We just presented a study this year looking at DCIS and competing causes of mortality in different age groups with different types of treatment. Among women with DCIS over 70 years of age, there was a significant difference in overall survival but none of the treatments conferred any benefit in disease-specific survival.
Active surveillance alone may be reasonable to consider in some patients. We can learn a lot from our colleagues who treat prostate cancer. They’re at least 10 years ahead of us in thinking about reducing the harms that have been introduced by screening for prostate cancer. When you look at breast cancer–specific and other-cause mortality in the setting of DCIS, the mortality curves look very similar to those with early-stage prostate cancer. Women with DCIS, regardless of what they are treated with, die of other causes and very rarely die of breast cancer.
When we compare such different options as mastectomy to active surveillance only, it’s really hard for a patient to feel that both of those approaches can offer them the same outcomes. But when you look at the actual data and evidence, the differences in recurrence or progression to invasive cancer don’t translate easily into a large difference in breast cancer mortality provided that patients are diagnosed at stage I or II, with more than a 90% survival from breast cancer.
We have an opportunity to take a big step back and redefine our goals of DCIS “treatment” from “curing” DCIS to trying to reduce breast cancer-specific mortality. This will help us reduce the harms that can result from screening and will reserve our aggressive treatments for those most likely to benefit from them.
Dr. Hwang is a professor of surgery at Duke University, Durham, N.C. She serves as a consultant for Genomic Health.