Identification of a lower grade muconodular subtype of gastric mucinous cancer

Prognostic factors in clinicopathology of oesophagogastric adenocarcinoma: a single-centre longitudinal study of 347 cases over a 20-year period

Oesophagogastric adenocarcinoma (EGA) includes oesophageal (EA), gastro-oesophageal junctional (GEJA), and gastric (GA) adenocarcinomas. The prognostic values of clinicopathological factors in these tumours remain obscure, especially for GEJA that has been inconsistently classified and staged. We studied the prognosis of EGA patients among the three geographic groups in 347 consecutive patients with a median age of 70 years (range 47-94). All patients were male, and 97.1% were white. Based on tumour epicentre location, EGAs were sub-grouped into EA (over 2 cm above the GEJ; n=3, 18.1%), GEJA (within 2 cm above and 3 cm below the GEJ; n=231, 66.6%), and GA (over 3 cm below the GEJ; n=53, 15.3%). We found that the median overall survival (OS) was the longest in EA (62.9 months), compared to GEJA (33.4), and GA (38.1) (p<0.001). Significant risk factors for OS included tumour location (p=0.018), size (p<0.001), differentiation (p<0.001), adenocarcinoma subtype (p<0.001), and TNM stage (p<0.001). Independent risk factors for OS comprised low-grade papillary adenocarcinoma [odds ratio (OR) 0.449, 95% confidence interval (CI) 0.214-0.944, p<0.05), mixed adenocarcinoma (OR 1.531, 95% CI 1.056-2.218, p<0.05), adenosquamous carcinoma (OR 2.206, 95% CI 1.087-4.475, p<0.05), N stage (OR 1.505, 95% CI 1.043-2.171, p<0.05), and M stage (OR 10.036, 95% CI 2.519-39.993, p=0.001)]. EGA was further divided into low-risk (common well-moderately differentiated tubular and low-grade papillary adenocarcinomas) and high-risk (uncommon adenocarcinoma subtypes, adenosquamous carcinoma) subgroups. In this grouping, the median OS was significantly longer in the low-risk (83 months) than in the high-risk (10 months) subgroups (p<0.001). In conclusion, the prognosis of EGA patients was significantly better in EA than in GEJA or GA and could be stratified into low and high-risk subgroups with significantly different outcomes.

The Prognostic Impact of Histology in Esophageal and Esophago-Gastric Junction Adenocarcinoma

Stage significantly affects survival of esophageal and esophago-gastric junction adenocarcinomas (EA/EGJAs), however, limited evidence for the prognostic role of histologic subtypes is available. The aim of the study was to describe a morphologic approach to EA/EGJAs and assess its discriminating prognostic power. Histologic slides from 299 neoadjuvant treatment-naïve EA/EGJAs, resected in five European Centers, were retrospectively reviewed. Morphologic features were re-assessed and correlated with survival. In glandular adenocarcinomas (240/299 cases-80%), WHO grade and tumors with a poorly differentiated component ≥6% were the most discriminant factors for survival (both p < 0.0001), distinguishing glandular well-differentiated from poorly differentiated adenocarcinomas. Two prognostically different histologic groups were identified: the lower risk group, comprising glandular well-differentiated (34.4%) and rare variants, such as mucinous muconodular carcinoma (2.7%) and diffuse desmoplastic carcinoma (1.7%), versus the higher risk group, comprising the glandular poorly differentiated subtype (45.8%), including invasive mucinous carcinoma (5.7%), diffuse anaplastic carcinoma (3%), mixed carcinoma (6.7%) (CSS p < 0.0001, DFS p = 0.001). Stage (p < 0.0001), histologic groups (p = 0.001), age >72 years (p = 0.008), and vascular invasion (p = 0.015) were prognostically significant in the multivariate analysis. The combined evaluation of stage/histologic group identified 5-year cancer-specific survival ranging from 87.6% (stage II, lower risk) to 14% (stage IVA, higher risk). Detailed characterization of histologic subtypes contributes to EA/EGJA prognostic prediction.

