The management of cancer in the older aged person represents one of the major immediate challenges of medicine. The response to this challenge involves answers to the following questions: I. Who is old? Currently. 70 years of age may he considered the lower limit of senescence because the majority of age-related changes occur after this age. Individual estimates of life expectancy and functional reserve may be obtained by a comprehensive and time-consuming multidimensional geriatric assessment. The current instrument may be fine-tuned and new instruments, including laboratory tests of ageing. may be developed. 2. Why do older persons develop more cancer? It is clear that ageing tissues are more susceptible to late-stage carcinogen. Older persons may represent a natural monitor system for new environmental carcinogens, and may also represent a fruitful ground to study the late stages of carcinogenesis. 3. Is cancer different in younger and older persons? Clearly. the behaviour of some tumors. including acute myeloid leukaemia, non-Hodgkin's lymphoma and breast cancer change with the age of the patient. The mechanisms of these changes that may involve both the tumour cell and the tumour host are poorly understood. 4. Can cancer he prevented in older individuals? Chemoprevention offers a new horizon of possibilities for cancer prevention: older persons may benefit most from chemoprevention due to increased susceptibility to environmental carcinogens. Screening tests may become more accurate in older individuals due to increased prevalence of cancer. hut may he less beneficial due to more limited patient life expectancy. 5. Do older persons benefit from cytotoxic treatment? The answer to this question partly stands on proper patient selection. partly on the development of safer forms of cancer treatment and prudent use of antidotes to chemotherapy toxicity. 6. What is the cost of treating older cancer patients? The treatment of older patients is generally more costly. This cost should be assessed against the cost of not treating cancer and promoting functional dependence. which by itself is extremely costly. 7. What are the endpoints of clinical trials in older cancer patients? With more limited life expectancy. the effect of treatment on quality of life is paramount. Reliable assessment of quality of life is essential for interpreting clinical trials in older individuals. 2000 Elsevier Science Ltd. All rights reserved.