U.S. cancer rates and deaths decline

"This welcome news on declining rates underscores the incredible progress we've made against cancer, but it also reminds us that our fight is far from over," said Health and Human Services Secretary Tommy Thompson. "It is clear that we must not only treat cancer, but beat this deadly disease." Health and Human Services has proposed an increase of $514 million for cancer-related research at NIH in 2002, a 12% increase over current yearly spending.

The report shows that the incidence rate for all cancers combined - the number of new cancer cases per 100,000 persons per year - declined an average 1.1% per year between 1992 and 1998. This overall trend reversed a pattern of increasing incidence rates from 1973 to 1992. Most of the decline can be attributed to a 2.9% yearly decline in cancer incidence among white males and a 3.1% yearly decline among black males. "I am most excited to see that rates of new cases of cancer declined in the 1990s for both black and white men. It will take time to tell, but this could be a sign that the disparities among racial and ethnic groups are lessening," said James S. Marks, director of the CDC's National Center for Chronic Disease Prevention and Health Promotion.

"More good news is the continuing fall in cancer death rates by 1.6% per year for men and 0.8% per year for women between 1992 and 1998," said John R. Seffrin, chief executive officer of the American Cancer Society. "Particularly welcome is that the largest decrease - 2.5% per year - occurred in black men, who bear the heaviest cancer burden." Overall cancer mortality declined 1.1% yearly for the period from 1992 to 1998.

Leading causes of death

Four cancer sites - lung, prostate, breast and colorectum - accounted for about 56% of all new cancer cases and were also the leading causes of cancer deaths for every racial and ethnic group.

Breast cancer makes up 16.3% of all cancer cases and accounts for 7.8% of all deaths due to cancer. Breast cancer death rates have continued to decline due to improvements in early detection and treatment. However, breast cancer incidence rates have increased by more than 40% from 1973 to 1998.

One explanation for the increase in breast cancer incidence rates comes from analyses that indicate that more early-stage disease is being diagnosed, suggesting that use of aggressive screening and early detection, primarily via mammography, may account for part of this increase. "The extent to which other factors, such as more obesity and post-menopausal hormone use, may contribute to the increase is unknown," said Brenda K. Edwards of the NCI, final author of the report.

Prostate cancer, which accounts for 14.8% of all cases, saw a sharp increase in incidence rates starting in the late 1980s with the introduction of screening for prostate specific antigen. Subsequently, however, rates have started to decline. Death rates have also declined in recent years. Much of the wide variation in prostate cancer incidence rates across the country can be attributed to differing rates of PSA screening, with geographic areas of high usage of PSA screening reporting high incidence rates, often the result of discovery of clinically insignificant tumors.

Lung cancer accounts for 29% of cancer deaths and 13.2% of cancer cases in the United States. Overall, lung cancer incidence rates decreased 1.6% per year between 1992 and 1998, due mainly to a decline of 2.7% per year in men and a leveling off for women, both manifestations of reductions in tobacco smoking since the 1960s. Lung cancer mortality began to decrease in 1990 in men, but an increase in mortality continued until at least 1998 in women. Long-term trends show that women lag behind men in lung cancer incidence and death rates.

Reducing future incidence

Authors of the report identified several strategies for reducing future incidence of cancer and death from the disease, the most critical being the reduction of tobacco use in all segments of the population, since smoking causes an estimated 30% of all cancer deaths. Another strategy would be to improve the use of currently effective but underutilized cancer screening tools. Other strategies identified include developing and applying state-of-the-art diagnostic tests and treatments, as well as identifying and reducing health disparities across diverse populations. PR