Assessing progress in reducing the burden of cancer mortality, 1985-2005

Measuring the effect of cancer interventions must take into account rising cancer incidence now that people live longer because of declines in mortality from cardiovascular disease (CVD). Cancer mortality rates in the population do not accomplish this objective. We sought a measure that would reveal the effects of changing mortality rates from other diseases.

We obtained annual breast, colorectal, lung, and prostate cancer mortality rates from the Surveillance, Epidemiology, and End Results registries; we obtained noncancer mortality rates from national death certificates, 1975 to 2005. We used life-table methods to calculate the burden of cancer mortality as the average person-years of life lost (PYLL) as a result of cancer (cancer-specific PYLL) and quantify individual-and perhaps offsetting-contributions of the two factors that affect cancer-specific PYLL: mortality rates as a result of cancer and other-cause mortality.

Falling cancer mortality rates reduced the burden of mortality from leading cancers, but increasing cancer incidence as a result of decreasing other-cause mortality rates partially offset this progress. Between 1985 and 1989 and between 2000 and 2004, the burden of lung cancer in males declined by 0.1 year of life lost. This decline reflects the sum of two effects: decreasing lung cancer mortality rates that reduced the average burden of lung cancer mortality by 0.33 years of life lost and declining other-cause mortality rates that raised it by 0.23 years. Other common cancers showed similar patterns.

By using a measure that accounts for increased cancer incidence as a result of improvements in CVD mortality, we find that prior assessments have underestimated the impact of cancer interventions.