching hospital and private laboratories in Erbil city for the period from Jan.2018 - Jan.2020. A total of 75 formalin fixed, paraffin embedded archival tissue blocks of total or partial gastrectomy samples for gastric carcinoma cases were collected, then E-cadherin immunohistochemistry was tested. Results: Twenty-one cases (28%) were categorized as high expression for E-Cadherin immunoexpression. At the same time 38 (50.7%) of the cases were classified as low expression and 16 (21.3%) of cases were labelled with no expression. E-Cadherin status was significantly associated with the tumor type and tumor grade, in which high E-Cadherin expression about (61.9%) was demonstrated in intestinal type tumors, (38.1%) in diffuse type tumors and about (57.1%) was performed in well-moderately differentiated tumors and (42.9%) in poorly differentiated tumors. While no significant association was found between E-Cadherin expression and other clinico. Conclusions: Our result support the hypothesis that the E-Cadherin immunostain is commonly expressed in Gastric cancer, and it was significantly related with type and grade of the tumor.

62: WHICH GASTRIC CANCER PATIENTS COULD BENEFIT FROM STAGING LAPAROSCOPY? A GIRCG MULTICENTER COHORT STUDY

Abstract Background and aim Staging laparoscopy is an important step of the staging of gastric cancer patients, however, its indication are universally accepted by the different guidelines.This study aimed to define those factors which could help in defining the most appropriate use of staging laparoscopy in a western population. Methods A retrospective cohort study was carried out, including 330 (226 cM- and 104 cM+) gastric cancer patients who had undergone staging laparoscopy between 2010–2020 in seven GIRCG centers. A model including easily-accessible clinical, biochemical and pathological markers was constructed to predict the risk of carcinomatosis. ROC curve and decision curve analyses were used to verify its accuracy and net benefit. Results In the cM- population staging laparoscopy could detect 70 cases who had peritoneal carcinomatosis or positive cytology, for a yield of 31.0%. In cM+ patients staging laparoscopy could exclude carcinomatosis in 15 cases. In cM- patients, intestinal type tumors (0.36, 0.14–0.92; P = 0.035), the presence of signet ring cells (2.58, 1.04–6.33; P = 0.039) and cancers of the upper third (3.36, 1.43–7.92; P = 0.005) were associated with the presence of peritoneal carcinomatosis and/or positive cytology. The ROC curve analysis of the model including the three variables showed an AUC of 0.75 (0.66–0.80, P &amp;lt; 0.001). The decision curve analyses showed that the model had a higher net benefit than the treating all strategy between threshold probabilities of 16 and 50%. Conclusion Staging laparoscopy is a useful tool to address the patient with gastric cancer to the most adequate treatment. In cM- patients the assessment of the location of the tumor, the Lauren’s histotype and the presence of signet ring cells may help in providing additional elements in indicating or not the use of staging laparoscopy.

Evaluation of Human Epidermal Growth Factor Receptor 2 Expression in Gastric and Gastroesophageal Cancers in Tanzania.

The incidence of human epidermal growth factor receptor 2 (HER2) positivity in gastric cancers differs widely across various populations and is unknown in many low-resource settings. To evaluate the rates of HER2 positivity in gastric and gastroesophageal adenocarcinoma at a national referral hospital in East Africa. We also assessed the association between HER2 overexpression and patient clinicopathologic characteristics. A retrospective review of cases diagnosed as either gastric or gastroesophageal adenocarcinoma between 2013 and 2017 was performed at Muhimbili National Hospital in Dar es Salaam, Tanzania. Of 1205 specimens meeting inclusion criteria, stratified random sampling was conducted to select 150 cases for HER2 immunohistochemistry and clinicopathologic analysis. The median age of patients was 56.5 years, with 65.3% (98 of 150) of the cohort composed of male patients, and 34.7% (52 of 150) of female patients. HER2 overexpression was identified in 6.0% (9 of 150) of cases. Approximately half of the tumors (51.3%; 77 of 150) were intestinal-type gastric adenocarcinoma, and 36.0% (54 of 150) were moderately differentiated. Intestinal-type (P = .01) and well-differentiated tumors (P = .001) were associated with HER2 overexpression. HER2 overexpression was primarily seen in intestinal-type and well-differentiated tumors. Therefore, prioritizing HER2 testing for patients with intestinal-type, well-differentiated, or moderately differentiated gastric and gastroesophageal adenocarcinomas may be appropriate in Tanzania in efforts to allocate testing for patients who are most likely to benefit from trastuzumab therapy.

