Table 2.
Patient demographic data for single versus bilateral breast cancers
| Unilateral n (%) |
Bilateral simultaneous n (%) |
Bilateral metachronous n (%) |
P-value* | |
|---|---|---|---|---|
| Patient age | 622 (92.3) | 20 (3.0) | 32 (4.7) | |
| Age at diagnosis, years | ||||
| ≤64 | 413 (66.4) | 10 (50.0) | 24 (75.0) | 0.17 |
| ≥65 | 209 (33.6) | 10 (50.0) | 8 (25.0) | |
| Mean ± SD | 58.8±13.5 | 64.3±15.5 | 54.7±13.9 | |
| Ethnicity | ||||
| Caucasian | 391 (66.2) | 13 (72.2) | 22 (71.0) | 0.92 |
| African American | 177 (29.9) | 5 (27.8) | 7 (22.6) | |
| Native American Indians | 11 (1.9) | 0 | 1 (3.2) | |
| Others | 12 (2.0) | 0 | 1 (3.2) | |
| Body mass index | ||||
| Underweight | 15 (2.9) | 0 | 1 (3.3) | 0.94 |
| Normal weight | 119 (22.8) | 4 (25.0) | 8 (26.7) | |
| Overweight | 389 (74.4) | 12 (75.0) | 21 (70.0) | |
| Atherosclerosis | ||||
| None apparent | 456 (73.3) | 12 (60.0) | 26 (81.3) | 0.24 |
| Present | 166 (26.7) | 8 (40.0) | 6 (18.8) | |
| Smoking | ||||
| Nonsmoker | 331 (55.5) | 10 (50.0) | 18 (60.0) | 0.78 |
| Smoker | 265 (44.5) | 10 (50.0) | 12 (40.0) | |
| Thrombosis | ||||
| No thrombosis | 554 (89.1) | 18 (90.0) | 24 (75.0) | 0.05143 |
| Thrombosis | 68 (10.9) | 2 (10.0) | 8 (25.0) | |
| Handedness | ||||
| Right | 169 (91.4) | 7 (87.5) | 2 (66.7) | 0.32 |
| Non-right | 16 (8.7) | 1 (12.5) | 1 (33.3) | |
| Number of primaries | ||||
| Single primary | 534 (85.9) | 18 (90.0) | 0 | 0.0000 |
| Two primaries | 80 (12.9) | 2 (10.0) | 25 (78.1) | |
| Three/more primaries | 8 (1.3) | 0 | 7 (21.9) | |
| Breast cancer laterality | ||||
| Left | 324 (52.1) | 19 (59.4) | 0.72 | |
| Right | 298 (47.9) | 13 (40.6) | ||
| Family history of breast cancer | ||||
| First-degree relatives | 157 (27.9) | 3 (16.7) | 18 (66.7) | 0.00006 |
| Second-degree relatives | 100 (17.8) | 7 (38.9) | 2 (7.4) | |
| No family history | 306 (54.4) | 8 (44.4) | 7 (25.9) | |
| Tumor multicentricity | ||||
| Unifocal neoplasm | 385 (79.6) | 6 (31.6) | 27 (93.1) | 0.0000 |
| Multifocal neoplasm | 99 (20.5) | 13 (68.4) | 2 (6.9) | |
| Initial stage | ||||
| 0/I | 243 (39.1) | 1 (5.0) | 8 (25.0) | 0.01487 |
| II | 228 (36.7) | 12 (60.0) | 18 (56.3) | |
| III | 113 (18.2) | 5 (25.0) | 3 (9.4) | |
| IV | 38 (6.1) | 2 (10.0) | 3 (9.4) | |
| Overall survival, years | ||||
| Mean ± SD | 6.66±6.48 | 4.69±4.86 | 16.05±8.00 | 0.0000 |
| Median | 4.78 | 3.37 | 14.83 | |
| At 5 | 55 | 30 | 97 | 0.0000 |
| At 10 | 28 | 18 | 90 | |
| At 15 | 17 | 0 | 66 | |
Note:
*
Statistically significant difference between bilateral simultaneous and bilateral metachronous breast cancers.
Abbreviation: SD, standard deviation.