CHICAGO-The average cost of therapy for advanced colon cancer was twice as expensive in Western Washington compared to British Columbia, Canada. Despite the higher cost of therapy in Western Washington, survival outcomes were not better than British Columbia. The study findings were reported at the 2018 ASCO Annual Meeting (Abstract LBA3579).
"The U.S. and Canada have very different health care systems," said lead study author Todd Yezefski, MD, a senior fellow at the Fred Hutchinson Cancer Research Center in Seattle and the University of Washington School of Medicine. "Most patients in the U.S. are covered by private health care plans that are generally employer-sponsored. Public coverage is generally reserved for the elderly and low-income patients. On the contrary, Canada has universal public coverage with additional private coverage for ancillary services, such as prescription drugs.
"Several studies have shown that overall health care utilization and costs in the U.S. are higher than in Canada; however, outcomes are generally similar, if not worse, in the U.S.," he continued. "There have really though been very few studies that have looked at treatment patterns, costs, and outcomes associated with a specific disease, such as colorectal cancer."
Analysis Details
To evaluate treatment patterns, costs, and outcomes for Western Washington and British Columbia patients with advanced colorectal cancer, study researchers obtained health claims data from the B.C. Cancer Registry and the Hutchinson Institute for Cancer Outcomes Research database, which links the SEER cancer registry to claims data from two of the largest health insurers in the region. Health claims data for Medicare patients in Western Washington were not obtained or analyzed.
Health claims data were obtained for patients with metastatic colorectal cancer diagnosed in 2010 or later in Western Washington and British Columbia, yielding data for 575 patients from Western Washington and 1,622 from British Columbia. Information was collected on demographics, systemic therapy use, disease, cost, and survival; all costs were represented in 2009 U.S. dollars.
Study Findings & Limitations
As expected, Yezefski said, patients in Western Washington were slightly younger than those in British Columbia with a median age of 60 or 66 years. British Columbia had a significantly higher proportion of men (57% vs. 48%) and de novo disease (61% vs. 36%) than Western Washington. Systemic therapy use was more common in Western Washington than British Columbia (79% vs. 68%).
The pattern of treatment regimen used differed between groups. In Western Washington, FOLFOX was the most common choice, while FOLFIRI plus bevacizumab was the most common in British Columbia. Duration of first-line therapy was similar between the two groups, about 6 months.
As for cost of therapy, in general, the cost in Western Washington was significantly higher than in British Columbia. For first-line systemic therapy, average monthly costs per patient in Western Washington were generally more than $12,000 compared to about $6,000 in British Columbia. The average lifetime cost of systemic therapy was nearly $8,000 per patient per month in Western Washington compared to nearly $5,000 in British Columbia. Despite the cost differences, median overall survival was similar for patients in Western Washington and British Columbia (17.4 months vs. 16.9 months).
Yezefski noted that the most common first-line regimen in Western Washington, FOLFOX, was still more expensive than FOLFIRI plus bevacizumab, even though bevacizumab is generally considered an expensive drug.
"This provides a nice glimpse into differences in the price of cancer drugs, which is a big driver of spending on cancer in the U.S.," said Nancy Keating, MD, MPH, Professor of Health Care Policy and Medicine at Harvard Medical School and a physician at Brigham and Women's Hospital. However, she noted, "To really fully understand the survival data better, it will be helpful to have a more comparable population and understand a little bit more information about who these patients are in these cohorts."
The study authors provide little information about the patients and their disease. For instance, it's unclear when patients were diagnosed or how recurrence was identified. She explained that comparing the groups is hard because the patient populations are different, particularly the fact that the Western Washington does not have Medicare data, thereby slanting the population to a much younger, privately insured group.
"Despite that, survival looked pretty similar, and if anything, you would think that the patients of British Columbia should do worse because they're older, and in fact, they look to be the same," noted Keating. She said it is "encouraging" that despite some differences in treatment, it's not leading to worse outcomes in British Columbia.
Cost Implications
About the cost differences, Keating said, "In some ways, this isn't surprising. We've known for a long time that medications cost less in Canada, and I think it's very clear by looking at these data that regardless of the regimen, the drug prices are much lower, and we know that drug prices currently make up a big chunk of total cost of treating patients who are getting chemotherapy.
"The pattern that they show here is consistent with what we know about the price of all kinds of drugs compared in the U.S. and in Canada. I have not seen a comparison like this looking specifically at cancer drugs. So it's nice to have these data because we know that cancer drugs are such a big proportion of the cost of delivering cancer care in America," she added. "It helps us know that it doesn't have to be this way necessarily, and hopefully it will give us in the U.S. some more encouragement to try to adjust the high cost of drugs."
Next Steps
The study researchers plan to continue this work by including claims data for Medicare patients in the Western Washington cohort. Yezefski said that adding Medicare claims data "should hopefully increase the age and make the two groups a little bit more comparable."
Also, the researchers plan to evaluate other aspects of health care utilization, such as total duration of chemotherapy, hospital use, radiation, and surgery.
Christina Bennett is a contributing writer.