Evaluation of BRCA1 and BRCA2 mutations and risk-prediction models in a typical Asian country (Malaysia) with a relatively low incidence of breast cancer

Table 1 Family characteristics

	Total (n = 187)	Malay (n = 44)	Chinese (n = 118)	Indian (n = 22)	Others (n = 3)
	No. (%)	No. (%)	No. (%)	No. (%)	No. (%)
Age of onset of breast cancer in index case (years)
20 to 29	14 (7)	3 (7)	10 (8)	1 (5)	0 (0)
30 to 39	64 (34)	21 (48)	36 (31)	6 (27)	1 (33)
40 to 49	49 (26)	8 (18)	35 (30)	5 (23)	1 (33)
≥ 50	60 (32)	12 (27)	37 (31)	10 (45)	1 (33)
Personal cancer history of breast, or breast and ovarian cancer
Breast only	182 (97)	43 (98)	117 (99)	19 (86)	3 (100)
Both breast and/or ovarian	5 (3)	1 (2)	1 (1)	3 (14)	0 (0)
Bilateral breast cancer	25 (13)	6 (14)	15 (13)	4 (18)	0 (0)
Family history of breast and ovarian cancer in pedigree
1 case (no family history)	^a73 (39)	24 (54)	40 (34)	8 (36)	1 (33)
2 cases	76 (41)	13 (30)	54 (46)	9 (41)	1 (33)
3 cases	24 (13)	4 (9)	17 (14)	2 (9)	0 (0)
≥ 4 cases	14 (7)	3 (7)	7 (6)	3 (14)	1 (33)

A total of 187 breast cancer patients were analysed for mutations in BRCA1 and BRCA2 by DNA sequencing and multiple ligation dependent probe amplification (MLPA) analysis. Table 1 shows the distribution of patients according to their self-declared ethnicity, personal history of breast and ovarian cancer, and family history of breast and ovarian cancer in first- and second-degree relatives. ^aNotably, the 73 individuals with no family history of breast and ovarian cancer were included in the study because they had either early age of onset of breast cancer (≤ 40 years of age: 45 individuals; 41 to 55 years of age: nine individuals), bilateral breast cancer (16 individuals), both breast and ovarian cancer (one individual) or family history of prostate cancer in the third degree (three individuals).

ISSN: 1465-542X