Kay Washington

7th Edition of the AJCC Cancer Staging Manual: Stomach

Despite declining incidence in the United States and many other western countries, gastric cancer continues to be a worldwide health problem, with more than 600,000 cases reported annually, far higher than pancreatic cancer with 125,000 cases. The highest rates occur in Japan, China, Eastern Europe, and South America, with 42% of worldwide cases occurring in China. Development of an evidence-based universally applicable staging system for gastric carcinoma is challenging for a number of reasons. For instance, evidence is accumulating that the anatomic location of the primary tumor in the stomach influences survival, with tumor location in the antrum or distal stomach associated with better prognosis. This influence of tumor location means that any system best suited for TNM staging of distal gastric tumors may not be ideal for staging more proximal tumors, which are more commonly seen in western countries. Thus, any data set used for development or refinement of a gastric cancer staging system should incorporate cases from both Asian and western countries, or should be tested on such a set for validation purposes, if the goal is development of a TNM system applicable worldwide. In addition, two-thirds of gastric cancers occur in developing countries, and to be widely applicable a staging system must be based on data elements easily obtained in the setting in which the tumors most commonly occur. This limitation means that elements based on molecular or immunohistochemical features of the tumor—if such were available—are not practical for the majority of gastric cancers, and staging must continue to rely on the TNM classification for the near future. There is a critical need for the staging system for tumors arising in the gastric cardia or esophagogastric junction to be harmonized with that for tumors of the distal esophagus. Many tumors in this region are bulky at the time of diagnosis, and ascertainment of the anatomic site of origin of the tumor in the esophagus or stomach may be problematic. With the 6th edition of the AJCC Tumor Staging Manual, a tumor predominantly located at the esophagogastric junction could be staged as esophageal or gastric carcinoma, depending on the judgment or bias of the physicians involved, resulting in different stage groupings depending on the designation. Eliminating this potential source of ambiguity was one of the overriding goals of the revision of gastric cancer staging for the AJCC 7th edition. A secondary goal was harmonization of tumor (T) categories across the tubular gastrointestinal tract, from esophagus to colorectum, to simplify the conceptualization of this important staging element. With these goals in mind, the AJCC Foregut Task Force worked with the Esophageal Staging Group of the Thoracic Task Force to examine ways to harmonize the gastric cancer and esophageal cancer staging systems. The revised esophageal cancer staging system is based on a data set of 4,627 treatment naı̈ve surgically resected cases assembled by the Worldwide Esophageal Cancer Collaboration and analyzed using Random Forest Analysis. However, the staging system and stage groupings as optimized for esophageal cancer did not perform sufficiently well for distal gastric cancers. Based on further analysis using data sets from Japan and Korea contributed by Dr. Takeshi Sano from National Cancer Center Hospital in Tokyo and Dr. Han-Kwang Yang from Seoul National University, and with consideration of requests from UICC and the international community, the anatomic stage/prognostic grouping as outlined below was developed. A consensus was reached to use the esophageal cancer staging system for esophagogastric junction cancers, and any cancer arising in the proximal 5 cm of the stomach and crossing the esophagogastric junction. Society of Surgical Oncology 2010

Targeted disruption of the Kvlqt1 gene causes deafness and gastric hyperplasia in mice.

The KvLQT1 gene encodes a voltage-gated potassium channel. Mutations in KvLQT1 underlie the dominantly transmitted Ward-Romano long QT syndrome, which causes cardiac arrhythmia, and the recessively transmitted Jervell and Lange-Nielsen syndrome, which causes both cardiac arrhythmia and congenital deafness. KvLQT1 is also disrupted by balanced germline chromosomal rearrangements in patients with Beckwith-Wiedemann syndrome (BWS), which causes prenatal overgrowth and cancer. Because of the diverse human disorders and organ systems affected by this gene, we developed an animal model by inactivating the murine Kvlqt1. No electrocardiographic abnormalities were observed. However, homozygous mice exhibited complete deafness, as well as circular movement and repetitive falling, suggesting imbalance. Histochemical study revealed severe anatomic disruption of the cochlear and vestibular end organs, suggesting that Kvlqt1 is essential for normal development of the inner ear. Surprisingly, homozygous mice also displayed threefold enlargement by weight of the stomach resulting from mucous neck cell hyperplasia. Finally, there were no features of BWS, suggesting that Kvlqt1 is not responsible for BWS.

