Navigation Links
New strategy developed to diagnose melanoma

A UCSF research team has developed a technique to distinguish benign moles from malignant melanomas by measuring differences in levels of genetic markers. Standard microscopic examinations of biopsied tissue can be ambiguous and somewhat subjective, the researchers say, and supplementing standard practice with the new technique is expected to help clarify difficult-to-diagnose cases.

In a large study of previously diagnosed cases, the new technique distinguished between benign, mole-like skin lesions and melanomas with a success rate higher than 90 percent. It also succeeded with most of the previously misdiagnosed cases, which were among the most difficult to distinguish.

This is the first large-scale study to demonstrate both the high diagnostic accuracy and practicality of a multi-biomarker approach to melanoma diagnosis, said Mohammed Kashani-Sabet, MD, professor of dermatology at UCSF and director of the Melanoma Center at the UCSF Helen Diller Family Comprehensive Cancer Center.

Kashani-Sabet is lead author on a paper reporting the new finding in the Proceedings of the National Academy of Sciences, which is scheduled for online publication the week of March 30, 2009. The paper also will appear in a future print issue of PNAS.

Melanoma is the deadliest form of skin cancer. It can spread to almost any organ of the body and is difficult to treat in its advanced stages. Progress in survival rates has been made principally through earlier diagnosis. The genomics-based approach combined with current diagnostic practice can aid earlier detection and contribute to more accurate assessment, report the UCSF scientists who developed the diagnostic tool.

The molecular diagnosis strategy is now being developed for clinical use by a diagnostics company.

To develop the diagnostic tool, the researchers first used a microarray a "gene chip" -- to identify about 1,000 human genes that were present at different levels in malignant melanomas compared to benign moles. They narrowed their study down to five genes that all showed higher levels of activity in melanomas than in moles and could be studied with standard antibody techniques.

Focusing on the proteins produced by the five genes, they stained the proteins with antibodies to assess the level of gene expression in mole and melanoma tissues. The new diagnostic technique distinguished moles from melanomas by differences in both the level and the pattern of activity of the five proteins.

To develop and test the diagnostic technique, the researchers examined levels of the five biomarkers in 693 previously diagnosed tissue samples. To ensure that the diagnosis based on tissue examination had been correct, all samples were reviewed by the study's pathologist. They analyzed the samples with the new procedure and found that the increased protein production by the melanomas compared with the moles was statistically significant, and thus a reliable diagnostic indicator. Unexpectedly, the proteins also showed different patterns of activity in the two types of tissue, yielding a second, even more discriminating diagnostic indicator.

"We hoped for clear diagnostic differences in the intensity of gene expression," Kashani-Sabet said. "We found what we had hoped for, but then we got a bonus. The pattern of protein activity from the top to the bottom of the tissue was strikingly different between the benign and the malignant tissue, providing an additional trait valuable for diagnosis."

Although some of the genes and their proteins were stronger indicators than others, the research team found that the combination of all five achieved the highest diagnostic accuracy. The multi-biomarker diagnostic correctly diagnosed 95 percent of the benign moles -- a measure known as specificity. The accuracy rate was 91 percent for diagnosing malignant melanomas the sensitivity rate. In addition, the strategy correctly diagnosed 75 percent of the most difficult cases, which had previously been misdiagnosed. The technique also accurately diagnosed other difficult-to-diagnose moles, known as dysplastic and Spitz nevi.

"We have a test that can help patients and help clinicians who treat melanoma," said Kashani-Sabet. "With this added diagnostic tool we can shed light on lesions that are difficult to classify and diagnose."


Contact: Susan Cohen
University of California - San Francisco

Related medicine news :

1. North Texas LEAD Offers Unique Approach to Job Search Strategy
2. Single embryo transfer is the cheapest and most effective strategy for assisted reproduction
3. Licorice compound offers new cancer prevention strategy
4. MRSA study suggests strategy shift needed to develop effective therapeutics
5. New strategy to weaken traumatic memories
6. New York State health IT strategy may be model for the nation
7. LCA-Vision New Excimer Laser Strategy to Reduce Operating Expenses in Excess of $3 Million Annually
8. How to Increase Sales Margin 1 Percent to 10 Percent and Lower Your Risk by Building a Negotiation Strategy into Your Sales Process
9. LCA-Vision Reports Tangible Results from Business Strategy
10. New health reform strategy would insure everyone, improve health and slow spending growth
11. Health Care Workers Call on ARH Board Members to Meet, Develop Real Strategy to Deal With Hospitals Bottom Line
Post Your Comments:
(Date:11/27/2015)... ... ... MPWH, the No.1 Herpes-only dating community in the world, revealed that over 50% of its ... 3.7 billion people under the age of 50 – or 67% of the population - ... estimates of HSV-1 infection . , "The data shocks us highly!" said Michelle Li, ...
(Date:11/27/2015)... ... November 27, 2015 , ... A simply groundbreaking television series, ... interesting show that delves into an array of issues that are presently affecting Americans. ... from open dialogue, this show is changing the subjects consumers focus on, one episode ...
(Date:11/27/2015)... ... 2015 , ... CBD College is proud to announce that on ... accreditation to its Diagnostic Medical Sonography program. CBD College is honored to join this ... colleges and universities in the state of California make the cut. CBD College is ...
(Date:11/27/2015)... ... 27, 2015 , ... Avid collector, Andrew Hawley from Vintage Rock Posters, announces ... This is one of Joplin's most famous and beautiful concert posters. The concert was ... in Ann Arbor. The According to Hawley, "It is hard to believe that Joplin's ...
(Date:11/26/2015)... ... 2015 , ... Inevitably when people think Thanksgiving, they also think Holiday sales ... Black Friday and Cyber Monday massage chair sales to receive the best ... low to find the best massage chair deals, they can see all of the ...
Breaking Medicine News(10 mins):
(Date:11/25/2015)... , Nov. 26, 2015  The total global healthcare industry ... over 2015-2016. Latin America has the ... , (excluding Japan ), is second with ... continues to face increased healthcare expenditure. In 2013-2014, total government ... from 43.5% in 2008-2009 to 41.2% in 2013-2014. In real ...
(Date:11/25/2015)... N.C. , Nov. 25, 2015 ... the planned investment of at least $15.8  Million ... Wilmington, NC . The expansion ... capacity to meet the growing demands of the ... site expansion will provide up to ...
(Date:11/25/2015)... AVIV, Israel , November 25, 2015 ... (NASDAQ: KTOV ) (TASE: KTOV), a biopharmaceutical company ... simultaneous treatment of various clinical conditions, today announced the ... 3,158,900 American Depository Shares ( ADSs ), each representing ... purchase up to 3,158,900 ADSs. The ADSs and warrants ...
Breaking Medicine Technology: