Global Inequities in Unpaid Cancer Caregiving: A Systematic Review and Exploratory Meta-Analysis of Time and Cost Burden.

[BACKGROUND] Unpaid caregiving is a critical but often under-recognised component of the cancer care continuum. As cancer prevalence rises globally, particularly in lower-income countries, quantifying the time and economic burden of unpaid caregiving across regions is essential for health resource planning, economic participation and support services. This systematic review aimed to quantify the global burden of unpaid cancer caring by examining care hours and associated costs, disaggregated by country income level based on the Socio-Demographic Index (SDI).

[METHODS] We systematically searched databases for studies published up to January 2026 that reported unpaid cancer caregiving hours and/or costs. Data were extracted and synthesised narratively, and where appropriate, pooled using random-effects meta-analysis for unpaid care hours. Study quality was assessed using standard checklists appropriate to the study design.

[RESULTS] Twenty-six studies met the inclusion criteria, with the majority conducted in high-income countries. Unpaid care hours ranged from 1.3 to 113.8 h per week, with a pooled estimate of 48.35 h (95% CI: 17.81-78.89), though heterogeneity was high (I = 100%). Unpaid care costs varied widely, with monthly costs averaging US$2249 (range: US$346-US$5626) in high-SDI countries; US$196 in high-middle SDI countries; US$26 in middle SDI countries; US$24 in low-middle SDI countries; and US$37 in low-SDI countries. Costing methods varied, with opportunity cost and replacement cost approaches most commonly used.

[CONCLUSIONS] Unpaid carers dedicate substantial time to support people living with and beyond cancer, offering essential assistance that fills critical gaps in health services. This contribution represents a substantial economic burden that remains largely uncompensated. There is a striking lack of data from low- and middle-income countries, where the incidence of cancer is rising, and unpaid care resources are limited. Future research must prioritise recognition, valuation and support for unpaid carers, thus helping increase economic productivity, particularly in underserved settings.