Gastrointestinal pathology in patients with common variable immunodeficiency and X-linked agammaglobulinemia

Review of the medical records of 43 patients with common variable immunodeficiency (CVID) and 23 patients with X-linked agammaglobulinemia (XLAG) revealed a high incidence of chronic gastrointestinal complaints, most commonly diarrhea. Thirty-eight biopsies, four small-bowel resection specimens, and one autopsy from 10 patients with CVID and one patient with XLAG showed a wide range of abnormalities. A pattern resembling acute graft-versus-host disease, with apoptotic bodies and lymphocytes in crypts, was seen in the stomach (four patients), small bowel (three patients), and colon (three patients). Small-bowel specimens from three CVID patients with malabsorption showed mild to severe villous atrophy. Three CVID patients had Giardia in biopsies. Two cases of small bowel lymphoma associated with nodular lymphoid hyperplasia were identified in CVID patients. One patients small bowel contained foamy histiocytes in the lamina propria, resembling Whipples disease or chronic granulomatous disease, with numerous apoptotic bodies in crypts. Ultrastructurally, the histiocytes contained cellular debris. The patient with XLAG had recurrent fissuring necrosis of small bowel resembling Crohns disease; a patient with CVID had colitis with features similar to ulcerative colitis. Poorly formed granulomas were seen in the stomach (one CVID patient) and the colon (two CVID patients). Lymphocyte populations were dominated by T cells; B cells were scarce except in lymphoid follicles in CVID patients with nodular lymphoid hyperplasia. Patients with CVID and XLAG manifest a spectrum of abnormalities in the gastrointestinal tract, with patterns superficially resembling graft-versus-host disease, inflammatory bowel disease, and Whipples disease, but often lacking some of the diagnostic features of the diseases. Many of the CVID patients with chronic gastrointestinal complaints (62%) also had evidence of autoimmune phenomena, suggesting that in some patients the inflammatory process in the gastrointestinal tract has an autoimmune component.

Assessment of hepatic steatosis by expert pathologists: the end of a gold standard

Background:The presence of fat in the liver is considered a major risk for postoperative complication after liver surgery and transplantation. The current standard of quantification of hepatic steatosis is microscopic evaluation by pathologists, although consistency in such assessment remains unclear. Computerized image analysis is an alternative method for objective assessment of the degree of hepatic steatosis. Methods:High resolution images of hematoxylin and eosin stained liver sections from 46 consecutive patients, initially diagnosed with liver steatosis, were blindly assessed by 4 established expert pathologists from different institutions. Computerized analysis was carried out simultaneously on the same sections. Interobserver agreement and correlation between the pathologists’ and computerized assessment were evaluated using intraclass correlation coefficients (ICC), Spearman rank correlation coefficients, or descriptive statistics. Results:Poor agreement among pathologists (ICC: 0.57) was found regarding the assessment of total steatosis, (ICC >0.7 indicates acceptable agreement). Pathologists’ estimation of micro- and macrosteatosis disclosed also poor correlation (ICC: 0.22, 0.55, respectively). Inconsistent assessment of histological features of steatohepatitis (lobular inflammation, portal inflammation, hepatocyte ballooning, and Mallory hyaline) was documented. Poor conformity was also shown between the computerized quantification and ratings of 3 pathologists (Spearman rank correlation coefficients: 0.22, 0.82, 0.28, and 0.38). Conclusion:Quantification of hepatic steatosis in histological sections is strongly observer-dependent, not reproducible, and does not correlate with the computerized estimation. Current standards of assessment, previously published data and the clinical relevance of hepatic steatosis for liver surgery and transplantation must be challenged.

A multicenter, double-blinded validation study of methylation biomarkers for progression prediction in Barrett’s esophagus

