During Introduction of Mammography Screening Analysis of Three Tumor Size Intervals in Screened and Post-Screened Periods Clarified the Short and Long Term Efficacy of Screening
Roland B Sennerstam*
Department of Oncology and Pathology Karolinska Hospital and Karolinska Institutet Stockholm, Sweden
- *Corresponding Author:
- Roland B Sennerstam
Department of Oncology and Pathology
Karolinska Hospital and Karolinska
Institutet Stockholm, Sweden
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E-mail: [email protected]
Received date: June 12, 2013; Accepted date: June 28, 2013; Published date: July 01, 2013
Citation: Sennerstam RB (2013) During Introduction of Mammography Screening Analysis of Three Tumor Size Intervals in Screened and Post-Screened Periods Clarified the Short and Long Term Efficacy of Screening. J Cancer Sci Ther S7:006. doi:10.4172/1948-5956.S7-006
Copyright: © 2013 Sennerstam RB. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The present study focused on mammography screening during two periods representing 2 years (1991) to 8 years (1997/98) after the introduction of screening in 1989 in the Stockholm Gotland County, Sweden for women aged 50-69 years. Subjects were sorted by age, as younger (<50 years) unscreened women, screening women aged 50-69 years and analyzed in two decades between 50-59 years and 60-69 years respectively, and unscreened women of ≥ 70 years. Tumor size was compared with an unscreened cohort from 1987, 2 years before screening was introduced. Resolution was increased by focusing on three tumor-size intervals instead of mean tumor size, which showed a tending reduction in tumors ≥ 20 mm for women diagnosed with breast cancer aged 50-59 years in the 1991 sample but a significant decline for women aged 60-69 years having attended two screening tests. After 8 years of biennial screening (1997/98) patients with tumor size ≤ 10 mm at diagnosis had significantly increased, and tumors ≥ 20 mm declined significantly–most clearly among 60-69-year-old women after attending up to five screening tests. A transient increase in tumor sized 10 mm to 20 mm was seen due to the stepwise-altered distribution in size. Women in the two unscreened age groups <50 years and ≥ 70 years, were compared with screened women aged 60-69 (1997/98) according to tumor size, genomic instability, proliferation index , lymph node metastases, cyclin-A and ki67, alteration in breast tumor stage I and stage IIB and survival rate. In all parameters except ki67, only in relation to unscreened women <50 years old showed a significant reduction. A post-screening effect was also found for women aged 70-79 years with tumors size > 20 mm still being reduced compared with controls and the tumors ≤ 10mm decreasing significantly to the control level.