Dataset for Pathology Reporting of Colorectal Cancer: Recommendations From the International Collaboration on Cancer Reporting (ICCR).

OBJECTIVE: The aim of this study to describe a new international dataset for pathology reporting of colorectal cancer surgical specimens, produced under the auspices of the International Collaboration on Cancer Reporting (ICCR). BACKGROUND: Quality of pathology reporting and mutual understanding between colorectal surgeon, pathologist and oncologist are vital to patient management. Some pathology parameters are prone to variable interpretation, resulting in differing positions adopted by existing national datasets. METHODS: The ICCR, a global alliance of major pathology institutions with links to international cancer organizations, has developed and ratified a rigorous and efficient process for the development of evidence-based, structured datasets for pathology reporting of common cancers. Here we describe the production of a dataset for colorectal cancer resection specimens by a multidisciplinary panel of internationally recognized experts. RESULTS: The agreed dataset comprises eighteen core (essential) and seven non-core (recommended) elements identified from a review of current evidence. Areas of contention are addressed, some highly relevant to surgical practice, with the aim of standardizing multidisciplinary discussion. The summation of all core elements is considered to be the minimum reporting standard for individual cases. Commentary is provided, explaining each element's clinical relevance, definitions to be applied where appropriate for the agreed list of value options and the rationale for considering the element as core or non-core. CONCLUSIONS: This first internationally agreed dataset for colorectal cancer pathology reporting promotes standardization of pathology reporting and enhanced clinicopathological communication. Widespread adoption will facilitate international comparisons, multinational clinical trials and help to improve the management of colorectal cancer globally.

Diagnostic challenges of focal nodular hyperplasia: interobserver variability, accuracy, and the utility of glutamine synthetase immunohistochemistry.

AIMS: The diagnosis of focal nodular hyperplasia (FNH) and the interpretation of glutamine synthetase (GS) staining can be challenging on biopsies. We aimed to evaluate the reproducibility of needle biopsy diagnosis of FNH, the effect of GS immunohistochemistry on FNH diagnosis, and which histological features are most useful for the diagnosis of FNH. METHODS AND RESULTS: The study included virtual needle biopsies generated from 75 resection specimens (30 FNHs, 15 hepatocellular adenomas, 15 hepatocellular carcinomas, and 15 non-lesional liver specimens). Pathologists were reasonably accurate (83.1%) in the diagnosis of FNH with haematoxylin and eosin alone. Ductular reaction and nodularity had the highest sensitivity for a diagnosis of FNH (88.1% and 82.2%, respectively), whereas central scar was the most specific feature (90.6%). The presence of two or more of the classic histological features had 89.6% sensitivity and 86.2% specificity for a diagnosis of FNH. Diagnostic accuracy was significantly higher with the addition of a GS stain. A map-like GS staining pattern was highly specific (99.3%) for FNH. However, GS staining was interpreted as non-map-like in 14.4% of reviews of true FNH cases, and overall interobserver agreement for interpretation of the GS staining pattern was only moderate (kappa = 0.42). CONCLUSIONS: Pathologists are reasonably accurate in the diagnosis of FNH on virtual biopsies, and GS staining improves accuracy. However, a subset of FNH cases remain challenging. Steatosis and a pseudo-map-like GS staining pattern were associated with increased difficulty. Therefore, although a map-like GS staining pattern is useful for confirmation of a diagnosis, the lack of a map-like GS staining pattern on needle biopsy does not necessarily exclude a diagnosis of FNH.

Tumor histopathology predicts outcomes after resection of colorectal cancer liver metastases treated with and without pre-operative chemotherapy.

