Who should be screened for breast cancer?
Historically Breast Cancer has been a huge subject in the war against cancer, perhaps because of it’s prevalence being one of the most common, or perhaps because of it’s symbol as one of the front issues of women’s health. Either way, screening was first not enough, then too much, so it’s important to look at the evidence of the matter. Evidence supports a mammography (X-ray) every 2 years for women between the ages of 50-74 years old. Women who have an increased risk of being diagnosed with breast cancer (family history, BRCA gene) may start their mammography examinations from the age of 40. However, this is weak evidence supporting the benefits of mammography exams for women under the age of 50 in the absence of increased risk.
What are the downsides to getting screened?
The first and main risk is over-diagnosis. What does this mean exactly? If there is a woman who has a tumor in her breast, that is slowly growing and doesn’t otherwise bother her, there may not be a need to treat this tumor. Invasive treatments such as surgery or chemotherapy do a fair amount of damage to the body, but we only recommend such treatments if we believe that the benefits outweigh the costs. However, these are educated guessed based on history, and are never 100%. Therefor the risk of over-diagnosing leads to the risk of over treating, and therefor causing unneeded harm.
Other risks to excess test include exposure to radiation, pain during the procedures, and anxiety, which are all risks that should not be taken lightly.
Does screening really work?
As women get older, the benefits of screening for breast cancer are more clearly supported with evidence. The evidence of benefit on mortality in the age group 39-49 is not statistically significant. In the past few decades the mortality rate has drastically been lowered for breast cancer, and we can attribute a large portion of that success to the increasing awareness and screening. It’s also important to keep in mind that there has been huge improvements on biological treatments, and surgical procedures have become more accurate. All of these things combined have incredible importance in the fight against breast cancer.
What can we do about it?
As previously mentioned, there are constantly improving therapies including medications and surgical treatments. Many of the factors influencing the strategy of treatment depend on the size, stage, and type of the tumor. Therefor, early diagnosis can lead to decisions including surgery that preserves the breast, and potentially prevent other painful treatments like chemotherapy for example. That being said, it’s important to keep in mind the evidence at hand, and the difference in final outcome and mortality. There is evidence supporting a reduction in mortality when the disease is treated early, but those benefits are marginal.
Are these the only recommendations?
Of course not. There are many different bodies providing different recommendations. However, this is based on large amounts of data, and many studies that were conducted. It’s very important to understand the data in order to make rational decisions that are based on evidence, and not put yourself through excessive risk, harm, pain and anxiety.
*Please comment to us if you found this information useful, or if you have any questions about the topic.
Here are a few studies which prove the efficacy of screening and early treatment for breast cancer. Feel free to contact us for more information about the matter, we would be happy to provide it for you.
Nelson HD, Tyne K, Naik A, Bougatsos C, Chan B, Nygren P, et al. Screening for Breast Cancer: Systematic Evidence Review Update for the US Preventive Services Task Force. AHRQ Publication No. 10- 05142-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; 2009. [PMID: 20722173]
Nelson HD, Tyne K, Naik A, Bougatsos C, Chan BK, Humphrey L; U.S. Preventive Services Task Force. Screening for breast cancer: an update for the U.S. Preventive Services Task Force. Ann Intern Med. 2009;151:727-37. [PMID: 19920273]
Nelson HD, Cantor A, Humphrey L, Fu R, Pappas M, Daeges M, et al. Screening for Breast Cancer: A Systematic Review to Update the 2009 U.S. Preventive Services Task Force Recommendation. Evidence Synthesis No. 124. AHRQ Publication No. 14-05201-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; 2016.
Marmot MG, Altman DG, Cameron DA, Dewar JA, Thompson SG, Wilcox M. The benefits and harms of breast cancer screening: an independent review. Br J Cancer. 2013;108:2205-40. [PMID: 23744281]