Improved breast cancer survival following introduction of an organized mammography screening program among both screened and unscreened women: a population-based cohort study

Table 1 Baseline characteristics of women with incident breast cancer in Norway 1985 to 2004, diagnosed before (pre-program) and after (post-program) introduction of population-based mammography screening program in their county of residence

^#unknown represents either missing values or values we were not able to classify.
* staging is based on the classification of tumor-stage in the Cancer Registry of Norway: I = localized cancer, II = regional cancer (represents no of node 0 positive tumors), III = cancer fixed to either skin or to the chest wall, IV = cancers with distant metastases.
^‡the treatment variable indicates that treatment was given.
**surgical procedures in the axilla were not specified until 1993 in the database; percentage is calculated based on breast cancer patients diagnosed from 1993 to 2004.
Ax = axillary dissection; BCT = breast-conserving surgery; SN = sentinel-node dissection.

ISSN: 1465-542X