Posts Tagged ‘diagnostic test’

New Diagnostic Test for Prostate Cancer.

Friday, October 31st, 2014

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After 30 years without progress in screening methods a new screening test has been identified for detecting prostate cancer. The  only place in the southeast part of the United States that offers the new technique–the MRI-US image fusion technique-is the University of Alabama in Birmingham. The researchers say ” We are utilizing prostate MRI and fusing it with real time ultrasound for image-guided prostate biopsies;  this can detect prostate cancer with high accuracy, and it accurately targets lesions of concern defined by MRI. ” ” This improves overall detection compared to standard biopsies and, more importantly, has the potential to give clinicians and patients a more accurate picture of their true disease burden by allowing improvements in staging.” The new technique allows direct tissue sampling of suspicious areas seen on MRI as opposed to the traditional method of random, systematically sampling that is essentially performed blind in different regions of the prostate.

Researchers say studies show the technique increases the overall cancer detection rate, increases the high risk detection rate, and improves staging for patients who are considering active surveillance where the doctor monitor low risk prostate cancer for changes.  the technique is a clinical based  procedure that can be performed under local anesthesia and the patient’s experience of this new biopsy compared to previous biopsy without MRI guidance is the same but with more accurate outcomes based on the targeted approach. The procedure has been offered for the past year at the U of Alabama.

 

 

 

Detecting BRCA1 and BRCA2 Mutations with New Diagnostic Test.

Friday, October 18th, 2013

logo1267406_mdBuilding upon the recognition of a causal link between mutations in BRCA1 and BRCA2 genes and an increased risk of breast and ovarian cancer in women a report in the Journal of Molecular Diagnostics  described a new technique using second-generation sequencing technology that is as sensitive as standard methodology but has the potential of improving the efficiency and productivity of genetic testing laboratories that are currently time consuming and costly. The authors say “In our laboratory, approximately 25% of high risk patients who undergo BRCA1 or BRCA2 testing will generate a result with a real or ambiguous relationship to heredity cancer risk, and so testing for these mutations is an important  tool  to identify individuals who would benefit from preventative surgery or increased breast cancer surveillance./”   He expects demand for testing to rise and  wait time to increase and thus a need for faster and low-cost testing.

Second generation testing describes the evolution of sequencing terminology from the first generation and are expected to have a significant impact on detection, management, and treatment of genetic diseases such as ovarian and breast cancer. Ther second generation sequencing assay described in this report used automated small amplicon PCR followed by sample pooling and sequencing with a second-generation instrument. The target region selected was thought to encompass the majority of pathogenic sequence changes in BRCA1 and BRCA2.

Ninety one patient genomic DNA samples (45 selected retrospectively and 43 prospectively) were used to test the assay. Comparing their results to standard dideoxy sequencing methodoly, researchers found 100% agreement between the two methods with no false positive or false negative predictions. After technical adjustments the new method proved sensitive and specific for detecting variants in genetic sequencing.

Less Invasive Diagnostic Test For Lung Cancer Being Studied

Friday, May 27th, 2011

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Research presented at the American Thoracic Society (ATS) 2011 International Conference concluded that a minimally invasive test using cells from the interior of the nose might be useful in detecting lung cancer at an early stage. The earlier studies used gene expression difference in cells in the bronchial airway to identify lung cancer in the early stages. Using this model the researchers developed a hypothesis that “the upper airway epithelium of smokers with lung cancer displays a cancer-specific gene expression pattern, and that this airway gene expression signature reflects the changes that occur in lung tissue.”
Nasal epithelial cells were collected from 33 smokers who were undergoing medically-indicated bronchoscopies for suspected lung cancer. From this group 11 had benign disease, and 22 had lung cancer. Brushing were taken from the left and right nostril and profiled on microarrays, a process for studying gene expression change, to determine genes that differed in their expression between those with lung cancer and those with benign disease. One hundred seventy genes were discovered that differentially expressed between the two groups of patients. The researchers stated that results show an initial indication that simple nasal brushings could offer an alternative to lung biopsies or other invasive techniques used currently to diagnose lung cancer. A large study to validate the results from this pilot study is planned.

Pap Test may Still be Useful for Detecting Cervical Cancer

Friday, January 15th, 2010

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According to a report in the Journal of the American Medical Association in October, 2009 a study of nearly 90,000 women in the Netherlands concluded that the liquid-based cytology. a commonly used alternative to conventional Pap tests, was not superior to the Pap test in detecting cervical cancer precursors or cancer. In the study, researchers compared the screening performance of Pap tests and liquid-based cytology in terms of tests positivity rates, histological detection rates and positive predictive values (PPV). In the randomized control study, 89,784 women ages 30 to 60 who participated in the Dutch screening program at 246 family practice sites were included. One hundred twenty two practice sites were assigned to use the liquid-based cytology and screened 49,222 patients, and the other 124 practice sites were assigned to use the conventional pap test and screened 40,562 women. Subjects were screened for cervical intraepithelial neoplasms (CIN) and followed for 18 months.
Results showed that the adjusted detection rate ratio for CIN grade 1+ was 1.01; for CIN grade 2+ was 1.00, for CIN grade 3+ was 1.05; and for carcinoma was 1.69. “The adjusted positive predictive value ratios, considered at several cytological cutoffs and for various outcomes of CIN did not differ significantly from unity.” Further, “Because of the randomization, it can plausibly be assumed that the prevalence of CIN was equal in both groups. Therefore, the lack of difference in detection rates and PPV in this trial demonstrates that liquid-based cytology is neither more sensitive nor more specific in detecting cervical cancer precursors than the conventional Pap test.