Genomic Profiling of Premenopausal HR+ and HER2- Metastatic Breast Cancer by Circulating Tumor DNA and Association of Genetic Alterations With Therapeutic Response to Endocrine Therapy and Ribociclib.

PURPOSE: This analysis evaluated the genomic landscape of premenopausal patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative advanced breast cancer and the association of genetic alterations with response to ribociclib in the phase III MONALEESA-7 trial. METHODS: Premenopausal patients were randomly assigned 1:1 to receive endocrine therapy plus ribociclib or placebo. Plasma collected at baseline was sequenced using targeted next-generation sequencing for approximately 600 relevant cancer genes. The association of circulating tumor DNA alterations with progression-free survival (PFS) was evaluated to identify biomarkers of response and resistance to ribociclib. RESULTS: Baseline circulating tumor DNA was sequenced in 565 patients; 489 had evidence of ≥ 1 alteration. The most frequent alterations included PIK3CA (28%), TP53 (19%), CCND1 (10%), MYC (8%), GATA3 (8%), receptor tyrosine kinases (17%), and the Chr8p11.23 locus (12%). A treatment benefit of ribociclib was seen with wild-type (hazard ratio [HR] 0.45 [95% CI, 0.33 to 0.62]) and altered (HR 0.57 [95% CI, 0.36 to 0.9]) PIK3CA. Overall, patients with altered CCND1 had shorter PFS regardless of treatment, suggesting CCND1 as a potential prognostic biomarker. Benefit with ribociclib was seen in patients with altered (HR 0.21 [95% CI, 0.08 to 0.54]) or wild-type (HR 0.52 [95% CI, 0.39 to 0.68]) CCND1, but greater benefit was observed with altered, suggesting predictive potential of CCND1. Alterations in TP53, MYC, Chr8p11.23 locus, and receptor tyrosine kinases were associated with worse PFS, but ribociclib benefit was independent of alteration status. CONCLUSION: In this study-to our knowledge, the first large study of premenopausal patients with hormone receptor-positive and human epidermal growth factor receptor 2-negative advanced breast cancer-multiple genomic alterations were associated with poor outcome. A PFS benefit of ribociclib was observed regardless of gene alteration status, although in this exploratory analysis, a magnitude of benefits varied by alteration.

Psychosocial aspects and life project disruption in young women diagnosed with metastatic hormone-sensitive HER2-negative breast cancer.

Metastatic breast cancer (MBC) diagnosis in young women negatively impacts on quality of life (QoL) and daily activities, disrupting their life project and forcing them to face new psychosocial challenges. The recently published results on the improvement of the overall survival of pre- or perimenopausal women with hormone-receptor-positive, HER2-negative MBC treated with CDK4/6 inhibitors plus endocrine therapy, while preserving, and in some items improving their QoL, will change the landscape of the management of this patient population. Their extended survival and potential improvement in QoL will, therefore, modify their specific needs in terms of psychosocial support. The complexity of the care of young women with MBC is described herein, based on an extensive literature review. Further research about the specific psychosocial requirements of these women and a new multidisciplinary holistic approach is paramount to properly address their concerns and preferences. The communication with and support of their partners, parents and children is an important factor affecting the QoL of these patients. Altogether, a multidisciplinary care, open communication and personalized support is required to address the psychosocial implications of the new prognostic expectations on these patients with the incorporation of new targeted therapies.