Older Women, Mammograms and Confusion
The mature patient should continue having the screening. Or maybe she shouldn’t.
THE SHUTDOWNS AND fears provoked by the Covid-19 pandemic threw a monkey wrench into many aspects of routine medical care, especially for older people justifiably wary about being exposed to the virus in a medical setting. While many facilities have now created “safe spaces” to resume in-person exams, some of the resulting postponements of routine checkups can have a major impact on the severity of an undetected or untreated disease and sometimes even the chances of survival.
One of these is screening mammography, especially for women 75 and older, a group that has received conflicting advice for years about the need for, and ideal frequency of, routine breast exams.
There’s no denying that breast cancer becomes increasingly common as women age and that finding this cancer in its early stages typically results in simpler and more effective treatment. Indeed, the earliest stage of invasive breast cancer has a five-year survival rate of 99 percent.
But some older women might be better off not ever knowing they have breast cancer because they are likely to die of some other cause long before an undiagnosed and untreated breast cancer threatens their health and lives. Yet once a woman is told she has breast cancer after a routine mammogram, she faces a decision on treatment that can have a negative impact on her well-being.
Further complicating matters is the current inability of cancer specialists to say with certainty which breast cancers found on a mammogram may not warrant any treatment because they are too slow-growing to be life-threatening or may even have the potential to disappear on their own. A Norwegian study published in 2008 found fewer invasive breast cancers among women screened only once in six years than among a comparable group screened biannually for six years, suggesting that some mammogram-detected cancers in the latter group would have regressed spontaneously.
Although the incidence and mortality associated with breast cancer increase with age, there is evidence to suggest that the disease in older women tends to be less aggressive and more likely to have a favorable prognosis. It is now possible to get a genetic test called Oncotype DX that predicts the risk of a breast cancer recurrence and the disease’s likely response to chemotherapy.
Making a rational decision about screening can be challenging, especially for women who know others found to have curable cancers in their later years.
The American Cancer Society guidelines for women with an average risk of developing breast cancer advises yearly mammograms starting at age 45 (or 40 if a woman prefers), changing to every other year (or every year if preferred) at age 55 and continuing every year or two for as long as they remain healthy enough to have a life expectancy of 10 or more years.
The U.S. Preventive Services Task Force, however, recommends stopping routine mammograms at age 75 regardless of a woman’s remaining life expectancy. Yet there are other professional guidelines recommending continued exams for women in generally good health who have a life expectancy of at least five years.
Then there are data from an analysis of 763,256 mammography screenings done between 2007 and 2017 that found cancer in 3,944 women, 10 percent of whom were 75 and older. The study’s author, Dr. Stamatia Destounis, radiologist at Elizabeth Wende Breast Care in Rochester, N.Y., reported that most of the cancers in the older women were invasive and of a grade that should get treated. Nearly two-thirds had the potential to spread and grow quickly.
Women are living longer and spending more of those added years in reasonably good health. For them, Dr. Destounis said, finding early invasive cancers that can be treated with minimal surgery and postoperative therapy can mean a lot to the patients, their families and their communities.
Still, according to Diana Miglioretti, a biostatistician at the University of California, Davis: “There is no evidence from randomized controlled trials on whether screening women ages 75 or older reduces breast cancer mortality. Evidence suggests the benefits of screening are not seen until 10 years later.” She said there is also a risk of overdiagnosis that increases with age.
Dr. Mara A. Schonberg, internist at Beth Israel Deaconess Medical Center in Boston, noted that among women age 75 to 84 who die in the next five years, 12 times more will succumb to heart disease than to breast cancer.
To help women decide about whether continuing to get regular getting mammograms after age 75 is in their best interests, Dr. Schonberg and colleagues devised a decision aid.
It asks 10 questions, including body weight, physical ability and pre-existing health conditions like diabetes. The lower a woman’s health risks, the lower her score, and the more likely that a mammogram may help her live longer.
Dr. Schonberg said she hopes that before handing their older patients prescriptions for a mammogram, doctors would first have them complete the decision aid.
For years, women 75 and older have received conflicting advice about the need for routine breast examinations.