Michele Johnson

The Prevalence of BRCA2 Mutations in Familial Pancreatic Cancer

Mutations in the BRCA2 gene have been implicated in pancreatic cancer susceptibility through studies of high-risk breast and ovarian cancer families. To determine the contribution of mutations in BRCA2 to familial pancreatic cancer, we screened affected probands from 151 high-risk families identified through pancreatic cancer clinics for germ-line BRCA2 mutations. Of these families, 118 had two or more first- and second-degree relatives with pancreatic cancer, and an additional 33 had two or more affected second-degree relatives. The average age of onset for pancreatic cancer was 62.8 years. Five BRCA2 truncating mutations were identified, three in families with two or more first- and second-degree relatives with pancreatic cancer. Three of the families with mutations had a history of breast cancer but not ovarian cancer. Four of five families with mutations were identified through probands with early-onset (<55 years) pancreatic cancer. The results of this study were combined with those from a BRCA2 mutation study of 29 other families from the same Johns Hopkins University National Familial Pancreatic Tumor Registry to estimate the frequency of BRCA2 mutations. A total of 10 carriers from 180 families were identified, suggesting that BRCA2 mutations account for 6% of moderate and high-risk pancreatic cancer families. (Cancer Epidemiol Biomarkers Prev 2007;16(2):342–6)

Anaplastic lymphoma kinase immunoreactivity correlates with ALK gene rearrangement and transcriptional up-regulation in non–small cell lung carcinomas

Recently, the fusion gene EML4-ALK was identified in non-small cell lung carcinoma, which could be a potential therapeutic target. We investigated the prevalence of anaplastic lymphoma kinase protein expression in these tumors by immunohistochemistry and correlated the results with data from ALK molecular studies. Gene expression profiling was performed on 35 adenocarcinomas to identify cases with ALK gene up-regulation, which was correlated with protein overexpression by immunohistochemistry. Immunohistochemistry was also performed on an independent cohort consisting of 150 adenocarcinomas and 150 squamous cell carcinomas to evaluate the utility of anaplastic lymphoma kinase immunostaining as a screening tool. Florescence in situ hybridization for the ALK locus and reverse transcriptase-polymerase chain reaction for EML4-ALK were performed on tumors positive for anaplastic lymphoma kinase by immunohistochemistry. Transcriptional up-regulation of ALK was identified in 2 (6%) of 35 adenocarcinomas by gene expression profiling. These 2 cases were positive for anaplastic lymphoma kinase by immunohistochemistry, whereas the remaining 33 cases were completely negative. In the independent cohort, anaplastic lymphoma kinase immunostaining was positive in 1 of 150 squamous cell carcinomas and in 3 of 150 adenocarcinomas. The 6 cases positive for anaplastic lymphoma kinase by immunohistochemistry showed evidence of ALK locus rearrangement by florescence in situ hybridization but were negative for EGFR and KRAS mutation. The presence of EML4-ALK fusion transcript was confirmed in 2 cases by reverse transcriptase-polymerase chain reaction. In conclusion, anaplastic lymphoma kinase immunoreactivity in non-small cell lung carcinomas was associated with transcriptional up-regulation, ALK locus rearrangement, and the presence of EML4-ALK fusion transcript. Anaplastic lymphoma kinase immunohistochemistry may have utility as a screening tool or as a surrogate marker for the molecular techniques to detect the EML4-ALK fusion gene in these tumors.

BRAF mutation analysis in fine needle aspiration (FNA) cytology of the thyroid.

BRAF mutations have been detected in 30% to 80% of papillary thyroid carcinomas (PTC). Several detection methods for BRAF mutation have been reported, but a direct comparison between different assay methods has not been previously reported. In this study, we examined the diagnostic utility of BRAF (T1799A) mutation in 71 cases of thyroid fine needle aspiration specimens using 4 different methods, including direct sequencing, Colorimetric Mutector Assay, real-time LightCycler polymerase chain reaction (LC PCR) with fluorescence resonance energy transfer probes, and an allele-specific LC PCR with CYBR green 1. BRAF mutation was detected in 31 of 58 cases of PTC, but not in 13 cases of non-PTC lesions. The 4 assay methods used in this study were sensitive, reliable, and comparable with each other (100% of specificity and 53.5% of sensitivity). PTC harboring BRAF mutation had higher extrathyroidal invasion and/or lymph node metastasis than PTC with wild-type BRAF. BRAF mutation analysis should be useful for the clinical diagnosis of PTC in cases of indeterminate fine needle aspiration specimen, because of the high degree of specificity. Our results indicate that there is similar sensitivity for the four detection methods. However, the allele-specific LC PCR with CYBR green 1 method is most rapid, easier to perform, and least expensive technique, and it can be readily performed in most molecular diagnostic laboratories.