BACKGROUND AND OBJECTIVES: Study objectives, included determination of: (i) associations between radiologic and pathologic responses of colorectal cancer liver metastases (CRCLM) to chemotherapy; and (ii) whether CRCLM histopathology is associated with recurrence free survival (RFS) after resection among patients not treated with pre-operative chemotherapy (untreated). METHODS: Demographics, clinicopathologic characteristics, and outcomes among patients who underwent CRCLM resection from 2007 to 2014 were reviewed. Tumor regression grade (TRG) of 1-2 and 4-5 depict low and high proportions of viable tumor relative to fibrosis, respectively. RESULTS: Of 138 patients, 84 (60.9%) were treated with pre-operative chemotherapy. In these patients, there was no difference in proportions with TRG 1-2 among those with verses without radiologic response (26.9% vs. 18.8%, P = 0.393). TRG 1-2 was associated with superior RFS on univariable (median 15 vs. 6 months, P < 0.001) and multivariable (P = 0.005) analyses. Radiologic response was not associated with RFS. Among untreated patients (n = 54), TRG 4-5 was associated with poor RFS on univariable (median 44 vs. 15 months, P = 0.011) and multivariable (P = 0.012) analyses. CONCLUSIONS: High proportions of CRCLM fibrosis occur in 20% of patients without radiologic response to chemotherapy. Among untreated patients, high proportion of viable tumor relative to fibrosis is associated with poor RFS after resection. J. Surg. Oncol. 2016;113:456-462. © 2016 Wiley Periodicals, Inc.

CT colonography for the detection of nonpolypoid adenomas: sensitivity assessed with restricted national CT colonography trial criteria.

OBJECTIVE: The purpose of this study was to determine the prevalence of nonpolypoid adenomas and the sensitivity of CT colonography (CTC) in their detection by use of the restricted criteria of height-to-width ratio<50% and height elevation≤3 mm. MATERIALS AND METHODS: In the National CT Colonography Trial (American College of Radiology Imaging Network protocol 6664), a cohort of 2531 participants without symptoms underwent CTC and screening colonoscopy. The CTC examinations were interpreted with both 2D and 3D techniques. Nonpolypoid adenomatous polyps identified with CTC or colonoscopy were retrospectively reviewed to determine which polyps met the restricted criteria. The prevalence of nonpolypoid adenomas and the prospective sensitivity of CTC were determined. Descriptive statistics were used to report the prevalence, size, and histologic features. The sensitivities (with 95% CIs) for nonpolypoid and polypoid lesions were compared by two-sided Z test for independent binomial proportions. RESULTS: The retrospective review confirmed 21 nonpolypoid adenomas, yielding a prevalence of 0.83% (21 of 2531 participants). Eight (38.1%) were advanced adenomas, many (50% [4/8]) only because of large size (≥10 mm). The overall per polyp sensitivity of CTC (combined 2D and 3D interpretation) for detecting nonpolypoid adenomas≥5 mm (n=21) was 0.76; ≥6 mm (n=16), 0.75; and ≥10 mm (n=5), 0.80. These values were not statistically different from the sensitivity of detecting polypoid adenomas (p>0.37). CONCLUSION: In this large screening population, nonpolypoid adenomas had a very low prevalence (<1%), and advanced pathologic features were uncommon in polyps<10 mm in diameter. Most nonpolypoid adenomas are technically visible at CTC. The prospective sensitivity is similar to that for polypoid adenomas when the interpretation combines both 2D and 3D review.

The National CT Colonography Trial: assessment of accuracy in participants 65 years of age and older.

