Navigation Links
Researchers identify need to sample multiple tumor zones in breast cancer
Date:6/14/2012

Philadelphia, PA, June 15, 2012 Certain short strands of RNA, known as microRNAs (miRNAs), have been linked to the progression and metastasis of breast cancer and may provide information about prognosis. However, studies of miRNA expression profiles often report conflicting findings. While the potential for using miRNAs in breast cancer diagnosis is promising, scientists report in a new study published online today in The Journal of Molecular Diagnostics that differences in the amount and types of miRNA within breast tumors can be misleading.

"Personalized medicine will be the future of cancer care," explains lead investigator Stefanie Avril, MD, of the Technical University of Munich. "However, taking a single tumor biopsy for defining individual treatment is probably oversimplified, and we need to take into account the heterogeneity of tumors. "We found considerable differences in the expression of miRNAs associated with breast cancer within a single tumor (referred to as intratumoral heterogeneity). The use of miRNA for diagnosis or prognosis requires sampling at several different tumor locations and of several tumor-involved lymph nodes."

Researchers collected 132 tumor samples from 16 patients who underwent either lumpectomy or mastectomy for large primary invasive breast cancer. Samples were taken from defined tumor zones: the center of the tumor, the periphery, and the area between. Samples were also taken from lymph nodes, if metastases were present. The expression of four miRNAs (miR-31, miR-335, miR-10b, and miR-210) and four control genes (let-7a, miR-16, RNU48, and RNU44) was assessed.

The researchers found significant variation in miRNA expression, from samples both within primary breast cancers and within lymph node metastases from the same patient. The extent of heterogeneity was very similar within the defined tumor zones and between different zones.

To illustrate why intratumoral heterogeneity may produce misleading results if only a single sample is used, the researchers assessed the variation of miRNA expression between different patients. The mean expression of miR31, which is associated with cancer metastasis, from all zones of the primary tumor site in patient 5 was significantly lower than the mean expression from all zones of the primary tumor site of patient 6. However, a sample from a single tumor zone from patient 5 showed a higher expression level than the lowest case from patient 6. "This might in part explain conflicting previous findings regarding miRNA expression profiles," Dr. Avril notes.

"An important strength of this study is the systematic and predefined prospective sampling of tumors in 8 to 10 different areas, whereas previous studies have commonly only analyzed different areas of one tumor section, or core biopsies of the same tumor," says Dr. Avril. "Reliable assessment of breast cancer miRNA profiles should include sampling of the primary tumor in several locations or sampling several tumor-involved lymph nodes when deriving miRNA expression profiles from metastases."


'/>"/>

Contact: David Sampson
jmdmedia@elsevier.com
215-239-3171
Elsevier Health Sciences
Source:Eurekalert

Related biology news :

1. London researchers discover novel mechanism involved in key immune response
2. NTU researchers study little mighty creature for scientific breakthrough
3. UTMB researchers create powerful new method to analyze genetic data
4. Researchers at GW receive federal funds to study the effect earthquakes have on nuclear reactors
5. Stanford researchers help predict the oceans of the future with a mini-lab
6. Researchers complete the first epigenome in Europe
7. UC Santa Barbara researchers develop synthetic platelets
8. Researchers say tart cherries have the highest anti-inflammatory content of any food
9. CSHL researchers solve structure of human protein critical for silencing genes
10. Researchers identify genetic markers to predict male fertility
11. University of Hawaii Cancer Center researchers create new anti-cancer drug
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:12/15/2016)... Advancements in biometrics will radically ... wellbeing (HWW), and security of vehicles by ... vehicles begin to feature fingerprint recognition, iris ... monitoring, brain wave monitoring, stress detection, fatigue ... detection. These will be driven by built-in, ...
(Date:12/8/2016)... 2016 Market Research Future published a half cooked research ... Biometric Security and Service Market is expected to grow over the ... Market Highlights: ... Mobile Biometric Security and Service Market ... need of authentication and security from unwanted cyber threats. The increasing ...
(Date:12/7/2016)...   Avanade is helping Williams Martini Racing, ... history, exploit biometric data in order to critically analyse ... competitive edge against their rivals after their impressive, record-breaking ... has worked with Williams during the 2016 season to ... rate, breathing rate, temperature and peak acceleration) for key ...
Breaking Biology News(10 mins):
(Date:1/23/2017)... 23, 2017 Atlas Genetics Ltd., the ... its Series D financing, raising $35 million from a syndicate ... Biotech. ... Development of the Atlas Genetics io® system has been completed ... test announced in February 2016.  This new Series D equity ...
(Date:1/21/2017)... ... January 20, 2017 , ... G&L Scientific Inc, ... industry ( http://www.gandlscientific.com ), has announced the opening of new offices in Cambridge, ... consultants and contractors. This is the latest step in G&L’s expansion of its ...
(Date:1/21/2017)... Aratana Therapeutics, Inc. (NASDAQ: PETX ... development and commercialization of innovative biopharmaceutical products for companion ... North America 2016. ... on the FDA approval of three innovative therapeutics in ... (capromorelin oral solution) and NOCITA ® (bupivacaine liposome ...
(Date:1/20/2017)... -- http://www.Financialbuzz.com - According to ... of death worldwide. There were 8.2 million cancer related ... deaths increased gradually over time, the death rates have ... cancers continues to drive demand of biological therapies for ... Insights, Inc. cancer biological therapy market size was USD 61.3 ...
Breaking Biology Technology: