Report to the Nation, 19752004/Espey et al.
TABLE 8 (continued)
Liver and IBD
Oral cavity and pharynx
Melannoma of the skin
Cancer site or typea
Source: Surveillance, Epidemiology, and Ends Results and National Program of Cancer Registries areas are reported by the North American Association of Central Cancer Registries as meeting high-quality data
standards from 1999 through 2004.
CHSDA indicates Indian Health Service (IHS) Contract Health Service Delivery Area; AI/AN, American Indian/Alaska Native; NHW, non-Hispanic white; RR, rate ratio; 95% CI, 95% confidence interval; NOS, not otherwise specified; IBD, intrahepatic bile duct.
a Cancers are sorted in descending order according to sex-specific rates for AI/AN. Greater than 15 cancers may appear to include the top 15 cancers in every IHS region. All sites excludes myelodysplastic syndromes and borderline tumors. Rates are per 100,000 persons and were age-adjusted to the 2000 U.S. standard population (19 age groups, Census p25–1130). The RR was statistically significant (P <.05). Statistic could not be calculated when <16 cases were reported. Years of data and registries used (30 states), 1999–2004: Alabama, Alaska, California, Colorado, Connecticut, Florida, Idaho, Indiana, Iowa, Louisiana, Maine, Massachusetts, Montana, Nebraska, Nevada, New Mexico, New York, North Dakota, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, Texas, Utah, Washington, Wyoming; 1999–2003: Arizona, Wisconsin; 2000–2004: Michigan. Percent regional coverage of AI/AN CHSDA data to all AI/AN in region: Alaska, 100%; East, 12.2%; North Plains, 38.1%; Pacific Coast, 55.1%; South Plains, 65%; Southwest, 86.1%. b c d
high incomes and education levels.70 The drop in incidence rates over the last several years may be associated in part with the small but significant decline in mammography use.68,70 A decrease in breast cancer incidence attributable to lower mam- mography use would represent an artifact of under- diagnosis or delayed diagnosis and not a true decrease in the rate of invasive breast cancer. Treat- ment of ductal and lobular carcinomas in situ, most of which are identified by screening mammography, also may have contributed to the observed decrease in breast cancer incidence.73
Recent reports also highlight the contribution from the dramatic decrease in HRT among postmeno- pausal women for the decrease in breast cancer inci- dence rates, primarily in those ages 50 to 69 years, and among women with estrogen receptor-positive tumors, which are dependent on hormones for their growth.69 Follow-up of women in the Women’s Health Initiative may provide valuable answers to the impact of HRT cessation on breast cancer risk or timing and whether the impact can be sustained over time or throughout a woman’s life. Whether the decline in inci-
dence will accelerate the existing mortality decline also needs to be determined.
Because HRT is also a risk factor for ovarian can- cer,74 the decline in breast cancer incidence rates prompted further examination of recent trends in ovarian cancer. Ovarian cancer incidence rates have been declining since the mid-1980s. However, in this study, the rate of decline among white women chan- ged from 1.0% per year during 1995 through 2001 to 3.3% per year during 2001 through 2004. The earlier declines in ovarian cancer incidence rates have been attributed in part to oral contraceptive use,75,76 whereas the most recent downturn, such as that observed in breast cancer, may be related to the abrupt reversal in HRT use.
The incidence of kidney cancer has been rising among men and women since 1975, but death rates have been declining since 1992. Similar incidence patterns are observed in fixed-interval trends for 1995 through 2004 for most racial/ethnic popula- tions. Much of the increase in incidence has been attributed to small tumors77 or tumors diagnosed unexpectedly in patients who undergo diagnostic