Thursday, August 20, 2015
Large DCIS Breast Cancer Study Is 'Compelling Case' for Change
New results from an observational study of more than 100,000 women with ductal carcinoma in situ (DCIS) provides a "compelling case" that it is "time for a change" in the management of the disease, according to a pair of experts.
Instead, for patients who underwent lumpectomy, the addition of radiotherapy was associated with a reduction in the risk for ipsilateral invasive recurrence at 10 years (2.5% vs 4.9%; adjusted HR, 0.47; P < .001), but not of breast-cancer-specific mortality at 10 years (0.8% vs 0.9%; HR, 0.86; P = .22).
Thus, the more intense therapy for DCIS (lumpectomy plus radiation), compared with the less intense therapy (lumpectomy alone), was good at reducing the risk for invasive disease, but not at reducing the risk for death.
In their editorial, Drs Esserman and Yau note that this has been reported previously, but nevertheless highlight this as "key" finding: "aggressive treatment (radiation therapy after lumpectomy) of almost all DCIS does not lead to a reduction in breast cancer mortality."
They also call for a change in management: "Radiation therapy should not be routinely offered after lumpectomy for DCIS lesions that are not high risk because it does not affect mortality," they write.
There were also women in the study who underwent mastectomy. Again, the investigators found the same pattern — the more intensive treatment was good for reducing recurrence, but not death.
Although risk for ipsilateral invasive recurrence at 10 years was lower in patients who underwent unilateral mastectomy than in those who underwent lumpectomy (1.3% vs 3.3%), the risk for breast-cancer-specific mortality was higher in mastectomy patients than in lumpectomy patients (1.3% vs 0.8%). This finding is not as surprising, however, because the mastectomy patients had larger and higher-grade tumors, on average. In fact, when those factors were controlled for, the difference in 10-year survival was not significant.
However, it was still the case that the more intensive treatment (mastectomy) improved recurrence but not mortality.