AACR 2021: Can Gut Microbiota Influence Treatment Response in Metastatic Breast Cancer
Posted: Friday, April 30, 2021
The CDK4/6 inhibitor palbociclib is used for the front-line treatment of hormone receptor–positive metastatic breast cancer, and its use in combination with immune checkpoint inhibitors is increasingly being studied. During an ongoing phase I trial of palbociclib plus pembrolizumab and letrozole, the stool microbiome was collected and analyzed. The results, which were presented by Chi Wah Wong, PhD, of the City of Hope National Medical Center, Duarte, California, and colleagues during the virtual edition of the American Association for Cancer Research (AACR) Annual Meeting 2021 (Abstract 336), revealed that the gut microbiota seem to play a role in the pathogenesis of breast cancer and perhaps response to systemic therapy.
A total of 11 postmenopausal women with histologically proven stage IV hormone receptor–positive, HER2-negative disease were enrolled. At baseline and during treatment, 47 stool samples were collected and analyzed using metagenome sequencing through a machine learning model.
For predictive modeling, the validation area under the receiver operating characteristic curve was 0.71, and the area under the precision recall curve was 0.83. Patients with a larger relative abundance of Gemmiger formicilis seemed to have an increased probability of responding to therapy (P < .05); on the other hand, a larger relative abundance of Bacteroides vulgatus appeared to be associated with a reduced probability of responding to therapy (P < .05). According to the investigators, studies have reported the relative abundance of G formicilis at baseline to be higher in patients who had a long-term benefit from therapy.
Disclosure: For full disclosures of the study authors, visit abstractsonline.com.
