Declines in the rates of cigarette smoking in several states mirrored declines in prostate cancer deaths between 1999 and 2010, according to a new epidemiologic analysis. This suggests the prostate cancer mortality reduction is an added beneficial effect of reduced smoking rates.
“In the United States, prostate cancer mortality rates have declined since the 1990s,” wrote study authors led by Miranda R. Jones, PhD, of the Johns Hopkins Bloomberg School of Public Health in Baltimore. “These declines are due, at least in part, to the combination of prostate specific antigen (PSA)-based prostate cancer screening and better treatment of men diagnosed with prostate cancer and men who progress to metastatic disease. However, these factors do not entirely explain the decline.”
The new analysis included analysis of smoking rates and prostate cancer mortality in men aged 35 years or older in California, Kentucky, Maryland, and Utah; the data came from the Behavioral Risk Factor Surveillance System and the Centers for Disease Control and Prevention’s Wide-Ranging Online Data for Epidemiologic Research (CDC WONDER) database. The results were published in Preventing Chronic Disease.
Smoking rates declined in each of the states studied. In Maryland, smoking prevalence declined by 3% per year from 1999 through 2010 (from 20.9% to 15.6%), while prostate cancer mortality declined by 3.5% per year (from 68.4 per 100,000 to 43.6 per 100,000). In Kentucky, these rates of both smoking and prostate cancer mortality rate decline were the same as in Maryland, at 3% and 3.5%, respectively.
Utah began with the lowest rates of smoking (14.8% in 1999), and saw a 3.5% per year decline through 2010. Prostate cancer mortality rates in Utah declined by 2.1% per year. In California, smoking rates declined by 3.5% per year as well, and prostate cancer mortality declined by 2.5% per year.
The researchers also divided the populations by race, and found that while smoking rates declined significantly among white men in all four states, the prevalence declined significantly among black men in Maryland only. Prostate cancer mortality also came down significantly among black men in Maryland and in California, though it did not in Kentucky.
The authors noted that this study was an “ecological analysis” and was thus unable to conclude any causal association between smoking and prostate cancer mortality. Previous research, however, has shown that smoking significantly increases the risk of mortality from prostate cancer. The authors also pointed out that the decreases in prostate cancer mortality occurred in spite of increasing obesity prevalence over the study period.
“These findings support the need for targeted smoking cessation efforts, which could reduce prostate cancer mortality rates in this population burdened by both higher rates of prostate cancer and an elevated prevalence of cigarette smoking,” they concluded.