Researchers discover a DNA marker may indicate differences in breast cancer

June 2, 2012, North Shore-Long Island Jewish Health System

Researchers and doctors at the North Shore-LIJ Health System and the Feinstein Institute for Medical Research have discovered a potential explanation for why breast cancer is not experienced the same way with African American and Caucasian patients. This data will be presented at the 2012 American Society of Clinical Oncology (ASCO) Annual Meeting to be held from Friday through Tuesday (June 1-5) in Chicago, IL.

Breast cancer is more common in Caucasian women than in African American women; however, African American women experience a more aggressive form of breast cancer that occurs almost a decade earlier than Caucasian women. Because of this, African American women have a lower breast cancer survival rate than Caucasian women. To explore the reasons why, researchers and doctors at the North Shore-LIJ Health System and the Feinstein Institute for Medical Research conducted a study to determine 1) why the expression of a embedded in deoxyribonucleic acid (DNA), called microRNA, differs between African American and Caucasian women, and 2) if variation in microRNAs may explain the observed survival difference between African American and Caucasian women.

In this study, microRNA profiles from the blood of 32 female patients were collected before removal of . The mean age of the patients was 50 years, ranging from age 31 to 68, and 10 of the patients had stage III triple-negative breast cancer (five were African American and five were Caucasian), 10 patients had stage III estrogen-receptor or progesterone-receptor positive breast cancer (five were African American and five were Caucasian), and 12 patients were controls (six were African American and six were Caucasian). Triple-negative breast cancer refers to any breast cancer that does not express three receptors known to advance most breast cancers; estrogen receptors, progesterone receptors and human 2 (HER2). Although triple-negative breast cancer is negative, progesterone-receptor negative and negative, and the most successful treatments for breast cancer target these receptors, triple-negative breast cancer typically responds to chemotherapy.

The study found that, 1) female who had triple-negative breast cancer overexpressed 20 microRNAs (15 times higher than the controls), and none of the microRNAs these patients had were found in any of the African American patients, 2) female African American breast cancer patients overexpressed only six microRNAs (15 times higher than the controls), and none of these microRNAs were detected in Caucasian patients who had triple-negative breast cancer, and 3) four microRNAs in African American patients and eight microRNAs in Caucasian patients were not previously reported in association with breast cancer, which suggests that they may be connected to how the patient reacts to cancer.

"The striking difference in the patterns of microRNA expression between African American and Caucasian breast cancer patients may provide insight into answering why, when receiving similar treatments, outcomes are different between African Americans and Caucasians," said Iuliana Shapira, MD, director of the Cancer Genetics Program at the North Shore-LIJ Health System's Monter Cancer Center. "Breast cancer patients who have the most devastating outcome may carry the microRNAs that promote cancer. What we saw in this study is that may carry microRNAs that protect against cancer while African American women do not express those microRNAs. The lack of expressing these microRNAs in African Americans could be the cause of poor outcomes seen in these women. Methods to increase microRNAs in the blood before surgery for cancer, such as giving chemotherapy before surgery for cancer, may improve survival rates in with triple-negative ."

Explore further: Childbearing may increase risk of hormone receptor-negative breast cancer in African-American women

Related Stories

Childbearing may increase risk of hormone receptor-negative breast cancer in African-American women

August 16, 2011
African-American women are at higher risk for hormone receptor-negative breast cancer, one of the most difficult subtypes to treat, but this risk could be ameliorated somewhat by breast-feeding their children.

Vitamin D influences racial differences in breast cancer risk

April 4, 2012
American women of African ancestry are more likely than European Americans to have estrogen receptor (ER) negative breast cancer. There continues to be discussion about the role of low levels of vitamin D in the development ...

Recommended for you

How cancer metastasis happens: Researchers reveal a key mechanism

January 18, 2018
Cancer metastasis, the migration of cells from a primary tumor to form distant tumors in the body, can be triggered by a chronic leakage of DNA within tumor cells, according to a team led by Weill Cornell Medicine and Memorial ...

Modular gene enhancer promotes leukemia and regulates effectiveness of chemotherapy

January 18, 2018
Every day, billions of new blood cells are generated in the bone marrow. The gene Myc is known to play an important role in this process, and is also known to play a role in cancer. Scientists from the German Cancer Research ...

These foods may up your odds for colon cancer

January 18, 2018
(HealthDay)—Chowing down on red meat, white bread and sugar-laden drinks might increase your long-term risk of colon cancer, a new study suggests.

The pill lowers ovarian cancer risk, even for smokers

January 18, 2018
(HealthDay)—It's known that use of the birth control pill is tied to lower odds for ovarian cancer, but new research shows the benefit extends to smokers or women who are obese.

Researchers develop swallowable test to detect pre-cancerous Barrett's esophagus

January 17, 2018
Investigators at Case Western Reserve University School of Medicine and University Hospitals Cleveland Medical Center have developed a simple, swallowable test for early detection of Barrett's esophagus that offers promise ...

Scientists zoom in to watch DNA code being read

January 17, 2018
Scientists have unveiled incredible images of how the DNA code is read and interpreted—revealing new detail about one of the fundamental processes of life.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.