Listen up, ladies—getting our ta-tas smashed by a machine from the moment we’re 40 years old, and on after that, might not be strictly necessary anymore! A research article, published on Feb. 11, 2014, started talking realistically about the effectiveness of mammograms, and immediately the health world began to spaz out. The reason being is that the study is essentially saying that routine mammograms do not seem to help prevent deaths from breast cancer.
Essentially, mammograms are just X-rays of the breasts to screen for the presence of breast cancer that has not manifested through signs, symptoms, or palpable lumps. This means that the cancer that mammograms typically discover during a standard screening is very small (less than two centimeters). Another screening tool that is typically used is the physical breast exam, either by yourself or by a trained healthcare provider.
This research article was only looking at the use of mammograms to screen, and not those used for diagnostic purposes. The study had two groups composed of women aged 40 to 59 to compare—one that received mammograms and one that only received physical breast exams if they were in the 50 to 59 age range (40 to 49 group didn’t get anything). The main outcome the researchers were looking for at the end of the study was death from breast cancer. After 25 long years and 89,835 participants later, this was the end verdict:
“Annual screening in women aged 40–59 does not reduce mortality from breast cancer beyond that of physical examination or usual care, concludes a 25-year study from Canada…
…22 percent of the screen detected invasive cancers in the mammography arm were over-diagnosed—that is, one over-diagnosed breast cancer for every 424 women who received mammography screening in the trial.”
If this is the case, then why have our mothers and grandmothers been regularly going to get their breasts smashed by the mammography machine for so many years? The primary reason that the medical world has placed so much weight behind mammograms is because the screening can catch those very small cancers that would not normally be found from a physical exam. But, what was not taken into account is the fact that breast cancer can progress at different rates. There are slow-growing, nonaggressive breast tumors and there are fast-growing, very aggressive breast tumors. Since the more aggressive tumors grow faster, they are more likely to be felt during a physical exam in between mammograms, and even then the prognosis for this type is not as positive. The slow-growing, nonaggressive tumors are typically not as malignant, and since they grow slowly they are more likely to be found by mammography screenings while they are small, because they take so much longer to get to a palpable size. Since the slow-growing have a better prognosis in comparison to the more aggressive types, this makes it look like the mammogram screenings are increasing the patients’ length of survival. In reality, the increased survival is not due to the xrays and the subsequent treatment, but to the fact that the types of cancers detected tend to be less malignant. Therefore, the population that gets mammograms appears have a better survival rate than those not undergoing the treatment. This issue encompasses length-time bias and lead-time bias, which are always an issue in epidemiological studies like this one. Basically it all boils down to perceived versus actual survival time.
In the end though, the important thing to remember is that this is just one study and it’s not all black and white. Granted, it’s a study that had nearly 90,000 participants, lasted 25 years, and has very few limitations, but it is only one study in the grand realm of research. Not all slow-growing tumors are mild-mannered, and not all fast-growing tumors sound the death knell. Also, it is up to you to decide the screening tests that you wish to engage in. Breast cancer is the fifth most deadly cancer, worldwide—with an estimated 521,000 dying from breast cancer in 2012. Treatment has come a long way, but catching it early always helps the prognosis. If it runs in your family and you want to be proactive, then self breast exams are an easy way to check in on the girls monthly. As you get older and new recommendations come out, it is always up to you to choose the steps you want to take. So keep your ears perked up for any new recommendations, and get familiar with your bewbs, darlings!
What are your thoughts on the latest mammogram hubbub and breast cancer? Tweet us @litdarling!