TUESDAY, Jan. 27, 2004 (HealthDayNews) -- Mammograms are less likely to detect breast cancer in women who have implants.
However, women with implants don't seem to be diagnosed with breast cancer any later than women without implants.
Those findings, which appear in the Jan. 28 issue of the Journal of the American Medical Association, corroborate previous research.
"There's nothing there that doesn't fit in with all the previous studies and nothing about it that doesn't make good sense," says Dr. Nolan Karp, an associate professor of surgery at New York University School of Medicine and a plastic surgeon with New York University Medical Center.
According to the study authors, about a quarter of a million U.S. women received breast implants for cosmetic reasons in 2002, 11 percent more than in 2000.
The study included data on 10,533 women with implants and without breast cancer, and 974,915 women without implants and without breast cancer at seven locations throughout the United States. The study authors also looked at 137 women with implants who had breast cancer, and 685 women without implants who had breast cancer.
Screening mammography missed 55 percent of breast cancers in women who had undergone breast augmentation, compared to 37 percent in women who had not undergone the procedure.
But when women with and without implants were diagnosed with breast cancer, the stage, size and type of tumor was not significantly different, the researchers found.
No one is sure why this seeming paradox exists, but there are some convincing theories.
"When you put the implant underneath the breast it's like a platform, so you're more likely to feel a [cancerous] mass," Karp says.
"It seems that [women with implants] are finding cancers manually," agrees study author Diana L. Miglioretti, an assistant investigator at the Center for Health Studies at the Group Health Cooperative in Seattle. "The breast implant is firm and it pushes the breast tissue up against the skin so it makes a lump easier to feel."
Miglioretti is a statistical consultant for Silimed Inc., which manufactures breast implants. The study was supported by the National Cancer Institute.
It's also possible that women with implants check their breasts more often and are more body conscious than women without the enhancements, Miglioretti adds.
The bottom line is that women with implants should still get mammograms. They should just be aware that cancers can be missed, and need to be attuned to what they feel in their own bodies.
"Our recommendation to all women who have breast augmentation is to go to a real breast imaging center where they can get multiple images of the breast," Karp says. "The other thing you can do is put the implant underneath the muscle. It's been shown statistically that if you do that, the percentage of the breast that is obscured by the implant is much less."
On the other hand, women who have had the cosmetic surgery can be reassured that implants don't seem to affect survival. "This shows that if you get breast cancer with implants, you don't live any shorter," Karp says.