Citations

Abstract Rationale Bronchoscopically collected cytology specimens are commonly used to obtain a diagnosis of cancer in patients with pulmonary lesions. However, the sensitivity of cytology is suboptimal, especially for peripheral lesions less than 2 cm in diameter. Objectives We assessed the performance of a testing algorithm using cytology and fluorescence in situ hybridization (FISH) as part of clinical practice. Methods Bronchial brushing specimens (n = 343) were obtained from patients undergoing bronchoscopy for indeterminate pulmonary lesions. Routine cytology was performed and specimens without a positive diagnosis (n = 294) were analyzed by FISH, using residual brushing material. Pathology-confirmed lung cancer or clinical/radiographic evidence of disease was considered diagnostic of malignancy. Measurements and Main Results Routine cytology had a sensitivity and specificity of 41% (23 of 56) and 100% (45 of 45) for central lesions and 20% (26 of 133) and 100% (109 of 109) for peripheral nodules, respectively. FISH detected an additional 32% of lung cancers (18 central and 43 peripheral) not detectable by cytology alone, while producing false positive diagnoses in 22% (10 of 45) and 6% (6 of 109) benign central and peripheral lesions, respectively. In peripheral nodules, FISH detected (relative to routine cytology) an additional 44% (15 of 34) and 28% (25 of 91) of lung cancers less than 2 cm and 2 cm or more in size, respectively. A positive FISH result had a likelihood ratio of 1.45 and 5.87 for central and peripheral lesions and 3.44 and 15.38 for peripheral nodules less than 2 cm and 2 cm or more in size, respectively. Conclusions FISH testing significantly increases the detection of lung cancer over routine cytology alone. It is especially useful for peripheral nodules.

Abstract Malignant gliomas are the most common primary brain tumors. Despite intensive clinical investigation and significant technical advances in surgical and radiation treatment, the impact on clinical outcome for patients with malignant gliomas is disappointing. We have previously shown that tumor necrosis factor–like weak inducer of apoptosis (TWEAK), a member of the tumor necrosis factor superfamily, can stimulate glioma cell survival via binding to the Fn14 receptor, activation of the NF-κB pathway, and upregulation of BCL-XL gene expression. Here, we show that TWEAK treatment of glioma cells leads to phosphorylation of Akt and BAD. TWEAK stimulation results in the phosphorylation of both Akt1 and Akt2. However, small interfering RNA (siRNA)–mediated depletion of either Akt1 or Akt2 showed that BAD serine 136 phosphorylation is dependent specifically on Akt2 function. Depletion of Akt2 expression by siRNA also abrogates TWEAK-stimulated glioma cell survival, whereas no effect on glioma cell survival was observed after siRNA-mediated depletion of Akt1 expression. Surprisingly, although siRNA-mediated depletion of BAD in glioma cells abrogates cytotoxic- and chemotherapy-induced apoptosis, TWEAK still displays a strong protective effect, suggesting that BAD serine 136 phosphorylation plays a minor role in TWEAK-Akt2–induced glioma cell survival. We also report here that AKT2 gene expression levels increased with glioma grade and inversely correlate with patient survival. Additionally, immunohistochemical analysis showed that Akt2 expression positively correlates with Fn14 expression in glioblastoma multiforme specimens. We hypothesize that the TWEAK-Fn14 signaling axis functions, in part, to enhance glioblastoma cell survival by activation of the Akt2 serine/threonine protein kinase. (Mol Cancer Res 2009;7(11):1871–81)

