Existential distress, marked by hopelessness, loss of meaning, and spiritual suffering, is prevalent among patients with advanced illness, and is associated with psychological burden and a wish to hasten death (WTHD).

This systematic review aimed to synthesize current evidence on meaning in life (MIL) in adult palliative care (PC) populations, focusing on its associations with quality of life (QOL), mental health, existential and spiritual well-being (SWB), and WTHD.

MEDLINE, Web of Science, Scopus, and the Cochrane Library were searched for eligible studies (English, 2016-2024) involving adult cancer patients receiving PC. MIL was examined as a central intervention component or outcome. Risk of bias was assessed: findings were synthesized narratively. The review was registered in PROSPERO.

Eight studies (n = 1733 participants) were included: four cross-sectional, two randomized controlled trials, one longitudinal observational study, and one qualitative study. Several studies had small samples and substantial attrition. Risk of bias was high (n = 7), and moderate in one cross-sectional study. MIL was inversely associated with depression, anxiety, demoralization, and WTHD; and positively associated with QOL and SWB. MIL may also mediate psychological outcomes (eg, purpose, coherence, and personal values). However, heterogeneity in MIL conceptualization and measurement, combined with low methodological quality, limited comparability and certainty of findings.

MIL may be relevant to psychosocial/existential outcomes in PC. Conclusions are constrained by a small and methodologically weak evidence base. Further high-quality, longitudinal research is needed before MIL-centered interventions can be recommended for routine clinical practice.