Lifewatch: Cancer detecting blood test - WECT TV6-WECT.com:News, weather & sports Wilmington, NC

12.05.08

Lifewatch: Cancer detecting blood test

Reported by Claire Hosmann - email
Posted by Debra Worley - email

(WECT) - More than half of those diagnosed with cancer will undergo chemotherapy.  For some patients it works, but for others it doesn't.

It can take months to find out whether the treatment is affective for you, but now a simple blood test can give patients and doctors the answer.

As cancer grows, fragments of the infected DNA shed into the bloodstream.

You would never know that just a few hours before she was making brownies with her kids, Ivelisse Page was told her stage-three colon cancer returned.

She was diagnosed in the early fall with the tumor, and 15 inches of her colon was removed.

"It seems like at every point, my husband and I have gotten the rug slipped from under us," said Ivelisse.

A new personalized blood test may be able to help Ivelisse decide her next plan of attack.

"It can tell you how much tumor you have, if you're responding to therapy or surgery or radiation," said Ivelisse.

As cancers grow, they shed fragments of DNA, laced with mutated genes into the bloodstream. Researchers at Johns Hopkins developed a test to measure those mutated genes.

In a study of 18 patients, the blood test not only identified cancer in all of them, but also measured the level of cancer.

"Right now when you get a biomarker test or even a CT scan, that might give you a hint of how much tumor you have, but it's not going to tell you exactly how much tumor you have that you can or can't see," said Oncologist, Dr. Luis Diaz.

The test may also help predict who will get cancer.

"Ultimately what we would ultimately like to do is to give this test to everyone in the country and tell them, you know, we're concerned you have a cancer because the causative mutation that causes cancer is found in your blood," said Diaz.

Ivelisse hopes the test will help people like her make the right decision for themselves and their families.

Dr. Diaz says the test could be applied to any cancer that is linked to a known gene mutation, including: breast, colon, lung and prostate cancers.

For more information, please contact:
Johns Hopkins Kimmel Cancer Center
Valerie Mehl, Public Relations
(410) 955-1287
mehlva@jhmi.edu

BACKGROUND: Colorectal cancer refers to cancer that starts either in the colon or the rectum. They are often joined by name because they have many common  features. Colon cancer forms in the tissues of the colon, the longest part of  the large intestine. Most cases of colon cancer are adenocarcinomas, or cancers  that arise in cells that make and release mucus and other bodily fluids.

Rectal cancer forms in the rectum, the last several inches of the large intestine. The American Cancer Society says excluding skin cancers, colorectal cancer is the third most common cancer diagnosed in the United States. National Cancer Institute estimates show 108,070 cases of colon cancer, 40,740 cases of rectal cancer and 49,960 cases of combined colon and rectal cancer were predicted to occur in the United States in 2008.

TREATMENT: As is the case for most other cancers, the four main types of treatment are surgery, radiation therapy, chemotherapy and targeted therapies, which are also called monoclonal antibodies. The main treatment for both colon and rectal cancers is surgery. For colon cancer, a colectomy is performed. This usually involves removing the cancer and part of the colon, as well as nearby lymph nodes. The two ends of the colon are then sewn back together. For rectal cancer, the type and invasiveness of the surgery depends on the location and size of the cancer. Some rectal surgeries can be done without cutting into the skin, but others require operating on the colon and other nearby organs as well.

SCREENING THE BLOOD FOR CANCER: Almost all cancers form through the mutation of genes that control the growth of cells. Because of this, as cancers grow, they shed fragments of DNA into the bloodstream. A new test measures levels of DNA from tumors that end up in the bloodstream. Researchers say the test can not only detect the presence of a tumor; it can also track its progress. A study assessing the test involved 18 patients with colorectal cancer. To test the patients, researchers first identified the mutations present in each patient's cancer. They then used a method called BEAMing to search for related mutant tumor DNA in the patients' plasma. In all 18 patients, the same mutations detected in their tissue were found in their plasma. The test also measures the level of tumor DNA circulating in the blood. The higher the level of mutant DNA, the more advanced the cancer.

Doctors hope the test will also be able to predict who is susceptible to cancer and, when a patient gets cancer, if it will recur. "We want to say with as much certainty as we can who will recur and who won't recur, because if we find out with good certainty who will recur, those patients are the ones to whom we recommend chemotherapy," Luis Diaz, M.D., an oncologist at the Johns Hopkins Kimmel Cancer Center in Baltimore, Md., told Ivanhoe. Another test that shows promise for predicting the responsiveness of colorectal cancer patients to treatment is microRNA expression. A recent JAMA study shows high levels of the microRNA called miR-21 may predict poor patient survival.

 

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