Young, Black Women at Higher Risk of Aggressive Breast Cancer

MONDAY, March 26 (HealthDay News) -- U.S. breast cancer patients with a particularly deadly form of the disease are more likely to be poor, black or Hispanic, and under 40 years of age, new research shows.

Patients diagnosed with "triple-negative" breast cancer lack three key hormonal cancer markers that are present in most other forms of the disease, experts explain.

The absence of these cell receptors deprives doctors and patients of critical diagnostic informationandprime targets for treatment, reducing a patient's therapeutic options and undercutting her expected survival.

"The paradox is that while African-American and Hispanic women have a lower overall risk for breast cancer, they have a higher mortality, which is probably due to the higher incidence of triple-negative [disease]," said study co-author Dr. Vincent Caggiano, research medical director of the Sutter Cancer Center at the Cancer Surveillance Program in Sacramento, Calif.

"So, in addition to the usual surgery that all women undergo, these triple-negative women are not eligible to receive any hormonal therapy," he added. "This leaves them with only chemotherapy to treat a very aggressive form of breast cancer. And although triple-negative patients respond well to chemotherapy, they relapse and their survival is shortened."

The findings are published in the May 1 issue ofCancer.

According to the American Cancer Society, breast cancer is the second most common cancer among women, after nonmelanoma skin cancer. Women living in North America are subject to the highest rate of breast cancer in the world, and nearly 180,000 new cases of breast cancer will be diagnosed in the United States this year alone.

In most cases of breast cancer, the presence of hormonal receptors in tumor tissue allows for the use of highly effective and narrowly targeted endocrine treatments --collectively known as "hormone adjuvant therapy" -- which have been developed in recent years as an alternative to systemic chemotherapy.

Hormone receptors are specialized protein molecules that can be located outside or inside either normal or cancerous cells. Such receptors attract and draw in particular hormones, such as estrogen or progesterone. As hormones "lock up" with hormone receptors, the effect is like flicking on a switch for certain cellular activities, including cancer cell growth.

Recognizing that no two cancers are alike, newer drugs -- including aromatase inhibitors and herceptin -- target hormone receptors specific to the patient's cancer cells.

But about 15 percent of patients have so-called "basal-like" breast cancer, which includes all triple-negative cases. In such instances the tumor lacks hormone receptors for either estrogen (ER), progesterone (PR), or human epidermal growth factor receptor 2 (HER2).

To identify those women at highest risk for basal-like breast cancer, Caggiono and his team analyzed the demographics of 6,370 California women diagnosed with a primary case of triple-negative breast cancer between 1999 and 2003. The women were identified through the California Cancer Registry.