CLO19-059: A Systematic Review and Meta- Analysis of Randomized Controlled Trials to Evaluate the Risk of Health-Related Quality of Life Events in Patients With Hormone Receptor-Positive HER2-Negative Metastatic Breast Cancer Treated With CDK 4/6 Inhibitors

Background: Pain, fatigue, hot flushes, and rash significantly contribute to quality of life in breast cancer patients undergoing chemotherapy. Hormone receptor-positive breast cancer is a common entity among women worldwide. In cancer cells, CDK4/6 activity is over expressed, which can lead to amplification or overexpression of the genes encoding for CDK 4/6 or the cyclin D, ultimately leading to endocrine therapy resistance. We undertook a systematic review and meta-analysis of randomized controlled trials (RCT) to determine the risk of health-related quality of life (HRQOL) events associated with CDK 4/6 inhibitors. Methods: We conducted a comprehensive literature search using MEDLINE, EMBASE databases, and meeting abstracts from inception through September 2018. RTCs that mention HRQOL events as adverse effects were incorporated in the analysis. Mantel-Haenszel (MH) method was used to calculate the estimated pooled risk ratio (RR) with 95%CI. Random effects model was applied. Results: 8 RCTs (7 phase III and 1 phase II) with a total of 4,557 patients were eligible. The study arms used palbociclib/ribociclib/abemaciclib with letrozole or anastrozole or fulvestrant or other hormonal agent while the control arms utilized placebo in combination with letrozole or anastrozole or fulvestrant or other hormonal agent. The RR of all-grade side effects were as follows: fatigue, 1.226 (95% CI: 1.079–1.393; P=.002); back pain, 0.971 (95% CI: 0.844–1.117; P=.681); arthralgia, 0.978 (95% CI: 0.830–1.152; P=.790); headache, 1.046 (95% CI: 0.928–1.179; P=.459); alopecia, 2.635 (95% CI: 1.966–3.533; P<.001); hot flushes, 0.901 (95% CI: 0.766–1.060; P=.210); and rash, 2.068 (95% CI: 1.604–2.666; P<.001). The RR of high-grade side effects were as follows: fatigue, 3.487 (95% CI: 1.765–6.889; P<.001); back pain, 1.364 (95% CI: 0.695–2.679; P=.367); arthralgia, 1.148 (95% CI: 0.509–2.593; P=.740); headache, 0.807 (95% CI: 0.303–2.147; P=.667); and rash, 3.018(95% CI: 0.954–9.554; P=.060). Conclusions: Our study showed that the risk of developing all grades of fatigue and any-grade alopecia and rash was significantly with CDK 4/6 inhibitors. Prompt intervention with good supportive care is required.