Clinical Trials in Older Patients
The traditional clinical trial focus is on younger and healthier patient, i.e. with few or no co-morbidities. These restrictions have resulted in a lack of data about the optimal treatment for older patients  and a poor evidence base for therapeutic decisions. Most physicians extrapolate data from the younger cancer patients which could lead to over treatment, although under treatment of older patients is also common due to their reduced ability to tolerate the full treatment regimen. The main reasons for this under representation in clinical trial include restrictions on eligibility. Standard performance status, as measured by Karnofsky performance or the Eastern Cooperative Oncology Group (ECOG), is inadequate to evaluate eligibility in older patients. Thus, components of clinical trials such as eligibility, endpoints, survivorship, and dose-limiting toxicity need to be re-evaluated in the context of the older patient. Other organ specific eligibility requirements may be more flexible, such as adequate renal function, when the drugs used are known not to be nephrotoxic. Barriers that prevent the participation of ageing patients in clinical trials include also social aspects: transportation; financial difficulties since most trials request multiple visits; limited expectation of remaining life time of the patient leads the family to avoid aggressive therapy and accept palliative approaches.
An International Society of Geriatric Oncology was founded in 2000 with the mission of developing health professionals in this area and to optimize the treatment of older patients [8, 9] as some age-specific instruments that could predict chemotherapy toxicity are needed  and the endpoint of the studies may also be different . Most of them had as a main endpoint the patient survival. Due to the high risk of death in older patients due to other diseases, different endpoints need to be considered as response rate, clinical benefits, decreased pain scale, better quality of life may be more appropriate. Besides the common difficulties, older patients may also have cognitive differences that make it more difficult to understand the disease or personal care that should be taken during chemotherapy.
Another factor that should be investigated is the prior history of cancer. Patients aged 70 and more account for up to 50 % of the survivors of previous cancer [12-14]. These patients had specific problems, mainly associated with the remaining toxicities from the first treatment.