Table 1.
Characteristics of study participants from United States (Breast Cancer Surveillance Consortium) and Denmark.
|
|
||
|---|---|---|
| United States | Denmark | |
| Study base | 180 breast imaging facilities from 7 population-based mammography registries of the BCSC | All 47 diagnostic mammography clinics in Denmark (screening clinics not included) |
| Definition of diagnostic mammogram | Mammograms recorded as evaluation of breast problem (symptomatic) | All mammograms from diagnostic clinics1 |
| Study period | 1999–2001 | 2000 |
| Total number of women | 93,585 | 51,313 |
| Age distribution, years: number (%)2 | ||
| 20–29 | 2997 (3.2) | 1906 (3.7) |
| 30–39 | 19 632(21.0) | 8710 (17.0) |
| 40–49 | 31 421 (33.6) | 13 582 (26.5) |
| 50–59 | 20 147 (21.5) | 14 871 (29.0) |
| 60–69 | 10 510 (11.2) | 7653 (14.9) |
| 70–79 | 6725 (7.2) | 3697 (7.2) |
| 80–89 | 2153 (2.3) | 894 (1.7) |
| Breast cancer definition | Histology-confirmed invasive carcinoma or DCIS | Histology/cytology-confirmed invasive/DCIS |
| Breast cancer identification | Linkage with cancer registries and pathology databases | Linkage with nationwide cancer and pathology registries |
| Examinations supplemented with ultrasound | 37% to 52%3 | 74% |
| Breast cancer incidence4 | 97 (USA, white) | 84 (Denmark) |
1
Outside the two organized screening programmes, asymptomatic women can be referred to diagnostic mammography clinics for opportunistic screening. This happened seldom, as the annual utilization rate of all diagnostic mammography (symptomatic and asymptomatic women together) was only 2.7% in women aged >25 in 2000 (21).
2
Number of women (%)
3
Depending on registry.
4
Age-standardized rate per 100,000 (WHO World Standard Population) for the year 2000 (22).