Cancer is a disease of aging. Over 60% of all newly diagnosed cancers and 69% of all cancer deaths in the United States occur in people over 65 years of age. Americans over 65 are 10 times as likely to get cancer as are younger Americans.
But despite the disease's age-related aspects, researchers know surprisingly little about cancer treatment in the elderly and the elderly appear to be vastly underrepresented in clinical trials.
Kathy Albain, M.D., professor of medicine of Loyola University Medical Center and chair of the Committee on Women and Special Populations at the Southwest Oncology Group presented study results at the May meeting of the American Society of Clinical Oncology, that showed just how underrepresented the elderly are.
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The SWOG study was originally designed to look at the participation rates of African-Americans and women in clinical trials, special populations who have often been underrepresented, to improve their enrollment rates in trials.
"I don't think that in general people think of the elderly as a special population," Albain said. But as the data came in, the researchers noticed that while there wasn't significant underrepresentation for either of those two populations, the numbers on the elderly were striking.
"There is no active effort to exclude the elderly," Albain said, "But obviously something is going on. Why are so few being accrued?"
It is a question the SWOG study was not designed to answer, and one that very little research has addressed. It is a question Albain wants to explore in the future.
Barriers and Biases
Hymand Muss, Ph.D., associate director of the Vermont Cancer Center in Burlington, said there are probably many reasons why the accrual rates are so low.
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"You write it into a protocol, and it automatically becomes `experimental' and Medicare doesn't want to touch it," said Muss.
Other Hurdles
Both Albain and Muss pointed out that there are barriers restricting a doctor from accepting elderly patients into some clinical trials. Many protocols have exclusion criteria based on the overall health of the patient. Elderly patients are far more likely to be suffering from some additional disease besides cancer that would exclude them from these trials. The presence of this comorbidity makes things difficult for researchers. It weakens the patients and can add confounding factors to any analysis.
But there are also biases held by both patient and doctor that can prevent the elderly from participating in trials, said Muss. Many patients are unclear on what goes on in a clinical trial, and assume they will be taking an unnecessary risk. Some do not wish to be a burden to their families, or doubt that any treatment will do them much good.
The attitude that it may not do much good anyway is one that doctors can succumb to as well, but is less and less true. Census data from the Department of Health and Human Services show that the life expectancy of a 70-year-old woman is 15.5 years. That of an 80-year-old, 9.2 years.
Teasing out the real reasons and how to address them will be complex research. "You can't snap your fingers and just get answers,"Albain said.
The lack of elderly participation in clinical trials has created a vicious circle. There are few data on how older patients respond to most therapies, even the conventional ones. Meanwhile, many treatment studies are of aggressive treatments, such as bone marrow transplants and strong chemotherapy, not focused on elderly patients. Without firm knowledge of how elderly patients react, Muss said, "a lot of doctors are, with good reason, nervous about including them."
Muss argued that what needs to be done are studies that can give baseline data on the elderly. Before getting to the cutting edge treatments, researchers need to amass data on the treatments that are known to save lives: adjuvant therapy for colon cancer and breast cancer chemotherapies that are known to work. Muss would like a cohort of elderly patients that have been studied so that doctors can say, "Look, here is what they can handle; here are the toxicity problems; here's what isn't effective."
"We need the Vince Lombardi touch. Fundamentals. We don't need the razzle dazzle," said Muss.
There has been a move to start providing those fundamentals. The National Cancer Institute and the National Institute on Aging have begun attempts to stimulate further work in this area. Both institutes announced in October 1998 a joint program to make available $2.5 million a year for the NCI's Clinical Trials Cooperative Groups to conduct trials that will increase knowledge on the elderly and in May 1998 began a program on cancer pharmacology and treatment in older patients.
The "Right Place"
Rosemary Yancik, Ph.D., chief of the cancer section of the geriatrics program of the NIA, is encouraged with the response. "We would not have the wherewithal and expertise to do it alone. NCI had the right people in the right place at the right time."
Yancik said that the principle behind all of these programs is to help gather the kind of data needed to make best use of treatments for the elderly. "They must recognize the heterogenicity among the elderly," Yancik said. Like other patients, the elderly can't simply be lumped together and generalized about.
Muss also sees the issue of comorbidity as all the more reason to do studies.
"We need to know a lot more about the interaction of comorbidity," Muss said. "If you have bad heart disease and then you get breast cancer, how do we figure out the trade offs? What do I tell you if you're sitting in my office? Is it worth it giving you 6 months of chemotherapy if you've had two bypasses? We need models, and data, to figure this out."
An Aging Population
The population of the United States is living longer, and healthier. A study by the U.S. National Center for Health Statistics released in late 1998 put the U.S. life expectancy at an all-time high of 76.5 years. As the population ages, the elderly are going to be an even larger proportion of the cancer patient population than they are now.
"We're a country that's been blessed, despite complaints, with a pretty good health care system," Muss said, "As people get older and healthier, we will have less comorbidity among the aged." But an increasingly fit elderly population currently presents problems for clinicians who simply do not have good data to work with.
"You have a healthy 72-year-old woman with breast cancer in front of you," Muss asked, "What do you tell her?"
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