Esophageal adenocarcinoma risk in Barretts esophagus (BE) is increased 30- to 125-fold versus the general population. Among all BE patients, however, neoplastic progression occurs only once per 200 patient-years. Molecular biomarkers are therefore needed to risk-stratify patients for more efficient surveillance endoscopy and to improve the early detection of progression. We therefore performed a retrospective, multicenter, double-blinded validation study of eight BE progression prediction methylation biomarkers. Progression or nonprogression were determined at 2 years (tier 1) and 4 years (tier 2). Methylation was assayed in 145 nonprogressors and 50 progressors using real-time quantitative methylation-specific PCR. Progressors were significantly older than nonprogressors (70.6 versus 62.5 years; P < 0.001). We evaluated a linear combination of the eight markers, using coefficients from a multivariate logistic regression analysis. Areas under the ROC curve (AUC) were high in the 2-year, 4-year, and combined data models (0.843, 0.829, and 0.840; P < 0.001, <0.001, and <0.001, respectively). In addition, even after rigorous overfitting correction, the incremental AUCs contributed by panels based on the 8 markers plus age versus age alone were substantial (Delta-AUC = 0.152, 0.114, and 0.118, respectively) in all 3 models. A methylation biomarker-based panel to predict neoplastic progression in BE has potential clinical value in improving both the efficiency of surveillance endoscopy and the early detection of neoplasia.

Transforming Growth Factor β Receptor Type II Inactivation Promotes the Establishment and Progression of Colon Cancer

Deregulation of members of the transforming growth factor (TGF)-β signaling pathway occurs often in colon cancers and is believed to affect the formation of primary colon cancer. Mutational inactivation of TGFBR2 is the most common genetic event affecting the TGF-β signaling pathway and occurs in ∼20–30% of all colon cancers. By mating Fabpl4xat-132 Cre mice with Tgfbr2flx/flx mice, we have generated a mouse model that is null for Tgfbr2 in the colonic epithelium, and in this model system, we have assessed the effect of loss of TGF-β signaling in vivo on colon cancer formation induced by azoxymethane (AOM). We have observed a significant increase in the number of AOM-induced adenomas and adenocarcinomas in the Fabpl4xat-132 Cre Tgfbr2flx/flx mice compared with Tgfbr2flx/flx mice, which have intact TGF-β receptor type II (TGFBR2) in the colon epithelium, and we have found increased proliferation in the neoplasms occurring in the Fabpl4xat-132 Cre Tgfbr2flx/flx mice. These results implicate the loss of TGF-β-mediated growth inhibition as one of the in vivo mechanisms through which TGFBR2 inactivation contributes to colon cancer formation. Thus, we have demonstrated that loss of TGFBR2 in colon epithelial cells promotes the establishment and progression of AOM-induced colon neoplasms, providing evidence from an in vivo model system that TGFBR2 is a tumor suppressor gene in the colon.

Pathology of graft-versus-host disease in the gastrointestinal tract

Graft-versus-host disease (GVHD), a common complication of hematopoietic stem cell transplantation, is a clinical syndrome that requires synthesis of clinical, laboratory, and histopathologic findings for diagnosis. The gastrointestinal (GI) tract is commonly affected, and pathologists must recognize subtle morphologic alterations in GI mucosal biopsies to make the diagnosis and to rule out other causes of GI dysfunction such as cytomegalovirus infection and drug effects. This review summarizes the histopathologic features of GVHD in the GI tract and outlines recent recommendations for reporting of GI biopsies with suspected GVHD.

DNA hypermethylation regulates the expression of members of the Mu-class glutathione S-transferases and glutathione peroxidases in Barrett's adenocarcinoma.

Background: The accumulation of reactive oxygen species and subsequent oxidative DNA damage underlie the development of Barrett’s oesophagus (BO) and its progression to Barrett’s dysplasia (BD) and adenocarcinoma (BAC). Methods: The promoter regions of 23 genes of the glutathione S-transferase (GST) and glutathione peroxidase (GPX) families were systematically analysed. Quantitative bisulfite pyrosequencing, real-time RT-PCR, western blot and immunohistochemical (IHC) analysis methods were utilised in this study. Results: 14 genes were identified that have CpG islands around their transcription start sites: GSTs (GSTM2–M5, GSTA4, GSTP1, GSTZ1, GSTT2, GSTO1 and GSTO2) and GPXs (GPX1, GPX3, GPX4 and GPX7). Analysis of an initial set of 20 primary samples demonstrated promoter DNA hypermethylation and mRNA downregulation of GPX3, GPX7, GSTM2, GSTM3 and GSTM5 in more than half of the BAC samples. Further analysis of 159 primary human samples (37 normal, 11 BO, 11 BD and 100 BACs) indicated frequent hypermethylation (⩾10% methylation) of GPX3 (62%), GPX7 (67%), GSTM2 (69.1%) and GSTM3 (15%) in BACs. A significant inverse correlation between DNA methylation and mRNA expression level was shown for GPX3 (p<0.001), GPX7 (p = 0.002), GSTM2 (p<0.001) and GSTM5 (p = 0.01). Treatment of oesophageal cancer cell lines with 5-aza-2′-deoxycytidine and trichostatin-A led to reversal of the methylation pattern and re-expression of these genes at the mRNA and protein levels. The IHC analysis of GPX3, GPX7 and GSTM2 on a tissue microarray that contained 75 BACs with normal squamous oesophageal samples demonstrated an absent to weak staining in tumours (52% for GPX3, 57% for GPX7 and 45% for GSTM2) and a moderate to strong immunostaining in normal samples. Conclusion: Epigenetic inactivation of members of the glutathione pathway can be an important mechanism in Barrett’s tumourigenesis.

