The definition of a “cancer survivor” differs depending upon an organization’s interpretation of whether this status begins at the moment of diagnosis or if it instead begins upon completion of primary treatment (e.g., surgery, chemotherapy, or radiation therapy). Using the former less restrictive definition, there are more than 11.7 million cancer survivors in the United States and the number is increasing rapidly (1
). Cancer survivors are living longer, but not necessarily better, because they may experience side effects from their illness itself and its treatments. In worse cases, they may also experience secondary cancers stemming from their treatments, recurrence of their primary cancers, and, for those with advanced disease, years or even decades of care that may be palliative but not curative. Common side effects of treatments include conditions such as cardiac toxicity (2
), compromised bone health (3
), immune dysfunction, peripheral neuropathy (6
), neurocognitive effects (8
), sleep disturbance (12
), pain, and fatigue (13
). Cancer survivors often experience problems that begin during or shortly after treatment (e.g., fatigue, insomnia, and depression). Such side effects can be acute and may decrease within a relatively short period of time, but some side effects become chronic and continue well beyond primary or active treatment. Cancer survivors also experience a host of late
effects—problems that arise months or years after treatments are complete and even in the absence of detectable disease.
Several years ago, the National Cancer Institute (NCI) made a pioneering step to recognize the importance of cancer survivorship and its growing constituency by establishing the NCI Office of Cancer Survivorship (OCS). The OCS has served as a liaison among cancer survivors, researchers, and other NCI programs, such as the Cancer Cooperative Groups Program (see following section), to help establish and align research priorities in the area of cancer survivorship. The OCS has served as a voice not only for survivors but also for researchers in terms of aligning priorities for investigation.
Cancer survivorship research, as defined by OCS, encompasses research that addresses the health and well-being of individuals after the end of treatment. This research includes issues related to primary and secondary prevention (screening for and taking known measures to prevent the development of a new cancer that may be unrelated to the original cancer), tertiary prevention (monitoring for and preventing a recurrence of cancer and the adverse medical sequelae of illness), and quaternary prevention (a focus on promoting the health and well-being of survivors following treatment). Also included in this area of science are surveillance studies that track the natural history of cancer and its treatment sequelae.
More specifically, cancer control and survivorship research seeks to identify, examine, and enhance our understanding of the pathophysiology and mechanisms of early and late adverse cancer- and treatment-related outcomes, such as pain, peripheral neuropathies, fatigue, neurocognitive problems, sleep disorders, compromised bone health, cardiac toxicity, immune dysfunction, depression, lymphedema, sexual dysfunction, second cancers, recurrence, comorbidity, and poor quality of life. Cancer survivorship research also seeks to develop effective interventions for the prevention, control, and remediation of early and late adverse cancer- and treatment-related outcomes. Finally, cancer control and survivorship research aims to provide a knowledge base regarding optimal follow-up care and surveillance of cancer survivors and to optimize health during and after cancer treatment.