Variable | No. of patients (%) | ||||||
---|---|---|---|---|---|---|---|
Center 1 | Center 2 | Center 3 | Center 4 | Center5 | Center 6 | P | |
Patient age | |||||||
  < 60 years | 48.6 | 52.6 | 47.9 | 48.1 | 55.3 | 47.6 | 0.098 |
  > 60 years | 51.4 | 47.4 | 52.1 | 51.9 | 44.7 | 52.4 | |
Location | |||||||
 Central portion | 1.6 | 0.9 | 0.5 | 1.7 | 1.1 | 0.7 | 0.956 |
  Upper outer quadrant | 40.8 | 41.7 | 37.8 | 39.1 | 37.1 | 38.8 | |
  Upper inner quadrant | 17.4 | 18.9 | 20.5 | 20.7 | 19.2 | 20.1 | |
  Lower outer quadrant | 27.2 | 24.8 | 28.1 | 27.1 | 25.9 | 26.7 | |
  Lower inner quadrant | 13.0 | 13.7 | 13.5 | 11.4 | 16.7 | 13.7 | |
 Cancer stage | |||||||
  T1 (< 2 cm) | 47.7 | 56.1 | 52.7 | 51.8 | 50.5 | 51.2 | 0.068 |
  T2 (2-5cm) | 52.3 | 43.9 | 47.3 | 48.2 | 49.5 | 48.8 | |
 Cancer type | |||||||
  Invasive ductal carcinoma | 66.7 | 61.7 | 63.1 | 57.2 | 60.9 | 62.6 | 0.674 |
  Invasive lobular carcinoma | 22.3 | 24.6 | 27.2 | 27.7 | 26.8 | 26.6 | |
  Tubular carcinoma | 11.0 | 13.7 | 9.7 | 15.1 | 12.3 | 10.8 |