Findings presented at the American Psychiatric Association (APA) 2017 Annual Meeting in San Diego, California, show no association between lithium treatment in bipolar disorder and increased cancer incidence.
Lina S. C. Martinsson, MD, PhD, from Karolinska Institute in Stockholm, Sweden, and colleagues conducted a nationwide Swedish register study of incidence rate ratios (IRRs) of total and site-specific cancer in patients with bipolar disorder aged 50-84 years with and without lithium treatment from July 2005 to December 2009. The IRRs were compared with cancer rates in the general population with information from the Swedish Cancer Register, the National Patient Register, and the Drug Prescription Register.
The researchers found there was no difference in the risk for unspecified cancer in patients treated with lithium compared with the general population (IRR, 1.04; 95% CI, 0.89-1.23), nor in patients with bipolar disorder not treated with lithium compared with the general population (IRR, 1.03; 95% CI, 0.89-1.19).
There was also no significantly increased risk for site-specific cancer in patients with bipolar disorder receiving lithium treatment compared with the general population.
However, cancer risk was significantly higher in patients not receiving lithium in the digestive organs (IRR, 1.47; 95% CI, 1.12-1.93), in the respiratory system and intrathoracic organs (IRR, 1.72; 95% CI, 1.11-2.66), and in the endocrine glands and related structures (IRR, 2.60; 95% CI, 1.24-5.47).
Bipolar disorder was not associated with increased cancer incidence and neither was lithium treatment in these patients. Specifically, there was an increased risk of respiratory, gastrointestinal and endocrine cancer in patients with bipolar disorder without lithium treatment,” the researchers concluded.
Martinsson LSC. Lithium treatment and cancer incidence in bipolar disorder: a large nationwide Swedish register study. Presented at: American Psychiatric Association (APA) 2017 Annual Meeting; May 20-24, 2017; San Diego, CA. Abstract: P5-39.