PURPOSE: To conduct post-hoc analysis of National CT Colonography Trial data and compare the sensitivity and specificity of computed tomographic (CT) colonography in participants younger than 65 years with those in participants aged 65 years and older. MATERIALS AND METHODS: Of 2600 asymptomatic participants recruited at 15 centers for the trial, 497 were 65 years of age or older. Approval of this HIPAA-compliant study was obtained from the institutional review board of each site, and informed consent was obtained from each subject. Radiologists certified in CT colonography reported lesions 5 mm in diameter or larger. Screening detection of large (≥10-mm) histologically confirmed colorectal neoplasia was the primary end point; screening detection of smaller (6-9-mm) colorectal neoplasia was a secondary end point. The differences in sensitivity and specificity of CT colonography in the two age cohorts (age < 65 years and age ≥ 65 years) were estimated with bootstrap confidence intervals (CIs). RESULTS: Complete data were available for 477 participants 65 years of age or older (among 2531 evaluable participants). Prevalence of adenomas 1 cm or larger for the older participants versus the younger participants was 6.9% (33 of 477) versus 3.7% (76 of 2054) (P < .004). For large neoplasms, mean estimates for CT colonography sensitivity and specificity among the older cohort were 0.82 (95% CI: 0.644, 0.944) and 0.83 (95% CI: 0.779, 0.883), respectively. For large neoplasms in the younger group, CT colonography sensitivity and specificity were 0.92 (95% CI: 0.837, 0.967) and 0.86 (95% CI: 0.816, 0.899), respectively. Per-polyp sensitivity for large neoplasms for the older and younger populations was 0.75 (95% CI: 0.578, 0.869) and 0.84 (95% CI: 0.717, 0.924), respectively. For the older and younger groups, per-participant sensitivity was 0.72 (95% CI: 0.565, 0.854) and 0.81 (95% CI: 0.745, 0.882) for detecting adenomas 6 mm in diameter or larger. CONCLUSION: For most measures of diagnostic performance and in most subsets, the difference between senior-aged participants and those younger than 65 years was not statistically significant.

Sessile Serrated Adenoma With Dysplasia of the Colon.

OBJECTIVES: Sessile serrated adenomas with dysplasia (SSADs) of the colon are transitional lesions between sessile serrated adenomas (SSAs) and a subset of colorectal adenocarcinomas. We wished to gain insight into the relative percentages and significance of SSAD subtypes. METHODS: Retrospective (2007-2012) clinicopathologic review of colorectal polyps initially regarded as having mixed serrated and dysplastic elements. SSADs were subdivided into those with cap-like adenomatous dysplasia (ad1), non-cap-like adenomatous dysplasia (ad2), serrated dysplasia (ser), minimal dysplasia (min), and dysplasia not otherwise specified (nos). MLH1 immunostaining was performed on many. RESULTS: SSADser (7.7%) had a greater propensity for right colon, women, and MLH1 loss vs the entire cohort. SSAad1 (11.6%) had the least female preponderance, was least likely to have MLH1 loss, and was most likely to affect the left colorectum. SSAD with MLH1 loss was associated with an increased burden of SSAs in the background colon (P = .0003) but not tubular adenomas or hyperplastic polyps. Most SSADs (ad2 and nos groups, 80% combined) showed difficult-to-classify dysplasia, intermediate MLH1 loss rates, and intermediate clinical features. CONCLUSIONS: While some trends exist, morphologically subclassifying SSADs is probably not justified in routine clinical practice. MLH1 loss portends a greater burden of SSAs in the background colon.

Accuracy of CT colonography for detection of large adenomas and cancers.

BACKGROUND: Computed tomographic (CT) colonography is a noninvasive option in screening for colorectal cancer. However, its accuracy as a screening tool in asymptomatic adults has not been well defined. METHODS: We recruited 2600 asymptomatic study participants, 50 years of age or older, at 15 study centers. CT colonographic images were acquired with the use of standard bowel preparation, stool and fluid tagging, mechanical insufflation, and multidetector-row CT scanners (with 16 or more rows). Radiologists trained in CT colonography reported all lesions measuring 5 mm or more in diameter. Optical colonoscopy and histologic review were performed according to established clinical protocols at each center and served as the reference standard. The primary end point was detection by CT colonography of histologically confirmed large adenomas and adenocarcinomas (10 mm in diameter or larger) that had been detected by colonoscopy; detection of smaller colorectal lesions (6 to 9 mm in diameter) was also evaluated. RESULTS: Complete data were available for 2531 participants (97%). For large adenomas and cancers, the mean (+/-SE) per-patient estimates of the sensitivity, specificity, positive and negative predictive values, and area under the receiver-operating-characteristic curve for CT colonography were 0.90+/-0.03, 0.86+/-0.02, 0.23+/-0.02, 0.99+/-<0.01, and 0.89+/-0.02, respectively. The sensitivity of 0.90 (i.e., 90%) indicates that CT colonography failed to detect a lesion measuring 10 mm or more in diameter in 10% of patients. The per-polyp sensitivity for large adenomas or cancers was 0.84+/-0.04. The per-patient sensitivity for detecting adenomas that were 6 mm or more in diameter was 0.78. CONCLUSIONS: In this study of asymptomatic adults, CT colonographic screening identified 90% of subjects with adenomas or cancers measuring 10 mm or more in diameter. These findings augment published data on the role of CT colonography in screening patients with an average risk of colorectal cancer. (ClinicalTrials.gov number, NCT00084929; American College of Radiology Imaging Network [ACRIN] number, 6664.)

