WASHINGTON, D.C. -- Certain cancer signaling pathways that are activated in aggressive cancer can be detected very early, even in precancerous cells, among young African-American women at high risk for breast cancer. This may allow for earlier detection and prevention of cancer.
However, the early activation of these pathways, which are linked to how the body's cells consume and break down sugar, also raise the concern that certain conditions such as gestational diabetes and prediabetes, where the body produces more sugar, might stimulate precancerous cells promoting a conversion into cancerous cells.
Victoria L. Seewaldt, M.D., presented these study results at the Fourth AACR Conference on The Science of Cancer Health Disparities, held Sept. 18-21, 2011, in Washington, D.C.
"We see a lot of very aggressive triple-negative breast cancers among young African-American women and a very high death rate, with only 14 percent alive at five years," explained Seewaldt, professor of medicine and co-director of the breast and ovarian cancer program at Duke University in Durham, N.C. "We wanted to figure out why this was occurring among these women."
It was already known that aggressive cancer cells actively consume glucose and produce lactic acid, even in the presence of adequate oxygen. Seewaldt and colleagues said this shift toward lactate production is called the Warburg effect.
"One of the hallmarks of really aggressive cancers is that they start taking sugar, breaking it down and turning it into energy," she said. "It becomes their primary source of energy and that allows the cancer cells to grow rapidly."
Although the Warburg effect is normally assumed to be a late event in breast cancer, previous research indicated that this process occurs early, even during cancer initiation, in high-risk African-American women. Because this process is occurring earlier, the researchers theorized that they could test for it in young African-American women as a method of breast cancer prevention.
Seewaldt and colleagues looked at two independent groups of 39 and 38 high-risk premenopausal African-American women. High-risk women were normally those women who had mothers or sisters who died from breast cancer at an early age, according to Seewaldt.
"We found that in a high proportion of high-risk African-American women these precancerous cells were taking in a high amount of glucose, and they also had activation of insulin signaling," she said. "In these women, we would worry that if they developed gestational diabetes that the condition could really stimulate precancerous cells."
Luckily, conditions like obesity and gestational diabetes can be avoided or treated, said Seewaldt.
"Exercise, weight loss and the diabetes drug metformin provide important opportunities for preventing aggressive breast cancer in African-American women. These are things where a community approach could really make a difference," she said.
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The mission of the American Association for Cancer Research is to prevent and cure cancer. Founded in 1907, the AACR is the world's oldest and largest professional organization dedicated to advancing cancer research. The membership includes 33,000 basic, translational and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and more than 90 other countries. The AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants, research fellowships and career development awards. The AACR Annual Meeting attracts more than 18,000 participants who share the latest discoveries and developments in the field. Special conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment and patient care. The AACR publishes seven major peer-reviewed journals: Cancer Discovery; Cancer Research; Clinical Cancer Research; Cancer Epidemiology, Biomarkers & Prevention; Molecular Cancer Therapeutics; Molecular Cancer Research; and Cancer Prevention Research. AACR journals received 20 percent of the total number of citations given to oncology journals in 2010.