Cancer in the oldest old: The fastest growing age group in the US
A new report looks at cancer in adults 85 and older and finds incidence and mortality trends are generally similar to those in people 65 to 84, but screening is unexpectedly high and survival is poorer. The report appears in the American Cancer Society journal, CA: A Cancer Journal for Clinicians.
Adults aged 85 years and older—the "oldest old"—are the fastest-growing age group in the United States, yet relatively little is known about their cancer burden. To learn more, American Cancer Society investigators led by Carol DeSantis, MPH, and supported by leading geriatric oncology experts from City of Hope, University of Rochester Medical Center, and Duke University Medical Center, analyzed data from the National Cancer Institute, the North American Association of Central Cancer Registries, and the National Center for Health Statistics to provide comprehensive information on cancer occurrence in this population.
In 2019, there will be approximately 140,690 cancer cases diagnosed and 103,250 cancer deaths among the 85 and older population in the United States. The most common cancers in these individuals -lung, breast, prostate, and colorectum—are the same as those in the general population. Overall cancer incidence rates peaked in the oldest men and women around 1990 and have subsequently declined, with the pace accelerating during the past decade. This progress reflects declines in cancers of the prostate and colorectum, and more recently lung among men and breast among women.
Among men 85 and older, prostate and lung cancers are the most common causes of cancer death, accounting for 40% of cancer deaths. Among women, lung cancer is the leading cause of cancer death (19%) followed by breast cancer (13%). For men and women, colorectal cancer is the third leading cause of cancer death, representing 9% and 12% of cancer deaths, respectively, in this population.
The authors also note that patients aged 85 years and older are less likely to be diagnosed at an early stage compared to those aged 65 to 84. For example, 57% of breast cancers in the oldest old are diagnosed at a local stage versus 68% in patients 65-84 years; for prostate cancer it is 41% compared to 77%, respectively. Late stage at diagnosis among the oldest old partly reflects less screening, which is generally not recommended for those aged 85 years and older because of diminished life expectancy, the higher prevalence of other serious medical conditions, and limited evidence of survival benefit. For most individuals in this age group, the small potential benefit of extending life is outweighed by the possible harms from screening, which increase with age.
Despite these recommendations, data from the National Health Interview Survey indicate unexpectedly high rates of screening in adults aged 85 years and older. In 2015, more than one-third of women aged 85 years and older reported receiving a mammogram within the previous two years, and 18% reported receiving recent cervical cancer screening tests. More than one-half of adults aged 85 years and older reported receiving either a stool screening test within the past year or a sigmoidoscopy or colonoscopy within the past five to ten years. Nearly 30% of men in this age group reported receiving a PSA test within the past year.
People 85 and over are also less likely to receive surgical treatment; only 65% of breast cancer patients aged 85 years and older received surgery compared with 89% of those aged 65 to 84 years. This difference partly reflects the complexities of treating older patients, including the presence of multiple comorbidities, functional declines, and cognitive impairment, but also highlights potential undertreatment of otherwise fit older adults. Overtreatment of vulnerable individuals in this age group is also a concern. The authors note that, importantly, age alone does not predict life expectancy, physical function, or the ability to tolerate treatment and provide information about tools to enable clinicians to evaluate the functional age of patients as part of the treatment decision-making process.
"More research on cancer in the oldest Americans is needed to improve outcomes and anticipate the complex health care needs of this rapidly-growing population," write the authors. "The rapid growth and diversification of the population aged 85 years and older will increase demand and complexities for cancer care and could have a substantial impact on medical care resource allocation. There is an urgent need to develop a more comprehensive evidence base to guide treatment decisions for these understudied patients with cancer through increased enrollment in clinical trials and to leverage research designs and infrastructure for generating evidence on older adults with cancer."