Einfluss des Mammographie-Screenings in der Prävalenzphase auf Tumorstaging und Operationsverfahren bei Brustkrebspatientinnen

Breast cancer is the most common malignant neoplasm in western countries. The early detection is a special medical challenge since it is associated with a good prognosis and gives the possibility of curative therapy. Along with the constant improvement of therapeutic methods early detection has a great influence on the prognosis of breast cancer. Screening with radiography is currently the best method of early detection of breast cancer. The benefit of screening for breast cancer patients is not so much the cancer associated mortality than to improve the quality of life. Thus a population based quality-controlled screening was established in Germany. The objective of this study is to determine the effects of screening on tumor-staging and management. Screening and curative subgroups of patients with breast cancer between 11/2007 and 2/2009 were compared regarding prognostic and therapeutic parameters. Subgroups were determined whether cancer was first diagnosed clinically (“curative”) or due to population-based screening (“screening”). The histopathological report was used to analyse invasiveness, multifocal growth, grading, pT stage, lymph node involvement, resection status and method of surgical treatment. In total 652 patients were included of which 208 belonged to the screening group, 444 to the curative group. Univariate analysis showed statistically significant differences between the two groups concerning invasiveness, pT stage, multifocal growth, grading, lymph node status and method of surgical treatment. The screening group showed a greater percentage of in situ lesions (19,7 % vs. 2,7 %; p = 0,000), smaller tumors (85,4 % vs. 61,3 %; p = 0,000) and more well differentiated tumors (G1 percentage 28,5 % vs. 17,6 %; p = 0,01). There were no differences between the groups in resection status (p = 0,832). However the lymph node status showed a significant difference between the groups. The screening group included 77,2 % of pN0-status in comparison to 67,8 % analysed in the curative group (p = 0,037). Screening patients showed fewer multifocal tumors (9,6 % vs. 17,3 %; p = 0,01) and a higher rate of lumpectomies (95 % vs. 83 %; p = 0,02). Comparatively a subpopulation of the curative group (consisting of patients between the ages of 50 and 69) was defined as an age-adjusted curative subgroup which, compared to the screening group, basically achieved similar conclusions. The results show that radiograph screening allows earlier detection of tumors and thus less radical surgical treatment and a positive influence on the prognostic parameters that were analyzed. There was no follow-up of the patients which limits the conclusions regarding secondary mastectomy and mortality. All in all the ascertained results show a high conformity with the literature. Overdiagnosis and overtherapy, the critical points concerning the radiograph screening, were only partly analysed in this study. No statement can be made on overdiagnosis. However, the present data on the treatment method appear to reject the point of overtherapy in screening patients.