Background: Patients, clinicians, the Food and Drug Administration, researchers and pharmaceutical manufacturers have a stake in knowing if specific treatments impact cancer development. Clinical trials have known limitations for studying cancer as an adverse outcome. Postapproval safety studies frequently provide the best opportunity to characterize the risk of cancer from treatments but can be limited due to challenges in case identification, exposure assessment and data sources. Lack of access to high-quality, national cancer outcome data that can be linked with treated populations is an unmet need for rare cancers.
Objective: Provide current examples of cancer signals under study in the postapproval setting at the national level, identify limitations and discuss how cancer registries may play a role.
Methods: We review public information, including FDA postmarketing commitments to study rare cancer outcomes in nononcological drugs to describe the nature of the medication exposure (e.g., by age, prevalence) and the outcome ascertainment method used (e.g., medical claim, cancer registry) to estimate the current gap to be filled through access to a national, linkable cancer registry, if one existed.
Results: We describe current examples of cancer signals under study, including the treatment indication, origin of the signal (preclinical, clinical, or postapproval), approved approach to identify cancer outcome, and strengths and limitations of the design.
Conclusions: Postmarketing drug safety studies require the ability to properly identify and classify cancer outcomes. These studies also rely on proper treatment exposure classification and risk window assessment due to uncertain periods of cancer induction and latency. Cancer registries could play a vital role at the national level through linkages with treated cohorts from postapproval registries and database studies to efficiently and accurately quantify cancer risk for existing and emerging drug treatments.
