rs13387042

This pooled analysis of 872 women from two studies (Susan G. Komen Tissue Bank and BREAST Stamp Project) investigated the association between 62 established breast cancer susceptibility SNPs and terminal duct lobular unit (TDLU) involution, a breast cancer risk factor. Six SNPs (9.7%) showed nominal associations with at least one TDLU measure: rs616488 (PEX14), rs11242675 (FOXQ1), and rs6001930 (MKL1) with higher TDLU count (P=0.047, 0.045, 0.031); rs1353747 (PDE4D) and rs6472903 (8q21.11) with higher acini count per TDLU (P=0.007, 0.027); and rs1353747 (PDE4D) and rs204247 (RANBP9) with higher epithelial content (P=0.024, 0.017). Overall, breast cancer susceptibility SNPs showed limited enrichment for associations with TDLU involution.

A hospital-based case-control study in rural and urban India (1,204 cases; 1,212 controls) examined genetic and lifestyle risk factors for breast cancer. Four SNPs in FGFR2 (rs1219648, rs2420946, rs2981575, rs2981582) showed positive associations with breast cancer (ORs 1.32-1.47). Additional SNPs in obesity and metabolic genes (rs374748 in FBN2, rs2922763 in HNF4G, rs2116830 in KCNMA1, rs11121832 in MTHFR, rs16886165 in MAP3K1, rs11594610 in TCF7L2, rs2274459 in MLN) were associated with increased breast cancer risk. Waist-to-hip ratio ≥0.95 showed strong association (OR 3.78; 95% CI 2.92-4.89), and women living first 20 years in rural areas showed protective effect (OR 0.77).

Genome-wide association study of Ashkenazi Jewish women with familial breast cancer but no BRCA1/2 mutations identified 7 novel SNPs and confirmed 6 known variants. A 7-marker risk model including rs17663555, rs566164, rs11075884, FGFR2 haplotype (rs11200014, rs2981579, rs1078806, rs1219648, rs2420946, rs2981582), rs13387042, rs2046210 (ESR1), and rs3112612 (TOX3) achieved moderate discriminatory accuracy (AUC=0.74; 95% CI: 0.69-0.79) for predicting familial breast cancer risk in this population.

This multi-stage genome-wide association study in 11,705 BRCA1 mutation carriers identified three novel cancer risk-modifying loci: rs2290854 at 1q32 associated with breast cancer (HR=1.14), and rs17631303 (HR=1.27) and rs4691139 (HR=1.20) at 17q21.31 and 4q32.3 respectively associated with ovarian cancer. The 4q32.3 locus showed BRCA1-specific associations. These findings enable improved absolute risk estimation for BRCA1 carriers, with estimated breast cancer lifetime risks ranging from 28-50% for the lowest-risk 5% to 81-100% for the highest-risk 5%.

Population-based case-control study of 1,484 breast cancer cases and 1,307 controls examining 13 GWAS-identified SNPs for breast cancer susceptibility. Confirmed associations for 7 SNPs (rs13387042, rs4973768, rs10941679, rs2981582, rs3817198, rs3803662, rs6504950), with women in the highest quintile of a polygenic risk score having 2.2-fold increased breast cancer risk (95% CI: 1.67-2.88) compared to the lowest quintile. No significant interactions were detected between genetic loci and reproductive/menstrual risk factors.

This PhD thesis presents a comprehensive study of microRNA (miRNA) SNPs and their association with breast cancer risk in Australian Caucasian populations. The study identified three key findings: rs2910164 in MIR146A showed significant association (p=0.03 and p=0.00013 in two populations); rs353291 in MIR145 showed significant differences in allele frequencies (p=0.041 and p=0.023); and rs4284505/rs7336610 in the MIR17HG cluster showed significant association with protective effect (OR=0.75, 95% CI: 0.60-0.94, p=0.012).

This case-control study examined whether seven breast cancer susceptibility alleles (in FGFR2, TNRC9, MAP3K1, LSP1, and chromosomal regions 8q24 and 2q35) were associated with epithelial ovarian cancer risk. The pooled analysis of 1,383 ovarian cancer cases and 1,804 controls found no significant associations between these variants and ovarian cancer risk, with OR estimates for FGFR2 rs1219648 of 1.06 (95% CI=0.95-1.18) and rs2981582 of 1.04 (95% CI=0.93-1.15), suggesting that breast cancer risk alleles may be specific to breast cancer.

A nested case-control study of 692 invasive endometrial cancer cases and 1,723 controls within the Nurses' Health Study and Women's Health Study investigated whether seven breast cancer risk alleles were also associated with endometrial cancer risk. In contrast to breast cancer, the authors found an inverse association with rs2981582 (FGFR2) and endometrial cancer risk (OR=0.75, 95% CI: 0.60-0.95), and non-significant inverse associations with rs889312 (MAP3K1, OR=0.85) and rs1219648 (FGFR2, OR=0.86). No associations were observed with the other four SNPs, suggesting important biological differences between endometrial and breast cancer despite their shared hormone-related etiology.