SGO 2016: Advanced Ovarian Cancer Caused by Genetic Mutations Linked to Better PFS and OS Following Treatment Including Bevacizumab
Women with advanced ovarian cancer caused by genetic mutations—including in BRCA1 and BRCA2—lived significantly longer than those who did not have a mutation following treatment with a chemotherapy regimen that included bevacizumab (Avastin). According to a study, those with BRCA1 and a non-BRCA mutation lived an average of 1 year longer, and those with a BRCA2 mutation lived almost 3 years longer, compared to women with no mutations.
The original study, a phase III clinical trial (Gynecologic Oncology Group 218), was intended to examine the impact of adding bevacizumab to standard chemotherapy for advanced ovarian cancer. In this new study, researchers sought to determine whether having mutations in some homologous recombination genes affected the response to the combined treatment and found that they did not.
More importantly, however, the researchers found that the mutation status affected overall survival (OS) as well as progression-free survival (PFS).
“This is important prognostic information for patients, and highlights the importance of knowing genetic status in clinical trials in ovarian cancer,” said lead author Barbara S. Norquist, MD, Gynecologic Oncologist at the University of Washington in Seattle. She presented the results at the Society of Gynecologic Oncology’s 2016 Annual Meeting on Women’s Cancer on March 19 in San Diego, California (Presentation 1).
Study Findings
Dr. Norquist and colleagues sequenced DNA from blood or tumors or both from 1,195 women using the sequencing test BROCA-HR. A total of 307, or 25.6%, had a mutation in a gene predicted to affect homologous recombination. Of those with mutations 148 (48.2%) had mutations in BRCA1, 78 (25.4%) in BRCA2, and 81 (26.48%) in one of the other homologous recombination genes.
Median PFS and OS for women with no mutations were 12.6 and 42.1 months, respectively. For women with BRCA1 mutations, PFS and OS were longer at 15.7 and 55.3 months. For BRCA2, median PFS and OS were even longer at 21.6 and 75.2 months. And for mutations in non-BRCA genes, median PFS and OS were 16 and 56 months, similar to that seen for BRCA1 mutations.
“All three mutation-carrier groups had significantly better progression-free and overall survival when compared to those with no mutations,” Dr. Norquist said.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
