Regulatory and public health policies in the United States are predicated on the uncritical acceptance of an alleged explosion in cancer mortality rates. In reality, several studies offer evidence that cancer mortality went underreported as one goes back in time, due to progressive deficiencies in diagnostic and registration practices. Because the absence of historical records precludes a comprehensive direct verification, a group of experts were polled to estimate the impact of this bias on U.S. cancer mortality statistics. The nature of this exercise speaks against a numerical interpretation of the results; however, their broad analogic meaning suggests that age-adjusted mortality and probably the incidence of leading cancers have significantly declined for decades, with the major exception of respiratory tract cancers.