Breast Mammograms May Mean Over - Diagnosis of Breast Cancer

Today breast cancer is the second leading cause ofThe team looked at the findings of studies that
death in women, after lung cancer. As a result, yearlyspanned a 14-year period. 7 years before public
breast mammograms have become common formammography screenings were available, and 7 years
women over 40, or anyone at high risk of developingafter government run mammography-screening
this dangerous, disfiguring disease.programs were in place in five different countries
Now that programs like this are in place, experts had(United Kingdom, Canada, New South Wales,
expected that the number of cases of advancedAustralia, Manitoba, Sweden and areas in Norway)
breast cancer would drop off, but that's notThey found an over-diagnosis rate of 52% for all
happening.cancers, 35% for invasive breast cancer.
Instead the incidence of breast cancer seems toThe data shows a jump in breast cancer incidence
have gone up since widespread screening becamejust after the screening programs were put in place.
part of our yearly exams. Why?What this work suggests, as did the Norwegian
Women know that early detection of breast cancerstudy before it, that perhaps not all cancers need to
can save lives, but that doesn't make going for thatbe treated, some might grow too slowly to affect a
yearly mammogram any less nerve wracking orpatient and others may resolve on their own.
uncomfortable.It's important to know that no doctor or current
We endure the testing because we've been told wescreening technique can tell the difference between a
need to find lumps when they're too small to feel orcancer that's dangerous and one that might not be.
bring symptoms, before they have a chance to growIn a BMJ editorial that's published along with the
and cause trouble.research, professor of medicine Dr. H. Gilbert Welch
But do all cancers cause problems?of the Dartmouth Institute for Health Policy and
Late last year a large Norwegian study ofClinical Research recognizes the problem of
mammography screening for breast cancer foundover-diagnosis, understanding the trauma and terror a
that some invasive cancers might spontaneouslywoman endures after being given such news by her
regress over time, leaving no sign that they weredoctor.
ever present in a woman's body.Surgery and chemotherapy bring their own set of
Makes you wonder, now that we can screen for it, ifdifficulties that are physically demanding and
this type of cancer isn't over diagnosed or overemotionally draining, and a terrible trial for patients
treated.and families. Especially those whose cancers might
This latest BMJ report citing an over-diagnosis ratenot have needed to be treated at all.
for invasive breast cancer of 35% could truly haveWhile this latest study is still not an excuse, or
you re-thinking that yearly mammogram.recommendation, to put off your yearly
Besides this type of cancer, over-diagnosis has alsomammogram, it does raise some rather nagging
been mentioned for cancer of the prostate as wellquestions.
as neuroblastoma, melanoma, thyroid cancer and lungUntil we know more, each woman has to decide for
cancer.herself whether to continue with yearly breast
The latest work on over-diagnosis comes frommammograms, but it is clear that screening has let us
researchers out of the Nordic Cochrane Centre indetect earlier cancers and start treatment earlier.
Copenhagen.