Has there been a real drop in the number of expected cancer cases in the United States?

In 1993, after more than 20 years of increases, there was an observed decrease in the number of new cancer cases reported and in the overall cancer incidence rate in areas covered by the Surveillance, Epidemiology, and End Results Program based at the National Cancer Institute. Most of the decrease is attributed to a reduction in the number of prostate cancers diagnosed in 1993, a result of the introduction of a new screening tool for prostate cancer in the late 1980s. The article examines a number of possible reasons for the decrease in both overall cancer rates and prostate cancer rates and discusses whether the decrease is real or a statistical anomaly.