Background: The rare patient diagnosed with pure ductal carcinoma-in-situ (DCIS) develops distant breast cancer metastases (DM). We sought to identify clinical and pathologic predictors of DM.
Methods: The clinical and pathologic characteristics of patients with DM after a diagnosis of pure DCIS from 1996 to 2009 were analyzed.
Results: Twenty five patients with DM after an initial diagnosis of DCIS were identified; 3 were treated at our institution and 22 were originally treated elsewhere. The rate of DM was 0.14% among 2,123 patients originally treated at our institution. Among all patients with DM, 73.7% had DCIS with necrosis, and 62% had DCIS that did not express estrogen receptor. Twenty-four percent of patients with DM were African American, compared to 11.5% of the total study population. The median time from DCIS to DM was 4.5 years. Sixteen patients (66%) had a preceding or simultaneous invasive locoregional recurrence (LRR); nine (34%) did not. At last follow-up, 14 patients (56%) had died of disease; median time to death was 2.4 years. No dominant variables could be identified in patients who developed DM with or without a LRR.
Conclusions: DM after a diagnosis of pure DCIS is rare. Although most patients with DM have a preceding invasive LRR, some present with subsequent DM alone. Further study is required to identify clinical and pathologic predictors of this more rapid disease progression.