Arif B. Ekici

Association Between a Germline OCA2 Polymorphism at Chromosome 15q13.1 and Estrogen Receptor–Negative Breast Cancer Survival

BACKGROUNDnTraditional prognostic factors for survival and treatment response of patients with breast cancer do not fully account for observed survival variation. We used available genotype data from a previously conducted two-stage, breast cancer susceptibility genome-wide association study (ie, Studies of Epidemiology and Risk factors in Cancer Heredity [SEARCH]) to investigate associations between variation in germline DNA and overall survival.nnnMETHODSnWe evaluated possible associations between overall survival after a breast cancer diagnosis and 10 621 germline single-nucleotide polymorphisms (SNPs) from up to 3761 patients with invasive breast cancer (including 647 deaths and 26 978 person-years at risk) that were genotyped previously in the SEARCH study with high-density oligonucleotide microarrays (ie, hypothesis-generating set). Associations with all-cause mortality were assessed for each SNP by use of Cox regression analysis, generating a per rare allele hazard ratio (HR). To validate putative associations, we used patient genotype information that had been obtained with 5 nuclease assay or mass spectrometry and overall survival information for up to 14 096 patients with invasive breast cancer (including 2303 deaths and 70 019 person-years at risk) from 15 international case-control studies (ie, validation set). Fixed-effects meta-analysis was used to generate an overall effect estimate in the validation dataset and in combined SEARCH and validation datasets. All statistical tests were two-sided.nnnRESULTSnIn the hypothesis-generating dataset, SNP rs4778137 (C>G) of the OCA2 gene at 15q13.1 was statistically significantly associated with overall survival among patients with estrogen receptor-negative tumors, with the rare G allele being associated with increased overall survival (HR of death per rare allele carried = 0.56, 95% confidence interval [CI] = 0.41 to 0.75, P = 9.2 x 10(-5)). This association was also observed in the validation dataset (HR of death per rare allele carried = 0.88, 95% CI = 0.78 to 0.99, P = .03) and in the combined dataset (HR of death per rare allele carried = 0.82, 95% CI = 0.73 to 0.92, P = 5 x 10(-4)).nnnCONCLUSIONnThe rare G allele of the OCA2 polymorphism, rs4778137, may be associated with improved overall survival among patients with estrogen receptor-negative breast cancer.

The 5-HTTLPR polymorphism modulates the influence on environmental stressors on peripartum depression symptoms

BACKGROUNDnMaternal depression during the peripartum period has an incidence of about 13%. Individuals with specific genetic predispositions are more vulnerable to stressful life events suggesting that exploration of gene-environmental pathways might facilitate the identification of risk factors for peripartum depression. The aim of this study was to evaluate the influence of stressful life events in combination with the serotonin transporter gene 5-HTTLPR polymorphism on peripartum depressive symptoms.nnnMETHODSnIn a non-psychiatric cohort of 419 Caucasians, the severity of depression was assessed prospectively during pregnancy (3rd trimester) and the postpartum period (2-3 days and 6-8 months) using the Edinburgh Postnatal Depression Scale. Satisfaction with the partner and exposure to negative life events were evaluated using self-report questionnaires and the genotype of the 5-HTTLPR was assessed. Repeated measures generalized linear models were used to investigate the gene-environment interaction on depressive symptoms across late pregnancy and the postpartum period.nnnRESULTSnThe 5-HTTLPR S-allele carrier status predicted late postpartum depressive symptom severity only in the presence of negative life events. This interaction was not observed for depressive symptoms during the 3rd trimester or the early postpartum. In addition, S-allele carrier status increased the negative effects of dissatisfaction with the current partner on depressive symptoms in the late postpartum period.nnnCONCLUSIONSnIn this non-psychiatric cohort, the 5-HTTLPR interacts with both lifetime and current stressors to influence depressive symptoms in the late post partum period. These findings could have clinical implications by allowing identification of women at higher risk for developing postpartum depressive symptoms.

The UGT1A6_19_GG genotype is a breast cancer risk factor

Validation of an association between the UGT1A6_19_T>G (rs6759892) polymorphism and overall breast cancer risk. A pilot study included two population-based case-control studies from Germany (MARIE-GENICA). An independent validation study comprised four independent breast cancer case-control studies from Finland (KBCP, OBCS), Germany (BBCC), and Sweden (SASBAC). The pooled analysis included 7418 cases and 8720 controls from all six studies. Participants were of European descent. Genotyping was done by MALDI-TOF MS and statistical analysis was performed by logistic regression adjusted for age and study. The increased overall breast cancer risk for women with the UGT1A6_19_GG genotype which was observed in the pilot study was confirmed in the set of four independent study collections (OR 1.13, 95% CI 1.05–1.22; p = 0.001). The pooled study showed a similar effect (OR 1.09, 95% CI 1.04–1.14; p = 0.001). The risk effect on the basis of allele frequencies was highly significant, the pooled analysis showed an OR of 1.11 (95% CI 1.06–1.16; p = 5.8 × 10−6). We confirmed the association of UGT1A6_19_GG with increased overall breast cancer risk and conclude that our result from a well powered multi-stage study adds a novel candidate to the panel of validated breast cancer susceptibility loci.