In the past 10 - 15 years, an unanticipated epidemic of hematologic diseases in older individuals has been observed. Between 1965 and 2000, the number of people over 65 increased from 19 million to 35 million1 . During the same interval, the population over 80 increased from about 3 million to over 9 million. The burgeoning population over 80 was discovered to have a high incidence of certain hematologic diseases. In the next 25 years, the U.S. Census predicts that the number of people over 65 will double again and the number over 80 will continue to grow even faster.
To help project future needs, I have roughly estimated the incidence of certain hematologic diseases in the elderly based on published data that assess the current incidence of those diseases2 and U.S. Census projections. The estimates are provided to help in planning an effective response to the anticipated demand for hematologic services.
In this editorial, I draw attention to a selected group of serious diseases prevalent in the elderly: anemia, acute myelocytic leukemia (AML), myelodysplastic syndrome (MDS), venous thromboembolic disease (VTE), and anticoagulation for nonvalvular atrial fibrillation (nAF)3 . Other hematologic diseases common in the elderly will not be considered for the sake of brevity.
A special symposium4 at the 2005 ASH Annual Meeting highlighted anemia in the elderly, a diagnosis made in over 3 million older people in 2005. In 2030, as the population of older people doubles, a diagnosis of anemia may be made 6 million times. Anemia of any cause in elderly individuals has been reported to increase the risk of mortality. While a diagnosis can be made for most anemias, about 34 percent remain unexplained. For this reason and because of its complexity, evaluation of anemia in the elderly is often performed by a consulting hematologist.
In 2005, about 12,000 people were diagnosed with AML, an increase of more than 30 percent from a decade earlier. The increase could be attributed to the growth of the extremely old population in whom the annual risk of developing AML rises to over 15 per 100,000 individuals. Thus, by 2030, as the population over 80 more than doubles, the annual incidence of AML in that age group could be over 2,500 and the total number of cases of AML in people over 60 could be as high as 10,000. Statistical analysis of baseline characteristics suggests that a portion of the elderly population with AML may be predicted to do poorly if treated with a "standard" regimen. The same analysis suggests that elderly people without adverse risk factors are expected to respond more favorably to the regimen. Thus, hematologists are presented with the dual challenges of selecting elderly patients with AML who have favorable risk profiles and identifying the best alternative treatment regimen for those who do not. New tools are needed for evaluation and management of elderly patients with AML.
In reports of different populations, the incidence of MDS has ranged from 15 to 89 per 100,000 in elderly people. Many people with MDS progress to acute leukemia; indeed, MDS may not be diagnosed until after progression has occurred. The annual incidence of MDS is unknown but has been reported to be between 10,000 and 13,000 new cases/year. The diagnosis may be overlooked in elderly people because of its insidious onset, slow progression, and the lack of distinctive characteristics in many patients. Using a conservative estimate, by 2030 the number of people with MDS > 60 could be between 15,000 and 30,000.
The incidence of VTE has a striking relationship to age, increasing a thousandfold between the ages of 40 and 75. Several million elderly people are likely to develop VTE each year. The comorbidities frequent in elderly subjects with VTE complicate anticoagulation therapy.
Nearly 2 million elderly people are likely to have nAF by the year 2030. Morbidities associated with nAF include embolic stroke, the risk of which is based on age and other factors (for reference, see www.nhlbi.nih.gov/about/framingham/stroke.htm). Warfarin therapy requires close monitoring and frequent adjustment and may be complicated by serious adverse events. Improved therapeutic regimens are needed for elderly patients.
In summary, by 2030 more than 10 million elderly people/year will have diagnoses that could require evaluation and management by hematologists, and 25,000 to 40,000/year are likely to require management of AML and MDS. Millions would benefit from improvements in the prevention and therapy of thrombotic disorders. It would be wise for leaders in the field of hematology to prepare for the surge in demand for our services by developing a proactive strategy to direct the needed laboratory research and clinical trials and to train an appropriate number of health care professionals.
The opinions expressed in this article are those of the author and do not reflect official policy of the National Institutes of Health or the Department of Health and Human Services.
