44: Common Cancers

General Principles in Older Adults

Older patients with cancer provide a unique challenge to the oncologist, whether the intent is cure or palliation of symptoms. Curative therapy may require aggressive and potentially morbid operations, radiation therapy, or chemotherapy. Such aggressive approaches are often more toxic in older patients, who tend to be less resilient.

Cancers in older patients may demonstrate a distinct natural history that differs from that of younger patients. For example, breast cancers tend to have a more favorable prognosis in older populations, whereas acute leukemias have a worse prognosis. In addition, because toxicities from therapeutic intervention may be more frequent in older patients, more severe modifications in therapy may be required. Although radiation therapy is generally well tolerated, alterations in the radiation fields and doses may be necessary to decrease toxicity without significantly compromising efficacy.

Most of the antineoplastic agents are cytotoxic to rapidly dividing cells and are not specific for cancer cells. This lack of specificity results in myelosuppression, mucositis, and hair loss. In general, older patients experience more frequent and more severe normal tissue toxicities. Both the peripheral neuropathy from vincristine and the cardiotoxicity from doxorubicin develop at lower cumulative doses than is typically seen in younger patients. Similarly, mucositis from the combination of 5-fluorouracil (5-FU) and leucovorin is also more common and more severe in older patients. Alterations in renal and, to a lesser extent, hepatic function occur with age and should be considered in the selection and dosing of chemotherapy. Agents such as methotrexate, cisplatin, and bleomycin are normally excreted by the kidney and may produce excessive toxicity in older adults if administered in conventional doses. With an awareness of the normal aging physiology and knowledge of the pharmacology of antineoplastic agents, chemotherapy may be safely administered. Because most clinical trials have enrolled mostly younger individuals, evidence-based data that addresses the challenges of cancer treatment in the older population, is often lacking. Thus, in the addition to current age-based recommendations, life expectancy, functional status, and the patient’s preferences and goals of care should be taken into consideration when making decisions regarding cancer screening and treatment in the older population.

Treatment

Diagnosis-specific therapies are described in the sections below. If it has been determined that the cancer is not curable or that the patient is unable to tolerate aggressive therapy, the goal becomes palliation of cancer-related symptoms, which may include, but are not limited to, nausea, dyspnea, and pain. Cancer pain management should be tailored to the individual patient’s pain needs and may require nonpharmacologic interventions such as radiation therapy. Attention should be paid to the effective management of potential complications of pain management such as constipation and delirium (see Chapter 11, “Geriatrics & Palliative Care,” and Chapter 54, “Managing Persistent Pain in Older Adults”).

Breast Cancer

General Principles in Older Adults