Biopsy of Recurrent Breast Cancer Can Tell an Important Story

The rationale for recommending biopsy of recurrent breast cancer arises from the importance of confirming the original diagnosis and assessing the constancy of tumor markers. Recent findings have suggested that a fraction of patients have changes in tumor characteristics at recurrence that can influence individual treatment decisions. Now, two reports provide further insight into the frequency of marker discordance between primary tumors and sites of disease recurrence.

In the first study, Canadian researchers prospectively assessed estrogen receptors (ERs), progesterone receptors (PRs), and human epidermal growth factor receptor 2 (HER2) in primary and metastatic tumor tissue from 94 patients. Participating oncologists reported the treatmen…