Analyses of germline variants associated with ovarian cancer survival identify functional candidates at the 1q22 and 19p12 outcome loci.

We previously identified associations with ovarian cancer outcome at five genetic loci. To identify putatively causal genetic variants and target genes, we prioritized two ovarian outcome loci (1q22 and 19p12) for further study. Bioinformatic and functional genetic analyses indicated that MEF2D and ZNF100 are targets of candidate outcome variants at 1q22 and 19p12, respectively. At 19p12, the chromatin interaction of a putative regulatory element with the ZNF100 promoter region correlated with candidate outcome variants. At 1q22, putative regulatory elements enhanced MEF2D promoter activity and haplotypes containing candidate outcome variants modulated these effects. In a public dataset, MEF2D and ZNF100 expression were both associated with ovarian cancer progression-free or overall survival time. In an extended set of 6,162 epithelial ovarian cancer patients, we found that functional candidates at the 1q22 and 19p12 loci, as well as other regional variants, were nominally associated with patient outcome; however, no associations reached our threshold for statistical significance (p<1×10-5). Larger patient numbers will be needed to convincingly identify any true associations at these loci.

Lymphadenectomy in Early-Stage Intermediate-/High-Risk Endometrioid Endometrial Cancer: Clinical Characteristics and Outcomes in an Australian Cohort.

OBJECTIVE: The role of lymphadenectomy (LND) in early-stage endometrial cancer (EC) remains controversial. Previous studies have included low-risk patients and nonendometrioid histologies for which LND may not be beneficial, whereas long-term morbidity after LND is unclear. In a large Australian cohort of women with clinical early-stage intermediate-/high-risk endometrioid EC, we analyzed the association of LND with clinicopathological characteristics, adjuvant treatment, survival, patterns of disease recurrence, and morbidity. MATERIALS AND METHODS: From a larger prospective study (Australian National Endometrial Cancer Study), we analyzed data from 328 women with stage IA grade 3 (n = 63), stage IB grade 1 to 3 (n = 160), stage II grade 1 to 3 (n = 71), and stage IIIC1/2 grade 1 to 3 (n = 31/3) endometrioid EC. Overall survival (OS) was estimated using Kaplan-Meier methods. The association of LND with OS was assessed using Cox regression analysis adjusted for age, stage, grade, and adjuvant treatment. The association with risk of recurrent disease was analyzed using logistic regression adjusted for age, stage, and grade. Morbidity data were analyzed using χ2 tests. RESULTS: Median follow-up was 45.8 months. Overall survival at 3 years was 93%. Lymphadenectomy was performed in 217 women (66%), 16% of this group having positive nodes. Median node count was 12. There were no significant differences in OS between LND and no LND groups, or by number of nodes removed. After excluding stage IB grade 1/2 tumors, there was no association between LND and OS among a "high-risk" group of 190 women with a positive node rate of 24%. However, a similar cohort (n = 71) of serous EC in the Australian National Endometrial Cancer Study had improved survival after LND. Women who underwent LND had significantly higher rates of critical events (5% vs 0%, P = 0.02) and lymphoedema (23% vs 4%, P < 0.0001). CONCLUSIONS: In this cohort with early-stage intermediate-/high-risk endometrioid EC, LND did not improve survival but was associated with significantly increased morbidity.

Genetic modifiers of menopausal hormone replacement therapy and breast cancer risk: a genome-wide interaction study.

Women using menopausal hormone therapy (MHT) are at increased risk of developing breast cancer (BC). To detect genetic modifiers of the association between current use of MHT and BC risk, we conducted a meta-analysis of four genome-wide case-only studies followed by replication in 11 case-control studies. We used a case-only design to assess interactions between single-nucleotide polymorphisms (SNPs) and current MHT use on risk of overall and lobular BC. The discovery stage included 2920 cases (541 lobular) from four genome-wide association studies. The top 1391 SNPs showing P values for interaction (Pint) <3.0 × 10(-3) were selected for replication using pooled case-control data from 11 studies of the Breast Cancer Association Consortium, including 7689 cases (676 lobular) and 9266 controls. Fixed-effects meta-analysis was used to derive combined Pint. No SNP reached genome-wide significance in either the discovery or combined stage. We observed effect modification of current MHT use on overall BC risk by two SNPs on chr13 near POMP (combined Pint≤8.9 × 10(-6)), two SNPs in SLC25A21 (combined Pint≤4.8 × 10(-5)), and three SNPs in PLCG2 (combined Pint≤4.5 × 10(-5)). The association between lobular BC risk was potentially modified by one SNP in TMEFF2 (combined Pint≤2.7 × 10(-5)), one SNP in CD80 (combined Pint≤8.2 × 10(-6)), three SNPs on chr17 near TMEM132E (combined Pint≤2.2×10(-6)), and two SNPs on chr18 near SLC25A52 (combined Pint≤4.6 × 10(-5)). In conclusion, polymorphisms in genes related to solute transportation in mitochondria, transmembrane signaling, and immune cell activation are potentially modifying BC risk associated with current use of MHT. These findings warrant replication in independent studies.

