Oral Presentation Joint 2016 COSA and ANZBCTG Annual Scientific Meeting

Treatment Focussed Genetic Testing In Women with Breast Cancer – Why Do It? (#36)

Kelly-Anne Phillips 1
  1. Peter MacCallum Cancer Centre, Melbourne, VIC, Australia

Genetic testing for mutations in the BRCA1 and BRCA2 genes should be actively considered for all women with breast cancer. Women with BRCA-associated breast cancer have a similar prognosis, stage for stage, to those without mutations. They have a higher risk of subsequent contralateral breast cancer, so contralateral mastectomy (with completion mastectomy if required) may be considered to reduce that risk. Retrospective cohort study results suggest substantially improved survival for mutation carriers who undergo contralateral mastectomy, but this finding needs confirmation in prospective cohorts. BRCA1 or BRCA2 mutation status may also influence systemic therapy decisions. The TNT randomised study showed that mutation carriers with metastatic breast cancer have higher response rates and better progression free survival if treated with carboplatin rather than taxotere.   Data from Geparsixto also suggest a role for the addition of platinum in treatment of non-metastatic disease in mutation carriers with triple negative breast cancer.  There is some evidence that endocrine therapy alone may be suboptimal for mutation carriers with ER positive, early-stage disease.  PARP inhibitors, which exploit the DNA repair deficiency within BRCA-associated cancers, have demonstrated efficacy in the treatment of BRCA1 and BRCA2 mutation carriers with metastatic disease. The OlympiA trial, currently open at 14 Australian sites, through the ANZ BCTG, randomises BRCA mutation carriers with high risk, HER2 negative, non-metastatic breast cancer to 12 months of oral olaparib or placebo and will help determine whether PARP inhibitors improve outcomes in mutation carriers having treatment with curative intent.  Free genetic testing is available as part of the screening component of this trial.