[Alterations of stage distribution for breast cancer since the implementation of national screening program in the Netherlands during 1989-1995].

Objective: To determine the results of the nation-wide breast cancer screening on the basis of the stage distribution of diagnosed breast cancer 1989-1995.

Design: Descriptive, inventory.

Method: At the University of Nijmegen data concerning the numbers of diagnosed breast cancer cases and age and stage at diagnosis were obtained from the Netherlands Cancer Registry for the years 1989-1995. Population data were provided by Statistics Netherlands. With these data incidence figures were calculated.

Results: The number of invasive breast cancers rose from almost 8,000 in 1989 to almost 10,500 in 1994. In 1995, a small decrease was visible. The increase was largest in women aged 50-69 years, the target population of the screening programme (introduced in 1988), and less in older women. In women aged 50-69 years, the incidence of stage I tumours doubled, stage II tumours increased but had returned to original levels in 1995, whereas stage III and IV had decreased by more than 24%. The number of carcinomas in situ rose from 336 in 1989 to 829 in 1995 in all age categories, but most in women aged 50-69 years.

Conclusion: When the implementation scheme of the national screening programme is taken into account, the results are indicative of a reduction in breast cancer mortality. Whether such a mortality reduction actually will follow, has to be awaited.