Comparing mammography and thermography.
Breast cancer screening is used to identify breast cancer in women who have no physical symptoms. It is hoped that finding breast cancer early will enable women to undergo less invasive treatments, with better outcomes.
However, there is currently much debate about which methods should be used for screening, and how often women should be screened. At present, the most commonly recommended screening method is mammography.
During a mammogram, the breast is compressed between two plates and an X-ray is transmitted through the breast tissue.
The images that are captured are called mammograms.
Some breasts have dense tissue that appears white on the image film. This can mask the presence of tumors, which also appear white on film.
Other breasts are made up of low density fatty tissue, which appears grey on the image film. It is much easier to see white tumors or calcium buildups on these mammograms.
Benefits
Some evidence suggests that mammography screening is associated with a reduction in the number of women who will die from breast cancer.
However, different groups interpret the data in different ways. Some experts say that screening provides no benefit while others say that it does.
Those who say it does estimate that over the next 10 years, for every 10,000 women who get regular mammograms, the number of women whose lives will be saved thanks to the mammogram is approximately:
- 5 out of 10,000 women aged 40 to 49 years
- 10 out of 10,000 women aged 50 to 59 years
- 42 out of 10,000 women aged 60 to 69 years
The benefit of a mammogram is greater for women in high-risk groups, such as older women, or women with a history of breast cancer in the family.
The United States Preventive Services Task Force (USPSTF) recommend that only women aged 50 to 74 years undergo a screening mammogram every 2 years. Other organizations have different recommendations, as mentioned below.
Potential risks
There are some potential risks that are considered to be associated with mammography and mammograms. They include the following:
- They require repeated exposure to radiation, which may cause a very small risk of cancer if used over a lifetime.
- They can lead to non-invasive cancers being diagnosed and treated when treatment is not necessarily required.
- They are not as effective for women with dense breast tissue or breast implants.
- They can lead to women choosing double mastectomies as a preventive measure.
They have a high rate of false-positive results, which can result in unnecessary biopsies and additional screening. False-positive results are those that suggest that cancer is present when it is not.
In 2009, the USPSTF revised their 2002 suggestion of a mammogram every 1-2 years for women of 40 years and over. One of the reasons for this change was a number of studies that showed an increased risk of false-positive results when screening starts at a younger age or takes place every year.
The USPSTF now recommend that only women aged 50 to 74 years undergo a screening mammogram every 2 years. Although this advice is in line with that offered in many European countries, it differs with the recommendations of some other U.S. organizations.
The American College of Radiology and the Society of Breast Imaging both continue to recommend annual mammograms for women starting at age 40. The current guidelines issued by the American Cancer Society advise a mammogram every year for women of 45 to 54 years, and every 2 years for women of 55 years and older.
As has been shown, the heated debate concerning safe mammography policy and practice continues. In light of the debate, various emerging technologies are now being suggested as alternative options for breast cancer screening.
What is thermography?
Thermography is a test that detects and records temperature changes on the surface of the skin.
Digital infrared thermal imaging (DITI), a type of thermography used in the screening of breast cancer, uses an infrared thermal camera to take a picture of the areas of different temperature in the breasts. The camera displays these patterns as a sort of heat map.
The presence of a cancerous growth is associated with the excessive formation of blood vessels and inflammation in the breast tissue. These show up on the infrared image as areas with a higher skin temperature.
Benefits
It is a non-invasive, non-contact procedure, which does not compress the breast.
It does not involve exposure to radiation, and so it can be used safely over time.
It can detect vascular changes in breast tissue associated with breast cancer many years in advance of other methods of screening.
It can be used for all women, including those with dense breast tissue and breast implants.
Hormonal changes do not affect results.
Drawbacks
It has a high false-positive rate, which can result in the woman having to have the standard mammogram anyway.
It has a high false-negative rate, which can lead to avoidance of the standard mammogram as a woman may feel she has been adequately screened.
It is rarely covered by medical insurance.
A false-negative result is one that suggests that cancer is not present when it is. It is important to stress the high levels of false-positive and false-negative rates, as there are other screening options available.
Sursa: https://www.medicalnewstoday.com/articles/316632.php