Which gastric cancer patients could benefit from staging laparoscopy? A GIRCG multicenter cohort study

BackgroundThis study aimed to investigate which gastric cancer patients could benefit the most from staging laparoscopy. MethodsA retrospective cohort study was carried out, including 316 (216 cM- and 100 cM+) gastric cancer patients who had undergone staging laparoscopy between 2010 and 2020 in seven GIRCG centers. A model including easily-accessible clinical, biochemical and pathological markers was constructed to predict the risk of carcinomatosis. ROC curve and decision curve analyses were used to verify its accuracy and net benefit. ResultsIn the cM-population staging laparoscopy could detect 67 cases who had peritoneal carcinomatosis or positive cytology, for a yield of 30.5%. In cM-patients, intestinal type tumors (0.25, 0.12–0.51; p = 0.002), cT4 tumors (2.18, 1.11–4.28; p = 0.023) and cancers of the lower third (0.31, 0.14–0.70; p = 0.004) were associated with the presence of peritoneal carcinomatosis and/or positive cytology. The ROC curve analysis of the model including the three variables showed an AUC of 0.75 (0.68–0.81, p < 0.001). The decision curve analyses showed that the model had a higher net benefit than the treating all strategy between threshold probabilities of 15 and 50%. ConclusionsStaging laparoscopy is a useful tool to address the patient with gastric cancer to the most adequate treatment. In cM-patients the assessment of the location of the tumor, the Lauren's histotype and the cT status may help in providing additional elements in indicating or not the use of staging laparoscopy.

P-68 Response to neoadjuvant chemotherapy in gastric adenocarcinoma and gastroesophageal junction adenocarcinoma with FLOT-regimen in our setting

As a result of the FLOT4 trial, the FLOT-regimen has been proven effective in the perioperative treatment of locally advanced and potentially resectable gastric adenocarcinoma and gastroesophageal junction (GEJ) adenocarcinoma. Subsequent analyses revealed higher R0-resection and pathologic complete response (pCR) rates in intestinal-type tumors and GEJ location. This study was a retrospective descriptive analysis of data from patients who have been diagnosed with gastric and GEJ adenocarcinomas in a locally advanced and potentially resectable stage. The patients included were treated between April 2017 and September 2020 at the Hospital Universitario Virgen del Rocío, receiving perioperative chemotherapy with FLOT (docetaxel 50 mg/m2, oxaliplatin 85 mg/m2, 5-fluorouracil 2600 mg/m2, and leucovorin 200 mg/m2). The analysis aimed to evaluate the pathological response of the tumor after neoadjuvant chemotherapy, based on location (gastric and GEJ) and tumor histological subtype (diffuse/mixed type and intestinal type). Among the 34 patients included (73% males), 11 (32.4%) had an intestinal-type tumor, 21 (61.7%) had diffuse/mixed, and 2 (5.9%) had indeterminate type. The median age was 59.5 years, higher in the intestinal group (62 years) than in the diffuse/mixed group (53 years). The location of the tumor was gastric in 25 (73.5%) patients and CEJ in the remaining 9 (26.5%). Only 2 (5.9%) patients were HER2-positive, one with intestinal-type and the other with diffuse/mixed type; and 13 (38.2%) had signet ring cell, all of them with a diffuse/mixed tumor, except one with unknown histology. The complete surgical resection after the neoadjuvant (described as R0-resection) was achieved in 90.9% (n=10) of the intestinal group and in 71.4% (n=15) of the diffuse/mixed, while the R1-resections was achieved in only 14.3% (n=3) of the intestinal group. During the surgery, 6 (17.6%) patients were unresectable because of local progression and invasion of unresectable structures, or because of distant metastases appearance. Among this group, 3 had a diffuse/mixed tumor, 1 had intestinal-type, and 2 had an indeterminate type. The pathologic complete response in surgical specimens, defined as T0N0, was achieved in 5 (14.7%) patients, one of them had a diffuse/mixed tumor and the rest had intestinal type. Regarding the tumor location, 4 had a gastric tumor and 1 had GEJ. After the analysis of the post-neoadjuvant staging (following the 8th edition of the AJCC-TNM classification), the following results were obtained: 18 patients had a lower stage (10 intestinal and 8 diffuse/mixed), 10 had a higher stage (7 diffuse/mixed, 1 intestinal and 2 unknown), and the stage of the other 6 did not change (all of them diffuse/mixed). The results of this study are in accordance with those obtained in the published series, as the pathological response to neoadjuvant with FLOT in tumors with intestinal histology has been better than the response in diffuse/mixed (90.9% R0-resection and 36.3% pRC; 71.4% R0-resection and 4.7% pRC). However, the pRC rates and complete resection rates were lower for GEJ than gastric tumors (44.5% R0-resection and 11.1% pRC; 84% R0-resection and 16% pRC).

