Table 3. A comparison of breast cancer characteristics in women that participated in the mammography screening program and women that did not participate (diagnosis in the years 2010–2012).
| Participants | Non-participants | p-Value | |||
| N | % | N | % | ||
| Breast cancer cases | 444 | 100.0 | 277 | 100.0 | |
| Age at diagnosis, mean (SD) | 59.8 (6.0) | 59.1 (6.0) | 0.927 | ||
| Ductal carcinoma in situ (DCIS) | 93 | 20.9 | 36 | 13.0 | 0.007 |
| Invasive | 351 | 79.1 | 241 | 87.0 | |
| Invasive cancers | 351 | 100.0 | 241 | 100.0 | |
| of which: | <0.0001 | ||||
| T stage 1 | 263 | 74.9 | 138 | 57.3 | |
| T stage 2+ | 75 | 21.4 | 85 | 35.3 | |
| Treated neoadjuvantly | 13 | 3.7 | 18 | 7.5 | |
| N stage 0 | 241 | 68.7 | 154 | 63.9 | 0.624 |
| N stage 1+ | 97 | 27.6 | 68 | 28.2 | |
| Treated neoadjuvantly | 13 | 3.7 | 18 | 7.5 | |
| Missing | 0 | 0.0 | 1 | 0.4 | |
| Grading: | 0.001 | ||||
| Grade I | 98 | 27.9 | 46 | 19.1 | |
| Grade II | 177 | 50.4 | 113 | 46.9 | |
| Grade III | 75 | 21.4 | 81 | 33.6 | |
| Missing | 1 | 0.3 | 1 | 0.4 | |
| Receptor status: | 0.117 | ||||
| Hormone receptor positive, HER2-negative | 272 | 77.5 | 169 | 70.1 | |
| HER2-positive | 53 | 15.1 | 42 | 17.4 | |
| Triple-negative | 26 | 7.4 | 28 | 11.6 | |
| Missing | 0 | 0.0 | 2 | 0.8 | |
| Type of surgery: | <0.0001 | ||||
| Breast-conserving therapy | 280 | 79.8 | 150 | 62.2 | |
| Breast-conserving therapy + mastectomy | 15 | 4.3 | 22 | 9.1 | |
| Mastectomy | 56 | 16.0 | 66 | 27.4 | |
| Missing | 0 | 0.0 | 3 | 1.2 | |
| Indication for chemotherapy: | 0.042 | ||||
| Yes | 169 | 48.2 | 126 | 52.3 | |
| No | 169 | 48.2 | 97 | 40.3 | |
| Treated neoadjuvantly | 13 | 3.7 | 18 | 7.5 | |
| Type of surgery (including DCIS) | 444 | 100.0 | 277 | 100.0 | |
| Breast-conserving therapy | 355 | 80.0 | 174 | 62.8 | <0.0001 |
| Breast-conserving therapy + mastectomy | 23 | 5.2 | 27 | 9.8 | |
| Mastectomy | 66 | 14.9 | 73 | 26.4 | |
| Missing | 0 | 0.0 | 3 | 1.1 | |
HER2, human epidermal growth factor receptor 2; SD, standard deviation