BOSTON – Older adults with mental illness are less likely to undergo chemotherapy after a cancer diagnosis than those without mental illness, a study has shown. The findings are consistent with those from previous studies suggesting disparities in the care of chronic conditions among mentally ill older adults, Dr. Simha E. Ravven reported at the meeting.
“Even though adults with mental illness are often well connected to primary care, our findings suggest that they may not be receiving the same kind of cancer treatment and that they may need more support and counseling to get the same care,” said Dr. Ravven, a fellow at Harvard Medical School, Boston.
To determine whether cancer screening and treatment vary for people with prior mental illness, and if mortality after a cancer diagnosis differs in this population, Dr. Ravven and her colleagues reviewed records for the 19,045 participants of the year 2000 wave of the National Institute on Aging's nationally representative, longitudinal Health and Retirement Study (HRS). The study, conducted by the University of Michigan, Ann Arbor, surveyed adults born in 1947 or earlier to assess mental health, financial status, family support, and retirement planning among aging Americans, she said.
Of the full study cohort, about 14% had a history of mental illness, according to Dr. Ravven. While both men and women with a history of mental illness were as likely to receive clinical cancer screening, including a breast exam, a Pap test, mammography, and a prostate exam within 2 years prior to the survey as part of the general population, individuals with mental illness who had a recent cancer diagnosis were significantly less likely to receive chemotherapy, with an odds ratio of 0.33, she said. No significant differences wee found in receipt of radiation therapy, surgery, or biopsy, she reported.
When assessed by gender, the odds ratio for receiving chemotherapy among women with a history of mental illness was especially low relative to women without mental illness, with an odds ratio of 0.18. No significant difference was found between men with and without mental illness, Dr. Ravven said.
With respect to mortality, men with a history of mental illness and cancer were nearly three times more likely to die from their cancer within 2 years than were men without mental illness, while the opposite was true for women, Dr. Ravven noted. “Women with a history of mental illness who had had a cancer diagnosis had a significantly lower risk of mortality within 2 years than [did] those without,” she said.
While the reasons for the disparities are unclear, it is possible that patients with mental illness avoid chemotherapy because they are not psychologically prepared for the rigorous treatment or their physicians have concerns about treatment adherence, Dr. Ravven hypothesized.
The findings are limited by the study's retrospective design and failure to look at stage of cancer diagnosis or cancer site, Dr. Ravven acknowledged.
It is possible that treatment disparities relate to the fact that chemotherapy might not have been part of the standard treatment protocol for certain stage cancers.
Dr. Ravven and her colleagues plan to further investigate the treatment disparities, she said, noting that future research will include more detailed information, including cancer stage and site, and the nature and severity of the mental illness.