KIT is an independent prognostic marker for pancreatic endocrine tumors: a finding derived from analysis of islet cell differentiation markers.

Prediction of the biologic behavior of pancreatic endocrine tumor (PET) without local invasion or metastasis is often difficult. The 2004 World Health Organization (WHO) classification uses size, angioinvasion, mitotic activity, and Ki-67 index as prognostic criteria. Recently, cytokeratin 19 (CK19) was shown to be another prognostic marker, but the mechanism by which CK19 predicts prognosis is unknown. As CK19 is the first cytokeratin expressed in all epithelial cells in fetal pancreas, we sought to test expression of other markers of islet cell differentiation including KIT, Pdx-1, Pax4, and Pax6 in PET and correlation of these markers with clinical behavior. Clinical information and histology was reviewed in 97 PETs. All tumors were classified according to WHO criteria and a tumor, node, and metastases stage system. Immunohistochemistry was performed using antibodies to Ki-67, KIT, CK19, Pdx-1, Pax4, and Pax6. Associations of clinicopathologic and immunohistochemical features with prognosis were evaluated using Cox proportional hazards regression models. WHO and tumor, node, and metastases classifications, mitotic counts and Ki-67 labeling, infiltrative border, necrosis, perineural invasion, extrapancreatic extension, tumor size, and positive CK19 and KIT expression were significantly associated with death from disease in a univariate setting. In multivariate analysis, only WHO criteria and KIT expression were shown to be independent. An immunohistochemical classification system was derived from a combination of KIT and CK19 expression: low risk (KIT–/CK19–), intermediate risk (KIT–/CK19+), and high risk (KIT+/CK19+). Survival, metastases, and recurrence of PET were significantly different among the 3 groups. These results indicate that KIT is a new and independent prognostic marker for PETs. The classification system derived from KIT and CK19 was able to predict clinical behavior of PET.

Persistence of Nondysplastic Barrett’s Esophagus Is Not Protective Against Progression to Adenocarcinoma

© 2017 by the AGA Institute 1542-3565/

Acceptability, Accuracy, and Safety of Disposable Transnasal Capsule Endoscopy for Barrett's Esophagus Screening

36.00 http://dx.doi.org/10.1016/j.cgh.2017.02.019 Bfactor for esophageal adenocarcinoma (EAC). Gastrointestinal societies recommend endoscopic surveillance in patients with BE to enable early detection of dysplasia and malignancy. Recently, Gaddam et al have reported that persistence of nondysplastic BE (NBDE) on repeated biopsies predicts lower risk of progression, suggesting that these patients could undergo less intensive surveillance. Conversely, there is also evidence suggesting that the risk of progression in BE continues to increase over time. Therefore, we aimed to investigate if persistence of NBDE in consecutive surveillance biopsies reduces the risk of progression to EAC, providing justification for prolonging surveillance intervals.

Germ Line Fanconi Anemia Complementation Group C Mutations and Pancreatic Cancer

Background & Aims: Screening for Barretts esophagus (BE) with conventional esophagogastroduodenoscopy (C‐EGD) is expensive. We assessed the performance of a clinic‐based, single use transnasal capsule endoscope (EG Scan II) for the detection of BE, compared to C‐EGD as the reference standard. Methods: We performed a prospective multicenter cohort study of patients with and without BE recruited from 3 referral centers (1 in the United States and 2 in the United Kingdom). Of 200 consenting participants, 178 (89%) completed both procedures (11% failed EG Scan due to the inability to intubate the nasopharynx). The mean age of participants was 57.9 years and 67% were male. The prevalence of BE was 53%. All subjects underwent the 2 procedures on the same day, performed by blinded endoscopists. Patients completed preference and validated tolerability (10‐point visual analogue scale [VAS]) questionnaires within 14 days of the procedures. Results: A higher proportion of patients preferred the EG Scan (54.2%) vs the C‐EGD (16.7%) (P < .001) and the EG Scan had a higher VAS score (7.2) vs the C‐EGD (6.4) (P = .0004). No serious adverse events occurred. The EG Scan identified any length BE with a sensitivity value of 0.90 (95% CI, 0.83–0.96) and a specificity value of 0.91 (95% CI, 0.82–0.96). The EG Scan identified long segment BE with a sensitivity value of 0.95 and short segment BE with a sensitivity values of 0.87. Conclusions: In a prospective study, we found the EG Scan to be safe and to detect BE with higher than 90% sensitivity and specificity. A higher proportion of patients preferred the EG Scan to C‐EGD. This device might be used as a clinic‐based tool to screen populations at risk for BE. ISRCTN registry identifier: 70595405; ClinicalTrials.gov no: NCT02066233.