Table 4.

Correlation between clinical risk factors of hereditary breast cancer and having pathogenic germline mutations in the 20 breast cancer susceptibility genes

Risk factors		Mutation rate	OR (95% CI)*	P-value
Family history†	Yes	16.2% (37/228)	1.60 (0.90–2.88)	0.113
	No	11.1% (28/252)
Age of onset	≤ 40	12.7% (33/260)	1.26 (0.69–2.31)	0.452
	>  40	13.6% (27/198)
Triple negative breast cancer	Yes	14.2% (18/127)	1.27 (0.67–2.42)	0.469
	No	13.3% (47/353)
Bilateral breast cancer	Yes	29.6% (16/54)	3.27 (1.64–6.51)	0.0008
	No	11.5% (49/426)
Breast and ovarian cancer	Yes	50% (2/4)	5.90 (0.70–49.6)	0.103
	No	13.0% (63/476)
Male breast cancer	Yes	16.7% (1/6)	2.35 (0.25–21.9)	0.454
	No	13.1% (64/474)
No. of risk factors	1	10.4% (32/309)	1.82 (1.25–2.64)	0.002
	2	18.4% (27/147)
	3	19.1% (4/21)
	4	50% (1/2)
	5	100% (1/1)
All subjects		13.5% (65/480)

* The adjusted odds ratios (OR) of having a pathogenic mutation in the 20 genes were calculated using multivariable logistic regression with the six dichotomous risk factors; the odds ratio for the no. of risk factors was obtained using univariate logistic regression. The statistically significant P-values (< 0.05) are shown in bold. † The presence of family history was defined as two or more persons on the same lineage of the family having breast or ovarian cancer. If the study participant had breast cancer, only one family member with breast/ovarian cancer was needed to qualify as having family history