Cytotoxic therapy for the elderly with metastatic breast cancer: a review on safety, pharmacokinetics and efficacy.

As the incidence of invasive breast cancer, mainly developing at older age, is rising, the absolute number of elderly developing metastatic disease is also increasing. In view of improved life expectancy, sociocultural changes and better supportive measures for chemotherapy-induced toxicity, there is an increasing request for the administration of chemotherapy in elderly. At the moment, medical oncologists are still reluctant to use chemotherapy in elderly partly because of concern about increased toxicity and poor tolerability of this patient cohort, and the inability to appropriately select elderly that may benefit from chemotherapy. The question is whether this attitude remains justified. In this review, the current status of clinical research in the area of metastatic breast cancer regarding toxicity and activity of chemotherapy in older breast cancer patients is discussed. Further, data on pharmacokinetics are emphasised as age-related physiologic changes may affect these features with consequences for toxicity and decision-making. Moreover, data on assessment tools trying to characterise the 'functional age' are reviewed. In general, the literature data are scarce and hampered by major limitations, while pharmacokinetic data indicate that a different approach in older breast cancer patients does not always seem justified. To increase our knowledge aiming at optimisation of cancer treatment in elderly, there is a clear necessity for prospective, well-designed studies with emphasis on the particular requirements of older patients and incorporation of pharmacokinetic and -dynamic evaluation of cytotoxic agents used in this specific group. As in other research areas, maximal progress will be achieved by joined efforts of co-operative research groups.