Cancer Death Rates Edge Down But New Cases Stay the Same

SPRINGFIELD, Ill., Sept. 8 -- Americans' risk of dying from malignancies continues to edge down, largely because of smoking cessation a generation ago, but the rate of new cases remains unchanged, according to a report from the nation's leading cancer organizations.

Death rates for men, springing from a decrease in the incidence of lung cancer, have declined 1.6% annually for men from 1993 and 2003 and 0.8% annually for women from 1992 to 2003, according to an online report that will appear in the Oct. 5 issue of Cancer.

Death rates decreased for 11 of the 15 most common cancers in men and for 10 of the 15 most common cancers in women, said Holly Howe, Ph.D., of the North American Association of Central Cancer Registries (NAACCR) here and colleagues.

The authors attribute the decrease in death rates, in part, to successful efforts to reduce tobacco exposure, earlier detection through screening, and more effective treatment.

The findings emerged from the "Annual Report to the Nation on the Status of Cancer 1975-2003. The report, issued since 1998, is a collaborative effort of the NAACCR, the CDC, the American Cancer Society, and the National Cancer Institute. This year it included a special section on cancer among U.S. Hispanic/Latino populations.

Through 2003, prostate, lung, and colorectal cancer in men and breast, lung, colon and rectum cancer in women continued to be the leading types of cancer for incidence and mortality for each racial and ethnic group studied, the researchers reported.

Declining death rates for men included lung, prostate, colorectal, pancreas, leukemia, non-Hodgkin's lymphoma, bladder, stomach, brain, myeloma, and oral cavity cancers. Death rates increased for esophageal and liver cancers, but recently stabilized for kidney cancer and melanoma.

Declining death rates for women included breast, colorectal, non-Hodgkin's lymphoma, leukemia, brain, myeloma, stomach, kidney, cervix, and bladder cancer. However, women's death rates were unchanged for cancers of the pancreas, ovary, and uterus, and continued to increase at varying rates for liver cancer.

"The greater decline in cancer death rates among men is due in large part to their substantial decrease in tobacco use. We need to enhance efforts to reduce tobacco use in women so that the rate of decline in cancer death rates becomes comparable to that of men, said Betsy Kohler, M.P.H., president of the NAACCR.

Cancer incidence offered a mixed picture. After increasing from 1975 to 1992, the overall rates for all forms of cancer stabilized but did not decrease from 1992 to 2003, the researchers reported.

For men rates for all cancers decreased by 4.5% per year from 1992 to 1995 and were stable after that. For women, however, i rates for all cancers combined increased from 1987 to 2003 by 0.35 year.

Notably, the researchers said, the incidence of female breast cancer stabilized from 2001 through 2003, ending increases that began in the 1980s. Whether this is a trend or a random fluctuation cannot be determined until data reporting in the next few years is complete, the researchers said. This stabilization may be due to discontinuation of hormone replacement therapy and increased mammography screening, they suggested.

Also, the data suggest a small increase in the female lung cancer rates from 1991 through 2003, which is, however, a much slower rate of increase, than that found previously. This increase represents a change from last year's report, where rates appeared stable, they said. From 1995 to 2003, rates increased among women 65 and older, decreased among women ages 45 to 64, and were stable in women younger than age 45. In comparison, lung cancer rates for men decreased in all age groups.

Among cancers rates that had increased significantly, the researchers found thyroid cancer on the rise among women. The rate increased 2.2% per year from 1981 to 1993. The rate then increased 4.6% per year until 2000, and the 9.1% per year until 2003. These rising trends, they said, are likely explained in part by changes in medical surveillance, but may result from other risk factors.

For Latinos, the researchers reported, incidence rates declined from 1999 to 2003 for most cancers, but compared with non-Latino white populations, their rates were higher for myeloma and cervical cancer in women and cancers of the stomach, liver, and kidney for both sexes.

Latinos were less likely than the non-Hispanic white population to be diagnosed with localized cancers of the lung, colon and rectum, prostate, female breast, and cervix. Latinos were less likely than non-Latinos to be diagnosed at localized stages.

However, Latino children had higher rates of leukemia, retinoblastoma, osteosarcoma, and germ-cell tumors than non-Latino white children, the investigators found.

Many types of cancers with higher incidence rates in Latinos are associated with infections: human papilloma virus, H. pylori in stomach cancer, hepatitis B and C in liver cancer, for example. In addition, relative to the non-Hispanic white population, cancers varied among the different Latino groups (Mexican, Puerto Rican, and Central and South American).

Some factors that may contribute to differences in Latino cancer rates include a higher incidence of infection-related cancers, more environmental risk factors, limited English proficiency, lack of screening services, health-care coverage, and less information about possible genetic predispositions.