Background— Genetic testing for long-QT syndrome (LQTS) has diagnostic, prognostic, and therapeutic implications. Hundreds of causative mutations in 12 known LQTS-susceptibility genes have been identified. Genetic testing that includes the 3 most commonly mutated genes is available clinically. Distinguishing pathogenic mutations from innocuous rare variants is critical to the interpretation of test results. We sought to quantify the value of mutation type and gene/protein region in determining the probability of pathogenicity for mutations. Methods and Results— Type, frequency, and location of mutations across KCNQ1 (LQT1), KCNH2 (LQT2), and SCN5A (LQT3) were compared between 388 unrelated “definite” (clinical diagnostic score ≥4 and/or QTc ≥480 ms) cases of LQTS and >1300 healthy controls for each gene. From these data, estimated predictive values (percent of mutations found in definite cases that would cause LQTS) were determined according to mutation type and location. Mutations were 10 times more common in cases than controls (0.58 per case versus 0.06 per control). Missense mutations were the most common, accounting for 78%, 67%, and 89% of mutations in KCNQ1 , KCNH2 , and SCN5A in cases and >95% in controls. Nonmissense mutations have an estimated predictive value >99% regardless of location. In contrast, location appears to be critical for characterizing missense mutations. Relative frequency of missense mutations between cases and controls ranged from ≈1:1 in the SCN5A interdomain linker to infinity in the pore, transmembrane, and linker in KCNH2. These correspond to estimated predictive values ranging from 0% in the interdomain linker of SCN5A to 100% in the transmembrane/linker/pore regions of KCNH2. The estimated predictive value is also high in the linker, pore, transmembrane, and C terminus of KCNQ1 and the transmembrane/linker of SCN5A. Conclusions— Distinguishing pathogenic mutations from rare variants is of critical importance in the interpretation of genetic testing in LQTS. Mutation type, mutation location, and ethnic-specific background rates are critical factors in predicting the pathogenicity of novel mutations. Novel mutations in low-estimated predictive value regions such as the interdomain linker of SCN5A should be viewed as variants of uncertain significance and prompt further investigation to clarify the likelihood of disease causation. However, mutations in regions such as the transmembrane, linker, and pore of KCNQ1 and KCNH2 may be defined confidently as high-probability LQTS-causing mutations. These findings will have implications for other genetic disorders involving mutational analysis.

AbstractThe clinical management of amyloidosis is based on the treatment of the underlying etiology, and accurate identification of the protein causing the amyloidosis is of paramount importance. Current methods used for typing of amyloidosis such as immunohistochemistry have low specificity and sensitivity. In this study, we report the development of a highly specific and sensitive novel test for the typing of amyloidosis in routine clinical biopsy specimens. Our approach combines specific sampling by laser microdissection (LMD) and analytical power of tandem mass spectrometry (MS)–based proteomic analysis. We studied 50 cases of amyloidosis that were well-characterized by gold standard clinicopathologic criteria (training set) and an independent validation set comprising 41 cases of cardiac amyloidosis. By use of LMD/MS, we identified the amyloid type with 100% specificity and sensitivity in the training set and with 98% in validation set. Use of the LMD/MS method will enhance our ability to type amyloidosis accurately in clinical biopsy specimens.

Abstract The goal of this study was to assess the performance characteristics of the Automated Cellular Imaging System (ACIS III) for HER2 immunohistochemical analysis. The study was performed on 187 biopsy slides from patients who underwent HER2 testing between January and February 2008. Three scoring methods by the ACIS III were compared with the manual score and fluorescence in situ hybridization (FISH) results for HER2 amplification. The equal distribution score (EQD) method, in which 2 areas each of high-, moderate-, and low-intensity staining were measured, most closely matched the FISH HER2 amplification result. The numbers of immunohistochemically negative (0 or 1+)/FISH+ cases were equivalent for all methods. The EQD method had significantly fewer 2+ cases (n = 16) (P < .001) vs the manual method (n = 35) and yielded a higher positive predictive value (38%) for HER2 amplification compared with the manual method (20%). The EQD method may more accurately identify FISH-amplified HER2 cases with fewer 2+ cases that would be “reflexed” to FISH compared with the manual method.

Purpose To analyze the Radiation Therapy Oncology Group (RTOG) database of patients with glioblastoma and appraise whether outcome was influenced by time to initiation of radiation therapy (RT). Patients and Methods From 1974 through 2003, adult patients with histologically confirmed supratentorial glioblastoma were enrolled onto 16 RTOG studies. Of 3,052 enrolled patients, 197 patients (6%) were either initially rendered ineligible or had insufficient chronologic data, leaving a cohort of 2,855 patients for the present analysis. We selected four patient groups based on the interval from surgery to the start of RT: ≤ 2 weeks, 2 to 3 weeks, 3 to 4 weeks, more than 4 weeks to the protocol eligibility limit of 6 weeks. Survival times were estimated by the Kaplan-Meier method. Multivariate analysis incorporated variables of time interval, recursive partitioning analysis (RPA) class, and treatment regimen. Results No decrement in survival could be identified with increasing time to initiation of RT. Among our four temporal groupings, median survival time was unexpectedly and significantly greater in the group with the longest interval (> 4 weeks) than in those with the shortest delay (≤ 2 weeks): respectively, 12.5 months versus 9.2 months (P < .0001). On multivariate analysis, with overall survival as the end point, time interval more than 4 weeks and lower RPA class were both significant predictors of improved outcome. Treatment regimen was not a significant factor. Conclusion There is no evident reduction in survival by delaying initiation of RT within the relatively narrow constraint of 6 weeks. An unanticipated yet significantly superior outcome was identified for patients for whom RT was delayed beyond 4 weeks from surgery.