Table 3.
Clinical factors associated with carrying pathogenic variants in BRCA1/2 and other breast cancer predisposition genes in breast cancer cases (n = 831) in the Shanghai Breast Cancer Genetic Study
| Characteristics | No. of patients | Nonea | BRCA1 carriers | BRCA2 carriers | Other carriers | P | ||
|---|---|---|---|---|---|---|---|---|
| BRCA1 carriers vs none | BRCA2 carriers vs none | Other carriers vs none | ||||||
| Age at diagnosis | 0.98 | 0.39 | 0.18 | |||||
| Mean (SD) | – | 46.3 (5.2) | 46.3 (4.2) | 45.3 (5.2) | 47.9 (5.4) | |||
| Range | – | 28–58 | 39–52 | 33–55 | 34–56 | |||
| < 35 | 17 (2%) | 15 (2%) | 0 (0%) | 1 (3%) | 1 (5%) | |||
| 35–45 | 342 (41%) | 317 (41%) | 5 (38%) | 15 (48%) | 5 (23%) | |||
| > 45 | 472 (56%) | 434 (56%) | 8 (62%) | 15 (48%) | 15 (71%) | |||
| Family history of breast cancer | 0.001 | 0.0002 | 0.05 | |||||
| Yes | 70 (8%) | 52 (7%) | 5 (38%) | 9 (29%) | 4 (19%) | |||
| No | 761 (92%) | 714 (93%) | 8 (62%) | 22 (71%) | 17 (81%) | |||
| Family history of any cancer* | 1.00 | 0.04 | 0.58 | |||||
| Yes | 555 (76%) | 509 (75%) | 8 (80%) | 25 (93%) | 13 (68%) | |||
| No | 175 (24%) | 165 (25%) | 2 (20%) | 2 (7%) | 6 (32%) | |||
| Hormone receptor status* | 0.0004 | 0.50 | 0.16 | |||||
| Positive | 456 (71%) | 428 (72%) | 3 (23%) | 16 (67%) | 9 (56%) | |||
| Negative | 188 (29%) | 163 (28%) | 10 (77%) | 8 (33%) | 7 (43%) | |||
| Triple-negative diseases* | 0.01 | 0.67 | 0.60 | |||||
| Yes | 49 (10%) | 42 (8%) | 3 (50%) | 2 (11%) | 2 (18%) | |||
| No | 456 (90%) | 428 (92%) | 3 (50%) | 16 (89%) | 9 (82%) | |||
*Among patients with available data only
aNo pathogenic variants identified