Abstract
BACKGROUND: Although high-dose interferon (hd-ifn) is the sole approved adjuvant systemic treatment for melanoma in many jurisdictions, it is toxic. We sought to assess the population-level effects of hd-ifn toxicity, particularly neuropsychiatric toxicity, hypothesizing that such toxicity would have the greatest effect on mental health services use in advanced resected melanoma. METHODS: This retrospective population-based registry study considered all melanoma patients receiving adjuvant hd-ifn in Ontario during 2008-2012. Toxicity was investigated through health services use compatible with hd-ifn toxicity (for example, mental health physician billings). Using stage data reported from cancer centres about a subset of patients (stages iib-iiic), a propensity-matched analysis compared such service use in patients who did and did not receive hd-ifn. Associations between early hd-ifn discontinuation and health services use were examined. RESULTS: Of 718 melanoma patients who received hd-ifn, 12% were 65 years of age and older, and 83% had few or no comorbidities. One third of the patients experienced 1 or more toxicity-associated health care utilization events within 1 year of starting hd-ifn. Of 420 utilization events, 364 (87%) were mental health-related, with 54% being family practitioner visits, and 39% being psychiatrist visits. In the propensity-matched analysis, patients receiving hd-ifn were more likely than untreated matched controls to use a mental health service (p = 0.01), with 42% of the control group and 51% of the hd-ifn group using a mental health service in the period spanning the 12 months before to the 24 months after diagnosis. In the multivariable analysis, early drug discontinuation was more likely in the presence of pre-existing mental health issues (odds ratio: 2.0; 95% confidence limits: 1.1, 3.4). CONCLUSIONS: Stage iib-iiic melanoma patients carry a substantial burden of mental health services use whether or not receiving hd-ifn, highlighting an important survivorship issue for these patients. High-dose interferon is associated with more use of mental health services, and pre-treatment use of mental health services is associated with treatment discontinuation. That association should be kept in mind when hd-ifn is being considered.