New Haven, Conn.-- Women with cancer-causing genes who choose lumpectomy and radiation therapy appear to have an increased risk of getting a second tumor in the treated breast five to 10 years after treatment, a Yale study finds.
The results of this 14-year study, appearing in the Journal of Clinical Oncology's October issue, suggest that breast cancer patients who carry either the BRCA1 or BRCA2 gene may be at higher risk for late relapses than their counterparts who do not harbor these mutations.
"Previous studies have established that women with BRCA1 or BRCA2 genes have a very high rate of developing breast cancer," said Bruce G. Haffty, M.D., associate professor of therapeutic radiology at Yale University School of Medicine. "Our findings reveal that if these women elect breast conserving therapy, radiation and lumpectomy, there is possibly a greater risk of developing a second tumor in the conservatively treated breast."
The study also found that breast cancer patients with one of these cancer-causing genes don't have a risk of early relapse. They respond very well to treatment immediately following therapy, but begin developing second tumors long after therapy has been completed, up to 10 years or more after original treatment.
"In our study, women who developed second tumors can be effectively treated with mastectomy at the time of detection," said Dr. Haffty. "These findings are significant because drugs like tamoxifen or other estrogen reception modulators that prevent second tumors, can perhaps be prescribed earlier. The information may also be helpful in making treatment decisions."
The BRCA1 and BRCA2 genes are most predominant in breast cancer patients under age 40 and predisposes them to getting cancer at an early age. Lumpectomy and radiation therapy remains the preferable standard of care for the majority of early stage breast cancer patients with or without the BRCA1/2 gene.
"These genes have only recently been sequenced so the lack of data makes it difficult to determine the best treatment options," said Dr. Haffty. "Some clinicians are beginning to recommend double mastectomies for women with BRCA1 or 2 mutations who have not yet been diagnosed with breast cancer, but additional research with long-term follow-up is needed to make definitive treatment suggestions."
Because the number of patients in his research was small, Dr. Haffty stresses the importance of larger studies that will reinforce his findings and cautions that treatment recommendations should not be made solely on the results of this preliminary data. To help meet the need for additional research, Dr. Haffty is currently conducting a larger study of women under 40 with breast cancer to determine the actual risk of recurrence in women with and without the BRCA1 or BRCA2 gene.
Dr. Haffty's research collaborators at Yale include Bruce C. Turner, Elizabeth Harrold, Ellen Matloff, Tanya Smith, Andrew A. Gumbs, Malcolm Beinfield and Peter M. Glazer. The team also includes Brian Ward, Mark Skolnick and Alun Thomas from Myriad Genetics, Inc.
Journal
Journal of Clinical Oncology