Cardia Gastric Cancer Is Associated With Increased PIK3CA Amplifications and HER2 Expression Than Noncardia Gastric Cancer According to Lauren Classification.

BackgroundTo date, few reports have investigated genetic alterations and clinicopathological features in cardia and noncardia gastric cancer (GC).MethodsIn total, 435 GC patients receiving curative surgery were included. The clinicopathological features, recurrence patterns, prognoses and genetic alterations were compared between cardia and noncardia GC patients.ResultsAmong the 435 enrolled patients, 47 (10.8%) had cardia GC. Compared with noncardia GC, cardia GC was associated with more intestinal-type tumors and similar initial recurrence patterns and 5-year overall survival (OS; 50.8% vs. 50.5%, P = 0.480) and disease-free survival (DFS; 48.6% vs. 48.9%, P = 0.392) rates. For both intestinal-type GC and diffuse-type GC, the clinicopathological features and 5-year OS and DFS rates were not significantly different between the cardia and noncardia GC patients. Multivariable analysis showed that cardia GC was not an independent prognostic factor. Compared with noncardia GC, cardia GC was associated with increased PIK3CA amplification than in patients with intestinal-type GC and was associated with increased HER2 expression in patients with diffuse-type GC.ConclusionsCardia GC is not an independent prognostic factor. In cardia GC patients with intestinal-type GC, PIK3CA amplification was more common, and in those with diffuse-type GC, HER2 expression was more common. Targeted therapy may be beneficial for these patient subgroups.

Clinicopathological Prognostic Factors and Chemotherapeutic Outcome for Two Histopathological Types of Ampulla of Vater Adenocarcinoma

BackgroundAdenocarcinoma of the ampulla of Vater (AAV) is standardly treated using a complex operation, a pancreatoduodenectomy (PD), to remove the tumor. However, dicision-making in AAV clinical treatment remains difficult due to the broad range of AAV types, outcomes, and responses to special chemotherapeutics. Thus, this study aimed to explore clinicopathological prognostic factors associated with overall survival, as well as post-chemotherapeutic effects related to curative resection of AAV.MethodsWe retrospectively reviewed data for clinicopathological outcome of 47 patients diagnosed with AAV that had underwent a PD. Overall survival probabilities were obtained using the Kaplan–Meier estimate method and a Cox proportional hazards model.ResultsForty-five patients underwent LPD (laparoscopic pancreatoduodenectomy) and two patients underwent PD. The patient group was composed of 31 males (66%) and 16 females (34%) with a mean age of 65(34–91)years. We selected 45 patients for long-term survival analysis. One- and three-year overall survival rates after resection were 97.6% and 58.9% respectively. The median survival was 37.7 months for the intestinal-type and 26.9 months in pancreatobiliary-type ampullary tumors. Serum carbohydrate antigen (CA) 19-9 greater than 37 U/ml (HR 0.140, P = 0.007), perineural invasion (HR 0.141, P = 0.003), and classification as pancreatobiliary-type (HR 6.633, P = 0.006) were independently associated with poor survival. Serum carcinoembryonic antigen (CEA) greater than 5 µg/ml (P = 0.031), serum CA 19-9 greater than 37 U/ml (P = 0.002), tumor sizes greater than 2.5cm (P=0.002), and positive perineural invasion (P=0.003) were all associated with a poor prognosis in the histopathological subgroup. Serum CA 19-9 greater than 37 U/ml (P=0.002) and positive perineural invasion (P=0.001) were significantly associated with poor survival in of patients with intestinal-type ampullary tumors. Serum CEA greater than 5 µg/ml (P=0.013) and tumor sizes greater than 2.5cm (P=0.002) were significantly associated with poor survival in patients with pancreatobiliary-type ampullary tumors.ConclusionsPancreatobiliary-type ampullary tumors were associated with poor survival. Serum CA 19-9 in the intestinal-type and CEA in the pancreatobiliary-type were significantly associated with poor survival. Ajuvant chemotherapy could not predict the survival of AAV patients.

