Expert: Claes-Gustaf Nordquist, M.D. - 3/29/2007

Question
I have a friend who insists that in the years to come, mammorgraphy will be
shown to be a cause of breast cancer hence she is never going to get one.
She is 63!

Answer
Well breast cancer has been known for centuries (in my library I have a picture showing breast cancer surgery around 1500 AD but it was known LONG before that) long before mammography or even X-rays of ANY kind were used! It is true though that x-rays - and therefore also mammograms - increase the risk of cancer - and therefore also breast cancer - somewhat. However the benefits of mammograms are statistically vastly greater than these still rather small risks which is shown by the decreased mortality (death rate) of breast cancer in spite of the fact that this particular cancer has become somewhat more common - an increase that is mostly explained by more elderly women (cancer risks increase with age), higher age when first child was born (child births at a young age give a certain protection), fewer children per woman (many child births also give a certain protection) less breast feeding/nursing (same effect), younger age at first menstruation (same effect), older age at last menstruation (same effect), female sex hormone treatments (same effect but not very strong), more taller women (for some reason same effect) AND more overweight women (same effect). So while I can not rule out that mammograms have to some extent contributed to the present increase of breast cancer, I must point out that there are many other more important factors involved and that this contribution therefore must be rather small compared to the others! Every woman now runs about a 10% risk of developing breast cancer so she has about a 90% chance of living her life without one. Hopefully she will! I have also found it useless to argue with anyone with this kind of obsession! The choice is hers and so are its consequences! I do hope this has clarified matters!

P.S. There are also well known genetic factors involved.