According to Dermatopathologist, Dr. George Hollenberg, the use of FISH in malignant melanoma diagnosis is a “game changer”
|
|
(HealthNewsDigest.com) – Plainview, NY, November 2011 – Acupath Laboratories, Inc. in Plainview, New York announces that the New York State Department of Health has approved its validation for their new fluorescence in situ hybridization (FISH) test, AcuProbe™ FISH for Melanoma, which enables a more objective, accurate method of establishing the diagnosis of malignant melanoma. Acupath is one of few labs in the United States to offer this ground-breaking test.
Establishing an accurate diagnosis of malignant melanoma is among the most crucial that can be made in medicine. Malignant melanoma is the deadliest of the skin cancers, and according to the American Cancer Society, over 70,000 cases are expected to be diagnosed in the United States by the end of 2011.
“In many cases, the differentiation between benign melanocytic lesions from malignant melanoma can be made by conventional immunohistochemical studies. However, a significant number of cases fall into the “borderline” category where conflicting histological features can make the diagnosis of malignant melanoma subjective. This is especially true when the histological findings are ambiguous or mimic those of melanoma such as Atypical Dysplastic Nevi, Persistent Nevi, Spitz Nevi and Desmoplastic Spitz Nevi,” explains Dr. Hollenberg, Medical Director of Acupath Laboratories, Inc.
Routine histological evaluation vs. enhanced testing by FISH
When tissue is stained with immunohistochemistry (IHC) markers it allows expression of specific proteins to be identified throughout the entire tissue, providing an overview of the protein expression. This is considered to be a subjective overview of the protein expression, whereas FISH markers are more accurate because they are able to show which individual cells have chromosomal changes specific to malignant melanoma. FISH provides a quantitative analysis of the specific DNA in the biopsied area by only targeting the genetic material that has been previously observed in patients with malignant melanoma. FISH for Melanoma allows the pathologist to identify, with certainty, that these cells have genetic changes and when used in conjunction with histology, allows them to provide physicians with an objective diagnosis of malignant melanoma.
Test Sensitivity and Specificity
Acupath Laboratories, Inc. based the development of its Melanoma FISH panel in accordance with recently published studies which have confirmed that malignant melanomas exhibit unique genetic abnormalities that can be identified via FISH on formalin-fixed paraffin-embedded (FFPE) tissue.
There are four chromosomal loci whose relative gains and/or losses differentiate malignant melanoma from benign melanocytic lesions. The genes of interest are RREB1 (6p25 gain), MYB (6q23 loss), CCND1 (11q13 gain). CEP61 is used as an internal control in relation to RREB1 and MYB copy number. An additional probe, HRAS (11p15)2, which is used in conjunction with CCND1 (used as an internal control) is unique to Acupath and has been observed in cases of Spitz Nevi, especially Desmoplastic Spitz Nevi.
Acupath has designed original probes3 for these loci of interest, and they were specifically made to optimize the area of coverage allowing for an increased specificity and sensitivity.
In-house studies at Acupath Laboratories, Inc. have confirmed the published sensitivity for these probes to be approximately 87% to 95%, with 85% specificity.
The majority of cases tested exhibited relative gains of the RREB1 locus or gains of chromosome 6 (CEP6) entirely. Confirmation of malignant melanoma diagnosis for the cases tested was performed by a dermatopathologist by review of hematoxylin and eosin (H&E) stained slides in addition to a review of a panel of IHC markers, including S100 and Melanin-A.
“The Melanoma FISH Panel is a useful tool for distinguishing benign melanocytic lesions from malignant melanomas, particularly in histopathologically ambiguous tissues. It provides valuable genetic information previously unavailable to the dermatopathology community. We are hopeful that this newest advancement in diagnosing malignant melanoma will help save many lives,” adds Dr. Hollenberg.
AcuProbe™ FISH for Melanoma is now available at Acupath Laboratories, Inc. and can be ordered on any current or previously submitted FFPE tissue. The turnaround time is approximately 3-5 days. For information on how to order AcuProbe™ FISH for Melanoma, please visit www.acupath.com/acuprobe, send an email to [email protected] or call 1-877-PATHLAB (728-4522).
Acupath Laboratories, Inc. located in Plainview, New York, is an anatomic pathology and cancer genetics laboratory. Acupath’s mission is to deliver fast, accurate anatomic pathology, FISH, flow cytometry, molecular and cytogenetic analysis in a way that enhances the quality of medical care provided by practitioners while minimizing the risk of error. The research and development team continuously innovates, designing up to date methodologies for testing and new ways for doctors to access, exchange, record and analyze medical information. Acupath is committed to improve efficiencies of practice, superior service and greater patient knowledge and satisfaction. Acupath is accredited by the College of American Pathologists (CAP), the Occupational Safety and Health Administration (OSHA), the Joint Commission, and certified by the New York State Department of Health (DOH). www.acupath.com
References
Clemente, C., Bettio, D., Venci, A., et al. A fluorescence in situ hybridization (FISH) procedure to assist in differentiating benign from melanocytic lesions. Pathological 2008, Vol. 101 pp169-174
Moore, S., Persons, D., Sosman, J. Detection of Copy Number Alterations in Metastatic Melanoma by DNA Fluorescence In Situ Hybridization Probe Panel and Array Comparative Genomic Hybridization: A Southwest Oncology Group Study (S9431). Clin Cancer Res 2008; 14(10) pp2927-2935
Morey, A., Murali, S., McCarthy, S., et al. Diagnosis of cutaneous melanocytic tumors by four color fluorescence in situ hybridization. Pathology (June 2009) 41(4) pp383-387
Newman, M., Lertsburapa, T., Mirzabeigi, M. et al. Fluorescence in situ hybridization as a tool for micro staging in malignant melanoma. Modern Pathology (2009) 22 pp989-995
North, J., Kageshita, T., Pinkel, D. Distribution and Significance of Occult Intraepidermal Tumor Cells Surrounding Primary Melanoma. Journal of Investigative Dermatopathology (2008) Vol. 128 pp2024-2030
Bastian, B., LeBoit, P., Pinkel, D. Mutations and Copy Number Increase of HRAS in Spitz Nevi with Distinctive Histopathological Features. American Journal of Pathology (2000) Vol. 157, No.3 pp967-972
###
For advertising and promotion on HealthNewsDigest.com please contact Mike McCurdy: [email protected] or 877-634-9180
HealthNewsDigest.com is syndicated worldwide and has over 8,000 journalists as subscribers.