Can Genomic Profiling Predict Radioembolization Outcomes in Patients with Metastatic Breast Cancer?

A recent study found that PI3K pathway mutations in patients with metastatic breast cancer are associated with early imaging response after radioembolization, which is associated with  prolonged survival. The results were published in the Journal of Vascular and Interventional Radiology.

This retrospective, single-center study utilized an institutional database search to identify 31 women with liver metastasis from invasive ductal carcinoma who underwent resin and glass radioembolization between January 2011 and September 2017. All patients had been previously treated with ≥3 lines of chemotherapy and were considered heavily pretreated.

Genetic profiling was performed on 24 patients before radioembolization. If a patient had multiple specimens genotyped, all mutations from all specimens were recorded.

Positron-emission tomography/CT scans documenting imaging response were available for 26 patients, and were take an average of 38 days ± 35 before and 80 days ± 33 after radioembolization.

At the time of this study, the median survival from first radioembolization was 10.9 months (95% CI, 9.5–31.8). Of the patients with imaging follow-up, 69% (18 out of 26) had complete or partial response based on changes in fluorodeoxyglucose avidity. Imaging response was associated with longer survival (P = 0.005). All of the patients with PI3K pathway mutations showed an imaging response, but only 45% of patients without the mutation showed a response (P = 0.01).

“Imaging response was positively associated with overall survival: patients with PI3K pathway mutations had significantly improved survival compared with those with its wild-type counterpart. Thus, the study provides a promising introduction to the potential utility of genomic profiling into radioembolization outcome prediction in patients with breast cancer metastatic to the liver with PI3K pathway mutation,” the authors concluded.

--Kelsey Moroz

Reference:

Deipolyi AR, Riedl CC, Bromberg J, et al. Association of PI3K pathway mutations with early positron-emission tomography/CT imaging response after radioembolization for breast cancer liver metastases: results of a single-center retrospective pilot study. J Vasc Interv Radiol. August 2, 2018. pii: S1051-0443(18)31120-5. doi: 10.1016/j.jvir.20.