Are bisphosphonates the suitable anticancer drugs for the elderly?

Bone metastases represent an important problem in the elderly. These patients are exposed to a higher risk of developing skeletal-related events (SREs) with a subsequent decrease in quality of life and survival. Bisphosphonates have demonstrated to reduce and delay the appearance of SREs and to improve the quality of life also in elderly bone metastatic patients. Moreover, in vitro and in vivo preclinical studies suggest that bisphosphonates exert direct as well as indirect antitumor effect. Interestingly, recent clinical data confirm these results in bone metastatic cancer patients. However, randomized trials restricted to elderly patients with metastatic bone disease and focused to evaluate survival benefits have not yet been planned even if elderly patients, especially multiple myeloma, prostate and lung cancer patients, have been often included in trials. This review will examine in detail the preclinical rationale for using bisphosphonates as anticancer agents in elderly patients and will critically explore the first retrospective and prospective clinical evidences of an increased survival in patients treated with bisphosphonates. Moreover, we will analyze the safety of bisphosphonates in elderly population and discuss the clinical recommendations expressed by the SIOG Society for the use of bisphosphonates in elderly patients. Randomized clinical trials to assess the role of bisphosphonate therapy in the adjuvant setting are currently in progress and will be described in this review. If the results of these ongoing clinical trials will be positive, the indications for bisphosphonates could increase, including also elderly patients.