Greater risks of chemotherapy toxicity in elderly patients with cancer.

Complications of cytotoxic chemotherapy are more common in older patients (65 years of age and older) with cancer than in younger patients, and the occurrence of myelosuppression, mucositis, cardiodepression, peripheral neuropathy, and central neurotoxicity can complicate treatment. Age-related physiologic changes that can increase the toxicity of chemotherapy are decreased stem-cell reserves, decreased ability to repair cell damage, progressive loss of body protein, and accumulation of body fat. A decline in organ function can alter the pharmacokinetics of many of the commonly used chemotherapeutic agents in some elderly patients, making toxicity less predictable. Comorbidities increase the risk of toxicity through their effects on the body. Furthermore, the drugs used to treat comorbidities may interact with chemotherapeutic drugs, potentially increasing toxicity in elderly patients. Prospective trials in older patients with lymphoma or solid tumors have found that age is a risk factor for chemotherapy-induced neutropenia and its complications. Anemia may be present because of the disease or its treatment, and, if left uncorrected, it can alter drug activity and increase toxicity. Being able to predict which elderly patients are at greater risk of toxicity on the basis of pretreatment factors would be valuable, and there is a need for prospective trials to determine regimen- and patient-specific prognostic factors. Effective management of the toxicity associated with chemotherapy with appropriate supportive care is crucial, especially in the elderly population, to give them the best chance of cure and survival, or to provide palliation. For example, management of neutropenic complications with colony-stimulating factors makes treatment with standard-dose chemotherapy possible, which can lead to better outcomes. A better understanding of drug activity and toxicity in older patients is necessary for developing guidelines for safe and effective treatment. Few randomized controlled trials of antitumor drugs in older patients with cancer have been conducted, but a number of agents with favorable efficacy and toxicity profiles in elderly patients have been identified.