Outcomes research examining treatments, quality of life and costs in HER2-negative and triple-negative metastatic breast cancer: a systematic literature review.

AIM: With the aggregation of real-world data in healthcare, opportunities for outcomes research are growing. In this study, we summarize published literature examining comparative effectiveness research (CER), treatment patterns, quality of life (QoL) and costs in HER2-negative and triple-negative (TN) metastatic breast cancer (mBC).

METHODS: PubMed (2010-January 2016) and four conferences (2013-January 2016) were searched using MeSH/keywords, including mBC, QoL, morbidity and therapeutics. Studies relating to CER, treatment patterns, QoL, costs or treatment appropriateness in US patients with HER2-negative/TN mBC were included in the review.

RESULTS: Of 1782 identified records, 33 studies met full inclusion criteria: seven related to CER, 18 to treatment patterns, one to treatment appropriateness/navigation, two to QoL and five to costs. Studies varied in objectives, designs and outcomes. Study designs included retrospective chart reviews (52%), retrospective secondary database analyses (27%), economic models (12%), physician surveys (6%) and patient surveys (3%). 25 studies reported results on HER2-negative mBC, six on TN mBC and two on both subtypes. The most common end points examined were treatment patterns, overall survival and progression-free survival.

CONCLUSION: Outcomes research in HER2-negative mBC in the USA was limited, specifically among TN patients, indicating an opportunity for further research in this high unmet need population. Endpoints and treatment options varied, thus, it is difficult to draw summary conclusions about these studies. Outcomes research examining real-world data in mBC has increased in recent years, and may continue to grow with the implementation of new policy programs.