Table 4.

Odds of TNBC compared to non-TNBC according to family history of breast and/or ovarian cancer, stratified by participant’s age at diagnosis

Family history	Age of diagnosis < 50 y		Age of diagnosis ≥ 50 y
	TNBC	OR (95% CI)*	TNBC	OR (95% CI)*
	n /total (%)		n /total (%)
Breast cancer in first-degree relatives
No	66/361 (18.3)	1.00	50/418 (12.0)	1.00
Yes	21/58 (36.2)	2.61 (1.43–4.77)	11/77 (14.3)	1.38 (0.68–2.83)
	P-interaction = 0.14**
Breast cancer in first- or second-degree relatives
No	47/297 (15.8)	1.00	45/381 (11.8)	1.00
Yes	40/122 (32.8)	2.67 (1.63–4.37)	16/114 (14.0)	1.37 (0.73–2.56)
	P-interaction = 0.07**
Breast or ovarian cancer in first-degree relatives
No	66/357 (18.5)	1.00	46/402 (11.4)	1.00
Yes	21/62 (33.9)	2.31 (1.28–4.18)	15/93 (16.1)	1.61 (0.85–3.06)
	P-interaction = 0.36**

*Adjusted for country of residence (U.S. or Mexico).

**Interaction between age at diagnosis and family history on TNBC subtype.