Impact of subsequent metastases on costs and medical resource use for prostate cancer patients initially diagnosed with localized disease.

BACKGROUND: The impact of subsequent metastases on costs and medical resource use (MRU) for prostate cancer (PC) patients initially diagnosed with localized disease was estimated.

METHODS: Surveillance, Epidemiology, and End Results data, linked to Medicare (1999-2012), were used to identify 7482 patients diagnosed with subsequent metastases 12 months or more after the initial diagnosis of localized PC (cases), and they were matched to 25,709 localized PC patients without subsequent metastases (controls). Patients were followed for costs and MRU from 12 months before their index date (subsequent metastases or a matched date for controls) up to 12 months after it. Costs and MRU were stratified by the setting/type of care/service. Multivariate mixed effects regression analyses were used to construct and compare longitudinal trajectories of marginal predicted costs and predicted probabilities of MRU between cases and controls.

RESULTS: Among the controls, predicted monthly costs remained relatively stable throughout the entire observation period (weighted mean per patient per month, $2746; range during 24 months, $2603-2858). In contrast, among the cases, costs increased from $2622 (95% confidence interval [CI], $2525-2719) 12 months before the diagnosis of subsequent metastases to $4767 (95% CI, $4623-4910) 1 month before the diagnosis of subsequent metastases, peaked during the month of metastases at $13,291 (95% CI, $13,148-13,435), and remained significantly higher than costs for the controls thereafter (eg, $4677 at + 12 months; 95% CI, $4549-4805). Costs and MRU increased across a wide range of settings/types, including inpatient, outpatient, home health, and hospice settings.

CONCLUSIONS: In PC patients initially diagnosed with localized disease, a diagnosis of subsequent metastases is associated with substantially increased costs and MRU. Cancer 2017;123:3591-601. © 2017 American Cancer Society.