Veranderde stadiumverdeling van borstkanker sinds de invoering van de landelijke screening; onderzoek over de periode 1989-1995

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.