Role of HER2neu expression in gastric cancer.

Gastric cancer is one of the most common cancers in the world and is responsible for over a million deaths. Gastric cancer broadly consists of two main histological types, diffuse and intestinal, and can be further classified as proximal (cardia) and distal (corpus and pylorus) cancers. The presence of Her2neu in certain cancers including gastric cancers has helped in throwing some light on the prediction of prognosis of the tumours. This study was carried out to assess and evaluate the role of Her2neu immunohistochemical expression in gastric cancers. This study was carried out as a retrospective study on paraffin blocks of 70 gastrectomy specimens in the pathology department of our hospital. After the histological assessment and interpretation of data, appropriate blocks were chosen and sections of 3 micron thickness were cut and immunohistochemical staining of Her2neu was done and scoring was carried out. We found that gastric cancer occurred predominantly in men as compared to women. Antrum was the most common site involved in gastric cancer (60%). In our study Grade 2 predominated (54%) than Grade 1 (4.2%) and Grade 3 (41%). According to the scoring system of Her2neu expression by immunohistochemistry in gastric cancer it was positive (3+) in 8 cases (11.4%), equivocal (2+) in 10 cases (14.3%) and negative (0+,1+) in 52 cases (74.3%). Her2neu was seen positive 13.7% of intestinal type tumours and in only 5.3% of diffuse type of tumours (P < 0.05). Her2neu testing in gastric adenocarcinomas especially in histologically identified early gastric carcinoma is recommended.

External validity of clinical trials with diverse trastuzumab-based chemotherapy regimens in advanced gastroesophageal adenocarcinoma: data from the AGAMENON-SEOM registry.

Background:Trastuzumab combined with cisplatin and fluoropyrimidines, either capecitabine or 5-fluorouracile (XP/FP), is the standard first-line treatment for advanced, HER2-positive, gastric cancer patients based on the ToGA trial. Despite the lack of phase III trials, many clinicians administer trastuzumab with alternative regimens. One meta-analysis suggests that substituting cisplatin for oxaliplatin might lead to greater efficacy and less toxicity.Methods:594 patients with HER2-positive gastroesophageal adenocarcinoma were recruited from the AGAMENON-SEOM registry. The objective was to evaluate the external validity of clinical trials with chemotherapy and trastuzumab.Results:The regimens used in at least 5% of the patients were XP (27%), oxaliplatin and capecitabine (CAPOX) (26%), oxaliplatin and 5-fluorouracil (FOLFOX) (14%), FP (14%), triplet with anthracycline/docetaxel (7%), and carboplatin-FU (5%). Median exposure to trastuzumab was longer with FOLFOX (11.4 months, 95% CI, 9.1–21.0) versus ToGA regimens (7.5, 6.4–8.5), p < 0.001. Patients with HER2-IHC 3+ cancers had higher response rates than those with IHC 2+/FISH+, odds-ratio 1.97 (95% CI, 1.25–3.09). The results achieved with CAPOX–trastuzumab were comparable to those attained with ToGA regimens. FOLFOX–trastuzumab was superior to ToGA schemes in terms of overall survival (OS), with a greater magnitude of effect in IHC 2+/FISH+ tumors (HR 0.47, 0.24–0.92) compared with IHC 3+ (HR 0.69, 0.49–0.96), and in diffuse (HR 0.37, 0.20–0.69) versus intestinal-type tumors (HR 0.76, 0.54–1.06).Conclusion:We have updated the external validity of clinical trials with trastuzumab in first-line treatment of gastric cancer. Our data confirm the comparable outcomes of ToGA regimens and CAPOX–trastuzumab in clinical practice and point toward a possible benefit of FOLFOX–trastuzumab, contingent on the subtypes typically less sensitive to trastuzumab, to be confirmed in clinical trials.