gms | German Medical Science

MAINZ//2011: 56. GMDS-Jahrestagung und 6. DGEpi-Jahrestagung

Deutsche Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie e. V.
Deutsche Gesellschaft für Epidemiologie e. V.

26. - 29.09.2011 in Mainz

Population-based effects of mammography screening on distribution of tumour stages and consequences for therapy and care of breast cancer patients in Bavaria

Meeting Abstract

  • Ulrike Braisch
  • Simone Schrodi
  • Karla Geiss
  • Martin Radespiel-Tröger
  • Dieter Hölzel
  • Sylvia Heywang-Köbrunner
  • Jutta Engel
  • Martin Meyer

Mainz//2011. 56. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie (gmds), 6. Jahrestagung der Deutschen Gesellschaft für Epidemiologie (DGEpi). Mainz, 26.-29.09.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. Doc11gmds606

doi: 10.3205/11gmds606, urn:nbn:de:0183-11gmds6060

Published: September 20, 2011

© 2011 Braisch et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Objective: Systematic mammography screening was implemented in 2003 in the German federal state of Bavaria. Among a population of 6.3 million women, about 1.5 million women (23%) are affiliated to the target population (women aged 50 to 69 years) of the screening program. The objective of this project was the population-based evaluation of the effects of screening on the distribution of observed tumour stages and possible consequences for breast cancer care.

Material and methods: Women diagnosed with breast cancer between 2000 and 2008 and registered in one of the six Bavarian clinical cancer registries were analysed. 51.4% of these patients were aged 50-69 years and therefore constituted the target population for screening. Time trends of prognostic factors and standard therapies were calculated for three age groups (≤49, 50-69, ≥70) by means of annual percentages and incidence rates as well as 95%-confidence intervals for the percent and incidence difference. For interpretation of therapy trends, logistic regression models were calculated. Correlation coefficients were calculated in order to evaluate the possible association between population-based participation rate and the distribution of the TNM-T-category.

Results: In contrast to the other two age groups, the incidence of ductal carcinomas in-situ and invasive ductal carcinomas <10mm increased strongly over time and showed a significant correlation with the population-based participation rate among the screening population. However, in lobular carcinomas a stagnation of incidence in the target population regardless of TNM-T category was observed. In line with the observed stage-shift, trends of standard treatments show an increasing use of less invasive treatments, such as breast-conserving surgery (and therefore also an increase of radiation therapy) and sentinel-node biopsy. The shift to more favorable prognostic factors led to an increase of singular endocrine therapies, to a decrease of singular chemotherapies and therefore to a more gentle systemic therapy. These trends strengthened in the years following the introduction of screening, with a simultaneous rise of screening participants in the target population.

Conclusion: The evaluation of mammography screening in Bavaria already shows the expected trend towards more favorable prognostic factors. This may be one out of several reasons for the increasing use of more gentle therapies. However, depending on the type of breast cancer, not all women appear to benefit from screening. Whether the screening in Bavaria leads to the expected mortality reduction remains to be seen.