As the debate continues to swirl around the medical significance of dense breasts and whether extra screening should be done, a new study led by UC San Francisco has found that women with dense breasts may need only routine mammograms unless they are at high risk.
In their paper, the researchers said that five-year breast cancer risk is a critical component, and breast density should not be the sole factor in deciding whether supplemental screening is justified because not all women with dense breasts are at high risk of cancer.
Research has shown that women with dense breasts may be more likely to develop cancer.
The study was published May 18 in Annals of Internal Medicine.
The research focused on approximately 365,000 women ages 40 to 74 years old who had undergone a regular digital screening mammogram and had no history of breast implants or breast cancer.
Breast density is determined only by mammograms – having dense breasts makes it more difficult for X-rays to pass through the breast tissue and can mask tumors. Breasts are considered dense if the woman has a lot of fibrous or glandular tissue but not much fatty tissue, according to the American Cancer Society.
“Not all women with dense breasts have a high-enough risk of cancer to justify supplemental screening,” said lead author, Karla Kerlikowske, MD, a professor of medicine and epidemiology and biostatistics at UCSF and a primary care physician at the UCSF-affiliated San Francisco VA Medical Center. “We found that for the vast majority of women undergoing mammography – including those with dense breasts but low five-year breast cancer risk – the chance of developing breast cancer within 12 months of a normal mammogram was low. Women with extremely dense breasts and intermediate to high five-year breast cancer or heterogeneously dense breasts and high five-year breast cancer risk were at highest risk for developing breast cancer after a normal mammogram.”
“Our findings can help guide women and providers in discussing supplemental imaging and whether to consider extra testing,” said Kerlikowske. “This study provides a starting point to identify women who may have the most to gain from supplemental imaging or alternative imaging strategies.”