01 Nov Breast Cancer: MRI
Yesterday was the last day of the month of October and I thought it would be nice to end the month with the topic of Breast MRI for Breast Cancer. One has to remember, that with all of these tools, Ultrasound, Mammography, PET, MRI, Genetic Testing, and Hormone Testing that none of them on their own are the best diagnostic test, but in the correct combination based on each patients particular diagnosis, they can be essential tools that will lead to the best possible outcomes.
There have been several studies done to look at the benefits on the use of MRI with breast cancer. A report published by the American Cancer Society states that the addition of breast MRI along with traditional mammography in young, high-risk patients improve the screening success which leads to earlier detection.
This group of women, young and at high-risk, tend to have a larger majority of women that may decide to have a prophylactic mastectomy and to also have their ovaries removed. This is done to prevent them from developing breast cancer. The point is, that just because a woman may be at a high risk, it does not mean that they will 100% definitely develop breast cancer. If we can improve the ability to screen in this population of patients, and lead to better and earlier detection rates, then we can also offer less invasive surgeries, with better cosmetic and emotional outcomes for patients.
According to the data and article published by the ACS on their website on March 28, 2007 (Full Article) that they have changed their guideline to state that women with a high-risk of developing breast cancer and that our young, would benefit from the addition of MRI along with yearly mammograms. This screening protocal would allow women to have the greatest ability for earlier detection which would hopefully lead to better outcomes and survival rates.
MRI scans are more sensitive than traditional mammograms but they also are less specific then mammography as well. What this means, is that MRI might be able to detect smaller lesions that might be missed on a typical screening mammogram, but at the same time, the test is not as definitive to indicate whether or not those lesions detected are cancerous in nature. This also means that lesions detected by MRI and not by mammography would need to have additional follow up. This might mean more unnessecary biopsies, studies, and other invasive prcedures for a woman to have to go through, and thus more anxiety during the process.
“As with other cancer screening tests, MRI is not perfect and in fact leads to many more false-positive results than mammography,” explains Christy Russell, MD, chair of the ACS Breast Cancer Advisory Group and co-author of the new guideline. “Those false-positives, which can lead to a high number of avoidable biopsies, can create fear, anxiety, and adverse health effects, making it imperative to carefully select those women who should be screened using this technology.”
The most current and up to date American Cancer Society guidelines for breast screening are as follows:
1. For women with an average risk of developing breast cancer, that begining at age 40, an annual physical examination and mammograms should be done.
2. For women with a high-risk for breast cancer, physical examination, screening mammograms, and breast MRI should begin at age 30.
According to research published in the New England Journal of Medicine: Vol.351:427-437 July 29,2004 Number 5, (Full Article) they were able to verify that breast MRI was more sensitive then mammography in the detection of cancerous lesions in the breast.
The researchers felt that there wasn’t enough data for the use or benefit of using MRI for the screening of breast cancers in women. So what the researchers decided to do was to begin with the high-risk population of women. That would be a group of women that have a genetic or familial predisposition to developing breast cancer. They would then take this group of women and use mammography, along with physical examination, and breast MRI to see if there was any improvement in finding lesions at an early stage in this population of high-risk women.
There were a total of 1909 women enrolled on the study, including 358 women with a germ-line mutation for breast cancer. These women had a minimum of at least a 15% increased risk for developing breast cancer. The patients were then followed for about 3 years. During this time, patients would under go a clinical breast exam every 6 months and then a mammogram and a MRI every year. These imagining studies were then read independently by 2 seperate qualified radiologists. The findings of the cancers detected on MRI were then compared with the characteristics of breast cancers found in two different age-mathced control groups.
What they found in the 1909 women that were on the study for almost a 3 year period was that 51 cancers (44 invasive breast cancers, 6 DCIS, and 1 lymphoma) and 1 lobular carcinoma in situ were detected. The sensitiviy (ability to detect an abnormal looking lesion) and the specificity (ability to determine its cancerous) for each modaility was as follows:
Clinical Breast Examination: 17.9% and 98.1%
Mammogram: 33.3% and 95.5%
Breast MRI: 79.5% and 89.8%
In another study published in the American Journal of Radiology (Full Article) they took a prospective look at 46 patients that had a positive lesion detected on mammogram, ultrasound, or both, and then were found to be malignant with biopsy. They took this group of women and imaged them with Breast MRI. In their study they found that breast MRI was 100% successful in detecting malignant lesions within the breast. It was able to dtermine in 73.7% of the cases that the lesions were benign or malignant, meaning that the lesions needed additional work up studies.
This study also found that breast MRI was able to detect another additional 37 lesions, 23 of which were found to be cancerous, that were not intially detected by mammogram or ultrasound imaging. Breast MRI was then able to detect another 4 (9%) cancerous lesions in the opposite breast. The addition of MRI to these women only increased in an additional 14 biopsies for what was found to be benign lesions.
In this specific study, the additional information from breast MRI, mainly in having disease present in the opposite breast, resulted in a slight incremental increase in women deciding to have a mastectomy versus breast conserving surgery.
Both of these studies are imporant because it shows that when breast MRI is used in high-risk patients it will allow for earlier detection of potential breast cancers. This will then lead to earlier treatment intervention and have a significant increase in a women’s survival with this disease. In the latter of the studies, it is imporant since it shows that in early stage breast cancers, the additional information obtained under breast MRI may impact and change that patients treatment planning and management. It also means that there is a significant ability to catch other breast lesions in the opposite breast.
As always, if you or a loved one have any other questions, comments, or concerns; if you would like more information in regards to another cancer related topic, please contact me at: CANCERGEEK@GMAIL.COM