Results of a study published in the Journal of Clinical Oncology find that patients with severe mental illness demonstrated a 20% increased risk for breast cancer-specific death, although the association was not statistically significant.
Patients with severe mental illness were more likely to be diagnosed with later-stage breast cancer and more aggressive tumors compared with patients with no mental illness, explained the authors, led by Kristy Iglay, PhD, from the Rutgers School of Public Health in Piscataway, NJ.
Studies have shown that patients with mental illness have a much higher rate of mortality overall, and the life expectancy of people with severe mental disorders can be reduced by up to 24 years when compared with the general population. Cardiovascular disease and cancer are responsible for most deaths in people with mental illness.
Although the incidence of breast cancer is reported to be lower in women with mental illness, the mortality rate is higher.
This retrospective cohort study used SEER-Medicare data, which identified women 68 years or older diagnosed with stage I to IIIa breast cancer in the US from 2005 to 2007. Of the 19,028 patients with breast cancer, 2.6% had severe mental illness in the three years prior to breast cancer diagnosis, including bipolar disorder, schizophrenia, or other psychotic disorder. Almost 8.0% had depression, 6.0% had anxiety, and 3.6% had both anxiety and depression. Patients with dementia and personality disorder were excluded from the study.1
Demographic variables as well as tumor characteristics, tobacco use, and comorbid conditions were obtained.
Compared to women without mental illness, patients with severe mental illness were more likely to be diagnosed with breast cancer beyond stage I, and tumors were more aggressive (ie, at least one positive lymph node, tumor size >20 mm, poorly differentiated tumors). In addition, they reported more tobacco use as well as more comorbid conditions than women without mental illness.
Survival outcomes were compared with patients without mental illness after five years of follow-up. In women with severe mental illness compared to those without mental illness, the cumulative incidence for all-cause mortality was 38.0% and 19.4%, respectively (P <0.001); the cumulative incidence of breast cancer-specific death was 7.2% and 6.2%, respectively (P = 0.1223).
The authors explained that patients with mental illness face unique challenges. Physical symptoms are often mistakenly viewed as a manifestation of their mental illness. In addition, they may not understand the importance of screening, their diagnosis, symptoms, or treatment plan. Prescribed medications may have side effects that play a role in outcomes. For these reasons, it is important that primary care physicians and oncologists coordinate care with psychiatrists.
In an editorial that accompanied the study, Alison R. Hwong, MD, PhD, and Christina Mangurian, MD, MAS, from the University of California, San Francisco, suggested that preventive care, such as screening mammograms, should be integrated into treatment at mental health clinics. They point out that women with mental illness rarely use primary care and receive most of their care from mental health clinics, which typically do not provide preventative medical services.2
“Elderly patients with breast cancer with preexisting mental illness experience increased all-cause mortality,” the authors concluded. “This effect is strongest for those with severe mental illness who may also experience an increased risk of being diagnosed with advanced breast cancer and more aggressive tumor characteristics.”
- Iglay K, et al. J Clin Oncol. 2017 Dec 20;35(36):4012-4018.
- Hwong AR, Mangurian C. J Clin Oncol. 2017 Dec 20;35(36):3996-3998.