Mucinous adenocarcinoma and non-mucinous adenocarcinoma: differing clinicopathological characteristics and computed tomography features in gastric cancer

Mucinous gastric carcinoma (MGC) is a rare histological subtype of gastric cancer. The clinicopathological characteristics and CT features of MGC remain controversial. This study aimed to determine the clinicopathological characteristics and CT features of MGC. We reviewed 62 patients with MGC and 104 patients with non-mucinous gastric carcinoma (NMGC), pathologically confirmed between 2003 and 2015. There are significant differences in some clinicopathological characteristics and CT features between MGC and NMGC. NMGC occurs preferentially in males and more frequently in the lower third of the stomach. Patients with MGC were characterized by larger tumor size, more advanced tumor stages (II and III) and fewer lymphatic invasions. Layered enhancement (83.3%) was the main pattern of MGC, while the most common pattern in NMGC was homogeneous enhancement (52.6%), followed by heterogonous enhancement (34.6%). The degree of enhancement of the inner layer in MGC was significantly higher than in NMGC (ΔCT of portal venous phase: 54.57 Hu vs. 47.19 Hu, P = 0.034), while the middle or outer layer in MGC was significantly less enhanced (ΔCT of portal venous phase: 19.07 Hu vs. 33.09 Hu, P <0.001). Calcifications were more common in MGC (P <0.001). ROC curves revealed that the most effective variables in distinguishing MGC and NMGC were ΔCT of the middle or outer layer in the arterial phase (AUC=0.774) and portal venous phase (AUC=0.774), followed by the attenuation value of the middle or outer layer in the unenhanced phase (AUC=0.763). Calcifications had a high specificity (98.7%) in the diagnosis of MGC. The accuracy (86.1%), sensitivity (83.3%) and specificity (87.2%) of layered enhancement in diagnosing MGC were all high. Therefore, MGC was more likely to have larger tumor size and more advanced tumor stage (II and III) than NMGC. The thicker gastric wall, layered enhancement pattern and calcification were highly suggestive CT features for differentiating MGC from NMGC.

Impact of molecular alterations of BRAF in the pathogenesis of thyroid cancer

BRAF alterations represent a novel indicator of the progression and aggressiveness of thyroid carcinogenesis. So, the main aim of the study was to elucidate the involvement of BRAF gene mutations and its expression in Kashmiri (North India) patients and investigate their association with clinico-pathological characteristics. Mutational analysis of BRAF gene was performed by polymerase chain reaction followed by DNA sequencing, whereas analysis of BRAF protein expression was done by western blotting. Overall mutations in BRAF was found to be 25% (15 of 60) and all of them were transversions (T>A) affecting codon 600 (valine to glutamine), restricted only to papillary thyroid cancer and well-differentiated grade. Patients with well-differentiated disease and in particular elevated thyroid-stimulating hormone levels were significantly associated with BRAF mutations (P < 0.05). Overall, 90% (54 of 60) of thyroid cancer cases showed increased expression of BRAF and non-smokers being significantly associated with BRAF over-expression. Totally, 86.7% (13 of 15) of BRAF mutation-positive patients were having over-expression of BRAF protein, whereas 91.2% (41 of 45) of patients with wild-type BRAF status were having over-expressed BRAF protein (P > 0.05). We conclude that both mutational events as well as over-expression of BRAF gene is highly implicated in pathogenesis of thyroid cancer and the BRAF protein over-expression is independent of the BRAF mutational status of thyroid cancer patients.

The contribution of cell phenotype to the behavior of gastric cancer

BACKGROUND

Several histochemical studies suggest a role of tumor cell phenotype and related differentiation markers in the prognostic assessment of gastric cancer. Unfortunately, most studies have dealt with single or a few markers and have paid limited attention to their interplay with tumor histological types, which are potentially informative of prognosis.

METHODS

In this study, 292 invasive (T1b to T4) gastric cancers with prolonged follow-up and carefully analyzed histotype, inclusive of histotype-based grade, were investigated histochemically with a panel of 14 phenotypic markers known to be expressed in normal gut tissues and gastric cancer.

RESULTS

Three of seven intestinal type markers investigated showed a trend for improved prognosis, one of which, CDX2, was stage independent. Three among gastric and pancreatobiliary duct markers (MUC1, MUC6, and pepsinogen II), predicted more severe prognosis stage independently, as did a combination of eight potentially informative (p < 0.1 at univariable Cox analysis) markers. Cancers with predominantly intestinal phenotype had significantly better prognosis than those with predominantly gastric, mixed, or poorly defined phenotypes; among the latter, those with high lymphocyte response, with favorable outcome, were separated from anaplastic cancers, with ominous prognosis. At multivariable analysis, CDX2 and the eight marker combination proved to be stage- and grade-independent predictors.

