Applicability of Cost-Effectiveness Studies from Developed to Developing Countries
Many of the cost-effectiveness studies of cancer control interventions (prevention, screening, and treatment) have been performed in the context of high-income, developed countries; thus, the question arises whether such studies are applicable to health care delivery settings in developing countries. No simple rule is available to indicate how the results of cost-effectiveness studies in developed countries might translate to health care delivery settings in developing countries, but disease incidence and time horizon are major pertinent considerations in relation to cancer prevention and screening interventions. In relation to cancer treatment, other considerations have to be taken into account.
Factors Affecting the Applicability of Cost-Effectiveness Studies of Prevention and Screening
Cost-effectiveness analyses of cancer prevention and screening interventions are complex. Several parameters have a large influence on the results of these studies, including the following:
age-specific cancer incidence
all-cause life expectancy and temporal trends of major epidemics
population age structure
availability, effectiveness, and costs of cancer treatment
health system costs of the prevention or screening intervention.
As illustrated by the several examples described in this chapter, those parameters are likely to vary widely between developed and developing countries.
For example, age-specific cancer incidence in the absence of a preventive or screening intervention can have a major influence on the potential cost-effectiveness of a cancer prevention or screening intervention. Generally, the higher the background incidence of the cancer, the more cost-effective the cancer prevention or screening intervention will be. For that reason, the relative cancer incidence patterns in developed and developing countries for the cancer screening interventions described earlier need to be considered.
Figure 29.3 shows age-specific cancer incidence patterns for cervical and breast cancer for developed and developing countries. As the figure shows, the incidence of cervical cancer in developing countries is relatively high in comparison with the incidence of these cancers in developed countries, whereas the incidence of breast cancer is relatively low in developing countries compared with that in developed countries. Given the relatively high incidence of cervical cancer in developing countries, interventions for cervical cancer prevention and screening are likely to be more cost-effective in developing countries rather than developed countries, compared with interventions for breast cancer, all else being equal.
Factors Affecting the Applicability of Cost-Effectiveness Studies of Treatment
Many of the treatments for breast, colorectal, and lung cancer that have been shown to be efficacious in controlled clinical trials have been estimated to have cost-effectiveness ratios in the range of a few thousand U.S. dollars to a few tens of thousands of U.S. dollars per YLS. This range is considered quite favorable in developed countries but might be viewed as less favorable in low-and middle-income countries that face stringent constraints on health care resources. Disease incidence and time horizon do not loom as major considerations in the case of the cost-effectiveness of cancer treatment, because the cost of treatment applies only to those individuals already diagnosed with cancer and considered eligible for a specific treatment, not to a broader population considered to be at risk for developing cancer.
Thus, in low-income, low-cost countries with high mortality rates, because of the lack of primary treatment, the provision of basic cancer treatment may be a cost-effective first step toward cancer control, especially for highly treatable cancers with relatively low incidence in developing countries. For example, using a generalized cost-effectiveness approach, Ginsberg and others (2004) conclude that the provision of basic treatment for colorectal cancer in low-income African countries is likely to be a cost-effective first step toward cancer control.
Nevertheless, issues of economies of scale and scope may be associated with fixed investments in specialized medical equipment and skilled human capital. The centralization and regionalization of cancer treatment may be associated with a higher technical quality of care and might also be associated with the need to use these resources at economically efficient levels. Some cost elements, such as local labor and the availability of generic drugs since initial clinical trials were conducted, will clearly be lower in the contemporary setting of developing countries than in many of the cost-effectiveness studies reviewed earlier.
Finally, developments in cancer treatment, especially in relation to chemotherapy, are extremely dynamic. For example, the 1999 WHO list of essential drugs for cancer therapy (Sikora and others 1999; WHO 2003a), includes 5-fluorouracil as a priority one (essential) drug and irinotecan as a priority three (palliative benefit only) drug for the treatment of colorectal cancer. Just five years later, in many developed countries the following drugs, in addition to irinotecan, have been added to the basic regimen of 5-fluorouracil plus leucovorin for the treatment of colorectal cancer: oxaliplatin, bevacizumab, and cetuximab. Whereas 5-fluorouracil-based treatment of metastatic colorectal cancer increased median survival from 8 to 12 months, the newer drugs increase median survival to 21 months or more, at a significantly increased economic cost. In the United States, the drug cost of 5-fluorouracil-based therapy ranges from US$63 to US$263 for the initial eight weeks of therapy. Adding irinotecan or oxaliplatin increases the drug cost to about US$10,000, and adding bevacizumab or cetuximab adds another US$20,000 to US$30,000 to the cost of initial treatment. If the latter drugs are used over the longer term as envisioned, the average cost of supplying the drugs to a single patient could approach US$300,000. Those estimates do not consider the additional costs of chemotherapy preparation, administration, and supervision and supportive care (Schrag 2004). The situation is similar for other common cancers. Clearly, low-and middle-income countries cannot afford to make the newest cancer drugs widely available to cancer patients; however, this example illustrates the need for periodic updating of available chemotherapy options along with evaluations of the incremental costs and benefits associated with them.