Elderly women with breast cancer, mental illness show increased mortality

Elderly women with breast cancer who had severe pre-existing mental illness demonstrated significantly greater all-cause mortality than those without severe mental illness, according to findings from a retrospective cohort study.

Researchers suggested that patients with mental illness may need assistance in coordinating health care services.

“Although the incidence of breast cancer has been shown to be slightly lower in women with mental illness compared with those without, the mortality rate has been shown to be higher,” Melissa L. Santorelli, PhD, adjunct instructor and research scientist with the department of epidemiology at Rutgers School of Public Health, and colleagues wrote. “Nearly all known studies have shown a positive association between aggregate measures of mental illness and both all-cause and breast cancer-specific mortality. Many factors could explain these associations, with screening, access to care, diagnosis and treatment delays often cited as key considerations.”

The researchers used SEER-Medicare data to conduct a retrospective cohort study of 19,028 women aged 68 years or older who had stage I to IIIa breast cancer between 2005 and 2007. Santorelli and colleagues defined mental illness as all patients with recorded diagnosis of bipolar disorder, schizophrenia or other disorders on health care claims during the 3 years leading up to breast cancer diagnosis. Follow-up continued for up to 5 years after breast cancer diagnosis, at which point the researchers compared outcomes of patients with mental illness to outcomes of those without.

Severe mental illness had been diagnosed in 2.6%, whereas 80.1% had no previously diagnosed mental illness, 7.7% had depression, 6% had anxiety and 3.6% had both.

After adjustment for income, age, race, ethnicity and geographic location, women with severe mental illness faced a twofold greater all-cause mortality hazard (HR = 2.19; 95% CI, 1.84-2.6).

Patients with severe mental illnesses also demonstrated a 20% increase in breast cancer-specific mortality; however, this association was not statistically significant (HR = 1.2; 95% CI, 0.82-1.74).

“More research is needed to determine models of coordination that work best to improve outcomes among patients with severe mental illness and to further elucidate the causal pathways between mental illness and reduced survival among patients with breast cancer,” Santorelli and colleagues wrote. “An understanding of how factors, such as care use and quality and treatment decisions, influence outcomes in this vulnerable population can help to inform changes in clinical practice.” – by Andy Polhamus

Disclosures: Santorelli reports no relevant financial disclosures. Please see the full study for a list of all other authors’ relevant financial disclosures.