Cancer is a disease that increases in incidence and mortality with age. In the United States, 60% of all cancer cases develop in people age 65 years and over, which accounts for 12% of the population. Approximately 70% of all cancer deaths occur in this age group. Among this population, more than 50% are afflicted with at least one disability (geriatric syndrome) and 34%, with two or more. Thus, anyone who sees cancer patients must be aware of the many disabilities that may occur in the elderly and that may complicate or interfere with diagnosis or treatment. Not only should clinicians be aware of these syndromes, but they should also be able to evaluate their severity. The article by Drs. Naeim and Reuben provides short descriptions of common geriatric syndromes and methods of their assessment.
Factors Affecting Outcome in the Elderly
That said, the remarkable advances made in the management of cancer thus far have not benefited the elderly, in whom the mortality rate continues to rise. It is commonly assumed that geriatric syndromes are the cause of the increased mortality. Likewise, aging causes changes in liver and kidney functioning, thus altering the metabolism of drugs. Excessive toxicities have been seen in the elderly with regimens that are tolerated by younger cancer patients. Also, the elderly are not entered into clinical trials, making them less likely to benefit from modern agents.
While all these statements are true, one cannot assume that they are the cause of the less favorable results in the elderly. Most cancers are cured by surgery and radiation, and curiously, surgeons will operate on most patients irrespective of age. The impact of chemotherapy, however, is still limited to a few cancers that usually develop in younger patients.
The prevalence of smoking in the latter half of the 1900s is a major contributing factor to the increased incidence of disability and cancer among older people. Lung cancer is not a very treatable disease, except in stage I, and chemotherapy has not greatly extended the survival of lung cancer patients.
As a result of social and other factors, the elderly are not screened for breast or cervical cancer, yet the risk of breast cancer increases with age. Older women are the most likely to benefit from adjuvant therapy with tamoxifen(Drug information on tamoxifen) (Nolvadex), but they are less likely to receive mammograms and are more likely to have advanced disease. They are also less likely to be referred to a cancer specialist.
Colon cancer is the third most common cancer. Screening is important and underutilized, in part because of the cost and discomfort associated with colonoscopy. Fecal occult blood testing is also not widespread.
Finally, prostate cancer can be diagnosed with a simple blood assay—the prostate-specific antigen (PSA) test. Extensive use of this test has caused prostate cancer to become the most commonly diagnosed cancer among men. Despite this major increase in diagnosis, mortality has actually decreased. The PSA test cannot be the only factor causing these changes. The controversy continues as to who should be screened and who should be treated.
There are two major points to consider about cancer in the elderly: who should be treated, and the increase in associated diseases. First, as we get older, we will all have to cope with more disabilities. The oncologist who sees elderly patients with cancer must be able to distinguish whether the cancer or the disability is going to be the major determining factor affecting the patient’s duration and/or quality of life. Any proposed treatment must improve quality of life—not add to the disabilities—and not all disabilities make therapy more toxic or less effective. The oncologist must also be aware of the physiologic factors that will influence the effectiveness and toxicities of therapy.
The second point is that the oncologist must look at the physiologic and not just the chronologic age of the patient. There are many older people who are physiologically intact, and who swim, run, bicycle, golf, and walk. Recent data suggest that older Americans are actually less disabled now than they were decades ago. In these patients, diagnosis and treatment must be based on the overall assessment of the subject and not on the calendar birth date.
In the past, being over age 65 or 70 years excluded one from clinical trials. We now know that this is not scientifically rational. Many studies have shown that the same results can be achieved in the elderly as in younger patients, and that the toxicities are not any worse if the patient is physiologically intact. The most striking result I have witnessed was in treating a 95-year-old man with a hepatoma, with intra-arterial cisplatin(Drug information on cisplatin) (Platinol); the patient achieved a complete remission that lasted 8 years, until he died of unrelated causes at the age of 103. This patient has been the shining example encouraging me to treat the patient and not the calendar.