Dr. Lodovico Balducci’s presentation is a call for oncologists to recognize that the care of older cancer patients needs to be a priority. The aging of the population and the increased incidence of cancer with age will rapidly expand the population of older cancer patients. The field of medical oncology is moving toward personalized cancer care, with an emphasis on genetic evaluation and targeted therapy (Nat Rev Drug Discov 2010;9:363–366). The care of the elderly is the most comprehensive form of personalized care; it requires individual evaluation, as older cancer patients are a heterogeneous group.
It has long been recognized that the most significant risk factor for the development of cancer is aging. The traditional ways in which cancer is studied, namely, clinical trials focusing on younger, healthier patients, have left us with a void in the available data to manage the older patients in an evidence-based fashion. These trials fail not only to establish the validity of cancer treatment in the elderly but also to provide information related to the long-term complications of treatment, including decline in function (JAMA 2005;293:1073–1081).
Geriatric assessment
Fortunately, interest in geriatric oncology has been growing. As a result, there has been a marked increase in investigations into various aspects of geriatric assessment to aid oncologists in making treatment decisions. This has included the degree and severity of comorbidity; functional assessment; geriatric syndromes; the role of polypharmacy; and the various social, emotional, and financial problems facing older patients with cancer. The under-representation of older patients in clinical trials has been amply documented (N Engl J Med 1999;341:2061–2067).
One of Dr. Balducci’s pleas is to avoid undertreatment, particularly in those patients who should be able to tolerate standard therapies. The adverse outcomes associated with inadequate dosing and supportive care in both curative and palliative treatments have been demonstrated in a number of treatment settings (J Clin Oncol 1986;4:295–305; J Clin Oncol 2007;25:1858–1869). Even when clinical trials are available, barriers to participation of older patients have been shown to be due primarily to physician reluctance, based on fear of toxicity, limited expectation of benefit, or ageism (J Clin Oncol 2003;21:2268–2275).
A number of important strides have been made in the evaluation of older patients through various methodologies of geriatric assessment. The comprehensive geriatric assessment (CGA) developed by geriatricians is a multidisciplinary evaluation of the older patient encompassing a number of important clinical domains (N Engl J Med 2002;346:905–912). Researchers in this area have shown that traditional oncology measures of performance are not adequate in older patients and that geriatric-specific measures, ie, activities of daily living (ADL) and instrumental ADL (IADL), have a much greater predictive value (J Clin Oncol 1998;16:1582–1587).
Many of the geriatric oncology investigations are trying to determine which patients are most susceptible to the toxicity of chemotherapy, leading to the inability to complete a planned treatment regimen. These patients are the vulnerable elderly and the frail elderly. As Dr. Balducci points out, the frail patient would often be best served by a palliative treatment regimen.
Predictors of toxicity
In addition to the obvious goal of effective cancer therapy, the vulnerable elderly can often tolerate and benefit from treatment but may require modification of therapy to fit the specific circumstances. Another important goal in this population is maintenance of independence. The two trials presented at the 2010 Annual Meeting of the American Society of Clinical Oncology to which Dr. Balducci referred in his talk are milestones in the evaluation of the older cancer patient.
The study of Extermann et al presented a clinically applicable means of predicting significant differences in the risk of severe toxicity in older cancer patients starting a new chemotherapy regimen. It potentially can provide a useful tool to individualize treatment choices on an objective basis (J Clin Oncol 2010;28[15S]:9000). The study of the Cancer and Aging Research Group (CARG) presented by Dr. Arti Hurria identified risk factors for grades 3–5 chemotherapy toxicity in older adults. A risk-stratification schema based on the number of risk factors was developed (J Clin Oncol 2010;28[15S]:9001). Both of these trials, and the previous studies they were based on, are an important first step to developing a simplified geriatric assessment that would be acceptable to the practicing oncologist and feasible in a busy practice setting.