Like a lot of women, Jacqueline Canas had her first mammogram at age 40, and she wasn't swayed by a government panel's report in 2009 suggesting that women may not need breast cancer screening until age 50.
"I'd rather have it," said Canas. "I think it's great they do it early, just because if something is there and wrong they can catch it early on."
Now a new study by UCSF and California Pacific Medical Center (CPMC) in San Francisco has come down on her side, but with a twist.
"We found that how often a woman should have a mammogram depends on her risk of getting breast cancer," said CPMC's Dr. Steven Cummings, MD.
Cummngs and his colleagues examined various risk factors, including breast density. Research has suggested that women with denser, less fatty breast tissue are at a statistically higher risk of breast cancer.
"The more tissue a breast has, the greater the chance cells and tissues will result in breast cancer, and that's probably the reason that breast density is such a strong risk factor for breast cancer," said Cummings.
The denser tissue is visible on a mammogram as whiter, more solid looking patches. Cummings says radiologists can then rate the density on a scale of one to four, with one being the lowest density, and four the highest.
But in order to gather and interpret that kind of information, the Bay Area research team issued a key recommendation that women should have a baseline mammogram at the age of 40.
The results can then be used to create a personalized screening plan based on a woman's physiology and family history. Women at higher cancer risk may opt for mammograms every one to two years, while low risk women could have less frequent screenings, avoiding the false positives and unnecessary biopsies that critics say come with over-screening.
"We hope that this is widely adopted because it's simple and makes sense," said Cummings. "Get a mammogram at age 40 to help determine your risk, and once you know risk, then you can make decisions about whether to continue mammograms."
He says the system would also give patients like Canas more power to weigh their options.
"I think it would be great as long as they do have statistics to show that it works," said Canas.
To be clear, breast density is only part of the formula. Researchers also weigh the history of breast cancer in a woman's family and whether she's had a previous biopsy.
Written and produced by Tim Didion.
