(NaturalNews) 70 percent of breast cancer patients who undergo a double mastectomy do not actually need the procedure, according to a study to be presented at the Quality Care Symposium of the American Society of Clinical Oncology.
The study was conducted by researchers from the University of Michigan, Memorial Sloan-Kettering Cancer Center, the University of Southern California and Wayne State University, and funded by grants from the National Cancer Institute.
Worldwide, breast cancer accounts for 23 percent of all women's cancers and 14 percent of all women's cancer deaths. According to the American Cancer Society, 229,060 people will be diagnosed with breast cancer in the United States this year, and the disease will cause 39,920 deaths.
In recent years, many women have sought to reduce their risk of breast cancer recurrence by undergoing the removal of both breasts even when one of the breasts is healthy, a procedure known as contralateral prophylactic mastectomy. Many health advocates have raised concerns that this aggressive treatment option is being overused.
The researchers interviewed 1,446 women who had been successfully treated for breast cancer without experiencing recurrence. They examined the types of treatment received, as well as at the patients' clinical indications for double mastectomy. They found that among women who underwent a mastectomy, almost 20 percent had both breasts removed. Seven percent of all women in the study had a double mastectomy.
90 percent of women who had undergone a double mastectomy said that they had been very worried about the possibility of recurrence. Yet, according to the researchers' assessment of the actual risk of recurrence, a full 70 percent of women who underwent contralateral prophylactic mastectomy had done so without good cause. That's because in the vast majority of cases, a diagnosis of cancer in one breast is not correlated with an increased risk of cancer in the other breast.
"Women appear to be using worry over cancer recurrence to choose contralateral prophylactic mastectomy," researcher Sarah Hawley said. "This does not make sense, because having a non-affected breast removed will not reduce the risk of recurrence in the affected breast."
The only women in whom cancer in a single breast is associated with a risk of cancer in the other breast are those with either a history of breast or ovarian cancer in two or more immediate family members, or with a specific mutation in the BRCA1 or BRCA2 genes.
"For women who do not have a strong family history or a genetic finding, we would argue it's probably not appropriate to get the unaffected breast removed," Hawley said.
In addition to the extra cost and the impact on the patient's life of removing to breasts rather than one, a double mastectomy is associated with significantly more complications and a more difficult recovery than a single mastectomy.
The researchers are now working on a tool to help women make decisions about their breast cancer treatment options.
"A decision tool like ours will solicit common misconceptions about breast cancer treatment and give women feedback to help them fully understand the options and risks involved," Hawley said.