CONCLUSIONS

When individually considered, and with the exception of CDX2, the biomarkers investigated gave an appreciable, although moderate, contribution to the prognostic evaluation of gastric cancer. Combined analysis of all potentially informative markers gave more important information, highly additive to both stage and histotype-based grade.

Mucinous carcinomas of the gallbladder: clinicopathologic analysis of 15 cases identified in 606 carcinomas

CONTEXT

There are virtually no data in the literature regarding the incidence, patterns, and clinicopathologic characteristics of mucinous carcinomas (MCs) of the gallbladder (GB).

OBJECTIVE

To determine the incidence of mucinous differentiation in invasive GB carcinomas and the clinicopathologic characteristics of those that qualify as MC.

DESIGN

Primary invasive GB carcinomas (n  =  606) were reviewed for mucinous differentiation. Some degree of mucin production was identified in 40 cases (6.6%); however, only 15 (2.5%) were qualified for the World Health Organization definition of MC (stromal mucin deposition constituting >50% of the tumor).

RESULTS

The mean age was 65 years, and the female to male ratio was 1.1 (versus 3.9 for conventional pancreatobiliary-type GB adenocarcinomas; P  =  .04). A significant proportion of the cases (8 of 12, 67%) presented with the clinical picture and intraoperative findings that were interpreted as acute cholecystitis. Mean and median tumor sizes were larger than those of conventional adenocarcinomas (4.8 and 3.4 cm versus 2.9 and 2.5 cm, respectively; P  =  .01). Most (13 of 15, 87%) cases presented with pT3 tumors (versus 48% for ordinary GB carcinomas; P  =  .01). Two cases had almost an exclusive colloid pattern (>90% composed of well-defined stromal mucin nodules that contained scanty carcinoma cells, most of which were floating within the mucin). Eight cases were of mixed-mucinous type, showing a mixture of colloid and noncolloid patterns. Five others had prominent signet-ring cells, both floating within the mucin (which constituted >50% of the tumor by definition) and infiltrating into the stroma as individual signet-ring cells in some areas. Immunohistochemical analysis performed on the 7 cases that had available tissue revealed CK7 in 4 of 7 (57%), CK20 in 2 of 7 (29%), MUC1 in 4 of 7 (57%), MUC2 in 6 of 7 (86%), CDX2 in 1 of 7 (14%), MUC5AC in 6 of 7 (86%), MUC6 in 0 of 7 (0%), and loss of E-cadherin in 6 of 7 (86%). The MLH1 and MSH2 were retained in 6 of 7 cases (100%). Follow-up information was available for 13 cases: 11 (85%) died of disease (1-37 months) and 2 (15%) were alive (23 months and 1 month). Overall survival of MCs was significantly worse than that of conventional adenocarcinomas (13 versus 26 months; P  =  .01); however, that did not seem to be independent of stage.

CONCLUSIONS

Mucinous carcinomas constitute 2.5% of GB carcinomas. They present with an acute cholecystitis-type picture. Most MCs are a mixed-mucinous, not pure colloid, type. They are typically large and advanced tumors at the time of diagnosis and thus exhibit more-aggressive behavior than do ordinary GB carcinomas. Immunophenotypically, they differ from conventional GB adenocarcinomas by MUC2 positivity, from intestinal carcinomas by an often inverse CK7/20 profile, from pancreatic mucinous carcinomas by CDX2 negativity, and from mammary colloid carcinomas by a lack of MUC6. Unlike gastrointestinal MCs, they appear to be microsatellite stable.

Histotype-based prognostic classification of gastric cancer

AIM: To test the efficiency of a recently proposed histotype-based grading system in a consecutive series of gastric cancers.

METHODS: Two hundred advanced gastric cancers operated upon in 1980-1987 and followed for a median 159 mo were investigated on hematoxylin-eosin-stained sections to identify low-grade [muconodular, well differentiated tubular, diffuse desmoplastic and high lymphoid response (HLR)], high-grade (anaplastic and mucinous invasive) and intermediate-grade (ordinary cohesive, diffuse and mucinous) cancers, in parallel with a previously investigated series of 292 cases. In addition, immunohistochemical analyses for CD8, CD11 and HLA-DR antigens, pancytokeratin and podoplanin, as well as immunohistochemical and molecular tests for microsatellite DNA instability and in situ hybridization for the Epstein-Barr virus (EBV) EBER1 gene were performed. Patient survival was assessed with death rates per 100 person-years and with Kaplan-Meier or Cox model estimates.

