Breast cancer is primarily, although not exclusively, a disease of older women. Unfortunately, as the review by Jones, Leak, and Muss mentions, throughout most of the extensive and numerous randomized clinical trials conducted worldwide over the past 4 decades to evaluate and optimize the treatment of early-stage breast cancer, patients over the age of 65 have been decidedly underrepresented. The resulting paucity of clinical trial information, coupled with the challenges of evaluating the risks of competing mortality and the unique physical, functional, emotional, and psychological issues confronting elderly breast cancer patients, makes treatment decisions extremely difficult.[3,4] In addition, training programs have only recently begun to include formal education about concepts of geriatric oncology, although such concepts hopefully will extend their reach and be incorporated into other levels and types of training, such that these programs will be able to improve the skills of future generations of cancer care providers.
The article by Jones et al provides a timely update on current concepts of geriatric medicine as these relate to options for the adjuvant therapy of older patients with breast cancer. However, cancer treatment–related toxicity can also occur in those younger than 70.[6-8] Geriatricians would argue that biological age alone should not be used to estimate a patient's anticipated tolerance for cancer therapy.[4,9] Ideally, estimation of a patient's functional age should be attempted via the many intertwined aspects of a geriatric assessment, which include explorations of medical, affective, cognitive, spiritual, economic, nutritional, and social support dimensions. A patient's functional status occupies a central place in this model and interacts in a bidirectional manner with all the other dimensions. Measures of functional status can be more subjective (such as ability to perform activities of daily living, performance status, fall history) or more objective (such as physical performance).[4,9] Growing evidence supports the notion that a comprehensive geriatric medicine examination can assess all of these various domains in elderly cancer patients and thus has the ability to predict patients' morbidity and mortality.[10,11] Unfortunately, the performance of time-consuming comprehensive geriatric assessments on a large scale is not feasible, due to the high rate at which cancer patients outnumber geriatricians, as well as because of cost- and time-related inefficiency and the consequent possibility of treatment delay.[10,12] Therefore, simplified screening tests that might be done in the cancer care provider's office could help identify those patients who are at highest risk of cancer treatment–related morbidity and non-cancer–related mortality and who might benefit from a more elaborate, comprehensive geriatric medicine assessment and careful individualization of cancer treatment.
Many screening tools that predict treatment tolerability, and thereby facilitate the decision making process regarding benefits/risks of adjuvant systemic chemotherapy, have been or are in the process of being explored.[4,10,11,13-17] To summarize: currently, most of these screening tests rely on self-reported answers to surveys (exploring clinically meaningful domains that are potentially responsive to supportive measures, such as mood, memory, activities of daily living, quality of life, self-rated health, falls, nutrition, sleep, polypharmacy, socioeconomic status) or calculators (that incorporate geriatric assessment variables; laboratory test values; and patient, tumor, and treatment characteristics). At the current time, no recommendations can be made about the superiority of any of these tools.[10,11] Although screening instruments are becoming more efficient, they have thus far been implemented into clinical practice to only a minimal degree, likely because they require a change in patient flow in an often busy office practice to allow time for administration of the surveys or performance of the calculations, followed by processing, interpretation, and, if needed, arrangement of a geriatric medicine referral.
On the other hand, physical performance measures (eg, measures of fitness, gait/mobility, strength, and balance[9,18,19]), which provide insight into a patient's functional status, are gaining support as screening tools, and could be easily administered in the cancer care provider's office. Physical performance measures yield objective results. They have been shown to be a powerful complement to medical factors in predicting treatment tolerance, morbidity, and mortality—mostly in noncancer settings, but evidence for their use (eg, gait, speed[17,20]) in cancer settings is growing. Physical function measures can be easily implemented as an additional “vital sign” in a busy clinical oncology practice, since they can be administered quickly, can be obtained by nonmedical staff, and can be assessed in a serial manner to facilitate earlier detection of treatment toxicity. It has been hypothesized that a subset of cancer survivors might manifest changes that parallel those seen in the aging population—specifically, a vicious downward spiral of physical, psychological, and behavioral changes that can lead to functional limitation and eventual disability. Therefore, serial screening of a patient's physical function would permit easy and direct identification of a need for rehabilitative therapy, which is currently largely underutilized in the cancer population and not well integrated into cancer care.[18,22,23] Alfano et al have summarized nicely the concepts that rehabilitation interventions can “a) assesses and treat the chronic effects of cancer and prevent or mitigate the effects of late-occurring sequelae, b) address pre-existing or treatment-related comorbid conditions, c) offer self-management skills and health promotion interventions in the context of comprehensive cancer rehabilitation that have the potential to decrease the risk of additional late effects, d) provide a joint focus on optimizing functional status and quality of life, preserving the ability to remain in the workforce and other life roles, and maximizing health and longevity.”
Appropriately assessing functional age in early-stage breast cancer patients remains challenging. It is therefore of great importance that we gain more insight into which screening tools (or combinations of tools) and comprehensive geriatric assessment domains, including physical functional measures, are most efficacious as well as cost- and time-efficient in predicting treatment tolerability in older, but also younger cancer patients. The ability to more accurately determine the risk/benefit ratios of cancer treatments for particular patients will help make possible the higher level of individualized cancer treatment (and supportive care) necessary for patients of all ages.
Financial Disclosure: The authors have no financial interest or other relationship with the manufacturers of any products or providers of any service mentioned in this article.