Zero to hero.
The Study: It's easy to get concerned about over- or under-treating DCIS, so here is a prospective multi-institutional study of real-world management. It enrolled 339 women with pure DCIS amenable to lumpectomy based on conventional work-up. Their treatment was then guided by the addition of a pre-op MRI and post-op Oncotype DX DCIS score. MRI led to an additional biopsy in 20% with detection of occult cancer occuring in 6% of women overall. Prior to surgery, 80% of women preferred to have lumpectomy, 5% preferred mastectomy, and 15% didn’t know. Interestingly, MRI helped the majority of those undecided move to either the lumpectomy or mastectomy camp (half each). Nearly 20% ultimately underwent mastectomy, most frequently because of surgeon decision after MRI or because of patient preference. Only a small minority (<4%) had a positive-margin with lumpectomy following MRI. Roughly half of DCIS scores were low-risk, and over 90% of women elected to receive or omit radiation in concordance with their DCIS score recommendation.
Bottom Line: Pre-op MRI and post-op DCIS scores can help indecisive patients and physicians make joint decisions on the best individualized treatment plans for DCIS. | Lehman, JAMA Oncol 2019