Confirmed tumor biopsies led to altered breast cancer management in patients with distant metastases

In a prospective study, biopsies revealed differences in hormone-receptor status between primary tumor and distant metastases, resulting in a change in management for 20% of patients.

Researchers obtained 29 biopsies of suspected metastatic lesions and analyzed them for ER, progesterone receptor and HER-2 status. They compared the receptor status between metastatic and primary tumors. Patients’ primary oncologists completed questionnaires before and after the biopsies to determine whether they changed management and whether the change was related to the results of the biopsy.

Three of the 29 biopsies were diagnosed as benign and one as low-grade follicular lymphoma; the remaining samples confirmed metastatic disease. The researchers reported a 40% overall discordance rate for ER and progesterone receptor (P=.026) and an 8% rate for HER-2. Changes in hormone-receptor status included complete loss of ER, progesterone receptor or both; changes in HER-2 status included complete gain in HER-2 overexpression compared with the primary tumor, according to the researchers.

Based on the results of the biopsy, 20% of patients biopsied had a change in their treatment plan management (P=.002). Biopsy resulted in a change of treatment plan and prognosis for the four patients who had no evidence of metastatic disease. Based on biopsy results, two women who gained HER-2 overexpression experienced a change in disease management; both qualified for trastuzumab (Herceptin, Genentech) or a clinical trial.

“Our study has implications for the design of clinical trials that evaluate targeted therapies,” the researchers wrote. “Mandating a biopsy of metastases at study entry would ensure that the target is expressed and would allow for a more efficient study to be carried out.”

Simmons C. Ann Oncol. 2009;doi:10.1093/annonc/mdp028.