Mammograms Under or Over Diagnosis?

There has been a long debate, since mammograms were put into use in the early 1980s, if they over or under diagnose breast cancer. Now someone has finally decided to take another look at all this data. There are two main parts to this issue: Are small tumors that would never grow into something 'bad' being over diagnosed and over treated? Are too many other tumors missed in mammograms? This group of researchers examined data from 2001 to 2013 and determined that:

"The results showed that most overdiagnosis occurred in older patients with biologically favorable, slow-growing tumors."

These tumors are ones that will not become problematic 'go bad' for 15-20 years. These do not need treatment..... In addition they revised their thinking on which tumors were going to become 'problematic' (what a sanitary word for cancer diagnosis).  

""Until now, we thought that the lead time, or time until a cancer becomes problematic for a patient, for most breast cancers was about three or four years. This paper shows that lead times vary widely depending on the tumor type. A large portion of aggressive cancers have a lead time of two years or less, whereas another large portion of breast cancers grow so slowly that the lead time is 15 to 20 years,...""

This is new thinking.

"It is important that we educate physicians, patients, and the public on the indolent, slow-growing nature of some breast cancers. This knowledge will allow us to individualize treatment options, provide 'personalized medicine,' and avoid the major harms of overdiagnosis, which can result in overtreatment and the anxiety and fear that a cancer diagnosis causes,..."

So maybe instead of blindly following what we have been told in the past, we look at what is now known.... This is called progress.