RESULTS: Collectively, the four low-grade histotypes accounted for 22% and the two high-grade histotypes for 7% of the consecutive cancers investigated, while the remaining 71% of cases were intermediate-grade cancers, with highly significant, stage-independent, survival differences among the three tumor grades (P = 0.004 for grade 1 vs 2 and P = 0.0019 for grade 2 vs grade 3), thus confirming the results in the original series. A combined analysis of 492 cases showed an improved prognostic value of histotype-based grading compared with the Lauren classification. In addition, it allowed better characterization of rare histotypes, particularly the three subsets of prognostically different mucinous neoplasms, of which 10 ordinary mucinous cancers showed stage-inclusive survival worse than that of 20 muconodular (P = 0.037) and better than that of 21 high-grade (P < 0.001) cases. Tumors with high-level microsatellite DNA instability (MSI-H) or EBV infection, together with a third subset negative for both conditions, formed the T8 cell-rich HLR group, the largest group among low-grade histotypes. Coexisting HLR proved to be a factor in improved prognosis in tumors with microsatellite instability (P = 0.0015 vs HLR-/MSI-H tumors) or DR type human leukocyte antigen expression (P = 0.033 vs HLR^-/HLA-DR⁺ tumors).

CONCLUSION: Identification of low- and high-grade histotypes can improve the prognostic assessment of a substantial proportion of gastric cancers in routine diagnostic practice.

Correlation between genomic alterations assessed by array comparative genomic hybridization, prognostically informative histologic subtype, stage, and patient survival in gastric cancer

It is difficult to evaluate the prognostic value of histologic criteria in gastric cancer because of the high variability of morphologic patterns. Recently, histologic subtypes of low, intermediate, or high malignant potential have been identified, providing the basis for a prognostically informative grading system. Because array comparative genomic hybridization systems allow systematic analysis of chromosome alterations, which may be prognostically and pathogenetically informative, we applied high-resolution genome-wide array comparative genomic hybridization to archival material from 81 gastric cancer cases followed for a median of 150 months after surgery. The DNA extracted from paraffin sections gave useful results in 49 tumors, 18 of which were of low-grade, 24 of intermediate, and 7 of high-grade histotypes. Based on the number of chromosome aberrations and the presence/absence of amplifications, 3 tumor clusters of increasing genomic lesion severity were constructed, which proved to correlate significantly with histologic grade and stage as well as with patient survival. Further investigation documented the lower number and severity of genomic alterations in tumors with microsatellite DNA instability and high CD8-rich lymphoid response; the close association of 8p23.1 amplification with cardial cancer; the frequent amplification of genes involved in cell renewal (CDC6, HER2, GRB7, IGFBP4) at 17q12-q21.1, with close histochemical correlation with HER2 membranous expression; and more sporadic amplification of chromosome regions harboring important oncogenes like MYC, KRAS, NRAS, CRKL, CCNE1, or ZNF217. We conclude that genome-wide array comparative genomic hybridization of gastric cancer contributes prognostically relevant information providing a genetic background for histologic grading.

A combined histologic and molecular approach identifies three groups of gastric cancer with different prognosis

The limited prognostic value of currently used histologic classifications of gastric cancer and their failure to account for the complexity of the disease as revealed by more recent investigations prompted a combined reinvestigation of histologic, molecular, and clinicopathologic patterns in 294 extensively sampled, invasive gastric cancers representing all main histotypes and stages of the disease and followed for a median of 150 months. Among histologic parameters tested, only cellular atypia, angio-lympho- or neuroinvasion, Ki67 proliferation index, expansile/infiltrative type growth, and T8 cell-rich high lymphoid intra-/peritumor response (HLR) proved to be stage-independent predictors of patient survival. Among molecular tests, p53 gene exon 7 (loop 3) and 8 (loop-sheet-helix motif and S-10 band), but not p53 protein overexpression, TP53 LOH or 18qLOH, were found to worsen prognosis. Microsatellite DNA instability was a favorable prognostic factor when coupled with HLR. Patient survival analysis of the main histotypes and their subtypes confirmed the favorable prognosis of HLR, well-differentiated tubular, muconodular, and low grade diffuse desmoplastic cancers, and highlighted the worse prognosis of anaplastic and infiltrative-lymphoinvasive mucinous cancers compared to ordinary cohesive and diffuse cancers. Distinct roles of individual morphologic and molecular factors in tumor progression of the different histotypes have been recognized. The combination of survival-predictive histotypes and individual histologic or molecular parameters allowed us to develop a classification of all gastric cancers into three grades of increasing malignancy which proved to be of high prognostic value.

