The March 3 Columbian article about breast cancer mammography, “Is this ounce of prevention still worth it?” should have been titled “Doctors Ignore Scientific Data.”
Dr. Jennifer Oschner is quoted as saying, “But in this case I don’t think the data should change anything.” It is alarming that medical professionals would ignore scientific data related to their field of work.
In The Columbian article, the Canadian breast cancer screening study was described as “criticized,” “challenged,” and a “flawed study.” This study was published in the peer-reviewed British Medical Journal, and is not the only study that concludes annual mammograms for women ages 40 to 49 are not effective in reducing the mortality rate due to breast cancer.
In 2010, the U.S. Preventive Services Task Force also recommended against routine screening mammography in women ages 40 to 49. Its recommendation was based on a review of other published studies.
There are two reasons that cancer screenings are not as effective as we would like. It is still very difficult to distinguish benign, non-life-threatening tumors from more aggressive tumors, especially when those tumors are very small, and we lack effective treatments for very aggressive cancers. For these reasons, detection of very small tumors does not increase life expectancy and increases the chances of overdiagnosis.
It is not surprising that medical professionals take an unscientific view of cancer screening. Cancer is a frightening illness. Both patient and doctor want to do everything possible to eliminate the possibility of dying from cancer, even if the diagnostic and treatment options have proven to be ineffective. Medical professionals are not immune to being driven by emotions when it comes to their patients and cancer.
The choice to have any pre-cancer screening should be made based on an individual’s entire medical history and their overall risk for developing cancer.
Current studies on mammography are showing that increased age alone is not a sufficiently high risk factor to warrant mammography before age 49, and perhaps not before age 59. And no studies show any effectiveness of mammography for women older than 75 in terms of decreased mortality due to breast cancer.
Patients should always ask their doctors why they are recommending screening, and what data supports their recommendations. We cannot assume that doctors are basing their recommendations on scientific data.
Kathy Neary of Vancouver is pastor of the Orchards United Methodist Church and has a Ph.D. in human genetics from Yale University.