Is it possible that as much as 35% of invasive breast cancers will go away on their own if left alone? This is the conclusion of Norwegian researcher Dr. Per-Henrik Zahl, who analyzed data from more than 600,000 Swedish women, half of whom had regular mammogram screening and half who did not. Dr. Zahl suggests that breast cancers may be over diagnosed, in much the same way that prostate cancers are over diagnosed. The study was published in Lancet Oncology.