Characterization of Novel Injectable Lifting Agents Used in Colonic Polyp Removal: An Emerging Amyloid Mimic.

Colon polypectomy can require an injection of a submucosal lifting agent to fully visualize and completely remove the polyp. To the best of our knowledge, this is the largest morphologic series on the novel lifting agents Eleview and Orise. The study consisted of 1 polypectomy and 8 colon resections from 9 patients: 6 women, 3 men (mean age=64 y); Orise=6, Eleview=3; the median time interval between injection and resection=16 weeks. Pathologic diagnoses of the polyps included tubular adenoma (n=4), tubulovillous adenoma (n=4), and sessile serrated adenoma/polyp (n=1). We report that a histologically processed Orise aliquot from the manufacturer showed similar histology to that seen in the specimens from patients with confirmed Orise injection. The morphology of the agents in the patient specimens changed with time status postinjection: immediate resection of the lifting agent showed basophilic, amorphous, and bubbly-extracellular material with prominent hemorrhage, and resection ∼3 months after lifting agent injection showed prominent hyalinized, pink-amorphous ribbons and globules with a foreign body giant cell reaction and fibrosis. The epicenter of the lifting agents was in the submucosa, and the agents were neither refractile nor polarizable. Because of the morphologic overlap with amyloid, 5 cases were stained with Congo Red, and all cases were negative. In conclusion, awareness of the morphology of these new lifting agents is important for accurate diagnosis and to avoid the diagnostic pitfall of amyloid. These lesions can be definitively distinguished from amyloid by their nonreactivity on a Congo Red and familiarity with their characteristic clinicopathologic presentation.

Chromosomal changes in fibrolamellar hepatocellular carcinoma detected by array comparative genomic hybridization.

Fibrolamellar hepatocellular carcinoma is a rare subtype of hepatocellular carcinoma with distinct clinical and histological features, and better survival compared with conventional hepatocellular carcinoma in some but not all series. We performed a comparative genomic hybridization analysis on 11 fibrolamellar carcinomas and correlated the findings with clinicopathologic features and survival. Chromosomal imbalances were identified in six cases (55%), whereas the other five (45%) yielded normal results. The mean number of aberrations per case was 3.9 for all cases and 7.2 in abnormal cases. Among the six abnormal cases, gains or losses were observed at 3 loci in two cases, 7 loci in one case, 8 loci in two cases and 14 loci in one case. The most common abnormalities were observed in chromosomes 7, 8 and 18, with 7q gain in five cases and 7p gain in four cases. Aberrations associated with intermediate or advanced conventional hepatocellular carcinomas, including losses at 3q, 4q and 13q were identified in 17-33% of fibrolamellar carcinomas. There was no correlation of chromosomal changes with age, gender and tumor size. The 5-year survival among the six patients with no chromosomal abnormalities was 80% (4/5) compared with 33% (2/6) in patients with chromosomal abnormalities (P=0.1). In conclusion, fibrolamellar carcinomas show fewer chromosomal abnormalities compared with those reported in literature for conventional hepatocellular carcinoma. The most common abnormalities occur in chromosomes 7 and 8. Fibrolamellar carcinomas with chromosomal changes appear to behave more aggressively compared with cases with no cytogenetic abnormalities. The favorable outcome in some fibrolamellar carcinomas may be due to absent or low number of cytogenetic aberrations.

Chromosomal abnormalities determined by comparative genomic hybridization are helpful in the diagnosis of atypical hepatocellular neoplasms.

