Abstract ED02-04: Intersection of cancer, aging, and survivorship

Cancer is a disease associated with aging, with approximately 60% of cancer diagnoses occurring in patients age 65 and older. Of 10.8 million cancer survivors in the US, approximately 6.8 million are age 65 or older. With the aging of the baby boomer population and rises in life expectancy, the number of cancer cases and the number of cancer survivors is anticipated to grow over the coming decades.¹ Optimal care of this growing population of older adult cancer survivors will require an understanding of the interaction between cancer, cancer therapy, and the aging process. In particular there is a gap in knowledge regarding whether cancer and/or cancer treatment accelerates the aging process, and if so whether the accelerated aging is transient or permanent. This lecture will provide an overview of the available data regarding the intersection between aging and survivorship, as well as specific considerations in the assessment and treatment of older adult survivors.

Cancer and cancer treatment has a potential long term impact on the health status and physical function of older adults.^2–3 The Health and Retirement study evaluated the health and functional status of older cancer survivors in comparison to controls. Older cancer survivors were less likely to report excellent or good health (P<0.001), reported more mobility limitations (P<0.001), and reported more limitations with activities of daily living (P=0.01). Among older cancer survivors, obesity, lack of exercise, and poor diet are associated with a poorer quality of life.⁴ A randomized study tested the benefits of an exercise and diet intervention in older cancer survivors and demonstrated that the intervention was associated with a decrease in self-reported functional decline.⁵

Older cancer survivors have an increased number of comorbid conditions in comparison to individuals without a history of cancer.² The NIA/NCI Collaborative Study on Cancer and Comorbidity in the Elderly provided summary data on the comorbidity of 7,600 patients age 55 and older with a history of cancer. The most common comorbid conditions included hypertension (43%), heart conditions (39%) and arthritis (35%).⁶ Patients may be at increased risk for specific comorbid conditions based on their preexisting comorbid conditions and the therapeutic exposures received. For example, therapy with doxorubicin is associated with an increased risk of congestive heart failure and cardiomyopathy.^7–8 Risk factors include a history of diabetes mellitus, coronary artery disease, and hypertension. Therapy with an aromatase inhibitor is associated with a loss in bone mineral density and this risk is most pronounced in patients with pre-existing bone loss.⁹ These examples highlight the need to better understand the association between a history of cancer, patient characteristics (including pre-existing comorbid conditions), specific therapeutic exposure, and the subsequent development or acceleration of comorbid conditions.

Although our knowledge of the potential survivorship issues facing older adults is growing, several gaps in knowledge remain.¹⁰ As the number of cancer survivors is on the rise, it is critical to improve our evidence-based knowledge to identify and reduce the risk of late side effects from treatment. Prospective longitudinal studies of the long term impact of cancer therapies and interventions to decrease the risk are needed.

References:

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8. Hershman DL, McBride RB, Eisenberger A, Tsai WY, Grann VR, Jacobson JS. Doxorubicin, cardiac risk factors, and cardiac toxicity in elderly patients with diffuse B-cell non-Hodgkin's lymphoma. J Clin Oncol 2008;26:3159–65.

9. Eastell R, Adams JE, Coleman RE, et al. Effect of anastrozole on bone mineral density: 5-year results from the anastrozole, tamoxifen, alone or in combination trial 18233230. J Clin Oncol 2008;26:1051–7.

10. Carver JR, Shapiro CL, Ng A, et al. American Society of Clinical Oncology clinical evidence review on the ongoing care of adult cancer survivors: cardiac and pulmonary late effects. J Clin Oncol 2007;25:3991–4008.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):ED02-04.