Hyperplastic polyposis syndrome is associated with cigarette smoking, which may be a modifiable risk factor.

OBJECTIVES: Hyperplastic polyposis syndrome (HPS) confers an increased risk of colorectal cancer and is difficult to manage clinically. Because both polyps and resultant cancers display the CpG island methylator phenotype and mutation of the BRAF oncogene, and because sporadic cancers with these characteristics are associated with cigarette smoking, we hypothesized that cigarette smoking may predispose to the development of HPS. METHODS: This was a case-control study with two independent control series conducted at a tertiary hospital in Brisbane, Queensland, Australia. Cases comprised patients with HPS (n=32) recruited through the database of the Queensland Familial Bowel Registry, who satisfied the World Health Organization international classification for HPS. Cases were compared with colonoscopy controls (n=298) defined as consecutive patients undergoing colonoscopy for clinical indications, who were free from polyps. We also compared cases with a second set of population controls (n=645) selected at random from a population register serving the catchment area for cases. This was an observational study, and all participants completed a questionnaire to obtain a comprehensive smoking history. RESULTS: The prevalence rate of current smoking was 47% in HPS patients, 17% in colonoscopy controls, and 12% in population controls. HPS patients were significantly more likely to be current smokers than were either colonoscopy controls (odds ratio (OR)=8.3, 95% confidence interval (CI): 3.0-22.9) or population controls (OR=12.7, 95% CI: 4.9-33.1). CONCLUSIONS: Cigarette smoking is strongly associated with HPS, thus suggesting that smoking exposure may increase the expression of this condition. Further studies should examine the possible benefits of quitting smoking in HPS patients.

Association between invasive ovarian cancer susceptibility and 11 best candidate SNPs from breast cancer genome-wide association study.

Because both ovarian and breast cancer are hormone-related and are known to have some predisposition genes in common, we evaluated 11 of the most significant hits (six with confirmed associations with breast cancer) from the breast cancer genome-wide association study for association with invasive ovarian cancer. Eleven SNPs were initially genotyped in 2927 invasive ovarian cancer cases and 4143 controls from six ovarian cancer case-control studies. Genotype frequencies in cases and controls were compared using a likelihood ratio test in a logistic regression model stratified by study. Initially, three SNPs (rs2107425 in MRPL23, rs7313833 in PTHLH, rs3803662 in TNRC9) were weakly associated with ovarian cancer risk and one SNP (rs4954956 in NXPH2) was associated with serous ovarian cancer in non-Hispanic white subjects (P-trend < 0.1). These four SNPs were then genotyped in an additional 4060 cases and 6308 controls from eight independent studies. Only rs4954956 was significantly associated with ovarian cancer risk both in the replication study and in combined analyses. This association was stronger for the serous histological subtype [per minor allele odds ratio (OR) 1.07 95% CI 1.01-1.13, P-trend = 0.02 for all types of ovarian cancer and OR 1.14 95% CI 1.07-1.22, P-trend = 0.00017 for serous ovarian cancer]. In conclusion, we found that rs4954956 was associated with increased ovarian cancer risk, particularly for serous ovarian cancer. However, none of the six confirmed breast cancer susceptibility variants we tested was associated with ovarian cancer risk. Further work will be needed to identify the causal variant associated with rs4954956 or elucidate its function.

Mathematical models of ovarian cancer incidence.

BACKGROUND: Pike has proposed "protected time" as one summary method for modeling reproductive risk factors in relation to ovarian cancer incidence. We evaluate this and other approaches to summarizing risk for ovarian cancer. METHODS: We identified 472 incident cases of ovarian cancer during 2,298,068 person-years of follow-up of 24- to 55-year-old premenopausal women at cohort inception. Reproductive exposures, use of oral contraceptives, and history of tubal ligation were evaluated. RESULTS: Age at menopause is directly related to cumulative risk of ovarian cancer up to age 70 years (age 55 vs. age 45, risk increase = 62%; 95% confidence interval = 36 to 96%) and age at menarche is inversely related to risk (age 15 vs. 11, risk reduction = 31%; 27-34%). Use of oral contraceptives for 5 years before age 30 decreases risk of ovarian cancer to age 70 by 37% (32 to 41%). Tubal ligation reduces risk up to age 70 by 21% (-2 to 38%). Parity reduces risk, independent of age at first birth and age at last birth. A model summarizing years of ovulation offers a fit comparable to a more complex modeling of reproductive variables. The model fit is good, with a concordance statistic of 0.60 (0.57 to 0.62) indicating reasonable ability to differentiate those who will develop ovarian cancer from those who will remain disease free. CONCLUSION: This model may be applied in the identification of women at high risk for ovarian cancer, for example, in selecting candidates for prevention trials.