AIMS: To explore the utility of cytogenetic abnormalities in the distinction of hepatic adenoma (HA) and well-differentiated hepatocellular carcinoma (HCC). METHODS AND RESULTS: Array-based comparative genomic hybridization (CGH) was used to determine chromosomal abnormalities in 39 hepatocellular neoplasms: 12 HA, 15 atypical hepatocellular neoplasms (AHN) and 12 well-differentiated HCC. The designation of AHN was used in two situations: (i) adenoma-like neoplasms (n = 8) in male patients (any age) and women >50 years and <15 years old; (ii) adenoma-like neoplasms with focal atypical features (n = 7). CGH abnormalities were seen in none of the HAs (0/12), eight (53%) AHNs and 11 (92%) HCCs. The number and nature of abnormalities in AHN was similar to HCC with gains in 1q, 8q and 7q being the most common. Although follow-up information was limited, recurrence and/or metastasis were observed in three AHNs (two with abnormal, one with normal CGH). CONCLUSIONS: Adenoma-like neoplasms with focal atypical morphological features or unusual clinical settings such as male gender or women outside the 15-50 year age group can show chromosomal abnormalities similar to well-differentiated HCC. Even though these tumours morphologically mimic adenoma, they can recur and metastasize. Determination of chromosomal abnormalities can be useful in the diagnosis of AHN.

Prognostic significance of defective mismatch repair and BRAF V600E in patients with colon cancer.

PURPOSE: Colon tumors with defective DNA mismatch repair (dMMR) have a well-characterized phenotype and accounts for approximately 15% to 20% of sporadic colon cancer as well as those colon cancer patients with Lynch syndrome. Although the presence of dMMR seems to be a favorable prognostic marker, data suggest that these patients do not respond as well to adjuvant chemotherapy. EXPERIMENTAL DESIGN: In this study, we examined the prognostic significance of tumor MMR deficiency and the presence of a specific mutation in BRAF (V600E) in a group of patients (n = 533) who participated in a randomized prospective clinical trial through the North Central Cancer Treatment Group. RESULTS: Tumors with dMMR were found to be associated with higher tumor grade (P = 0.001), proximal location (P < 0.0001), and improved overall and disease-free survival (P = 0.05 and 0.04, respectively). Among all cases examined, evaluation of the BRAF V600E mutation status revealed no statistically significant differences in either disease-free or overall survival. Patients were then grouped into four categories for further analysis: dMMR/BRAF(-), dMMR/BRAF(+), pMMR/BRAF(-), and pMMR/BRAF(+). The dMMR/BRAF(-) group had a significantly improved overall survival (5-year overall survival of 100% versus 73%, P = 0.002) compared with all others. The remaining three groups had very similar survival outcomes. An additional cohort of tumors previously classified as having dMMR were also tested for the BRAF V600E alteration. Results remained significant (P = 0.006) when the two groups were combined for analysis. CONCLUSIONS: Overall, these data suggest that the underlying molecular etiology of those tumors having dMMR may influence the disease outcome in these patients.

Stool DNA and occult blood testing for screen detection of colorectal neoplasia.

