Table 1.

Pathology of invasive breast cancer in BRCA1 and BRCA2 mutation carriers and ORs for predicting BRCA2 mutation carrier status

BRCA1, n (%)aBRCA2, n (%)aORb (95% CI)ORc (95% CI)
Morphology
 Invasive ductal2,387 (80)1,515 (83)1.00- (—)
 Invasive lobular67 (2.2)153 (8.4)3.3 (2.4–4.4)- (—)
 Medullaryd281 (9.4)40 (2.2)0.25 (0.18–0.35)- (—)
 Other258 (8.6)116 (6.4)0.81 (0.63–1.02)- (—)
ER, PR, HER2, TN
 ER-positive625 (22)1,475 (77)11.4 (9.8–13.2)10.0 (8.2–12.1)
 PR-positive539 (21)1,084 (64)6.8 (5.8–7.9)5.5 (4.5–6.6)
 HER2-positive138 (10)121 (13)1.5 (1.1–2.1)1.3 (0.9–1.9)
 Non-TN (vs. TN)411 (31)700 (84)11.0 (8.8–13.8)9.0 (6.8–11.8)
Grade
 Grade 164 (3)100 (7)1.0 (—)1.0 (—)
 Grade 2481 (20)603 (43)1.01 (0.72–1.44)1.1 (0.67–1.8)
 Grade 31,822 (77)711 (50)0.32 (0.23–0.45)0.71 (0.44–1.17)
  • aNumber of tumors (n) of each morphology type or tumor grade, or number of receptor-positive tumors, and as percentage (%) of all BRCA1- or BRCA2-related tumors.

  • bORs for BRCA2 mutation carrier status, compared with BRCA1 mutation carrier status, associated with tumor morphology, receptor-positive tumors, or grade 2 versus grade 1, and grade 3 versus grade 1 tumors; analyses were adjusted for country and age at diagnosis.

  • cAnalyses adjusted for country, age at diagnosis, and tumor grade; ORs for analysis of grade, adjusted for country, age at diagnosis, and ER status.

  • dIncludes atypical medullary carcinomas.