New chemotherapies for metastatic colorectal cancer may be more effective, but at great cost

New chemotherapeutic agents for metastatic colorectal cancer offer improved survival time, however, at substantial cost, according to a recent economic analysis conducted by investigators at Emory University in Atlanta, and published online first (March 22 issue) in the Archives of Internal Medicine.

“Between January 1, 1995, and December 31, 2005, there were sizable increases in life expectancy and lifetime medical costs among elderly (ie, aged 66 or older) Medicare beneficiaries diagnosed with metastatic colorectal cancer and treated with chemotherapeutic agents. On balance, the cost per quality adjusted life year (QALY) gained was about $100,000,” reported the study authors.

Using the Surveillance, Epidemiology, and End Results (SEER)–Medicare database, the investigators compiled a sample of 12,473 patients, of whom 4,665 patients aged 66 and older diagnosed with metastatic colorectal cancer between January 1, 1995 and December 31, 2005, received chemotherapeutic agents including irinotecan, capecitabine, oxaliplatin, bevacizumab, or cetuximab within 6 months of diagnosis.

Upon analysis the investigators found that life expectancy (−0.01 months, 95% CI −0.10 to 0.07 months) and lifetime medical costs ($1,800, 95% CI −$1,100 to $4,700) among patients not receiving chemotherapeutic agents remained basically unchanged over the study evaluation period. However, among patients receiving chemotherapeutic agents, life expectancy increased over the study evaluation period by nearly 7 months and lifetime costs increased by $37,100 (2006 dollars); resulting in an implied cost effectiveness ratio of $66,200 (95% CI, $48,100 to $84,200) per life-year gained.

To test the robustness of their results, investigators conducted sensitivity (or ‘what if’) analyses in which they discounted life years and costs by 3.0%, factored in patients’ quality of life [assuming a health utility after diagnosis of 0.80 (where 0.0 represents death and 1.0 perfect health)], and included patients’ estimated out-of-pocket costs for Medicare-covered services. As a result, investigators found an even higher value for the incremental cost/QALY gained [$99,100 (95% CI, $72,300 to $125,900)].

When looking at each of the newer drugs’ incremental cost effectiveness independently, they found the incremental cost-effectiveness ratios to be $30,700 for irinotecan, $37,800 for capecitabine, $111,200 for oxaliplatin, and $40,500 for bevacizumab.

While somewhat arbitrary, many health economists have concluded that a healthcare intervention that results in an incremental cost-effectiveness ratio >$50,000 to $100,000/QALY gained may not be considered cost effective. The findings of this study suggest that newer chemotherapies are coming dangerously close to eclipsing this mark.

"New chemotherapeutic agents for colorectal cancer have been singled out as examples of high cost/low value medical care; no doubt they are the types of therapies that would receive close scrutiny if Medicare and other payers were to consider cost effectiveness in coverage decisions,” the investigators noted. "Our estimate of the cost per quality adjusted life year gained, $100,000, is below most estimates of the willingness to pay for a life year. However, 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."