TGF-β1 genotype and phenotype in breast cancer and their associations with IGFs and patient survival

Transforming growth factor-β (TGF-β)-mediated signals play complicated roles in the development and progression of breast tumour. The purposes of this study were to analyse the genotype of TGF-β1 at T29C and TGF-β1 phenotype in breast tumours, and to evaluate their associations with IGFs and clinical characteristics of breast cancer. Fresh tumour samples were collected from 348 breast cancer patients. TGF-β1 genotype and phenotype were analysed with TaqMan® and ELISA, respectively. Members of the IGF family in tumour tissue were measured with ELISA. Cox proportional hazards regression analysis was performed to assess the association of TGF-β1 and disease outcomes. Patients with the T/T (29%) genotype at T29C had the highest TGF-β1, 707.9 pg mg−1, followed by the T/C (49%), 657.8 pg mg−1, and C/C (22%) genotypes, 640.8 pg mg−1, (P=0.210, T/T vs C/C and C/T). TGF-β1 concentrations were positively correlated with levels of oestrogen receptor, IGF-I, IGF-II and IGFBP-3. Survival analysis showed TGF-β1 associated with disease progression, but the association differed by disease stage. For early-stage disease, patients with the T/T genotype or high TGF-β1 had shorter overall survival compared to those without T/T or with low TGF-β1; the hazard ratios (HR) were 3.54 (95% CI: 1.21–10.40) for genotype and 2.54 (95% CI: 1.10–5.89) for phenotype after adjusting for age, grade, histotype and receptor status. For late-stage disease, however, the association was different. The T/T genotype was associated with lower risk of disease recurrence (HR=0.13, 95% CI: 0.02–1.00), whereas no association was found between TGF-β1 phenotype and survival outcomes. The study suggests a complex role of TGF-β1 in breast cancer progression, which supports the finding of in vitro studies that TGF-β1 has conflicting effects on tumour growth and metastasis

Chromosome 3 Anomalies Investigated by Genome Wide SNP Analysis of Benign, Low Malignant Potential and Low Grade Ovarian Serous Tumours

Ovarian carcinomas exhibit extensive heterogeneity, and their etiology remains unknown. Histological and genetic evidence has led to the proposal that low grade ovarian serous carcinomas (LGOSC) have a different etiology than high grade carcinomas (HGOSC), arising from serous tumours of low malignant potential (LMP). Common regions of chromosome (chr) 3 loss have been observed in all types of serous ovarian tumours, including benign, suggesting that these regions contain genes important in the development of all ovarian serous carcinomas. A high-density genome-wide genotyping bead array technology, which assayed >600,000 markers, was applied to a panel of serous benign and LMP tumours and a small set of LGOSC, to characterize somatic events associated with the most indolent forms of ovarian disease. The genomic patterns inferred were related to TP53, KRAS and BRAF mutations. An increasing frequency of genomic anomalies was observed with pathology of disease: 3/22 (13.6%) benign cases, 40/53 (75.5%) LMP cases and 10/11 (90.9%) LGOSC cases. Low frequencies of chr3 anomalies occurred in all tumour types. Runs of homozygosity were most commonly observed on chr3, with the 3p12-p11 candidate tumour suppressor region the most frequently homozygous region in the genome. An LMP harboured a homozygous deletion on chr6 which created a GOPC-ROS1 fusion gene, previously reported as oncogenic in other cancer types. Somatic TP53, KRAS and BRAF mutations were not observed in benign tumours. KRAS-mutation positive LMP cases displayed significantly more chromosomal aberrations than BRAF-mutation positive or KRAS and BRAF mutation negative cases. Gain of 12p, which harbours the KRAS gene, was particularly evident. A pathology review reclassified all TP53-mutation positive LGOSC cases, some of which acquired a HGOSC status. Taken together, our results support the view that LGOSC could arise from serous benign and LMP tumours, but does not exclude the possibility that HGOSC may derive from LMP tumours

BRCA1 Promoter Methylation and Clinical Outcomes in Ovarian Cancer: An Individual Patient Data Meta-Analysis

Background: BRCA1 methylation has been associated with homologous recombination deficiency, a biomarker of platinum sensitivity. Studies evaluating BRCA1-methylated tubal/ovarian cancer (OC) do not consistently support improved survival following platinum chemotherapy. We examine the characteristics of BRCA1-methylated OC in a meta-analysis of individual participant data. Methods: 2636 participants' data across 15 studies were analyzed. BRCA1-methylated tumors were defined according to their original study. Associations between BRCA1 methylation and clinico-pathological characteristics were evaluated. The effects of methylation on overall survival (OS) and progression-free survival (PFS) were examined using mixed-effects models. All statistical tests were two-sided. Results: 430 (16.3%) tumors were BRCA1-methylated. BRCA1 methylation was associated with younger age and advanced-stage high-grade serous OC. There were no survival differences between BRCA1-methylated and non-BRCA1-methylated OC (median PFS = 20.0 vs 18.5 months, HR = 1.01, 95% CI = 0.87-1.16, P=0.98; median OS = 46.6 vs 48.0 months, HR = 1.02, 95% CI = 0.87-1.18, P=0.96). Where BRCA1/2 mutations were evaluated (n = 1248), BRCA1 methylation displayed no survival advantage over BRCA1/2 intact (BRCA1/2 wild type non-BRCA1-methylated) OC. Studies used different methods to define BRCA1 methylation. Where BRCA1 methylation was determined using methylation-specific PCR and gel electrophoresis (n = 834), it was associated with improved survival (PFS: HR = 0.80, 95% CI = 0.66-0.97, P=0.02; OS: HR = 0.80, 95% CI = 0.63-1.00, P=0.05) on mixed-effects modelling. Conclusion: BRCA1-methylated OC displays similar clinico-pathological features to BRCA1-mutated OC, but is not associated with survival. Heterogeneity within BRCA1 methylation assays influences associations. Refining these assays may better identify cases with silenced BRCA1 function and improved patient outcome