Mayo Clinic study suggests that proper management of asthma will decrease odds of breast cancer metastasis to the lung

Wednesday, October 15, 2008

SCOTTSDALE, Ariz. — In a study investigating how allergic respiratory inflammation leads to the recruitment of cells to the lung, researchers at Mayo Clinic in Arizona have discovered a link between asthma and the metastasis of breast cancer to the lung.

The findings will be published in the October 15, 2008, issue of Cancer Research.

Beginning with research on mice, Mayo Clinic researchers have identified the localized tissue inflammation associated with asthma as a potentially significant contributor to lung metastasis of cancer. More importantly, this research led to a retrospective review of a breast cancer surgical patient database which appears to confirm that a similar relationship may exist in humans.

"If you are a breast cancer patient with asthma, taking your anti-inflammatory inhaled steroids may be more important to you than simply stopping your wheezing" says James Lee, Ph.D., a Mayo Clinic researcher in Arizona and the senior author of the study. "The prognosis of any breast cancer patient with metastatic disease in the lung is very poor, and thus strategies preventing this event may have a significant impact on patient survival."

Approximately 7.4 percent of women in the U.S. have asthma. In contrast, the study found that the prevalence of asthma among breast cancer patients with recurrence of their disease as metastases in the lung is two-fold higher than among non-asthmatic women with breast cancer.

Metastases from solid tumors to distant sites are the main cause of malignancy-related death in cancer patients. Thus, this work suggests that existing treatments targeting the lung inflammation associated with asthma may help patient survival after diagnosis of breast cancer by suppressing and/or preventing metastasis to the lung in the 7 to 8 percent of breast cancer patients with this respiratory disease.

Interestingly, the underlying causes of the increase in lung metastasis among asthmatics may not be breast cancer-specific, and asthma may also increase the metastasis of other solid tumors to the lung.

"It appears that inflammation changes the lung environment, encouraging the recruitment of circulating cells. As a result, the aggressive treatment of asthma may also have a considerable effect on the survival of a spectrum of cancer patients with this respiratory disease," says Dr. Lee.

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Mayo Clinic Cancer Center is one of only 39 U.S. medical centers that have been named as a National Cancer Institute (NCI) Comprehensive Cancer Center. To receive this designation, an institution must meet rigorous standards demonstrating scientific excellence and the ability to integrate diverse research approaches to address the problem of cancer. Mayo Clinic Cancer Center is the only national, multi-site center with the NCI's Comprehensive Cancer Center designation. In Arizona, Mayo's clinical and research experts work together to address the complex needs of cancer patients, with a dedication to understanding the biology of cancer; discovering new ways to predict, prevent, diagnose and treat cancer; and transforming the quality of life for cancer patients today and in the future.

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About Mayo Clinic

Mayo Clinic is the first and largest integrated, not-for-profit group practice in the world. Doctors from every medical specialty work together to care for patients, joined by common systems and a philosophy of "the needs of the patient come first." More than 3,700 physicians, scientists and researchers, and 50,100 allied health staff work at Mayo Clinic, which has campuses in Rochester, Minn; Jacksonville, Fla; and Scottsdale/Phoenix, Ariz.; and community-based providers in more than 70 locations in southern Minnesota., western Wisconsin and northeast Iowa. These locations treat more than half a million people each year. To obtain the latest news releases from Mayo Clinic, go to www.mayoclinic.org/news. For information about research and education, visit www.mayo.edu. MayoClinic.com (www.mayoclinic.com) is available as a resource for your health stories.