BACKGROUND: Stool DNA testing is a new approach to colorectal cancer detection. Few data are available from the screening setting. OBJECTIVE: To compare stool DNA and fecal blood testing for detection of screen-relevant neoplasia (curable-stage cancer, high-grade dysplasia, or adenomas >1 cm). DESIGN: Blinded, multicenter, cross-sectional study. SETTING: Communities surrounding 22 participating academic and regional health care systems in the United States. PARTICIPANTS: 4482 average-risk adults. MEASUREMENTS: Fecal blood and DNA markers. Participants collected 3 stools, smeared fecal blood test cards and used same-day shipment to a central facility. Fecal blood cards (Hemoccult and HemoccultSensa, Beckman Coulter, Fullerton, California) were tested on 3 stools and DNA assays on 1 stool per patient. Stool DNA test 1 (SDT-1) was a precommercial 23-marker assay, and a novel test (SDT-2) targeted 3 broadly informative markers. The criterion standard was colonoscopy. RESULTS: Sensitivity for screen-relevant neoplasms was 20% by SDT-1, 11% by Hemoccult (P = 0.020), 21% by HemoccultSensa (P = 0.80); sensitivity for cancer plus high-grade dysplasia did not differ among tests. Specificity was 96% by SDT-1, compared with 98% by Hemoccult (P < 0.001) and 97% by HemoccultSensa (P = 0.20). Stool DNA test 2 detected 46% of screen-relevant neoplasms, compared with 16% by Hemoccult (P < 0.001) and 24% by HemoccultSensa (P < 0.001). Stool DNA test 2 detected 46% of adenomas 1 cm or larger, compared with 10% by Hemoccult (P < 0.001) and 17% by HemoccultSensa (P < 0.001). Among colonoscopically normal patients, the positivity rate was 16% with SDT-2, compared with 4% with Hemoccult (P = 0.010) and 5% with HemoccultSensa (P = 0.030). LIMITATIONS: Stool DNA test 2 was not performed on all subsets of patients without screen-relevant neoplasms. Stools were collected without preservative, which reduced detection of some DNA markers. CONCLUSION: Stool DNA test 1 provides no improvement over HemoccultSensa for detection of screen-relevant neoplasms. Stool DNA test 2 detects significantly more neoplasms than does Hemoccult or HemoccultSensa, but with more positive results in colonoscopically normal patients. Higher sensitivity of SDT-2 was particularly apparent for adenomas.

Altered DNA mismatch repair expression in synchronous and metachronous colorectal cancers.

BACKGROUND & AIMS: It is not clear what proportion of synchronous or metachronous colorectal cancers (CRCs) are associated with DNA mismatch repair (MMR) alterations or unsuspected Lynch syndrome. On the basis of tissue analyses, the aims were to evaluate DNA MMR expression in metachronous, synchronous, and isolated sporadic CRCs and to assess within-patient concordance of MMR expression in metachronous and synchronous CRCs. METHODS: Tissue was evaluated from 34 patients with metachronous CRC, 34 matched solitary CRC patients, and 40 patients with synchronous CRCs. Subjects with known hereditary CRC were excluded. Immunohistochemical staining for MLH1 and MSH2 was performed on all tissues. RESULTS: Absent MLH1 or MSH2 staining of the initial metachronous tumor was observed in 27% compared with 21% of control CRCs, P = .58. The odds of metachronicity with absent immunostaining were 1.33 (95% confidence interval, 0.46-3.84). Loss of MMR expression was observed in at least one cancer in 30% of patients with synchronous CRC. MMR expression loss was discordant in 70% of metachronous CRCs and 50% of synchronous CRCs. Lynch syndrome was subsequently diagnosed in 2 patients with synchronous CRCs, both with concordant tumor MMR loss but in no patient with metachronous CRC. CONCLUSIONS: Among those without known Lynch syndrome, development of multiple primary CRCs appears to be due largely to somatic events and often occurs via different molecular pathways within the same patient. Altered MMR expression in sporadic CRC has low predictive value for metachronicity. MMR expression analysis in cases of multiple primary CRC might identify a small number of patients with unsuspected Lynch syndrome.

Predictors of family risk for celiac disease: a population-based study.

