METHODS: Genotyping was performed as part of the OncoArray project. Samples with >60% Asian ancestry were included in the analysis. Genotyping was performed on 533,631 SNPs in 3238 Asian subjects diagnosed with invasive or borderline EOC and 4083 unaffected controls. After imputation, genotypes were available for 11,595,112 SNPs to identify associations.
RESULTS: At chromosome 6p25.2, SNP rs7748275 was associated with risk of serous EOC (odds ratio [OR] = 1.34, P = 8.7 × 10-9) and high-grade serous EOC (HGSOC) (OR = 1.34, P = 4.3 × 10-9). SNP rs6902488 at 6p25.2 (r2 = 0.97 with rs7748275) lies in an active enhancer and is predicted to impact binding of STAT3, P300 and ELF1. We identified additional risk loci with low Bayesian false discovery probability (BFDP) scores, indicating they are likely to be true risk associations (BFDP <10%). At chromosome 20q11.22, rs74272064 was associated with HGSOC risk (OR = 1.27, P = 9.0 × 10-8). Overall EOC risk was associated with rs10260419 at chromosome 7p21.3 (OR = 1.33, P = 1.2 × 10-7) and rs74917072 at chromosome 2q37.3 (OR = 1.25, P = 4.7 × 10-7). At 2q37.3, expression quantitative trait locus analysis in 404 HGSOC tissues identified ESPNL as a putative candidate susceptibility gene (P = 1.2 × 10-7).
CONCLUSION: While some risk loci were shared between East Asian and European populations, others were population-specific, indicating that the landscape of EOC risk in Asian women has both shared and unique features compared to women of European ancestry.
METHODS: From October 2008 to February 2015, we established a hospital-based cohort of ovarian cancer patients and the germline status of all 218 women with invasive epithelial ovarian cancer was tested using targeted amplification and sequencing of the intron-exon junctions and exonic sequences of BRCA1, BRCA2, PALB2 and TP53.
RESULTS: BRCA1 and BRCA2 mutations were found in 8% (17 cases) and 3% (7 cases) of the ovarian cancer patients, respectively. Mutation carriers were diagnosed at a similar age to non-carriers, but were more likely to be Indian, have serous ovarian cancer, and have more relatives with breast or ovarian cancer. Nonetheless, 42% (10/24) of mutation carriers did not have any family history of breast or ovarian cancer and offering genetic counselling and genetic testing only to women with family history would mean that 35% (6/17) of BRCA1 mutation carriers and 57% (4/7) of BRCA2 mutation carriers would not be offered genetic testing.
CONCLUSIONS: Our data suggest that, similar to Caucasians, a significant proportion of Asian ovarian cancer was attributed to germline mutations in BRCA1 and to a lesser extent in BRCA2.