Mammography is the gold standard in breast-cancer detection, spotting many cancers before they can be felt, but it isn’t a 100 percent safety guarantee.

Women whose likelihood of developing breast cancer is well above average, putting them squarely in the high-risk category, often need more screening.

There’s been ongoing movement nationwide toward making magnetic resonance imaging of the breasts part of that further screening.

Patients with one clearly elevated risk factor, like a specific gene mutation linked to breast cancer, are among those told they may need breast MRI. So are patients whose higher risk stems from multiple, cumulative factors.

Breast MRI can find hidden cancers a mammogram or ultrasound could miss, said Dr. Vanessa Prowler, a Lakeland Regional Health general surgeon specializing in breast cancer.

“It’s more sensitive than a mammogram or ultrasound,'' said Judy Rosell, radiologic and MRI technologist at Radiology and Imaging Specialists. “We can see all the way into the lymph nodes.”

Identifying the patients with high enough lifetime risk to need annual breast MRI still is an evolving process.

Lifetime risk-prediction models get modified to improve accuracy and comprehensiveness. Imaging centers change which model they use.

Women’s personal risk factors, part of the overall equation, also change.

Some who weren’t high risk before are being told they’re high risk now. They get a letter or phone call telling them guidelines recommend breast MRI.

For many, if not all, this provokes uncertainty and questions.

Radiology and Imaging Specialists switched to a screening tool called the Tyrer-Cuzick model that Dr. Angela Sroufe, one of its diagnostic radiologists, said is more comprehensive.

The new screening tool looks at age, extended family history of breast and ovarian cancer, body mass index, exposure to post-menopausal hormones, likelihood of BRCA-1 and BRCA-2 gene mutations and other personal risk factors.

The previous model RIS used has been shown to underestimate risk in some women, she said. The newer one is expected to avoid that by finding women whose risk previously was below the radar.

Considering breast MRI isn’t as easy a decision as getting a follow up mammogram for clearer images.

MRI’s added sensitivity can result in falsely positive findings that lead to more testing or biopsy, said Dr. Toan Nguyen (pronounced win), director of breast oncology at LRH Hollis Cancer Center.

If MRI finds a cancer missed by mammogram or ultrasound, however, it can be a lifesaver for some women.

WHO SHOULD GET BREAST MRI?

The American Cancer Society issued guidelines 10 years ago on using breast MRI as adjunct screening for high-risk women.

Lifetime breast-cancer risk of at least 20 percent or greater became one of its recommended reasons for suggesting breast MRI screening.

Other criteria considered sufficient for annual breast MRI screening are having a BRCA1 or BRCA2 gene mutation, having a first degree relative with BRCA1 or BRCA2, having received radiation to the chest between the ages of 10 and 30 and having some rare genetic diseases.

MRI isn’t recommended as screening on its own, instead of mammograms, because it can miss some cancers a mammogram would find. Women need their annual mammograms, said Prowler, who heads the high-risk clinic at Hollis Cancer Center.

The American College of Radiology’s criteria for breast MRI as screening are like those of the ACS. It recommends screening MRI for women with BRCA gene mutations and their untested first-degree relatives as well as women with a lifetime risk of breast cancer of about 20 percent or greater.

WHAT COMES NEXT?

A woman’s primary care doctor, often her gynecologist, is likely to be the one fielding questions about MRI and what makes a particular patient high risk.

“I usually would say just because you have increased risk for something does not mean you’re going to get that disease,” said Dr. Jennifer Nixon, obstetrician-gynecologist with Women’s Care Florida Lakeland OB-GYN.

“Is a risk of 22 percent the same as 42 percent? Not really.”

She advises them to see whether their insurance company will pay for them to have breast MRI. If insurance won’t, patients need to decide whether they want to pay out of pocket, which could lead to additional questions.

“A general OB-GYN would be the best person to handle the initial discussion,” Nixon said.

Watson Clinic and Hollis Cancer Center breast surgeons consult with women diagnosed as high risk. Each group has a high-risk clinic.

Watson Clinic uses American College of Radiology and National Cancer Institute guidelines for identifying high-risk patients. The ones with above average risk are offered evaluation through its high-risk clinic, said Dr. Elisabeth Dupont, breast surgeon and medical director of breast health services at Watson.

“Significant discussion and patient preference are major factors in the decision,” Dupont said, noting that risk is re-evaluated in the clinic. Genetic counseling and-or close surveillance may be other options.

A second risk assessment might be done. Some women are high risk by one model and not by another.

“Every woman needs to be counseled,” said LRH’s Nguyen. “It should be a comprehensive analysis.”

UNDERSTANDING RISK

Although many risk factors for breast cancer can’t be controlled, others can. Those include obesity, drinking alcohol and being physically inactive.

Factors women can’t change including getting older, starting menopause after age 55 and having dense breasts.

Dense breasts increase risk of breast cancer, doctors interviewed said, and make it harder to see tumors on a mammogram.

Prowler said she’s more likely to recommend breast MRI for women with extremely dense breasts.

More than half of states require breast density be reported to patients. Florida isn’t among them, but legislation was proposed this session that would require it here, Nguyen said.

If the legislation passes, it typically will be up to obstetrician-gynecologists and primary care doctors to explain individual breast density to their patients.

“It’s a way to empower patients and share the knowledge,” Sroufe said.

Robin Williams Adams can be reached at robinwadams99@yahoo.com