Association between Lithium Use and Melanoma Risk and Mortality: A Population-Based Study

Area of Science:

• Oncology
• Pharmacology
• Epidemiology

Background:

• Lithium activates the Wnt/ß-catenin signaling pathway, which laboratory studies suggest may inhibit melanoma progression.
• No prior epidemiologic studies have investigated the association between lithium use and melanoma risk.

Purpose of the Study:

• To examine the association between lithium exposure and the risk of developing cutaneous melanoma.
• To investigate the impact of lithium use on melanoma-associated mortality.

Main Methods:

• Retrospective cohort study of over 2.2 million adult members of Kaiser Permanente Northern California from 1997-2012.
• Lithium exposure identified via pharmacy databases; serum levels confirmed via laboratory databases.
• Melanoma incidence and mortality data obtained from an established cancer registry; Cox proportional hazards models used for analysis.

Main Results:

• Melanoma incidence was lower in lithium-exposed individuals (67.4 per 100,000 person-years) compared to unexposed individuals (92.5 per 100,000 person-years).
• Unadjusted analysis showed a 32% lower melanoma risk for lithium users, though this was attenuated in adjusted models.
• No lithium-exposed individuals were diagnosed with thick or advanced-stage melanoma; melanoma-associated mortality was lower among lithium users.

Conclusions:

• Findings suggest lithium may be associated with reduced melanoma risk and mortality.
• Further research is warranted to confirm these potential protective effects of lithium in melanoma prevention and outcomes.