Many of us know someone who has been affected by breast cancer, which is the second-leading cause of cancer-related death in women. In a recent installment of Ask Stanford Med, we invited a Stanford breast cancer surgeon to respond to questions about breast cancer diagnostics and therapies. He was unable to participate due to scheduling conflicts, but filling in is Debra Ikeda, MD, a professor of radiology who sees patients at the Stanford Cancer Institute.
@erikaamaya_ asks: How often do false-positive breast cancer screenings occur? Are there more effective tests than mammography alone?
False positive studies depend on the breast density, since overlapping tissue can cause false masses, the experience of the mammographer and if old films are available for comparison. Breast cancer screening with mammography is the gold standard for finding breast cancer by screening because it has been exhaustively studied with decades of follow up. Mammography finds 5-8/1000 prevalent cancers on the first screening, 2-3/1000 on subsequent screenings in randomized controlled population trials of invitation to screening mammography. Breast ultrasound screening finds about 3 cancers/1000 not seen by mammography, but has a high false positive rate with positive predictive values of 5.6 percent to 6.6 percent. Breast MRI is the most sensitive and specific study, but is more expensive. For more information visit breastdensity.info.
Erin P. asks: Lawmakers in my home state are currently considering passing legislation similar to California’s breast density notification law. I understand that similar legislation was introduced in Congress in 2011 and it is expected to be reintroduced this session. How would enacting a federal law benefit women vs. having each state decide the issue on its own?
Each state has passed its own law thus far. California legislation mandating notification had the intent to inform women of their density regarding masking of breast cancer, as a risk for breast cancer, and to inform women to speak to their physician if they desire supplemental screening. It has had the effect of increasing scrutiny on breast cancer risk assessment in breast imaging and primary care clinics because it turns out that density is a risk factor for breast cancer in populations studied in various publications. But by itself density is much less of a risk factor than, for example, family history of breast cancer or positive genetic tests for breast cancer that screen for the BRCA1 or BRCA2 genes.
Nancy asks: Is there a link between dense breast tissue, cysts and breast cancer?
Dense breast tissue and cysts may be seen together or separately, and may or may not be related. Breast density is a risk factor for breast cancer certain populations that have been studied in the literature. But by itself is much less of a risk factor than, for example, family history of breast cancer or positive genetic tests for breast cancer (BRCA1 or BRCA2).
@humzaman1 asks: Do breast implants have anything to do with increasing beast cancer risk?
No. This was shown in meta-analyses of silicone breast implants and breast cancer risk mandated by the FDA.
Previously: Ask Stanford Med: Surgeon taking questions on breast cancer diagnostics and therapies, California’s new law on dense breast notification: What it means for women and Five days instead of five weeks: A less-invasive breast cancer therapy
Photo by Wellcome Images