Results from a meta-analysis published in Lancet Psychiatry suggest that patients with psychiatric disorders are less likely to receive cancer screenings compared with the general population, a worrisome issue given the elevated mortality from cancer in people with mental illness. Underscreening trends were particularly pronounced in patients with schizophrenia.

Marco Solmi, MD, PhD, of the neurosciences department at the University of Padua in Italy, led study efforts to assess cancer screening trends in patients with psychiatric disorders. The investigators searched PubMed and PsycINFO through May 5, 2019 for observational studies focused on screening for any type of cancer in patients with mental illness. The study included depressive disorders; bipolar disorders; schizophrenia; eating disorders; and anxiety disorders, specifically obsessive-compulsive disorder, post-traumatic stress disorder, and panic disorder.

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Studies that did not define mental illness using structured criteria or validated scales were excluded from the meta-analysis. The primary outcome measure was odds ratio (OR) of cancer screening in patients with mental illness compared with the general population. The Newcastle-Ottawa Scale was used to ascertain study quality and the risk of bias was assessed with the Egger’s test.  

A total of 47 publications reporting data from 46 samples were included in analyses. The pooled study cohort comprised 4,717,839 individuals (age range, 18 to 79 years; 69.85% women), of whom 501,559 had a documented mental illness. Overall, study quality was high.

Screening was significantly less common in patients with mental illness compared with the general population for any cancer (odds ratio [OR], 0.76; 95% CI, 0.72-0.79), breast cancer (OR, 0.65; 95% CI, 0.60-0.71), cervical cancer (OR, 0.89; 95% CI, 0.84-0.95), and prostate cancer (OR, 0.78; 95% CI, 0.70-0.86), with all P <.001. The same trend was not observed in colorectal cancer screening (OR, 1.02; 95% CI, 0.90-1.15). Patients with schizophrenia spectrum disorders had even lower odds of screening for any cancer (OR, 0.62; 95% CI, 0.53-0.74; P <.001), breast cancer (OR, 0.52; 95% CI, 0.43-0.62; P <.001), and cervical cancer (OR, 0.75; 95% CI, 0.60-0.93; P =.010) compared with the general population. Risk for publication bias was generally low, and patients with mental illness remained at lower odds for screening even in trim-and-fill analyses.

In additional analyses of study settings, which included Europe, Canada, the United States, Australia, and Asian countries, the cancer screening gap between people with mental illness and the general populace increased alongside overall participation in screenings nationally for any, cervical, and colorectal cancer (all P <.001).

The study highlights a significant unmet need for cancer screening in patients with mental illnesses, particularly women with schizophrenia.

As study limitations, investigators noted the substantial heterogeneity between studies, and different mental illness and cancer screening guidelines across countries may limit the generalizability of these data.

The study authors concluded by noting some possible factors influencing disparities in screening rates, including psychiatrists’ rarely conducting physical examinations, socioeconomic depravation in patients with mental disorders, and diagnostic overshadowing of psychiatric vs somatic symptoms. “Specific strategies, which should ideally involve mental health departments, general practitioners, and…primary care departments, should be tested and implemented in order to fill this important health­care gap,” the researchers noted.

Reference

Solmi M, Firth J, Miola A, et al. Disparities in cancer screening in people with mental illness across the world versus the general population: prevalence and comparative meta-analysis including 4 717 839 people [published online November 29, 2019]. Lancet Psychiatry. doi:10.1016/S2215-0366(19)30414-6