San Diego, CA—Childhood cancer therapy can be a double-edged sword: it often leads to a cure, but long after treatment ends, some cancer survivors are still suffering its side effects.
“Compared with children without cancer, childhood cancer survivors have higher rates of prescription drug use across many drug classes, which is indicative of their higher burden of medical morbidities,” said Andrew Brian Smitherman, MD, St. Baldrick’s Fellow in Pediatric Hematology-Oncology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, at the 2017 Cancer Survivorship Symposium.
Dr Smitherman presented the results of a retrospective analysis of commercial claims data, which suggests that many chronic problems are evident within the first 3 years of stopping cancer therapy. Survivors of childhood cancers were far more likely than individuals in the general pediatric population to fill prescriptions after treatment, and they filled their prescriptions from a greater number of unique drug classes compared with children without cancer.
Furthermore, the increased prescription drug fill rate of antibiotics, antidepressant drugs, and opioids persisted for 3 years among the majority of cancer survivors.
Increased Prescription Fill Rate
To understand the late effects of treatment-associated morbidities in survivors of childhood cancers, Dr Smitherman and colleagues used the Truven Health MarketScan Commercial Claims Database to identify survivors of childhood leukemia, lymphoma, central nervous system (CNS), bone, or gonadal tumors who completed therapy between 2000 and 2011. Prescription drug fill rates from the 1414 cancer survivors were then compared with age- and sex-matched children without cancer.
Across all 5 cancer subtypes, cancer survivors were more likely than their comparators to fill prescriptions in each of the first 3 years after stopping cancer therapy.
“We anticipated that survivors would fill more prescriptions, especially in the first year after therapy, but I expected to see more of a return to normal as some of the acute treatment-associated morbidity [resolved],” said Dr Smitherman. “However, the risk clearly persists: even 3 years off therapy, childhood cancer survivors are using more prescriptions than the general pediatric population,” he added.
Dr Smitherman and colleagues also observed significant differences in the density of prescriptions, with cancer survivors filling prescriptions from more drug classes than individuals in the general pediatric population.
“While the general pediatric population, on average, fills 1 unique class of drugs in any given year, survivors of childhood cancers are filling upwards of 8 classes of drugs in the first year of therapy,” said Dr Smitherman. “It decreases a little with time, but CNS survivors are still filling 6 unique classes of drugs per year compared to just 1 in the general population. That’s indicative of the breadth of the morbidities that they’re experiencing,” he added.
Depression and Opioid Use on the Rise
When analyzed by the specific drug class and cancer type, the data revealed additional findings. For example, survivors of leukemia, lymphoma, CNS, or bone tumors had 2 to 4 times the risk for being prescribed an antidepressant drug.
“In the prepubescent general population, the prevalence of depression is around 2% to 3%,” said Dr Smitherman. “Around 6% of leukemia survivors, however, were found to be on antidepressants. And lymphoma survivors, who are older, filled prescriptions for antidepressants at a rate between 10% and 13%,” he added.
Cancer survivors were also at an increased risk for chronic opioid use. According to the study data, survivors were 2.5 to 5 times more likely to fill opioid prescriptions than individuals in the general population. Although that risk begins to decline after the first year of stopping cancer therapy, it never returns to baseline values, said Dr Smitherman.
“Compared with the general population, childhood cancer survivors are consistently at increased risk for filling opioid prescriptions,” Dr Smitherman concluded. “Many of these children are still experiencing pain years out from therapy. As providers, we need to consider ways to address this pain, other than prescribing opioids,” he added.
The higher prescription fill rates by survivors of childhood cancers indicate that they have a greater morbidity burden than does the general pediatric population. “Providers need to pay closer attention to emerging morbidities during the early off-therapy period,” stated Dr Smitherman.