High-Risk Women Should Stagger Breast Tests

CancerWise - March 2009

For women at high risk for breast cancer, alternating mammograms and magnetic resonance imaging (MRI) every six months, instead of having both once a year, may offer the best chance of catching tumors.

Researchers from M. D. Anderson reported this study at the Cancer Therapy and Research Center-American Association for Cancer Research (CTRC-AACR) San Antonio Breast Cancer Symposium in December 2008.

Significance of research

Annual breast cancer screening for women who are at high risk typically includes a mammogram and MRI along with a breast examination.

"We wanted to test the effectiveness of alternating between a mammogram and a breast MRI every six months,” says Huong Le-Petross, M.D., assistant professor in the Department of Diagnostic Radiology at M. D. Anderson and the study's first author. “This way a woman receives an imaging modality screening every six months."

Background

MRI is known to be more sensitive in detecting certain breast cancers than mammography, but MRI is more expensive.

“To date, the mammogram is the only imaging modality proven to have an impact on mortality,” Le-Petross says. “We do not have long-term follow-up information on MRI yet.”

Research methods

Researchers Le-Petross and Banu Arun, M.D., associate professor and director of the High-Risk Breast Clinic and co-medical director of Clinical Cancer Genetics at M. D. Anderson, looked at the medical records of 334 women in a cancer-screening program for women at high risk for breast cancer between 1997 through 2007.

The women were considered to be at high risk if they had:

• Hereditary breast and ovarian cancer syndrome
• Personal history of breast cancer
• Atypia or lobular carcinoma in situ (LCIS)
• 20% or higher lifetime risk of breast cancer

Of these women, 86 (26%) alternated mammograms and MRIs every six months. They completed between one and four screening cycles.

• 46% completed the first cycle
• 28% completed the second cycle
• 13% completed the third cycle
• 4% completed the fourth cycle

The other 248 women had prophylactic mastectomy (surgical removal of a non-cancerous breast) or took chemoprevention medication.

All study participants were given clinical breast exams every six months. They were followed for an average of two years.

Primary results

The alternating MRI and mammography screening program detected nine cancers.

These included:

• Five invasive ductal carcinomas
• Three invasive lobular carcinomas
• Two ductal carcinomas in situ

Of these cancers:

• Five (55%) were found by MRI but not mammography
• Three (33%) were found by MRI and mammography
• One (11%) cancer was not found by either technique
• None were detected by mammography alone

In five of the eight cancers found by MRI, the mammogram six months earlier was normal or suggested benign findings.

"The global picture is that MRI can pick up cancers that mammography cannot," Le-Petross says. "This would suggest it’s more beneficial for high-risk patients to have screening MRIs so we can pick up small lesions before a mammogram can detect them."

What’s next?

Hello I found this study where MDAnderson is challenging the only mammogram yearly standard. You can find it on their website but I copied and pasted it here. I too had a mammogram in Nov of 08 that was normal. It actually said come back in two years. Jan 09 felt a enlarged lymph node. 14 diagnostic mammograms showed nothing. It did show on u/s and MRI. So I too asked this question what about followup when I finish radiation in Dec 09. Here (MDAnderson) they said I should alternate u/s and MRI every 6 months. In Canada they said only followup is yearly mammogram or scans if symptomatic. I am thinking if I get a local recurrence I want to catch it before it leaves the breast. How can I expect to catch it with a mammogram? It defies logic for me. Mammogram is not as effective if you have dense breasts. I was not ever told I had dense breasts but I think important info to know when assessing whether mammogram is effective. At least it is one factor. Also if tnbc moves fast is once yearly adequate during the first 3 years pot treatment during our most at risk time? 

Questions and thoughts I have regarding follow-up

Donna

Researchers are not certain if alternating MRI and mammography will save lives.

"That’s going to take a 10-year follow-up to determine," Le- Petross says. "It’s an exciting question because mammography has always been the gold-standard examination, and now we are challenging that standard."

— Adapted by Dawn Dorsey from an M. D. Anderson news release