Metabolic Disorders in Elderly Patients with Hematologic Malignancies. A Review

Abstract

Over recent decades, due to the gradual rise in life expectancy and the consequent aging of the population, the incidence of some hematological malignancies most common in the elderly is expected to increase. In elderly cancer patients, the older age is an adverse prognostic factor because of specific age-related conditions, such as changes in cellular biology and reduced functional reserve in multiple organ systems, as well as in consequence of comorbidities. Some age-related pathological conditions, such as diabetes mellitus, renal failure, chronic obstructive pulmonary disease, cardiovascular dysfunction, liver disease and other disorders may predispose the elderlies to develop metabolic abnormalities. In the elderly, the occurrence of hematological malignancies can cause some metabolic disorders or worsen pre-existing dysmetabolic conditions that increase the outcomes of these patients. Hyperuricemia is the most common metabolic abnormality; hyperuricemia less commonly may be associated with hyperkalemia, hyperphosphatemia and hypocalcemia, in the framework of oncologic emergency that is the Tumor lysis syndrome. Hypercalcemia is relatively common in patients with multiple myeloma and adult T-cell Lymphoma. Cases of Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) in patients with hematological malignancies have also been reported. Idiopathic hyperammonemia may occur in oncohematological patients after receiving intensive chemotherapy or following bone marrow transplantation. Moreover, there is evidence that patients with lymphoma, leukemia and multiple myeloma can develop Type B lactic acidosis. Non–islet cell tumor hypoglycemia and Hyperglycemia are other potential metabolic abnormalities occurring in patients with hematological malignancies. The pathogenesis of these metabolic disorders is often unclear and several theories have been postulated; possible mechanisms include: increase in neoplastic cell turnover and apoptosis, blast crisis, cytotoxic effects of chemotherapy, tumor secretion of hormones, peptides or cytokines, immune cross-reactivity between malignant and normal tissues, malignancy-induced enzyme dysfunction. Parenteral nutrition, sarcopenia, cachexia, stress, immune deficiency and infections could contribute. Although successful treatment of the underlying tumor often improves metabolic disorders, these conditions often worse prognosis and are associated with poor survival; thus it is important to consider early detection and effective treatment.