OBJECTIVE: Patients with cancer face difficult decisions regarding treatment and the possibility of trading quality of life (QoL) for length of life (LoL). Little information is available regarding patients' preferences and attitudes toward their cancer treatment and the personal costs they are prepared to exchange to extend their life. The aim of this review is to determine the complex trade-offs and underpinning factors that make patients with cancer choose quality over quantity of life. METHODS: A systematic review of the literature was conducted using MeSH terms: cancer, longevity or LoL, QoL, decision making, trade-off, and health utility. Articles retrieved were published between 1942 and October 2018. RESULTS: Out of 4393 articles, 30 were included in this review. Older age, which may be linked to declining physical status, was associated with a preference for QoL over LoL. Younger patients were more likely to undergo aggressive treatment to increase survival years. Preference for QoL and LoL was not influenced by gender, education, religion, having children, marital status, or type of cancer. Patients with better health valued LoL and inversely those with poorer physical status preferred QoL. CONCLUSION: Baseline QoL and future expectations of life seem to be key determinants of preference for QoL versus LoL in cancer patients. In-depth studies are required to understand these trade-offs and the compromises patients are willing to make regarding QoL or LoL, especially in older patients with naturally limited life expectancy.