Women With Schizophrenia Only Half as Likely to Receive Mammograms

Women with schizophrenia are only half as likely as women in the general population to receive mammograms, reports a meta-analysis posted November 14, 2019, in Psychiatric Services in Advance.

The finding helps explain previous research indicating that breast cancer is detected at later stages in women with serious mental illness and is characterized by larger and higher-grade tumors and more lymph node involvement.

Lead author Alison Hwong, M.D., Ph.D., and colleagues at the University of California, San Francisco, wrote that further work is needed to understand underlying causes of the disparity in screening and to develop interventions to promote breast cancer screening for this vulnerable population.

“Our finding that women with schizophrenia and psychosis were about half as likely to be screened as the general population supports the argument that persons with severe mental illness should be designated as a health disparity population, with special funding to target disparities in care,” they wrote. “Future studies are needed to determine whether women who have schizophrenia experience further differences in mammography screening rates on the basis of race or ethnicity.”

Hwong and colleagues compiled data from 11 clinical studies that looked at mammography screening rates of women with schizophrenia or other psychotic disorders. The 11 studies were conducted in four countries with diverse health care systems—seven in the United States, two in the United Kingdom, one in Denmark, and one in Canada—and in a range of settings (inpatient and outpatient settings, community clinics, and multisite research centers) with privately and publicly insured populations.

The studies included data from 446,475 participants in control groups and 25,447 women with diagnoses of schizophrenia or other psychotic disorders. The primary outcome of interest was the rate of mammography screening for women with schizophrenia and psychotic disorders compared with that of the general eligible population.

The pooled odds ratio from the 11 studies was 0.50 for women with schizophrenia (indicating they were half as likely as the general population to receive a mammography). The odds ratios in the seven studies from the United States varied dramatically from a high of 1.05 (indicating women with schizophrenia were actually more likely than the general population to get mammography screens) to a low of 0.04. The authors noted that one reason for the wide differences seen in the U.S. studies may be due to variations in severity of illness among women included the studies.

Hwong and colleagues, as well as one expert who reviewed the report, suggested that logistics of scheduling appointments may be paramount in explaining the discrepancy in screening rates. “With time constraints, primary care providers and psychiatrists may not prioritize cancer screening for patients with serious mental illness,” the authors wrote. Physicians may focus on psychiatric and metabolic symptoms first, which “may lead to deferring routine preventive screening discussion for future visits, but the future discussion never occurs

Deanna Kelly, Pharm.D., director of the Treatment Research Program (TRP) at the Maryland Psychiatric Research Center, reviewed the report for Psychiatric News and said the findings are not surprising. She was the principal investigator of the DAAMSEL (Dopamine Partial Agonist, Aripiprazole, for the Management of Symptomatic Elevated Prolactin) trial looking at prolactin levels and galactorrhea in women receiving antipsychotic medication (Psychiatric News). As part of that trial, women were prospectively provided with breast exams, and Kelly said many women reported typically missing mammography appointments.

“I made several referrals for mammograms due to potential lumps and keloids,” she said.

She said typically women are commonly given an order for a mammogram during an annual appointment with an obstetrician-gynecologist, requiring a separate appointment for the exam. “I think one of the most challenging barriers is the logistics of scheduling appointments,” she told Psychiatric News.

She added that care coordination is less than ideal between mental health professionals and other medical professionals. “Given that breast cancer is higher in women with schizophrenia, and since we now know screening is subpar, those treating women with schizophrenia should inquire about general medical care that patients may or may not be receiving and encourage our patients to seek preventative care and see their physicians for regular checkups.”

Kelly added that there is some research—not conclusive—suggesting that some antipsychotics may increase risk for breast cancer. “We do know that some, although not all, antipsychotic medications increase prolactin, and we also know that the National Nurses’ Health Study showed that higher prolactin was associated with higher rates of breast cancer in pre- and post-menopausal women.”

Kelly said clinicians should consider using prolactin-sparing antipsychotic medications in patients who have family and other risk factors for breast cancer, especially knowing that screening rates are not ideal. ■

“Breast Cancer Screening in Women With Schizophrenia: A Systematic Review and Meta-Analysis” is posted here. “Bioactive Prolactin Levels and Risk of Breast Cancer: A Nested Case–Control Study” is posted here.