Outpatient cancer drug costs: changes, drivers, and the future

To the authors' knowledge, no analysis has examined the specific components of drug spending for overall cancer care. The authors' objective was to quantify and characterize trends in outpatient drug expenditures for cancer patients.

The authors retrospectively analyzed pharmacy and outpatient professional claims data from commercial and Medicare health maintenance organization enrollees with a solid tumor diagnosis in 1995 and 1998. Charges were subdivided by type of drug (antineoplastic drugs, chemotherapy adjuncts, supportive drugs, and drugs unrelated to cancer treatment).

In 1995, 14,663 cancer patients received outpatient drug treatment and 13,829 patients in 1998. Total charges increased from $17.9 million (mean charge of $1218 per patient) to $27.9 million (mean charge of $2003 per patient), an average annual increase of 16%. Antineoplastic therapy constituted the largest component of cancer-related drug costs (67%) and represented 76% of the increase from 1995 to 1998. Most charges were incurred in the professional setting for agents administered by injection. The primary explanation for the increases appeared to be a shift in treatment patterns toward newer, more expensive antineoplastic agents. Supportive therapy represented 17% of the increase in cancer drug costs, followed by chemotherapy adjuncts (7%). Charges for drugs unrelated to cancer therapy increased by 21% per year.

Antineoplastic therapy administered in an office or clinic was the single most important cost driver, with newer more expensive agents replacing older, less expensive drugs. Attempts to understand and control outpatient drug cost increases for cancer patients should focus primarily on antineoplastic therapy, especially the appropriate substitution of newer agents for older, less expensive alternatives. Some non-chemotherapy cancer drugs may offer an opportunity to improve quality of life with a relatively small effect on overall cancer drug costs.