Table 2.
Treatment characteristics of cases and controls with stage I-III breast cancer
| Characteristic | BC-P cases N = 50 | Controls for BC-P cases N = 113 | BC-PP cases N = 52 | Controls for BC‒PP cases N = 113 | P value for comparison of BC‒P cases and their controlsb | P value for comparison of BC‒PP cases and their controlsb | P value for comparison of BC‒P cases to BC‒PP casesb |
|---|---|---|---|---|---|---|---|
| Breast surgery(N, %) | |||||||
| Mastectomy | 33 (67%)a | 81 (74%) | 32 (65%) | 65 (58%) | 0.42 | 0.39 | 0.83 |
| Breast conservation | 16 (33%) | 29 (26%) | 17 (35%) | 47 (42%) | |||
| Margins (N, %) | |||||||
| Positive | 4 (9%) | 5 (4%) | 2 (4%) | 4 (4%) | 0.21 | 0.78 | 0.17 |
| Negative | 34 (74%) | 96 (86%) | 41 (89%) | 96 (86%) | |||
| Close | 8 (17%) | 11 (10%) | 3 (7%) | 11 (10%) | |||
| Nodal evaluation (N, %) | |||||||
| None | 0 (0%) | 1 (1%) | 0 (0%) | 0 (0%) | 0.18 | 0.67 | 0.20 |
| Sentinel node biopsy | 8 (19%) | 35 (32%) | 14 (30%) | 37 (34%) | |||
| Axillary node dissection | 35 (81%) | 72 (67%) | 32 (70%) | 72 (66%) | |||
| Reconstruction (N, %) | |||||||
| None | 30 (75%) | 47 (47%) | 21 (51%) | 62 (58%) | 0.01 | 0.73 | 0.08 |
| Implant | 5 (12%) | 28 (28%) | 11 (27%) | 23 (21%) | |||
| Autologous | 5 (12%) | 24 (24%) | 9 (22%) | 22 (21%) | |||
| Radiation (N, %) | 28 (78%) | 64 (65%) | 30 (77%) | 66 (70%) | 0.17 | 0.43 | 0.93 |
| (Neo)adjuvant chemotherapy (N, %) | 40 (80%) | 89 (83%) | 40 (78%) | 84 (86%) | 0.63 | 0.26 | 0.85 |
| Endocrine therapy (N, %) | 14 (48%) | 61 (86%) | 21 (75%) | 72 (92%) | < 0.001 | 0.02 | 0.04 |
| HER2-targeted therapy (N, %) | 5 (22%) | 14 (54%) | 7 (33%) | 8 (36%) | 0.02 | 0.84 | 0.39 |
a
All percentages based on non-missing values
b
P values for Chi-squared tests performed on non-missing proportions