Aug. 7 (UPI) -- Cancer rates and mortality among the oldest Americans are higher than younger groups, a new study says.
As the fastest-growing age group in the United States, adults older than age 85 have higher incidences and death rates from cancer than those between ages 65 and 84.
The findings were published Wednesday in CA: A Cancer Journal for Clinicians.
"The purpose of our study was to provide a comprehensive review of cancer in the oldest old using the most up to date national data," Carol Desantis, a researcher at American Cancer Society and study author, told UPI. "We hope that these data spur additional research on cancer in this vulnerable and rapidly growing population."
The researchers analyzed comprehensive data on cancer among older Americans using information from the National Cancer Institute, the North American Association of Central Cancer Registries and the National Center for Health Statistics.
They found lung and prostate cancers made up about 40 percent of cancer deaths among men older than 85. Also, more women in the same age group died of breast and lung cancers than any other cancers. Meanwhile, colorectal cancer was the third leading cause of death for both men and women over 85.
Despite the high cancer rates, many health professionals feel the potential risk of harm from screenings far outweighs the health benefits.
Yet, screening rates for adults older than age 85 remain high. As of 2015, for example, more than one-third of women in that group received a mammogram within the last two years. And close to 30 percent of men in the same group reported getting a PSA test within the past year.
The high rate of testing hasn't resulted in a high number of early-stage cancer detections. About 57 percent of breast cancer cases for people over age 85 are diagnosed at a local stage compared to 68 percent between ages 65 and 84. With prostate cancer, only 41 percent of cases are caught at an early stage for men over 85 versus 77 percent for the younger group.
"Most older patients are either overtreated or undertreated for their cancer because treatment decisions are based on chronological age, not health status," said William Dale, a researcher at City of Hope and study co-author.
For example, only 65 percent of breast cancer patients over age 85 received surgery versus 89 percent between ages 65 and 84. The difference in treatment in the two groups could reflect the reluctance of some doctors to perform surgery on older patients due to associated health risks.
"Many patients 85+ have other pre-existing medical conditions, as well as age-related declines in physical and mental function resulting in poorer overall health status and the reduced ability to withstand surgery," Desantis said. "Thus, no surgical treatment can be appropriate in some patients."
Dale says the physical condition of an older patient should determine whether they receive treatments for cancer such as surgery or chemotherapy. To help make that decision, he recommends doctors consult the Geriatric Assessment.
The assessment takes into account a patient's falls, depression status, cognition level and nutrition. And these characteristics vary widely among people over age 85, Dale says. On average, the least healthy 25 percent within the group live 2.9 years while the healthiest 25 percent die within nearly 10 years.
The American Cancer Society estimates 140,690 people over 85 will be diagnosed with cancer and 103,250 people will die from the disease in 2019. Breast, colorectum, lung and prostate cancers are the most common cancers for older Americans, in addition to all other age groups in the United States.
"From a clinical care perspective, it's important to realize that many older adults get late-stage cancer and die from it," Dale said. "To avoid discrimination, we should detect and screen cancers based on health status using a Geriatric Assessment; rather than rely primarily on chronological age."