BackgroundCombining cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitors with endocrine therapy is an effective strategy to improve progression-free survival in hormone receptor-positive (HR+), human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. There is a lack of comparative data to help clinicians decide if CDK4/6 inhibitors can best be added to first- or second-line endocrine therapy. Improvement in median progression-free survival in first-line studies is larger than in second-line studies, but CDK4/6 inhibitors have not consistently shown to improve overall survival or quality of life. They do come with added toxicity and costs, and many patients have lasting disease remission on endocrine therapy alone. No subgroup has been identified to select patients who are most likely to benefit from the addition of CDK4/6 inhibition in any line of treatment. Altogether, these factors make that the optimal strategy for using CDK4/6 inhibitors in clinical practice is unknown.MethodsThe SONIA study is an investigator-initiated, multicenter, randomized phase III study in patients with HR+/HER2-negative advanced breast cancer. Patients are randomly assigned to receive either strategy A (first-line treatment with a non-steroidal aromatase inhibitor combined with CDK4/6 inhibition, followed on progression by fulvestrant) or strategy B (first-line treatment with a non-steroidal aromatase inhibitor, followed on progression by fulvestrant combined with CDK4/6 inhibition). The primary objective is to test whether strategy A is more effective than strategy B. The primary endpoint is time from randomization to second objective progression (PFS2). Secondary endpoints include overall survival, safety, quality of life, and cost-effectiveness. Five-hundred seventy-four events yield 89% power to show that strategy A has statistically significant, clinically meaningful superior PFS2 (according to ESMO-MCBS) in a log-rank test at the two-sided 95% confidence level. Given an accrual period of 42 months and an additional 18 months follow-up, inclusion of 1050 evaluable patients is required.DiscussionThis study design represents daily clinical practice, and the results will aid clinicians in deciding when adding CDK4/6 inhibitors to endocrine therapy will benefit their patients most. Additional biomarker analyses may help to optimize patient selection.Trial registrationhttp://clinicaltrials.gov: NCT03425838 (8 February 2018). EudraCT-number: 2017–002334-23 (29 September 2017).Electronic supplementary materialThe online version of this article (10.1186/s12885-018-4978-1) contains supplementary material, which is available to authorized users.
PurposeAromatase inhibitors (AIs) are an important component of the adjuvant treatment of hormone receptor positive breast cancer (BC) but concerns regarding their cardiovascular safety remain. In this cross-sectional study nested in a breast cancer cohort, we investigated the association between AI exposure and early markers for cardiovascular disease in BC survivors.
MethodsThe study population consisted of 569 women, who were 5-7 years (n=277) or 10-12 years (n=292) after BC diagnosis. All participants underwent carotid ultrasound, skin auto uorescence measurement and laboratory evaluation. To quantify AI exposure, we obtained the AI ratio by dividing the duration of AI use by the total duration of endocrine therapy (ET). Patients were classi ed according to their AI ratio into low (no ET or AI ratio <0.40), intermediate (0.40≤ AI ratio ≤0.60) or high AI exposure (AI ratio >0.60). The association between AI ratio and carotid intima media thickness (cIMT), advanced glycation end products (AGEs) and the presence of dyslipidemia was assessed using linear and logistic regression.
ResultsMedian age at study visit was 55.5 years (range 45.2-63.8). Forty percent (n=231) of the study population had used AIs, of whom the majority sequentially with tamoxifen; median duration of AI use was 3.0 years. Mean cIMT and mean AGEs did not differ across AI exposure groups in univariable and multivariable analysis. The occurrence of dyslipidemia did not vary across AI exposure groups. Intermediate AI exposure was associated with more frequent occurrence of the combined endpoint (elevated cIMT, elevated AGEs and/or dyslipidemia). This association, however, was not present in the group with highest AI exposure.
ConclusionAI exposure was not associated with cIMT, AGEs or the presence of dyslipidemia. Our results are reassuring for the cardiovascular safety of patients who receive treatment with AIs to reduce the risk of BC recurrence.Trial registration number (clinicaltrials.gov): NCT02485626,
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