Childhood Cancer
Nearly one in two men and more than one in three women in the United States will be diagnosed with cancer at some point in his or her lifetime (Clapp, Howe, & Lefevre, 2005). In 2001, cancer accounted for 24% of all deaths in Oregon, making it the second leading cause of death in the state (Oregon DHS, 2004). The most commonly diagnosed cancers in Oregon include breast cancer, prostate cancer, and lung cancer. In 2002 Oregon had the second highest melanoma mortality rate in the nation and Oregon is consistently among the nation’s top five states for incidence of breast cancer (Oregon Partnership for Cancer Control, 2005). Approximately three-quarters of the nation’s cancer deaths are associated with environmental factors, broadly defined to include smoking, diet and infectious disease, as well as pollution, some chemicals and radiation (American Cancer Society, 2006). Our estimates, however, do not include the impact of smoking, diet, and infectious disease in the calculations.
Childhood Cancer
The most frequently occurring childhood cancers nationwide and in Oregon are leukemias, brain cancer, and other central nervous system cancers (American Cancer Society, 2007; Riddell & Pliska, 2007). There is evidence that all of these cancers are associated with environmental contaminants (Janssen, Solomon, & Schettler, 2004). Chemicals in outdoor air such as benzene and 1,3-butadiene have been association with elevated rates of cancer in children (Steffen, Auclerc, & Auvrignon, 2004; Crosignani et al., 2004; Knox, 2005). Many studies have demonstrated that pesticide exposure is associated with an increased risk of childhood cancer, with several studies reporting significantly increased risk for leukemia and cancers of the brain among children exposed to pesticides in and around the home (Daniels, Olshan, & Savitz, 1997; Zahm & Ward, 1998; Menegaux et al., 2006; Ma et al., 2002). In 2004, there were 165 cancers diagnosed in Oregon children (0-20 years of age) (Riddell & Pliska, 2007). To estimate the costs of childhood cancer in Oregon, we followed the methods and assumptions of Landrigan et al.
Method of Landrigan et al.
Landrigan et al. derived an estimate of national costs from childhood cancer on a cost-per-case basis. They estimated that the national average cost per child was approximately $623,000 in 1997 dollar. This estimate includes direct health care costs (physician fees, inpatient services, outpatient services) of $509,000 and indirect costs (loss of parental wages, loss of future income due to loss of IQ, cost of treating a second primary cancer ) of $114,000.
Landrigan et al. then multiplied this cost by the annual incidence of 7,722 cases of cancer per year for children less than 15 years old to yield an estimate of $4.8 billion for annual costs of childhood cancer nationwide. They then added costs of mortality as a lump cost of $1.8 billion (the costs of premature loss of life due to primary and secondary cancer in the cohort of children), which is roughly $233,100 in additional costs per case in 1997 dollars. This leads to an estimated annual cost of childhood cancer of $6.6 billion in 1997 dollars.
Nationally, the cost per child is equivalent to $815,830 in 2007 dollars, the costs of premature death are equivalent to $2.36 billion in 2007 dollars, and the total estimated annual cost of childhood cancer nationally is equivalent to $8.64 billion in 2007 dollars. This gives a cost per case estimate of $1.12 million in 2007 dollars when the costs of mortality are included.
Environmentally Attributable Fraction: To assess the environmentally attributable fraction of childhood cancer, Landrigan et al. convened a panel of experts in pediatric oncology, epidemiology, and environmental medicine. Based on the scientific evidence, the panel concluded that EAFs of 2, 5, and 10% most accurately reflected the data at the time. These numbers are conservative since there is a great deal of uncertainty regarding the environmental risk factors for cancer. In addition, these numbers do not account for childhood environmental exposures that lead to cancer development later in life. In this study, we will use an EAF of 5% as our best estimate and a range of 2-10%.
Costs in Oregon
This estimate of the costs of childhood cancer in Oregon attributable to environmental contaminants is based on the following assumptions:
- Oregon annual incidence is 165 childhood cancer diagnoses per year (0-20 years of age) (Riddell & Pliska, 2007);
- Total cost per case is $1.12 million per case per year in 2007 dollars; and
- An EAF of 5% with a range of 2-10%.
Annual costs of childhood cancer in Oregon = $184.8 million in 2007dollars.
Applying the EAFs of 0.02, 0.05, and 0.10 yielded the following results:
- EAF 0.02 = $3.7 million
- EAF 0.05 = $9.2 million
- EAF 0.10 = $18.5 million
Using these assumptions, the best estimate of the annual costs of childhood cancer attributable to environmental contaminants in Oregon is $9.2 million per year, with a range of $3.7 to $18.5 million. These costs underestimate the total yearly costs of cancer because the calculations only consider the costs of new cases. The costs for the ongoing management and treatment of all existing childhood cancer cases (prevalence) are not available for Oregon and therefore are not included.
