Table 3 BRCA1/2 mutation frequencies in patients with TNBC and non-TNBC, by age-at-diagnosis, family phenotype and ethnicity
Variables | TNBC (N = 192) | Non-TNBC (N = 331) | P a | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
No. of cases | No. of mutations (%) in | Non- | No. of cases | No. of mutations (%) in | Non- | ||||||
BRCA1 | BRCA2 | BRCA1/2 | carriers | BRCA1 | BRCA2 | BRCA1/2 | carriers | ||||
Family phenotype | |||||||||||
 1 early-onset BC (≤ 30 years) | 90 | 13 (14.4) | 0 (0) | 13 (14.4) | 77 | 147 | 8 (5.4) | 6 (4.1) | 14 (9.5) | 133 | 0.03 |
 Familial BC | 76 | 37 (48.7) | 2 (2.6) | 39 (51.3) | 37 | 159 | 19 (12.0) | 11 (6.9) | 30 (18.9) | 129 | < 0.0001 |
 Familial BC and OCb | 26 | 21 (80.8) | 0 (0) | 21 (80.8) | 5 | 25 | 7 (28.0) | 1 (4.0) | 8 (32.0) | 17 | 0.0005 |
Age at diagnosis of familial BC/OC (years) | |||||||||||
  ≤ 30 | 41 | 24 (58.5) | 2 (4.9) | 26 (63.4) | 15 | 25 | 11 (44.0) | 0 (0) | 11 (44.0) | 14 | NS |
 31–40 | 32 | 22 (68.8) | 0 (0) | 22 (68.8) | 10 | 59 | 9 (15.2) | 6 (10.2) | 15 (25.4) | 44 | < 0.0001 |
 41–50 | 20 | 11 (55.0) | 0 (0) | 11 (55.0) | 9 | 71 | 5 (7.0) | 3 (4.2) | 8 (11.3) | 63 | < 0.0001 |
  > 50 | 9 | 1 (11.1) | 0 (0) | 1 (11.1) | 8 | 29 | 1 (3.4) | 3 (10.3) | 4 (13.8) | 25 | NS |
Early-onset BC (regardless of a family history of BC/OC) | |||||||||||
  ≤ 30 years | 131 | 37 (28.2) | 2 (1.5) | 39 (29.8) | 92 | 172 | 19 (11.0) | 6 (3.5) | 25 (14.5) | 147 | 0.0003 |
Ethnicity | |||||||||||
 Punjabi | 151 | 56 (37.1) | 2 (1.3) | 58 (38.4) | 93 | 229 | 28 (12.2) | 9 (3.9) | 37 (16.2) | 192 | < 0.0001 |
 Pathan | 19 | 6 (31.6) | 0 (0) | 6 (31.6) | 13 | 54 | 3 (5.6) | 4 (7.4) | 7 (13.0) | 47 | 0.01 |
 Othersc | 20 | 8 (40.0) | 0 (0) | 8 (40.0) | 12 | 48 | 3 (6.2) | 5 (10.4) | 8 (16.7) | 40 | 0.003 |
 Unknown | 2 | 1 (50.0) | 0 (0) | 1 (50) | 1 | 0 | 0 | 0 | 0 | 0 |  |