Will Blood Tests Replace Bone Marrow Biopsies?

[Guest guest]

[i doubt it. Bone Marrow Biopsies provide information that can

describe the disease progression. For example, the nature and

penetration of CLL cells into the bone marrow varies. Nodular,

interstital and diffuse patterns are all possible with CLL, and they

have prognostic value. Such information is impossible to obtain with

a simple blood test, no matter how sophisticated (at least as far as

I know).]

Posted on: Monday, 24 January 2005, 09:00 CST

New Blood Tests to Soon Replace Painful Bone Marrow Biopsies for

Leukemia and Lymphoma Patients

TETERBORO, N.J., Jan. 24 /PRNewswire-FirstCall/ -- Quest Diagnostics

Incorporated , the nation's leading provider of diagnostic testing,

information and services, announced today that The University of

Texas M. D. Cancer Center in Houston has granted the company

exclusive use of five proprietary blood testing methods, which, once

available in the form of laboratory diagnostic tests, may eliminate

the need for painful and expensive bone marrow and other tissue

extractions. The methods are the subjects of two U.S. patent

applications. The tests are intended to provide a safer, less painful

tool for the diagnosis, treatment and monitoring of leukemia and

lymphoma in cancer patients. The initial tests are expected to be

available following validation, which could be as early as the end of

this year. Additional terms of the licensing transaction were not

disclosed.

Current diagnostic and monitoring tests for leukemia and lymphoma

patients often require patients to undergo painful procedures, such

as bone marrow biopsies which require extraction of tissue with a

bone-piercing, large-gauge needle. The new tests are in development

at Quest Diagnostics' research and development center, Nichols

Institute in San Capistrano, Calif. They have the potential to

provide a more clinically useful assessment of prognosis, disease

progression, and therapeutic success, which could enable oncologists

to advance the efficacy of therapies.

" Our research has shown that testing for tumor constituents in the

blood provides a more clinically useful assessment of a patient's

disease status because it shows what is happening in the entire body,

compared with biopsies where a tissue sample only provides

information about a specific area, " said J. Keating, M.D.,

Professor of Medicine and Deputy Department Chairman for the

Department of Leukemia at M. D. Cancer Center. " It also

offers a less painful and more cost-effective way to monitor

patients. As a result, the new blood tests may allow oncologists to

assess patients more frequently and thus provide more clinically

relevant monitoring of their progress. "

Quest Diagnostics is developing new tests, based on the M. D.

technology, that are designed to detect certain proteins

that are expressed on the surface of tumor cells, as well as

molecular targets from the tumor cells. The assays will look for the

proteins, called CD20, CD33 and CD52, as well as tumor-specific DNA

and RNA in blood plasma. The tests are intended to help doctors

diagnose lymphoma and leukemia, assess patient response to cancer

treatment and monitor the patient post-treatment. By measuring tumor

constituents in the blood, as opposed to assessing a tissue sample,

physicians might one day replace the current bone marrow biopsies

that are painful for patients to endure.

" We are very excited about this opportunity to develop new tests to

help patients with lymphoma and leukemia, " said Surya N. Mohapatra,

Ph.D., Chairman and Chief Executive Officer of Quest Diagnostics. " We

hope to provide physicians with tests that avoid the pain associated

with bone marrow biopsies. "

The technology underlying the new tests was developed under the

leadership of Maher Albitar, M.D., Medical Director for

Hematopathology at Quest Diagnostics. Prior to joining Quest

Diagnostics in 2003, Dr. Albitar was a tenured professor at M. D.

, where he served as Chief of the Leukemia Section in the

Department of Hematopathology, with a joint appointment in the

Department of Leukemia. Dr. Albitar is a co-inventor of the two

current U.S. patent applications by M. D. and is the lead

author on numerous publications on this subject(1). He is a recipient

of a Physician Scientist Award from the National Institutes of

Health.

The new concept that Dr. Albitar and his team at M. D.

observed is that in hematologic diseases, tumor cells pour into

circulation their DNA, RNA, and proteins, and these components can be

detected in plasma. The common assumption had been that only proteins

that were secreted (made by the tumor cell and then transported to

the surface and released into plasma) could be present in the plasma.

Most proteins are not secreted but rather embedded in the cell

surface or inside the cell. The breakthrough was finding that non-

secreted cell-surface proteins as well as their DNA and RNA are

actually in the plasma and available for detection.

Quest Diagnostics will validate the testing technology by comparing

the new tests that are based on peripheral blood plasma with

conventional methods using bone marrow biopsies in patients with

leukemia and lymphoma. Some of these studies are planned in

coordination with M. D. researchers.