ASCO Issues Updated Recommendations For Breast Cancer Tumor Marker Testing

Main Category: Breast Cancer
Also Included In: Cancer / Oncology
Article Date: 24 Oct 2007 - 14:00 PDT

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The American Society of Clinical Oncology (ASCO) has updated its clinical practice guideline on the use of tumor markers in breast cancer. The guideline authors observed that although researchers have made progress in developing tumor markers in areas such as diagnosis and treatment planning, mammography remains the gold standard in screening for breast cancer.

A tumor marker is a substance found in a person's blood, urine, or body tissue. The presence of a tumor marker, or higher- or lower-than-normal levels of a tumor marker, may indicate an abnormal process in the body, such as cancer, and can provide further information if cancer is diagnosed. Doctors may suggest tumor marker tests at various stages in the diagnosis or treatment of cancer. These tests can provide helpful information about both the cancer and the treatment.

"Increased use of tumor markers represents a shift in our understanding of the basic biology of breast cancer, which will affect how we treat patients," said guideline co-author Lyndsay Harris, MD, Vice Chair of ASCO's Tumor Markers Expert Panel and Associate Professor and Director of the Breast Cancer Disease Unit at Yale University. "The cancer research community needs to continue to conduct more clinical trials to examine exactly how tumor markers can help with the early detection of breast cancer."

To update its clinical practice guideline, first published in 1996 and subsequently updated in 2001, the ASCO expert committee reviewed the use of tumor markers in breast cancer and made recommendations based on their effectiveness for early detection of the disease, as well as their benefit in helping to plan treatment, monitoring response to treatment, and determining a patient's prognosis.

Much progress has been made in the area of tumor markers over the past 10 years. Since the 2001 guideline, researchers have identified six new categories of tumor markers. Although currently there are insufficient data to recommend the use of any of these new tumor markers in diagnosing breast cancer, both ER/PR and HER 2 testing are still recommended for diagnosis, as noted in previous versions of this guideline. However, two new tumor marker tests were recommended for their use in determining a breast cancer patient's treatment or whether or not breast cancer is likely to return after initial treatment.

The updated recommendations covered two new tumor marker tests for patients with newly diagnosed node-negative breast cancer, or cancer that has not spread to the lymph nodes.

The Oncotype DX tumor marker test is recommended for patients with node-negative breast cancer that is ER-positive and/or PR-positive, which is the case for 50 percent of breast cancer patients. The test measures multiple genes at once to estimate the risk of breast cancer recurrence. Patients with a low recurrence score may be able to receive only hormone therapy and avoid chemotherapy. Sparing patients from unnecessary treatment may not only improve their quality of life, but it also will reduce overall health care costs.

Other tumor markers that doctors can test are urokinase plasminogen activator (uPA) and plasminogen activator inhibitor (PAI-1) markers. Testing these tumor markers can help estimate a patient's prognosis. Patients with tumors that do not have uPA and PAI-1 have a good prognosis and may not need chemotherapy. However, the test is not currently commercially available in the United States, but it is in Europe. More studies of this tumor marker are currently under way.

The guideline also encourages patients to enroll in clinical trials that focus on the use of additional tumor markers as a surveillance tool for breast cancer.

"Tumor markers can predict whether or not a patient will respond to treatment," Dr. Harris said. "The goal of these guidelines is to help doctors provide their patients with the best possible care. Patients will benefit from knowing whether or not a treatment will help them before beginning the treatment regimen."

ASCO also released Guideline Clinical Tools on Breast Cancer Tumor Markers, including one to guide doctors to the appropriate tests for patients by their diagnoses. In addition, ASCO released an updated patient guide, Tumor Markers for Breast Cancer: 2007 Update, a patient version of the clinical practice recommendations that is available on ASCO's patient Web site, People Living With Cancer, at http://www.PLWC.org.

Doctors, patients, and the public can access a copy of the guideline and available supplemental materials at http://www.asco.org/guidelines, or e-mailing: guidelines@asco.org.

"Update of Recommendations for the Use of Tumor Markers in Breast Cancer" by Lyndsay Harris, et al., Yale University, New Haven, CT.

This guideline is being published in the November 20 print issue of the Journal of Clinical Oncology (JCO), the semi-monthly peer-reviewed journal of the American Society of Clinical Oncology (ASCO), the world's leading professional society representing physicians who treat people with cancer.

The American Society of Clinical Oncology (ASCO) is the world's leading professional organization representing physicians of all oncology subspecialties who care for people with cancer. ASCO's nearly 25,000 members from the United States and abroad set the standard for patient care and lead the efforts to discover more effective cancer treatments, increase funding for clinical and translational research, and, ultimately, improve cancer care for the estimated 10 million people diagnosed with cancer worldwide each year. ASCO publishes the Journal of Clinical Oncology (JCO), the preeminent, peer-reviewed, medical journal on clinical cancer research, and produces People Living With Cancer, a comprehensive consumer Web site providing oncologist-vetted cancer information to help patients and families make informed health-care decisions.

American Society of Clinical Oncology

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