Surgeons make different choices in how they excise abnormal cells that are an early precursor to a breast cancer called ductal carcinoma, or DCIS. And surgeons make a wide range of recommendations on whether a woman diagnosed with DCIS should receive radiation therapy after surgery.
Those physician differences, says an article published on Monday in the Journal of the National Cancer Institute, play a pretty significant role in predicting whether a woman who has been treated for DCIS will have a recurrence of the condition or a later diagnosis of invasive breast cancer. A group of researchers from the Rand Corp. concluded that variations in the way surgeons treat DCIS account for as many as one in three recurrences over five years and three in 10 over 10 years. That was the case even after the researchers took account of factors that are already known to make a difference in a woman's risk of recurrence, such as a family history of breast cancer, diagnosis at a young age, and the presence of cells known for their aggressive ways.
DCIS itself is not lethal, and between 96% and 98% of those diagnosed and treated will be alive and disease-free 10 years after getting such a diagnosis. But rates of the diagnosis -- sometimes called "stage-zero breast cancer" -- have surged with more widespread screening for and earlier detection of breast cancer. In a still unknown proportion of cases, the presence of abnormal cells in the milk ducts of the breast will, in time, become invasive breast cancer. Because it's not known which cases of DCIS will lead to invasive breast cancer, physicians almost always treat it with surgery followed, in some cases, by radiation.