In the past we believed that breast screening should occur annually after a woman reached forty years of age. Nevertheless, now things are a little different due to the risk of false positives, needless biopsies, extra financial costs, and the psychological distress overtreatment causes.
Oguzhan Alagoz, from the University of Wisconin-Madison in the United States, created a decision-making model aiming to give us a definitive answer to the question how often breast screening should occur . He notes that with the model, he can design breast cancer screening decisions to correspond to a woman’s calculated risk of invasive breast cancer – instead of just concentrating on her age.
The decision-making model takes into account not only the patient’s genetics, age and other personal risk factors, but also details on her screening history.
Alagoz revealed that the model shows how every extra piece of information might change which decision is optimal and help doctors make better screening decisions. He added that, unlike other cancers, including colorectal, none of the currently existing breast cancer population-based guidelines can take this into account.
Societies and government departments fail to reach an agreement on when women should start breast cancer screening. Some, including the American Cancer Society, still believe that the age 40 is the best time to start. The US Preventive Services Task Force, however, changed it to 50 years in 2011. It further commented that individual doctors and patients should decide on whether to start earlier or not.
Until a few years ago, annual mammographies were believed to lower national breast cancer rates by at least 20% to 30%. Nevertheless, several recent studies have proven this to be wrong. A Swedish research discovered that breast screening has very little or no impact at all on breast cancer mortality among females aged 40 to 69 years.
Nevertheless, another study conducted by researchers at the department of public health at the Erasmus MC at Rotterdam in the Netherlands showed that screening mammograms drove breast cancer death rates down by 49%.
For breast screening to be of help for society and individual patients, its benefits have to be maximized, while minimizing its potential harms, such as over- or under-screening. The decision-making guideline of Alagoz is based on sequential decision-making techniques. These techniques account for decisions that have been made several times and have a negative effect, such as an abnormal screening result which makes a patient to go for another screening six months later, or a set of risk factors which will make her start screening earlier and more often.
The model concentrates on each patient’s individual cancer risk. The calculations are based on a series of factors, such as her family history, lifestyle, as well as previous screening history. The woman’s risk of cancer – and risk of “transition” to new states, such as biopsy and treatment – would be lower if all her mammograms turned out to be negative. In such cases, doctors might not recommend breast cancer screening for an individual patient for several years.
According to Alagoz, his guideline will boost women’s quality of life, while reducing the total number of mammograms, which accounts for approximately $100 million in overspending per year in the United States.
Tailoring breast screening recommendations to individual patients will save many high risk lives and cut the number of unnecessary biopsies, pointless radiation exposure, over treatments, costs and stress for low risk women.
Alagoz further commented that his guideline can create a single statistics to describe multiple risk factors. This could ease communication among the radiologist, patient and referring physician, and perhaps even help shared decision-making.
Now, here is some info on the pros and cons of breast screening.
Most women tend to overestimate the risk of dying from breast cancer, but they also overestimate the benefits of screening mammography on lowering that risk. Some experts claim that most women would refuse mammographies if they knew how small, but statistically important, their influence on overall cancer death rates was.
Nobody seems to agree on what the benefits of mammographies to the overall health and life expectancy of populations are. Mammographies can also cause emotional distress and financial costs for women with benign formations.
Most of the patients accept the false positive risk in breast screening. Actually, they even note that it is not very stressful. In spite of the fact that many patients find these memories extremely frightening, they were relieved on hearing the good news.
Generally, routine breast screening considerably drives early breast cancer detection rates up, especially for the so called non-invasive pre-breast cancer, which very rarely ever forms a lump. Mammographies can detect such breast malignancies in their initial stages, but most of them never become life-threatening. This backs up the argument that we cannot claim that on a large scale mammographies save lives. Moreover, they can actually do cause unnecessary surgery, distress and financial costs for patients.
In conclusion, in October 2011, Scottish experts said for Health Technology Assessment that mammographic screening should be done once a year in high risk women and once every 3 years for others.