BACKGROUND & AIMS: There is an elevated prevalence of celiac disease (CD) in family members (FMs) of CD patients, but most prior studies have been done on selected populations. Our aim was to determine the clinical, serologic, and genetic predictors of CD in FMs of a population-based cohort of index cases. METHODS: Index cases from southeast Minnesota provided contact information for their first-degree relatives. FMs were examined for endomysial antibodies (EMAs), tissue transglutaminase antibodies (tTGAs), and HLA-DQ genotyping. Two questionnaires were applied, Bowel Disease Questionnaire and Short Form Health Survey. Intestinal biopsies were offered if there were any positive autoantibody or seronegative FMs with gastrointestinal symptoms and HLA-DQ at risk for CD. RESULTS: We recruited 111 index cases that had 579 FMs, of whom 344 (59%) were investigated. The average screening rate among families was 65%. A positive tTGA test was found in 47 (14%), 33 with a positive EMA test. CD was diagnosed in 39 (21 males), with an estimated prevalence of 11% (lambda(R) = 16.1). All affected FMs carried the at-risk genotypes. Twenty-one (54%) had "silent" disease, most with severe intestinal villous atrophy. Carrying HLA-DQ2 (odds ratio, 16.1; 95% confidence interval, 2.1-123) and being a sibling (odds ratio, 2.5; 95% confidence interval, 1.1-5.8) are high-risk factors for CD. CONCLUSIONS: CD is more common in first-degree relatives than previously reported in the United States, with siblings having the greatest risk. There is male preponderance of new cases, and many had silent disease despite severe histologic injury. A more proactive case-finding strategy in FMs might improve the diagnostic rate of CD in North America.

Epidermal growth factor receptor expression and gene copy number in conventional hepatocellular carcinoma.

Epidermal growth factor receptor (EGFR) is frequently overexpressed in hepatocellular carcinoma, but its relationship with EGFR gene copy number has not been studied. This study examined EGFR expression and gene copy number in hepatocellular carcinoma and evaluated their relationship to clinicopathologic features in 76 tumors. Moderate to strong expression of EGFR was observed by immunohistochemical analysis in 50 (66%) of 76 hepatocellular carcinomas. Fluorescence in situ hybridization (FISH) showed extra EGFR gene copies in 17 (45%) of 38 tumors. This was accompanied by gains of chromosome 7, indicating that this was the result of balanced polysomy rather than gene amplification. There was no correlation between EGFR expression by immunohistochemical analysis and gene copy number by FISH. EGFR expression showed borderline association with cirrhosis but not with other clinicopathologic parameters examined. EGFR overexpression is present in a majority of hepatocellular carcinomas, suggesting a role for EGFR antagonists in therapy. The increased expression does not correlate with an increase in the EGFR gene copy number.

Frequency of defective DNA mismatch repair in colorectal cancer among the Alaska Native people.

The frequency of colorectal cancer (CRC) among the Alaska Native people is the highest of any ethnic group in the United States. In this study, CRC from 329 Alaska Native people (165 Eskimo, 111 Indians, and 53 Aleut) were evaluated for evidence of defective DNA mismatch repair (MMR) by testing tumors for altered protein expression (hMLH1, hMSH2, and hMSH6) and for the presence of microsatellite instability. Of the 329 samples tested, 46 (14%) showed both microsatellite instability and altered protein expression; 42 (91%) with a loss of hMLH1, 3 (7%) hMSH2, and 1 (2%) hMLH1/hMSH6. Tumors with loss of hMLH1 were further evaluated for hMLH1 promoter hypermethylation and for the presence of the BRAF-V600E mutation. Among cases tested, all 19 (100%) tumors among the Eskimo patients showed hMLH1 promoter hypermethylation, whereas this was the case for only 3 of the 7 (42%) tumors among the Aleut (P=0.002) and 5 of the 10 (50%) tumors from the Indians (P=0.002). The majority of hypermethylated cases (23 of 27) tested positive for the V600E alteration. Of the nine tumors from the Aleut and Indian patients that did not exhibit hMLH1 hypermethylation, eight tested negative for V600E. Overall, the frequency of defective MMR among the three groups was not statistically different (P=0.75). However, the data suggest that the pathogenesis of CRC may differ between the three groups. The CRC with defective MMR among the Eskimo sample fit the typical profile for hMLH1-related cancer associated with sporadic CRC, whereas the pattern in the Aleut and Indian suggests the possibility that germ line hMLH1 mutations may be present.

Atrophic autoimmune pangastritis: A distinctive form of antral and fundic gastritis associated with systemic autoimmune disease.

