Cost of illness in patients with metastatic colorectal cancer.

OBJECTIVES: To estimate total costs and metastatic colorectal cancer (mCRC)-related costs and assess primary cost drivers of treating newly diagnosed mCRC patients after the introduction of biologic therapies.
METHODS: Using a large national claims database, costs of mCRC patients were estimated in 2004-2009 by examining (1) the cost difference between mCRC patient and their matched non-cancer cohorts, and (2) mCRC-related costs. Costs were further assessed by phase of disease (diagnostic, treatment, and death). The survival analysis technique was used to estimate cost of handling variable length of follow-up and data censoring.
RESULTS: A total of 6,746 mCRC patients met all eligibility criteria, 6,675 of them were matched to patients without cancer. Among the three phases of disease, the treatment phase was the longest (16.4 months). Compared with matched patients with no cancer, total monthly costs were $14,585 higher for mCRC patients, which was driven by higher inpatient ($7,546) and outpatient ($6,749) care (p < 0.001 for all comparisons). During the study period, cost share of biologics increased from 4.8% among patients diagnosed in 2004 to 9.4% for those diagnosed in 2008.
CONCLUSIONS: The costs associated with treating mCRC are substantial. Inpatient and outpatient care remain key cost drivers in the medical management of mCRC. Cost chare of biologics was low, but increased between 2004 and 2009. The study sample only included patients with commercial and Medicare supplemental insurance in the US thus may not be generalizable to patients with other insurance or in other countries. Indirect costs associated with mCRC were not examined.