About 25 years ago, my sister called to discuss her health issue with me. Her mammogram had shown an abnormality that was biopsied and diagnosed as ductal carcinoma in situ (DCIS) and her surgical oncologist recommended a bilateral subcutaneous mastectomy with subsequent staged breast reconstruction. Her reliance on my judgment to bless consenting to such extensive surgical intervention for a microscopic problem was based upon my 1973-75 stint as a clinical and research associate at the National Cancer Institute. I told her she was being rewarded for choosing vigilant cancer screening, as breast cancer has an inexorable course from an epithelial focus to local tumor mass to regional nodal spread and disseminated, incurable metastases. The surgical treatment proposed logically prevented this natural history.
Now a quarter century later, after total breast tissue extirpation, 2 staged reconstructive and 2 subsequent implant revisions, she is alive and well and a breast cancer survivor. Or at least that was the accepted storyline with minor alteration until mid-August of this year for her and the 60,000 American women that are diagnosed each year with Stage 0, DCIS.
On this date, this diagnosis’ dogma was severely challenged by the JAMA Oncology publication analyzing data collected from a national cancer
registry with DCIS and followed for 20 years. The vast majority had local control treatment of lumpectomy or total or bilateral mastectomy with or without adjuvant radiation. As a group, these women’s chances of dying from breast cancer in the 2 decades after treatment was 3.3 percent independent of treatment protocol. This figure is no different than the death rate from breast cancer in the general female population. If DCIS is an early cancer capable of eventually spreading without local treatment then the small cohort that had no local extirpation should have had worse prognosis-- this did not happen. If treating DCIS by extirpating part, most, or all breast tissue was preventing invasive cancer, then the incidence of cancer deaths should have dropped over 20 years as 60,000 woman with Stage 0 were being treated yearly and “removed” from risk--this also did not happen.
These revolutionary findings were, understandably, highly controversial. Experts complained that it was not a blinded, prospective randomized trial and a non-treatment of DCIS arm was absent. Pathologists do not look microscopically at the entire breast specimen and therefore could have missed microscopic invasive foci. Maybe some women were misdiagnosed as there was no pathological review and did not actually have DCIS. Still, the implication that 60,000 women each year will be unnecessarily subjected to extensive surgical over treatment with attendant morbidity is compelling. This is especially timely as certain prosaic and thyroidal “cancers” are now being scrutinized as to their clinical “benignity”. Paradoxically, the next major breakthrough in oncology may be redefining what cancer really is and devising strategies to predict which abnormal cluster of cells actually become invasive and metastasize and which stay abnormal looking, but pose no biological threat.
By Norman Silverman, MD, with Ryan McKennon, DO and Ren Carlton