PIK3CA mutations in androgen receptor-positive triple negative breast cancer confer sensitivity to the combination of PI3K and androgen receptor inhibitors

Conclusions:
While approximately one third of TNBC patients respond to neoadjuvant/adjuvant chemotherapy, recent studies have shown that patients with androgen receptor positive (AR+) TNBC are far less likely to benefit from the current standard of care chemotherapy regimens and novel targeted approaches need to be investigated. In this study, we show that activating PIK3CA mutations are enriched in AR?+?TNBC; and, we show that the growth and viability of AR?+?TNBC cell line models is significantly reduced after treatment with PI3K inhibitors used in combination with an AR antagonist. These results provide rationale for pre-selection of TNBC patients with a biomarker (AR expression) to investigate the use of AR antagonists in combination with PI3K/mTOR inhibitors.

Source: Breast Cancer Research - August 8, 2014 Category: Cancer & Oncology Authors: Brian LehmannJoshua BauerJohanna SchaferChristopher PendletonLuojia TangKimberly JohnsonXi ChenJustin BalkoHenry GómezCarlos ArteagaGordon MillsMelinda SandersJennifer Pietenpol Source Type: research