The overall incidence and death rates from cancer fell for the first time in the United States for men and women.  Death rates due to multiple myeloma decreased for both men and women.  However, the risk of developing myeloma remained the same in women and increased in men.

The incidence rate is a measure of the risk of developing a specific disease, and the death or mortality rate is the number of deaths in a population. Incidence and death rates for a disease are measured as the annual number of new cases and deaths, respectively, for every 100,000 persons in the general population.

Each year the American Cancer Society, the Centers for Disease Control and Prevention, the National Cancer Institute, and the North American Association of Central Cancer Registries issue a report on current cancer trends. In this year’s report, researchers analyzed both long-term trends from 1975-2005 and short-term trends from 1996-2005.

In the long term, the overall cancer incidence rate decreased, due mostly to a reduction in the three most common cancers among men (lung, prostate, and colorectal cancer) and two of the three most prevalent cancers among women (breast and colorectal cancer). Death related to lung cancer was observed to stagnate among women since 2003. Only California showed a decline in lung cancer mortality, while 18 midwestern and southern states actually showed an increase in incidence and mortality.

In contrast to overall decreases in cancer incidence, rates in men increased for cancers of the liver, kidney, and esophagus, as well as for melanoma, non-Hodgkin's lymphoma, and myeloma. Rates remained stable for cancers of the bladder, pancreas, and brain and for leukemia. Among women, an increase in incidence rates of cancers of the lung, thyroid, pancreas, brain, bladder, and kidney, as well as for leukemia, non-Hodgkin's lymphoma, and melanoma was found. The rates of uterine, ovarian, cervical, and oral cancers decreased.

Among the top 15 causes of cancer-related death, the death rates of 10 types of malignancies were found to decrease in the short-term trends. Decreases in mortality rates varied between men and women for most cancers. However, death rates attributed to myeloma decreased annually by 1.1% for men and 1.2% for women.

While the overall decrease in cancer incidence and death rates is encouraging, the authors warn that this should only be seen as a starting point. They go on to write that “a dual approach will be needed to sustain and extend this progress into the future. First, the application of existing knowledge must be improved so that evidence-based interventions reach all segments of the population. Second, ongoing research is needed to improve our current methods of prevention, early detection, and treatment.”

In regard to myeloma and several other cancers, the authors state that further research is needed to understand the origins of the diseases since incidence has increased and current risk factors may not be able to fully explain the observed trends.

The full report can be found in the November 25 issue of the Journal of the National Cancer Institute.