The 2 major recognized forms of atrophic gastritis are autoimmune and environmental atrophic gastritis. These differ in their topographical distribution in the stomach, histologic features, and etiology. Autoimmune atrophic gastritis results from immune-mediated destruction of specialized oxyntic glands, is restricted to the body and fundus, and shows characteristic neuroendocrine hyperplasia. Environmental atrophic gastritis is associated with long-standing Helicobacter pylori infection and preferentially involves antrum and transition zone mucosa. In this study, we describe a distinctive form of atrophic gastritis that differs markedly from both of these classic variants. This gastritis is characterized by: (1) intense mucosal inflammatory infiltrates, persisting even into the phase of severe glandular atrophy, (2) pangastric distribution with diffuse involvement of both body and antrum, (3) lack of association with H. pylori, and (4) lack of neuroendocrine hyperplasia. The 8 patients presented ranged from 1 to 75 years and showed a slight female predominance (5F:3M). All had systemic autoimmune and/or connective tissue diseases including autoimmune enterocolitis (4 cases), systemic lupus erythematosus, refractory sprue, autoimmune hemolytic anemia, and disabling fibromyalgia. Positive serum autoimmune markers were documented in 7 of 8 (87%) patients, but serologies for antiparietal cell and anti-intrinsic factor antibodies were undertaken in only 1 patient each and were negative. We propose that the distinctive histology of this form of atrophic pangastritis and its association with systemic autoimmune disease suggests an autoimmune process directed against multiple cell lineages in the stomach. The development of multifocal low-grade dysplasia in 1 patient, a 19-year-old woman, suggests that this condition might have neoplastic potential.

Severe hepatotoxicity associated with use of a dietary supplement containing usnic acid.

Dietary supplements containing usnic acid are marketed for weight loss and have been associated with hepatotoxicity. The specific ingredient responsible for the hepatotoxicity is currently unknown. We describe 2 patients who developed severe hepatotoxicity within 3 months of taking a dietary supplement containing usnic acid. One patient developed fulminant hepatic failure requiring emergency liver transplantation; the other developed submassive hepatic necrosis but did not require transplantation. Thorough investigation, including histopathological examination of the liver, revealed no other cause of acute liver injury. Usnic acid hepatotoxicity should be considered as a possible etiologic factor in patients presenting with fulminant hepatic failure, especially if they have been taking dietary supplements for weight reduction.

Epidermal growth factor receptor expression and gene copy number in fibrolamellar hepatocellular carcinoma.

Increased expression of epidermal growth factor receptor (EGFR), a transmembrane tyrosine kinase, is associated with tumor progression in many carcinomas. Epidermal growth factor receptor inhibitors have shown promise in treating some of these tumors. Fibrolamellar hepatocellular carcinoma (FL-HCC) is an aggressive neoplasm that occurs in young patients with no history of cirrhosis. This study examines the expression and gene copy number of EGFR in FL-HCC. Formalin-fixed, paraffin-embedded FL-HCC (n = 13) sections were stained with a monoclonal antibody against EGFR. Fluorescence in situ hybridization analysis was performed using probes against EGFR gene and centromeric region of chromosome 7 (CEP 7). Epidermal growth factor receptor and CEP 7 signals were counted in 50 tumor nuclei per case as well as 300 normal hepatocyte nuclei. The EGFR to CEP 7 signal ratio was calculated for each case. Most (92%, 12/13) of FL-HCC showed strong and diffuse staining with anti-EGFR antibody. Fluorescence in situ hybridization was informative in 11 cases, 10 of which showed extra EGFR gene copy numbers (mean, 3.69; range, 3.13-5.0). Epidermal growth factor receptor was overexpressed in all these cases. The mean number of EGFR signals per cell in FL-HCC was double that of normal hepatocytes (3.69 versus 1.80); the mean EGFR/CEP 7 ratio in tumor cells was 1.05. In conclusion, EGFR is strongly overexpressed on the cell membrane in nearly all cases of FL-HCC. Similar gains of chromosome 7 are observed, indicating that the extra EGFR gene copies are due to polysomy rather than gene amplification. The strong expression of EGFR in FL-HCC tumors suggests that they may respond to treatment with EGFR antagonists.