Mammograms - Are They Completely Without Risk?
Breast screening is an area where I believe women deserve balanced information about both the benefits and potential harms, so they can make informed decisions about their own health.
The surprising research on false-positive mammograms
A large Swedish study published in JAMA Oncology followed women for up to 20 years after mammography. Women who had received a false-positive mammogram - where something suspicious was detected but subsequent investigation did not diagnose cancer - had a greater likelihood of developing breast cancer later.
Over 20 years, breast cancer occurred in 11.3% of women who had experienced a false positive compared with 7.3% of women who had not. Breast-cancer mortality was also 84% higher.
An important clarification: the study did NOT find that mammograms caused an 84% increase in breast-cancer deaths. Rather, women with a previous false positive subsequently developed more breast cancers, which appears to explain their higher mortality.
Why might cancer appear later?
Interestingly, subsequent cancer was particularly likely to occur in the same breast that produced the false-positive result, especially during the first few years.
Researchers suggest that a very small cancer may occasionally have already been present but wasn’t detectable during the original follow-up. Alternatively, the suspicious tissue may have been a marker of increased future breast-cancer risk.
Certain benign proliferative breast changes increase breast-cancer risk. Breast density, genetics and potentially hormonal factors may also contribute.
This doesn’t mean ordinary breast cysts or cyclical lumpy breasts will become cancerous. Most common fibrocystic changes are benign. However, a false positive may provide useful information about a woman’s future risk rather than simply meaning “nothing was wrong.”
What about stress?
A breast-cancer scare can understandably cause significant stress and anxiety. Research into psychological stress and breast-cancer development is mixed: some studies have found associations between significant stress or stressful life events and subsequent breast cancer, while others have not.
We do know that chronic stress can influence neuroendocrine, inflammatory and immune pathways, making stress management an important part of supporting overall health.
My concerns about mammography - is it antiquated?
Mammography uses low-dose ionising radiation and requires breast compression which can be very painful. Other recognised potential harms of screening include:
* false positives and anxiety
* additional imaging and biopsies
* overdiagnosis and overtreatment
* limitations in detecting some cancers, particularly in dense breasts.
Overdiagnosis means finding a cancer through screening that would never have become clinically significant during that woman’s lifetime. Unfortunately, once found, we can’t always know which cancers will progress, so some women receive treatment for cancers that would never have harmed them.
What did the Cochrane review find?
A Cochrane review of randomised mammography trials involving approximately 600,000 women aged 39–74 raised important questions about this balance.
Using the review authors’ assumptions, for every 2,000 women invited to screening for 10 years:
1 woman may avoid dying from breast cancer.
Around 10 women may be overdiagnosed and treated unnecessarily.
And more than 200 may experience significant psychological distress following false-positive findings.
These figures don’t mean mammography has no benefit. They show why women deserve information about both benefits and harms.
What about thermography?
I have long been interested in clinical thermography because it is non-invasive, doesn’t compress the breasts and doesn’t expose breast tissue to ionising radiation.
Thermography measures temperature patterns and blood flow near the breast’s surface. It may be offered as an adjunctive assessment, but it has not been demonstrated to be sufficiently reliable as a stand-alone breast-cancer screening test as it doesn't seem to evaluate deeply enough into the breast tissue.
So what should women do?
Know your breasts. Become familiar with what is normal for you and how your breasts change throughout your menstrual cycle.
Breast tissue is highly hormone-responsive, so tenderness, swelling and lumpiness can fluctuate throughout the cycle. But don’t automatically assume a change is hormonal.
Look out for a new or persistent lump, nipple change or discharge, skin dimpling, change in breast shape, persistent focal pain or other unexplained change should always be investigated.
When considering screening, ask about your individual breast-cancer risk and breast density. Ask about the absolute benefits and potential harms of mammography for someone of your age and risk profile, and whether additional imaging such as ultrasound or MRI may be appropriate.
And take care of your breasts!
1. Support lymph flow - no bras in bed. Avoid under wire bras. Massage oil (coconut, sweet almond oil etc) into your breasts every day. This helps the circulation of blood & lymph. I’ve found this especially helpful for lumpy breasts.
2. Avoid fragrance especially those carried by phthalate’s as they are endocrine disrupting (EDCs).
3. If you have dense or lumpy or painful breasts try castor oil packing!
Shine bright, Nic
Naturopath & Medical Herbalist
Specialising in Women’s Health
References:
Comments