Dr. Hurria said she likens geriatric oncology to pediatric oncology, a specialty that is also defined by age. The term geriatric oncology "highlights that there is a segment of the population that is potentially vulnerable because of things other than chronologic age. ... We also need to develop an evidence base."
"The definition of geriatric oncology is that we have a population, in which we need to do additional screening and evaluation in order to give the proper treatment," agreed Dr. Extermann, professor of oncology and internal medicine at the H. Lee Moffitt Cancer Center and Research Institute in Tampa.
Who Needs an In-Depth Assessment?
If not all older patients are especially vulnerable, the challenge becomes determining which patients need extra attention. The following two-tiered approach to the evaluation and management of geriatric oncology patients would divide the elderly into two groups (Crit. Rev. Oncol. Hematol. 2005;55:241-52):
• The first step would be to screen all older patients for vulnerability to stressors – such as chemotherapy. This should include the assessment of nutritional status, performance status, psychological state (depression), cognition, daily activity, and comorbidities. Those who are considered fit would be managed like younger patients.
• Next, frailer patients would undergo a more thorough evaluation – a comprehensive geriatric assessment – so that an optimal treatment plan could be created. The in-depth evaluation would look at an elderly person’s functional ability, physical health, cognitive and mental health, and socioenvironmental situation.
With the two-tier evaluation, "the idea is that we need a more integrated approach that is going to include a good geriatric evaluation," said Dr. Extermann, a member of the task force that proposed the approach. The ultimate goal is to match the treatment to the patient and the cancer.
In a large academic setting, a multidisciplinary team can do a more in-depth screening if necessary, she added. For private practice oncologists, the initial evaluation may indicate which patients should be referred for special care.
Where Are the Clinical Trial Data?
Another hurdle in geriatric oncology is the need for more clinical trial data that include this patient population. It’s estimated by the National Cancer Institute that more than 60% of new cancer cases occur among the elderly, but they account for about a quarter of the patients enrolled in randomized clinical trials.
"As the population is aging and most of our patients are older adults, what we’re realizing is that the inclusion criteria for those trials [in the past] did not necessarily reflect the patient who’s sitting in front of us in daily practice," Dr. Hurria said.
Although there are exceptions (notably, recent trials assessing a carboplatin-paclitaxel regimen for non–small-cell lung cancer and the VISTA [Velcade as Initial Standard Therapy for Multiple Myeloma] regimen), the lack of data on the efficacy and safety of chemotherapy regimens in the elderly has left most oncologists to rely on their own judgment.
"There is a need to develop trials for patients who might not be fit enough to participate in standard clinical trials. We still realize that there is an evidence base that we need for those patients," she said.
Research in geriatric oncology has become a priority for several organizations, among them the Geriatric Oncology Consortium and the International Society of Geriatric Oncology.
Chemotoxicity Risk
A prominent area of geriatric oncology research is the assessment of chemotoxicity in an older patient population. Dr. Extermann and Dr. Hurria each presented data at this year’s annual meeting of the American Society of Clinical Oncology on the development of risk models/scores to assess an older patient’s risk of developing chemotoxicity.
Despite her experience in geriatric oncology, Dr. Extermann was surprised to find that sometimes her opinion of a patient could be widely divergent from that of the scoring tool she developed. In other cases, "when I was sitting on the fence about whether or not to treat a patient, the score helped me decide," she said.
"It’s also very important to realize that having one such toxicity does not necessarily make the patient sick," she noted. Usually toxicities lead to some modification of the treatment. So while greater risk of chemotoxicities may look foreboding, patients are often able to tolerate the regimen with modification and can function with some help.