Perspectives on comorbidity and cancer in older patients: approaches to expand the knowledge base.

Not only do persons 65 years and older bear a disproportionate burden of cancer, advancing age is associated with increased vulnerability to other age-related health problems. Newly diagnosed older cancer patients who have lived into later years of life may have concurrent ailments (eg, diabetes, chronic obstructive pulmonary disease, heart disease, arthritis, and/or hypertension) that could affect treatment choice, prognosis, and survival. The clinician must often make cancer treatment decisions in the context of an older individual's pre-existing health problems (ie, comorbidity). Ways to produce reliable information on comorbidity that can be effectively used in evaluation of older cancer patients are urgently needed. What is the nature and severity of the older patient's comorbid health problems? How do other age-related conditions influence treatment decisions and the cancer course? How do already compromised older patients tolerate the stress of cancer and its treatment? How are concomitant comorbid conditions managed? At present, no established, valid way to assess comorbidity in older cancer patients exists. Such technology, with a solid conceptual and scientific base, promises a high positive clinical yield to assure quality cancer care for older patients if reliable and valid instruments can be integrated into oncology practice. Much preliminary scientific work must be performed. A synthesis of viewpoints on what to include in comorbidity assessment of older cancer patients and development approaches were expressed in a multidisciplinary working group convened by the National Institute on Aging and the National Cancer Institute. We share the key issues raised regarding complexities of comorbidity assessment and suggestions for scientific inquiry.