Young women successfully treated for a very early form of breast cancer are at high risk for new breast cancers if they carry a breast cancer susceptibility gene, researchers say.
For many women under 45 with early-stage breast cancer called ductal carcinoma in situ, or DCIS, surgery to remove the cancerous lump and accompanying radiation seem the best way to get rid of the disease and preserve the natural breast. But for women who carry a damaged version of BRCA1 or BRCA2, genes predisposing them to breast cancer, such treatment may not be enough. Researchers at Jefferson Medical College have found that such women have a greater risk of relapsing or developing new tumors in the same or opposite breast years later compared to those women who had a lumpectomy and radiation therapy but don't carry one of these genes.
As a result, says Bruce Turner, M.D., Ph.D., assistant professor of radiation oncology at Jefferson Medical College of Thomas Jefferson University in Philadelphia, who led the work, women and physicians may want to rethink their treatment options.
Dr. Turner presents his team's findings October 23 at the annual meeting of the American Society for Therapeutic Radiology and Oncology in Boston.
Dr. Turner and his colleagues, including Lydia Komarnicky, M.D., assistant professor of radiation oncology at Jefferson Medical College, conducted a study with 50 early stage breast cancer patients under age 45 treated with lumpectomy and radiation at Jefferson, Yale University, and St. Barnabas Hospital in Livingston, N.J. between 1984 and 1996. Cancer returned in 18 of the 46 (36 percent) women. Using computer modeling, the researchers found that many (67 percent) patients with early stage breast cancer and who had a cancer that returned were predicted to have mutations in either one of the breast cancer susceptibility genes, BRCA1 or BRCA2. In contrast, 3 of 32, or 9 percent, of women whose cancer did not return following lumpectomy and radiation therapy were predicted to have a damaged gene.
When they further analyzed the cancers, they found that nearly all of the recurrent cancers were actually new breast cancers.
"Even in early stage breast cancer, like DCIS, women who get lumpectomy and radiation and have or would be predicted to have a mutation in BRCA1 or BRCA2 are at increased risk to develop second cancers in the same breast," Dr. Turner says. DCIS represents 20 to 25 percent of all breast cancers diagnosed or nearly 40,000 women every year are diagnosed with the disease in the United States.
"Having a second primary cancer is what we might expect," he says. Such women have a 50 percent risk of a cancer in the other breast as well.
"This study is additional evidence that the women who either are at high risk for a mutation in BRCA1 or BRCA2 or have a mutation in the gene, treatment with lumpectomy and radiation may cure them of the breast cancer, but they are still at high risk to develop a second cancer in the same breast, and in the other as well," he says.
Dr. Turner believes that the study results may present women and their physicians with some difficult decisions regarding appropriate treatments.
"For women who want breast-sparing therapy who have the mutation or predict to have it, lumpectomy followed by radiation therapy can cure them of their breast cancer, but they have to understand the long-term effects of developing second breast cancers. They may want to consider an alternative therapy such as mastectomy or have close follow-up with their physician following lumpectomy and radiation therapy."
DCIS is considered very curable, Dr. Turner says. But often when it recurs, the cancer comes back as invasive breast cancer, a much more dangerous situation. One problem with recurring cancer is the threat that the disease may spread.
Women at high risk who may need to consider testing for BRCA1 or BRCA2 mutations are those with strong family histories of breast or ovarian cancer and those who developed breast cancer at an early age.