Histopathology of Ulcerative Colitis in Initial Rectal Biopsy in Children

Definitive histologic diagnosis of ulcerative colitis relies upon mucosal architectural distortion and inflammation in the appropriate clinical setting. Although crypt branching, atrophy, and loss are usually present in first biopsies from adults with ulcerative colitis, it has been our impression that features of chronicity are often lacking in first biopsies from children. To test this hypothesis, initial rectal biopsies and follow-up biopsies and/or colonic resections from 53 children (age 15 months to 17 years) and 38 adults (age 21–76 years) with ulcerative colitis were examined in a blinded fashion for villiform surface, crypt atrophy, branching crypts, lamina propria inflammation, crypt abscesses, cryptitis, and basal plasma cells. Mucosal architecture was classified as normal, focally abnormal, or diffusely abnormal. Medical records were reviewed for confirmatory evidence of ulcerative colitis and for duration of symptoms before biopsy. In 87 of 91 biopsies, the lamina propria contained a mixed inflammatory infiltrate. Crypt abscesses and cryptitis were common in both groups. Initial biopsies from children were less likely to show diffuse architectural abnormalities (17 of 53, 32.1%) compared with biopsies from adults (22 of 38, 57.9% p <0.05). Duration of symptoms before diagnosis was significantly shorter in children (mean 17.5 weeks) compared with adults (mean 54.9 weeks). In summary, initial rectal biopsies from children with ulcerative colitis are less likely to show diagnostic mucosal architectural distortion than biopsies from adults. This difference may be related to a shorter duration of symptoms before biopsy.

Effective treatment of biliary cystadenoma.

Objective:Evaluate experience over 15 years with treatment of this lesion. Summary Background Data:Biliary cystadenoma, a benign hepatic tumor arising from Von Meyenberg complexes, usually present as septated intrahepatic cystic lesions. Methods:Data were collected concurrently and retrospectively on patients identified from hospital medical records reviewed for pertinent International Classification of Diseases, Ninth Revision, Clinical Modification and CPT codes, pathology logs, and from operative case logs. Pathology specimens were rereviewed to confirm the diagnosis of biliary cystadenoma or biliary cystadenocarcinoma by 2 GI pathologists. Results:From October 1989 to April 2004 at our institution, 19 (18F:1M) patients had pathologically confirmed biliary cystadenomas, including one with a biliary cystadenocarcinoma. The mean age was 48 ± 15 years at initial evaluation. Complaints included abdominal pain in 74%, abdominal distension in 26%, and nausea/vomiting in 11%. Only 1 patient presented with an incidental finding. Symptoms had been present for 3 ± 5 years, with 1 to 4 different surgeons and many other physicians involved in the diagnosis or treatment prior to definitive ablation. Eight patients had undergone 20 previous treatments, including multiple percutaneous aspirations in 4 and 11 operative procedures. CT or US was diagnostic in 95%, with internal septations present in the hepatic cysts. Definitive operative intervention consisted of hepatic resection in 12 patients, enucleation in 6 patients, and fenestration and complete fulguration in 1 patient. There were no perioperative deaths. No recurrences were observed after definitive therapy, with follow-up of 4 ± 4 years. Conclusions:Biliary cystadenoma must be recognized and treated differently than most hepatic cysts. There remains a need for education about the imaging findings for biliary cystadenoma to reduce the demonstrated delay in appropriate treatment. Traditional treatment of simple cysts such as aspiration, drainage, and marsupialization results in near universal recurrence and occasional malignant degeneration. This experience demonstrates effective options include total ablation by standard hepatic resection and cyst enucleation.