Dr. Anne Kearney is a professor of nursing at Memorial University, and has a clear stance on routine mammography screenings: we need to re-evaluate them. They could be doing more harm than good.
Dr. Kearney has been doing critical analysis of breast screening evidence for over 20 years. She is also one of the people who started our provincial breast screening program when it was launched in January 1996. Her duties included public education and recruitment into the program.
The program was launched based on now-outdated research from the 1980s, and even 70s, and is a “population-based” screening program, meaning it sees healthy women, aged 50-74, being screened every 1-2 years.
Over time, Dr. Kearney became convinced that these “population-based” screenings in Canada (and elsewhere) have gotten it completely wrong. There is no reliable evidence that screening healthy women of a particular age (50-74 in our province) on a regular basis saves lives, and she adds that “these conclusions are a result of a critical analysis of systematic reviews by the Cochrane Collaboration, the highest level of evidence in the world, among other evidence.”
While it’s true that rates of fatal breast cancer are significantly lower now, relative to the decade in which regular screenings were launched in our province, it is generally believed this is because of better treatment options, not because of “preventative mammography screening.”
In addition to the radiation risks associated with mammograms (radiation itself can cause cancer), one form of harm easily overlooked with regards to regular breast screenings is what Dr. Kearney calls “overdiagnosis” and subsequent “overtreatment.”
She refers to overdiagnosis and overtreatment as the detection and treatment of a breast lesion that wouldn’t have been picked up without a mammogram, and that likely wouldn’t have posed a health threat to the patient.
For example, there is a chance that a Stage 0 cancer a mammogram picked up wouldn’t have become a true cancer, but the woman is “overtreated” when she receives the same treatment regime as would a woman who definitively does have breast cancer.
Her argument is that we need to conduct further research into how breast cancer develops in women. Such research could ideally tell us which early lesions are likely to develop into a true case of cancer, and which would remain harmless in a woman’s body, not needing invasive overtreatment.
Dr. Kearney’s stance is clearly at least mildly controversial, yet her convictions are in line with the Cochrane Collaboration and other public health experts in the field. She’s advocating we cease screening of all well women of a targeted age, and expend our resources on closely monitoring women with a higher risk of breast cancer.
“It is a very difficult proposition for governments and breast screening programs to tell women, after 30 years of screening in some provinces in Canada, that we got it wrong,” she says, but it’s looking like we have gotten it wrong.
At the time of this interview, Dr. Kearney had just returned from an international conference in Quebec entitled “Preventing Overdiagnosis,” where there was not only a copy of her own academic poster on the walls, but several sessions critical of population-based mammography screening. The conference was part of a new movement to decrease unnecessary medical testing and treatment.
In the least, Dr. Kearney says we must get more comfortable with something called watchful waiting.“Watchful waiting is now recommended for very early breast lesions that may or may not progress into an invasive or true cancer,” she says. “It is not known with certainty which early lesions will stop growing, regress, or develop into a breast cancer that will grow so slowly that it won’t cause harm to the woman during her lifetime.”
Those kinds of lesions are only picked up with mammography screening. Treating all early lesions with the usual cancer treatments such as mastectomy, lumpectomy, radiation, and hormonal therapy, is harmful to women if the lesion would not have caused harm in the long term. “Women need to understand that watchful waiting may be the best course of treatment when a very early breast lesion is detected by mammography,”she says.
Dr. Kearney is a strong advocate of women receiving balanced information – in plain language – regarding the potential harms and benefits in all program promotional materials, websites, and consent forms.
“I just [reviewed] all websites of the 12 breast screening programs in Canada with two research partners,” she says, “and concluded that no breast screening program website in Canada is providing adequate balanced information to allow women to make an informed decision.”