TABLE 2.
Pathologic characteristics of bilateral breast cancer
| Characteristic |
sBBC (n = 28) |
mBBC (n = 99) |
p valuea | p valueb | p valuec | ||
|---|---|---|---|---|---|---|---|
| First tumor | Second tumor | First tumor | Second tumor | ||||
|
Tumor size (cm) (median [range]) |
2.65 (1.0–8.0) | 1.5 (0.5–7.0) | 2.5 (0.5–15) | 2.0 (0.4–10) | 0.005 | ns | ns |
| Tumor stage | 0.028 | ns | 0.028 | ||||
| Tis | 1 (3.6) | 8 (28.6) | 1 (1.0) | 4 (4.0) | |||
| T1 | 10 (35.7) | 13 (46.4) | 41(41.4) | 51 (51.5) | |||
| T2 | 12 (42.9) | 6 (21.4) | 36 (36.4) | 31 (31.3) | |||
| T3 | 2 (7.1) | 0 | 9 (9.1) | 8 (8.1) | |||
| T4 | 3 (10.7) | 1 (3.6) | 0 | 5 (5.1) | |||
| Unknown | 0 | 0 | 15 (15.2) | 0 | |||
| Lymph nodal status | 0.006 | ns | ns | ||||
| N0 | 12 (42.9) | 24 (85.7) | 48 (48.5) | 56 (56.6) | |||
| N1 | 5 (17.9) | 3 (10.7) | 17 (17.2) | 17 (17.2) | |||
| N2 | 7 (25.0) | 0 | 21 (21.2) | 10 (10.1) | |||
| N3 | 3 (10.7) | 1 (3.6) | 10 (10.1) | 16 (16.2) | |||
| Unknown | 1 (3.6) | 0 | 3 (3.0) | 0 | |||
| Stage | 0.002 | ns | ns | ||||
| 0 | 1 (3.6) | 8 (28.6) | 1 (1.0) | 3 (3.0) | |||
| I | 6 (21.4) | 11 (39.3) | 27 (27.3) | 38 (38.4) | |||
| II | 8 (28.6) | 7 (25.0) | 37 (37.4) | 31 (31.3) | |||
| III | 13 (46.4) | 2 (7.1) | 31 (31.3) | 26 (26.3) | |||
| IV | 0 | 0 | 0 | 1 (1.0) | |||
| Unknown | 0 | 0 | 3 (3.0) | 0 | |||
| Histopathologic type | 0.01 | ns | ns | ||||
| DCIS | 1 (3.6) | 10 (35.7) | 3 (3.0) | 7 (7.1) | |||
| IDC | 26 (92.9) | 17 (60.7) | 67 (67.7) | 81 (81.8) | |||
| ILC | 0 | 1 (3.6) | 11 (11.1) | 7 (7.1) | |||
| Others | 1 (3.6) | 0 | 7 (7.1) | 4 (4.0) | |||
| Unknown | 0 | 0 | 11 (11.1) | 0 | |||
| ER status of invasive cancers | ns | ns | ns | ||||
| Negative | 9 (33.3) | 3 (15.0) | 41 (41.8) | 40 (41.7) | |||
| Positive | 18 (66.7) | 17 (85.0) | 55 (56.1) | 56 (58.3) | |||
| Unknown | 0 | 0 | 2 (2.0) | 0 | |||
| PR status of invasive cancers | ns | ns | ns | ||||
| Negative | 11 (40.7) | 4 (22.2) | 40 (40.8) | 52 (54.2) | |||
| Positive | 16 (59.3) | 16 (80.0) | 56 (57.1) | 44 (45.8) | |||
| Unknown | 0 | 0 | 2 (2.0) | 0 | |||
| Lymphovascular invasion | ns | ns | ns | ||||
| No | 23 (85.2) | 19 (95.0) | 90 (91.8) | 82 (86.3) | |||
| Yes | 4 (14.8) | 1(5.0) | 8 (8.2) | 13 (13.7) | |||
p value has been calculated on the known components of the variables.
Abbreviations: mBBC, metachronous bilateral breast cancer; sBBC, synchronous bilateral breast cancer; DCIS, ductal carcinoma in situ; IDC; invasive ductal carcinoma; ILC, invasive lobular carcinoma; ER, estrogen receptor; PR, progesterone receptor (PR); ns, not significant.
a
Synchronous first tumor versus synchronous second tumor
b
Metachronous first tumor versus metachronous second tumor
c
Synchronous first tumor versus metachronous first tumor