Surgeons conducting the largest study yet of women who have cancer in one breast but have both removed have found that this option has grown rapidly despite a lack of evidence that it improves long-term life expectancy. Their findings were recently reported in a study of women whose cases are documented in the National Cancer Data Base (NCDB) of the American College of Surgeons (ACS). The study was published in the October issue of Annals of Surgical Oncology.
The researchers reviewed almost 1.2 million patients who had cancer diagnosed in one breast between 1998 and 2007. Results defined patterns in the use of the surgical procedure to remove the noncancerous companion breast during mastectomy for the primary cancerous breast, a procedure called contralateral prophylactic mastectomy (CPM). The researchers did not look at survival after the procedure, but study authors said they would investigate survival in the future once data has become mature.
“We have described a dramatic increase in the use of contralateral prophylactic mastectomy over the last 10 years,” David P. Winchester, MD, FACS, senior study author, medical director of cancer programs at the American College of Surgeons, stated in a press release. “The incidence increased from a fraction of a percentage, 0.4% in 1998, to 4.7% in 2007.”
Researchers noted the greatest increase among white women younger than age 40; more than 10.5% of whom with single-breast cancer underwent CPM. Women with private insurance were more than twice as likely to have contralateral mastectomy as uninsured women and Medicare beneficiaries. Likewise, women in the highest income zip codes were twice as likely to have CPM as women in lower income areas, the researchers reported.
Results showed that regionally, women in the Midwest had the highest rates of CPM, 6.4% in 2006 to 2007, followed by the South with 5.6%. The lowest rates were in the Northeast, 3.3%. Surgical procedure rates also varied depending on tumor size and type.
“In general, the trend showed the more early stage a cancer, the higher the rate for contralateral mastectomy as compared with a later stage cancer,” lead author Katharine Yao, MD, FACS, director of the breast program at NorthShore University HealthSystem, Evanston, Ill., and faculty member at the University of Chicago, stated.
Despite the paucity of published evidence that CPM prolongs life, Winchester, a surgeon at NorthShore University HealthSystem, Evanston, Ill., and faculty member at the University of Chicago said CPM makes sense for many women. He attributed its growth in utilization to greater awareness among women.
Another consideration for double mastectomy for single-breast cancer is a woman’s desire for breast symmetry and reconstruction.
The study underscores a need for thorough discussions between the surgeon and patient with breast cancer.
“Contralateral mastectomy may make a lot of sense in some cases, but it needs to be an objective, evidence-based discussion between the surgeon, patient, and family,” Winchester stated.