Recent findings from an observational study by researchers suggest that men between 65 and 80 years old who received treatment for early stage, localized prostate cancer lived significantly longer than men who did not receive treatment.

The study was published in the Wednesday issue of the “Journal of the American Medical Association.”

Research has shown that treatment options such as radiation therapy and the surgical removal of the prostate lead to unpredictable outcomes for early-stage prostate cancer.

Recently diagnosed men with early-stage prostate cancer are often advised to “watch and wait” to see how their situation is progressing.

“For this study we looked back over the data of a large population of prostate cancer patients, aged 65 to 80, with small tumors that were at a low or intermediate risk of spreading,” said senior author Dr. Katrina Armstrong, who worked on the study with colleagues from Penn’s Abramson Cancer Center, Center for Clinical Epidemiology and Biostatistics, Leonard Davis Institute of Health and Economics and the Division of Internal Medicine and Fox Chase Cancer Center.

“After accounting for all their differences, we discovered that the men – who within six months of diagnosis underwent surgery or radiation therapy – were 32 percent less likely to die than those who did not undergo treatment during that time,” Armstrong said.

The researchers analyzed data from the Surveillance, Epidemiology and End Results (SEER) Medicare database which included information on 44,630 men aged 65 to 80 who were diagnosed between 1991-1999 with prostate cancer and had survived more than a year after diagnosis. Of the 44,630 men, 33,022 were treated with either surgery or radiation therapy during the first six months after diagnosis. Meanwhile the remaining group of 12,608 did not undergo treatment.

In the treatment group, 88 percent of the men lived five years or longer and 66 percent lived 10 years or longer. In the non-treatment group, 78 percent lived five years or longer and 51 percent lived 10 years or longer.

During the 12-year follow up period, researchers found that the patients who received treatment had a 31 percent lower risk of death. In the observation-only group, 37 percent of the patients died in comparison to 23.8 percent of those in the treatment group.

The benefit for treatment was still present after adjusting for differences between the treatment and non-treatment groups, which included patient demographics and tumor characteristics.

“Our results must be validated by rigorous randomized controlled trials of elderly men with localized prostate cancer before the findings can be used to influence treatment decisions,” Armstrong said.

According to a medical oncologist at Fox Chase Center, studies have shown that low and intermediate-grade prostate cancers may grow slowly and many patients may never suffer complications from patients and their families.

“This makes decisions regarding treatment complicated for patients and their families,” said study author Dr. Yu-Ning Wong.

“Observational studies such as ours should be interpreted with caution, since men who received treatment, or specific types of treatment, may have been healthier than men who were not offered treatment, which raises the possibility that the treatment benefit may be due to the selection of healthier men.”

The study was funded by a grant from the Center for Population Health and Health Disparities at the University of Pennsylvania.