Lower- and higher-grade subtypes of diffuse gastric cancer

Diffuse gastric cancer, characterized by poorly cohesive, diffusely infiltrating cells with no or little gland formation, is known to show several morphologic variants, but their prognostic value, if any, is poorly documented. In this article, 119 cases of invasive (T1b to T4) diffuse gastric cancer, which had undergone potentially curative surgery and were followed postoperatively for a median time of more than 10 years, were investigated for histologic or histochemical patterns possibly predictive of survival. Among 5 histologic groups identified, a low-grade subtype (17 cases) with prominent desmoplasia closely surrounding individual tumor cells (tumor embedding desmoplasia) and no or scarce angio-lympho-neuroinvasion showed stage-independent improved survival compared with 36 non-low-grade desmoplastic, 24 signet ring, and 28 diffuse cancers not otherwise specified. Fourteen cases with anaplastic cells showed clinicopathologic patterns and outcome of highly malignant neoplasms. None of the tumor cell differentiation markers (including 6 mucins and 3 proteases) nor proliferative index or p53 protein expression had independent predictive power, although MUC1 was significantly less expressed in low-grade desmoplastic cases. Cox survival analysis showed the significantly better prognosis of 17 low-grade desmoplastic and worse prognosis of 14 anaplastic cancers compared with the remaining 88 cases. In conclusion, a low-grade desmoplastic and a high-grade anaplastic subtype should be separated histologically from the bulk of diffuse gastric cancers owing to their distinctive histologic, clinicopathologic, and prognostic aspects.

How molecular pathology is changing and will change the therapeutics of patients with follicular cell-derived thyroid cancer: Table 1

Well-differentiated thyroid carcinomas comprise two well-defined histological types: papillary and follicular (PTCs and FTCs, respectively). Despite being derived from the same cell (thyroid follicular cell), these two types of tumour accumulate distinct genetic abnormalities during progression. The molecular pathology of thyroid cancer is now better understood because of our ability to identify RET/PTC rearrangements and BRAF mutations in the aetiopathogenesis of the large majority of PTCs and the high prevalence of RAS mutations and PAX8/PPARγ rearrangements in follicular patterned carcinomas (FTCs and follicular variant of PTCs). This review summarises most of the molecular alterations currently used as targets for new biological treatments and looks at some of the changes that are already occurring or may occur in the treatment of patients with thyroid cancer. For simplicity, the review is divided up according to the major genetic alterations identified in well-differentiated thyroid carcinomas (RET/PTC rearrangements, BRAF mutations, RAS mutations and mitochondrial DNA deletions and mutations) and their respective treatments.

Intracellular, intercellular, and stromal invasion of gastric mucosa, preneoplastic lesions, and cancer by Helicobacter pylori

BACKGROUND AND AIMS

It is not clear how Helicobacter pylori, an apparently extracellular pathogen colonizing the luminal side of the gastric epithelium, invariably causes an immune-inflammatory response on the stromal side of the mucosa. Penetration of H pylori into epithelial cell lines and its interaction with immune-inflammatory cells have been documented in vitro. Several investigations also showed in vivo bacterial penetration into the epithelium up to the lamina propria; however, the identification as H pylori of the bacteria-like bodies observed in unchanged, metaplastic, or neoplastic mucosa remained sometimes questionable.

METHODS

To search for bacteria-like organisms, we used transmission electron microscopy on endoscopic biopsy specimens from 20 dyspeptic subjects and surgical specimens of neoplastic and nonneoplastic mucosa from 20 cancerous stomachs. To ascertain the H pylori nature of the organisms found, we used 6 different antibodies directed against bacterial lysates, purified vacuolating cytotoxin A, or purified cytotoxin-associated antigen A in immunogold tests. The results were compared with those of H pylori strains cultivated in vitro.

RESULTS

In nonmetaplastic gastric epithelium, cytochemically proven H pylori were detected, in the majority of cases, inside cytoplasm of epithelial cells, in intraepithelial intercellular spaces, and in underlying lamina propria, often in direct contact with immune-inflammatory cells and sometimes inside small blood vessels. Cytochemically proven H pylori were also observed inside 6 of 8 intestinal metaplasias and 9 of 20 cancers.

CONCLUSIONS

H pylori penetrates normal, metaplastic, and neoplastic gastric epithelium in vivo, intracellularly, or interstitially to cause a strong immune-inflammatory response and promote gastric carcinogenesis.