Contralateral breast cancer risk and endocrine therapy use in patients with ductal carcinoma in situ treated with unilateral mastectomy in the modern era.

BACKGROUND

In patients with ductal carcinoma in situ (DCIS), the risk of developing contralateral breast cancer (CBC) and the role of adjuvant endocrine therapy (ET) in decreasing CBC risk is not well understood.

METHODS

A retrospective review was performed on patients with DCIS who underwent a unilateral mastectomy (UM) from 2000 to 2010. CBC incidence, time to CBC and disease free survival were evaluated for women who took ET versus those who did not.

RESULTS

176 patients underwent a UM for DCIS, 72% were ER positive and 16% of patients took ET. At a median of 12 year follow up, 15 patients experienced CBC. Women over 63 years had highest incidence of CBC. CBC risk was not different between those who took ET versus those who did not.

CONCLUSION

The overall incidence of CBC was 9% in our DCIS cohort and was not significantly different among patients who took ET versus those who did not.