The population of cancer survivors over the age of 65 in the U.S. could jump by more than 40 per cent in the next decade, a new study estimates.

By 2020, more than 11 million cancer survivors will be 65 years old or older — a 42 per cent increase in 10 years, according to projections from the National Cancer Institute. The aging population has the biggest influence on increasing cancer prevalence. Wong Maye-E/Asociated Press

"Older adults are an overlooked, understudied, underserved, and vulnerable group of cancer survivors," Julia Rowland, of the institute's Office of Cancer Survivorship and her co-authors concluded in the October issue of Cancer Epidemiology, Biomarkers & Prevention.

"The potential magnitude of the impact of the rapidly growing population of older adult cancer survivors on health care delivery systems, and the associated cost of their care, is sobering."

The current costs of cancer care were estimated at nearly $158 billion US in 2010, with the potential to reach $173 billion US by 2020. The aging population contributes significantly, the authors noted.

In the four decades since U.S. President Richard Nixon declared a "war on cancer", the number of cancer survivors in the U.S. has increased about fourfold, from three million to 12 million.

The researchers made the new projections by analyzing data from the institute's Surveillance, Epidemiology and End Results (SEER) registry, which tracks cancer incidence and survival in the U.S.

Revamp geriatric care

The majority of people over 65 with a cancer history will be free of cancer, but most will have other health conditions that may be complicated by past cancer treatments, the study's authors said.

To provide high-quality care for older adult survivors, they called for:

• Geriatric assessments of health and quality of life.
• Geriatric cancer rehabilitation programs with multidisciplinary teams that have the expertise to meet the complex and unique needs of this group.

As screening and treatment improve the number of survivors living long term will increase, but the aging of the U.S. population has the biggest influence to increasing cancer prevalence, they noted.

The analysis was based on data from a population that is more urban, foreign-born and of lower socioeconomic status than the U.S. population, the researchers said.

They also acknowledged "an enduring and troublesome limitation" of the SEER database, which is that the prevalence figures do not include the health status of survivors at any given point in time.

In Canada, the aging population has also been raised as a driver of health-care costs.

The proportion of health-care spending in most industrialized countries is rising and, with aging populations, is expected to keep rising, the Conference Board of Canada said in May.

Last month, the Parliamentary Budget Office made a similar projection.

"Population aging will put downward pressure on revenues, as growth in economic activity, and therefore the tax base, slows. At the same time, aging will put upward pressure on programs whose benefits are mostly realized by Canadians in older age groups, such as health care and elderly benefits," the budget office report said.