Cost-Effectiveness of Chemotherapeutic Agents for Colorectal Cancer in a Medicare Population

The US Food and Drug Administration between June 14, 1996, and February 26, 2004, approved 6 chemotherapeutic agents for the treatment of colorectal cancer. Two of these drugs, bevacizumab and cetuximab, have been singled out as examples of high-cost/low-value medical care. In previous randomized controlled clinical trials, bevacizumab has been shown to extend median survival time by 3 to 5 months at a cost that can exceed $8000 per month.

Researchers recently conducted a study to compare trends in life expectancy and lifetime medical costs in a population of 4665 Medicare beneficiaries ≥66 years of age diagnosed with colorectal cancer and treated with chemotherapeutic agents between January 1, 1995, and December 31, 2005. Study results were reported in Archives of Internal Medicine [2010;170(6):537-542].

The study utilized the Surveillance, Epidemiology and End Results–Medicare database. Using the assumption that, in the absence of new chemotherapeutic agents, costs and survival would have been largely unchanged in the study population, the researchers measured the cost-effectiveness of the study drugs as a group by comparing the change in costs with the change in survival time. Based on observed costs and short-term survival rates, the researchers estimated life expectancy and lifetime medical costs.

The final study sample included 12,473 patients; 37.4% (n=4665) received chemotherapeutic agents within 6 months of diagnosis of colorectal cancer. Mean survival time among patients receiving chemotherapeutic agents increased by 4.5 months, and costs for those patients in the 2-year window after diagnosis increased by $17,800.

During the study period, life expectancy and lifetime medical costs for colorectal cancer patients not receiving chemotherapeutic agents remained basically unchanged. For the patients who did receive chemotherapeutic agents, there was an increase in life expectancy of 6.8 months and an increase in lifetime healthcare costs of $37,100. The implied cost-effectiveness ratio

is $66,200 (95% confidence interval [CI], $48,100-$84,200) per life-year gained.
Following adjustment for patients’ health utility and out-of-pocket payments and discounting life-years, the cost per quality-adjusted life-year gained is $99,100 (95% CI, $72,300-$125,000).

The researchers noted that the study finding of only a $37,000 increase in lifetime healthcare costs associated with treatment with chemotherapeutic agents apparently contradicts much larger increases often quoted in the media and in journal commentaries for the cost of new chemotherapeutic agents. They cited some possible reasons for the discrepancy: (1) not all patients treated with chemotherapeutic agents receive the newest agents; (2) commonly cited figures are based on manufacturers’ average wholesale prices (following the Medicare Prescription Drug, Implementation, and Modernization Act of 2003, Medicare based reimbursements on each manufacturer’s average sale price); and (3) commonly cited figures are costs for 6 to 12 months of therapy, yet, according to the researchers, many patients die or discontinue therapy within 1 year of diagnosis.

The researchers continued by noting that their estimates of the change in survival and costs were lower than they would have been had all patients been treated with newer chemotherapeutic agents. They also noted that their sample included only elderly patients, who are more medically frail and subject to a higher risk of death from other causes, possibly reducing the magnitude of benefit from aggressive treatment with chemotherapeutic agents.

In conclusion, the researchers said that their estimate of $100,000 as the cost per quality-adjusted life-year gained is below current estimates of willingness to pay for a life-year. They caution, however, that “continuation of Medicare’s open-ended coverage policy for new chemotherapeutic agents and other expensive technologies will prove difficult to sustain as costs for the program continue to rise.”—Tori Socha