Geriatric Oncology In Singapore: It's About Time.
Tuesday, 24 January 2007
What is Geriatric Oncology?
It is a sub-specialty that is committed to the prevention, screening, and treatment of cancers in the elderly.
What is defined as elderly in this context?
The elderly is arbitrarily defined as being 70 years and older. This cut-off is chosen because those over 70 years old are 10 times more likely to develop cancers than those below 70 years old. The vast majority (70%) of cancers occur in those more than 70 years old. The second reason this age of 70 is chosen is because of the steep deterioration in vital organ function at this age. A 70 year old person will have on average 50% of kidney function he/she would have had at 30.
What is the relationship between aging and cancer?
The three main processes of aging are namely:
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Internal natural degeneration of bodily functions such as immunity, and hormonal function, |
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External influences causing wear and tear to tissues, and |
| 3. |
Genetic traits that mandate a finite life span to each cell. |
The above are closely related to the causes and processes of how cancer develop. If we can unlock the key to understanding aging, we will understand cancer better and hopefully cure it.
But does time measure aging reliably?
Not always. An 80 year-old man may have an agile mind and exceptional physical fitness. This is vastly different to an 80 year-old man who may be demented and confined to a nursing home. Aging is strictly not defined by time. The study of the biology of aging is called gerontology. In this field, a key challenge is to measure aging more objectively by using a panel of tests for certain “aging” substances by way of tissue biopsy or blood sampling to determine true biological aging.
Why is Geriatric Oncology important in Singapore?
By 2015, we may have 1 million elderly persons aged more than 65 in Singapore. This is the main reason why cancer incidence is on the rise in Singapore. Cancer happens more often in the elderly.
Why is a special program needed to cater to the elderly cancer patient?
A
The reasons are manifold. The issues in clinical practice and research are very specialized.
The elderly frequently have more health problems in addition to the cancer. For example, an elderly with frail kidney function will not be able to efficiently excrete certain chemotherapy drugs used to treat cancer, this may result in more toxic side effects because of longer circulating time of these toxic substances in the blood stream. Conversely, if the specialist is more aware of such elderly health issues, dose adjustment will allow safe administration of such chemotherapy while enabling effective treatment of the cancer.
Lack of data in systematic research frequently results in over-treatment of the elderly cancer patients. Many will not die from their cancers; they simply die with the cancer. The prognostic factors in the elderly are different from the young. Unfortunately, not many clinical trials investigating new drugs or ways of treating cancer take into account the elderly population. Blind application of ever increasing intensive and prolonged expensive cancer treatment to the elderly patient without solid basis is potentially harmful. Furthermore, some tumors behave less aggressively in the elderly. It is an urgent imperative now to fill this scientific data gap through rigorous research so that harmful treatment without substantial benefit can be avoided.
Age bias on the other hand may lead to under-treatment of cancers in the elderly resulting in less chance for cure and higher death rate from cancer in this instance. Potentially curable cancers should be treated definitively regardless of age, if the elderly patient is able to tolerate the treatment required. We must remember that the life expectancy increases as a person grows older. At birth, a child’s life expectancy may be 75. But if the child lives to 75, his life expectancy is 85.
If an elderly 75 year-old gentleman has dementia, and has colon cancer at the same time, he may not need chemotherapy to reduce risk of relapse after surgery to remove the colon cancer. This is because his life expectancy with the diagnosis of dementia is likely to be shorter than if the cancer is to relapse. The diagnosis of dementia can sometimes only be detected using comprehensive geriatric assessment tools practiced in the geriatric oncology program.
What is integral to an ideal Geriatric Oncology Program?
It is first of all, a program that consists of members from all disciplines involved in oncology care of the elderly – the oncologists, nurses, social workers, geriatricians, geriatric psychologists/psychiatrists, dieticians, physiotherapists, occupational therapists, and speech therapists.
A comprehensive geriatric assessment is required for every elderly cancer patient, paying careful attention to physical function, mental/psychological function, concurrent health problems, and nutritional status. The specific treatment is then tailored to the individual elderly patient with cancer. A follow up program that is holistic and appropriate for the elderly will then ensue.
An ideal program should also determine the research agenda, conduct active research in this specialty, oversee the training of young specialists in this area, develop community resources and initiate public education so that the care of such elderly cancer patients can improve.
What is the desired outcome for the elderly cancer patient participating in such a program?
Use of toxic chemotherapy will be limited to those elderly patients who truly will benefit from it. The elderly patient will be able to live fully the remaining natural years of life without hindrance, or premature termination, secondary to cancer.
For more details, photos and media interviews on the above, please click [here].
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