Men diagnosed with prostate cancer are less likely to die from the disease than from largely preventable conditions such as heart disease, according to a new study from Harvard School of Public Health (HSPH). It is the largest study to date that looks at causes of death among men with prostate cancer, and suggests that encouraging healthy lifestyle changes should play an important role in prostate cancer management.

"Our results are relevant for several million men living with prostate cancer in the United States," said first author Mara Epstein, a postdoctoral researcher at HSPH. "We hope this study will encourage physicians to use a prostate cancer diagnosis as a teachable moment to encourage a healthier lifestyle, which could improve the overall health of men with prostate cancer, increasing both the duration and quality of their life."

The study was published July 25, 2012 in the Advance Access online Journal of the National Cancer Institute.

Prostate cancer is the most frequently diagnosed form of cancer, affecting one in six men during their lifetime. While incidence of prostate cancer has greatly increased in the United States, Sweden, and other Western countries in recent decades, the likelihood that a newly diagnosed man in these countries will die from the disease has declined. The researchers attribute this to the widespread use of the prostate-specific antigen (PSA) test, which has resulted in a higher proportion of men diagnosed with lower-risk forms of the disease.

The researchers examined causes of death among prostate cancer cases recorded in the U.S. Surveillance, Epidemiology, and End Results Program (over 490,000 men from 1973 to 2008) and the nationwide Swedish Cancer and Cause of Death registries (over 210,000 men from 1961 to 2008).

The results showed that during the study period, prostate cancer accounted for 52% of all reported deaths in Sweden and 30% of reported deaths in the United States among men with prostate cancer; however, only 35% of Swedish men and 16% of U.S. men diagnosed with prostate cancer died from this disease. In both populations, the risk of prostate cancer-specific death declined, while the risk of death from heart disease and non-prostate cancer remained constant. The five-year cumulative incidence of death from prostate cancer was 29% in Sweden and 11% in the United States.

Death rates from prostate cancer varied by age and calendar year of diagnosis, with the highest number of deaths from the disease among men diagnosed at older ages and those diagnosed in the earlier years of the surveys (especially in the years before the introduction of PSA screening).

"Our study shows that lifestyle changes such as losing weight, increasing physical activity, and quitting smoking, may indeed have a greater impact on patients' survival than the treatment they receive for their prostate cancer," said senior author Hans-Olov Adami, professor of epidemiology at HSPH.