When mental illness and cancer collide: An investigation of the predictors of outcomes for cancer patients with a history of mental health problems

OBJECTIVE: People with a serious mental health condition are no more likely to receive a diagnosis of cancer than the general population but fare more poorly in terms of outcomes. The current study investigated whether a background of mental health problems (measured by contact with mental health services and psychotropic medication) predicted treatment outcomes over and above demographic and medical confounds for cancer patients at Counties Manukau Health. METHODS: The sample consisted of 1652 patients diagnosed with cancer in the period 1 January 2016 to 31 December 2016. The sample was split into three groups: non-mental health, moderate mental health, and serious mental health. RESULTS: Patients in the serious and moderate mental health groups were more likely to have physical comorbidities. Those in the serious mental health group were also marginally more likely to have advanced cancer at diagnosis. There were no differences between groups in terms of treatment delays, but patients in the serious mental health group were more likely to be hospitalised and die in the 12 months following diagnosis. Whilst differences in mortality may be explained by greater clinical complexity (being older, having other physical comorbidities) and later stage at presentation, mental health history was independently associated with hospitalisations. CONCLUSIONS: Cancer patients with a history of more serious mental health issues fare more poorly than those with moderate mental health issues or no such history. The clinical complexity of working with these patients, indexed by mental and physical comorbidities, may be a factor contributing to this disparity.