Potential Risk of Mammograms
The American Cancer Society estimates the dose of radiation from 1 mammogram to be similar to the background radiation you would receive in a flight between California and New York. Background radiation is considered to be the amount of ionizing radiation a person receives from the earth, sun and other sources that are currently around them. Time frame wise, a mammogram is about 2 months worth of radiation. A chest Xray is is 5 days and CT's can be anywhere from 1 year to 6 years worth of background radiation depending on the site studied. This dose is considered "safe" by the organizations that regulate safety and risk for the average person. The only problem is that people who have germline p53 mutations are not the average; they are more susceptible to genetic damage from ionizing radiation. So how do you screen for potential breast cancers in a high risk population, without exposing them to more radiation? Some long term LFSers have had many mammograms and no breast cancer. Others avoid mammography if possible. You can use shields to protect your thyroid during the mammogram- but there is still a small chance the radiation can scatter internally to the chest wall. Technicians also are hesitant many times to use shields as they can impede the fit of the breasts and alignment with the plates. This increases the chance multiple xrays would have to be taken in order to get the best images, exposing the breast tissue to further radiation. Relatively speaking, the radiation risk of mammogram is small. If there is suspicion of a cancer lump, it is imperative to follow the recommendations of your provider and many times mammography is the quickest and best way to visualize a potential malignancy.
Recommendations for Women with LFS
There is a difference between diagnostic testing and screening when there are no symptoms. Sometimes when there is a suspected lump or malignancy, the best and quickest way to visualize the area will be to use Xray or CT and this includes a small dose of radiation. The body can handle this, the greater concern is repeated exposures when there isn't necessarily something that needs to be visualized, as with screening. Having a good relationship with your care team can help you minimize unnecessary exposures for preventative care. If you are concerned about exposure, speak up and never be afraid to ask if there are less damaging alternatives. A good provider will be sensitive to your concerns and work with you to get you the best care with minimal exposure to risk.
*The National Institute of Health recommends that LFS women have "an annual breast MRI and twice annual clinic breast exams beginning at age 20-25. Use of mammography is controversial because of radiation exposure and limited sensitivity. When included, annual mammograms should alternate with breast MRI, one modality every 6 months."
*MD Anderson recommends annual breast screening using MRI and Ultrasound beginning at age 20-25. According to their website, "Mammograms(for LFS women) are not usually recommended before age 25-30 because they may not be as effective in young women and because of the radiation involved".
*At the Li Fraumeni SyndromeWorkshop at NIH in 2010, Dr. Gareth Evans, a leading clinical researcher in the UK presented data on anecdotal evidence for radiation induced second malignancies in LFS patients. He recommended that LFS folks avoid CT as a means of regular screening and use of MRIs for breast screening as a best option for women in their 20's.
Ultrasound as an Imaging Tool
Ultrasound is a noninvasive and relatively inexpensive tool to image breasts. Often times, ultrasound technology is used to visualize known lesions during breast biopsies. Since ultrasound utilizes radiofrequency, there is also no risk of radiation exposure. This method could be limited because the quality of the screening is dependent on the person operating the machine and radiologist reading the results. The initial studies have been promising for ultrasound as a tool for breast imaging for women in high risk populations. According to the Society of Breast Imaging, "Women at increased risk of breast cancer because of personal or family history of breast cancer were two to three times more likely to have breast cancer seen only by sonography,"
Don't Forget to BE
When it comes down to it- as a woman with LFS, you have to consider your personal beliefs in conjunction with your risks. There are so many factors to take into account- such as access to various screening methods, cost, personal history and symptoms. For a woman with no direct family history of breast cancer and access to alternate screening methods such as MRI and ultrasound- these are low risk ways to monitor potential problems. For some, there is little or no access to MRI or it could be cost prohibitive. It is important to be familiar with your body and breasts and pay attention to changes. One method of screening you always have on hand is Self Breast Exam(SBE). It doesn't cost anything and it's painless. You set the hours and routine. Some women have dense, lumpy breasts and self exams as well as screening lead to anxiety and frustration as well as further possible stress and cost to examine the potential malignancy of lumps. These are all considerations when thinking about screening. Ultimately you have to be comfortable with what you choose, that is the most important criteria.
Everyone values different things and have different interpretations of risks. In making a decision as to what screening is right for you, it important to weigh the costs and benefits to you. If you value proactive screening and can't fathom the possibility of a cancer festering- a more regular regimen of multiple modalities might be instrumental for your peace of mind. One thing to remember is that screening is a choice. In a family cancer syndrome like LFS- we are not given a lot of choices- we don't know if, when, or where cancer may strike. Taking screening into our hands is a way to control our bodies, our knowledge and how we face this journey into the unknown. It is personal and it can be our own. Let the recommendations be the map- but you get to choose which road you take. Sometimes you may want to hop on a plane from LA to New York- maybe it's quicker- maybe it's cheaper- but that is a choice you get to make.
Sources:
NIH Gene Review Li Fraumeni Syndrome
http://www.ncbi.nlm.nih.gov/pubmed/22392042
Society of Breast Imaging
LFS Conference Webcast
