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Table 3 BRCA1/2 mutation frequencies in patients with TNBC and non-TNBC, by age-at-diagnosis, family phenotype and ethnicity

From: High prevalence and predominance of BRCA1 germline mutations in Pakistani triple-negative breast cancer patients

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  
  1. P values marked in bold are statistically significant
  2. BC breast cancer, NS non-significant, OC ovarian cancer, TNBC triple-negative breast cancer
  3. aFisher’s exact test; BRCA1 carriers vs. non-carriers. bOnly female index cases affected with BC were included. cOther: minor ethnic groups including Urdu speaking, Saraiki, Kashmiri, Balochi, Indian migratory, Sindhi, Gujrati, Persian speaking, mixed/multiracial