The impact of patients' awareness of disease status on treatment preferences and quality of life among patients with metastatic cancer: a systematic review from 1997-2014.

INTRODUCTION: Advances in cancer treatment present challenges to patients with metastatic cancer who have to make treatment decisions in the face of newer and more effective treatments. Patients' awareness of disease status has been an important factor in making treatment choices. We conducted a systematic review of the published literature from 1997-2014 to evaluate the evidence of the impact of patients' awareness of disease status on treatment preferences and quality of life among patients with metastatic cancer.
METHODS: Nine major electronic databases were searched and 490 articles were retrieved; 15 met inclusion criteria. An established quality assessment tool was used to assess the quality of the included studies.
RESULTS: The overall quality of the included 15 quantitative studies was adequate. A critical limitation of current literature is the lack of consistent conceptual or operational definitions for the concept of patients' awareness of disease status. The included studies conceptualized patients' awareness of disease status either as being informed or understanding one's disease prognosis. Significantly more patients who were aware of their disease status were less likely to choose life-extending treatment or measures. Mixed findings were shown regarding the impacts of patients' awareness of disease status on quality of life. Absence of qualitative studies limited the review's ability to critically synthesize the concept of awareness of disease status. Well-designed qualitative studies are needed to shed light on the conceptualization and operationalization of the concept to better capture the impact of patients' awareness of disease status on treatment preferences and quality of life.