A population-based review of more than 9,000 older men diagnosed with early-stage prostate cancer supports the controversial strategy of not treating less aggressive disease in the elderly.
Although most of the cancers went untreated, 10 years after diagnosis only 3%–7% of men with low- or moderate-grade disease had died of prostate cancer. Not surprisingly, mortality was higher, 23%, in men with high-grade disease.
“For elderly men, the survival benefit of treatment is most likely modest. The majority of patients died of other complaints or were still alive,” Grace Lu-Yao, Ph.D., lead investigator, said during a press Webcast in advance of a symposium on genitourinary cancers that was sponsored by the American Society for Clinical Oncology, the American Society for Therapeutic Radiology and Oncology, and the Society of Urologic Oncology.
Investigators used Medicare claims linked to the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database to identify 9,018 men diagnosed with stage I or II prostate cancer between 1992 and 2002. None had local therapy (surgery or radiation) or hormonal therapy in the 6 months after diagnosis, said Dr. Lu-Yao, an epidemiologist at the Cancer Institute of New Jersey, New Brunswick.
Although 2,675 men received treatment subsequently, long periods without therapy were common. Investigators reported the median interval between diagnosis and start of cancer therapy to be 10.6 years (127 months). About two-thirds of the population was categorized as either dying of other causes or not experiencing a cancer progression for which they were treated with surgery or radiation.
Compared with previous studies reporting higher mortality rates, the new analysis has the advantage of looking at many more men, older men, and men diagnosed in the era of prostate-specific antigen (PSA) screening. Dr. Lu-Yao said more than 5,000 participants were older than 75 years in the study; the median age was 77 years. Nearly two-thirds of the population had T1 disease.
She noted many men were unlikely to have been diagnosed before PSA screening, which can detect prostate cancer 6–13 years before the slow-growing disease is diagnosed clinically.