Schmidt, M.K.

Excess breast cancer risk in first degree relatives of CHEK2* 1100delC positive familial breast cancer cases (Article)

2013-05-01T00:00:00Z

Aim: The CHEK2*1100delC mutation confers a relative risk of two for breast cancer (BC) in the general population. This study aims to explore the excess cancer risk due to the CHEK2*1100delC mutation within a familial non-BRCA1/2 breast cancer setting. Patients and Methods: Cancer incidences were compared between first degree relatives of 107 familial breast cancer patients positive for the CHEK2*1100delC mutation (CHEK2 positive families) and first degree relatives of 314 familial breast cancer patients without the CHEK2*1100delC mutation (CHEK2 negative families). All families were derived from the same pool of familial non-BRCA1/2 breast cancer families (n = 2554). Medical information of 2188 first degree relatives of these families was analysed for cancer risk. CHEK2*1100delC status of relatives was unknown. Results: Increased breast cancer risk (hazard ratio (HR) 2.0 (95% confidence interval (CI): 1.4-2.7), p < 0.001) was observed in sisters of CHEK2*1100delC positive index cases compared to sisters of CHEK2*1100delC negative index cases. HR was 1.6 (95% CI: 1.0-2.4) for mothers of CHEK2 positive versus negative index cases (p = 0.041). For second primary breast cancers HR was increased in CHEK2*1100delC positive index cases (HR 2.1, 95% CI: 1.3-3.3, p = 0.003) and their sisters (HR 2.6, 95% CI: 1.1-6.1, p = 0.025). Conclusion: There is an excess breast cancer risk in first degree relatives of CHEK2*1100delC positive non-BRCA1/2 familial breast cancer patients compared to non-CHEK2*1100delC familial breast cancer relatives. Genotyping for the CHEK2*1100delC mutation in a familial breast cancer setting contributes to optimal clinical surveillance in countries in which this mutation is prevalent. Carriers and female relatives are eligible for stringent breast surveillance programs.

Correction of murine SCID-X1 by lentiviral gene therapy using a codon-optimized IL2RG gene and minimal pretransplant conditioning (Article)

2011-10-01T00:00:00Z

Clinical trials have demonstrated the potential of ex vivo hematopoietic stem cell gene therapy to treat X-linked severe combined immunodeficiency (SCID-X1) using γ-retroviral vectors, leading to immune system functionality in the majority of treated patients without pretransplant conditioning. The success was tempered by insertional oncogenesis in a proportion of the patients. To reduce the genotoxicity risk, a self-inactivating (SIN) lentiviral vector (LV) with improved expression of a codon optimized human interleukin-2 receptor γ gene (IL2RG) cDNA (coγc), regulated by its 1.1 kb promoter region (γcPr), was compared in efficacy to the viral spleen focus forming virus (SF) and the cellular phosphoglycerate kinase (PGK) promoters. Pretransplant conditioning of Il2rg-/-mice resulted in long-term reconstitution of T and B lymphocytes, normalized natural antibody titers, humoral immune responses, ConA/IL-2 stimulated spleen cell proliferation, and polyclonal T-cell receptor gene rearrangements with a clear integration preference of the SF vector for proto-oncogenes, contrary to the PGK and γcPr vectors. We conclude that SIN lentiviral gene therapy using coγc driven by the γcPr or PGK promoter corrects the SCID phenotype, potentially with an improved safety profile, and that low-dose conditioning proved essential for immune competence, allowing for a reduced threshold of cell numbers required.

Associations of breast cancer risk factors with tumor subtypes: A pooled analysis from the breast cancer association consortium studies (Article)

2011-02-02T00:00:00Z

Background Previous studies have suggested that breast cancer risk factors are associated with estrogen receptor (ER) and progesterone receptor (PR) expression status of the tumors. Methods We pooled tumor marker and epidemiological risk factor data from 35568 invasive breast cancer case patients from 34 studies participating in the Breast Cancer Association Consortium. Logistic regression models were used in case-case analyses to estimate associations between epidemiological risk factors and tumor subtypes, and case-control analyses to estimate associations between epidemiological risk factors and the risk of developing specific tumor subtypes in 12 population-based studies. All statistical tests were two-sided. Results In case-case analyses, of the epidemiological risk factors examined, early age at menarche (≤12 years) was less frequent in case patients with PR-than PR+tumors (P =. 001). Nulliparity (P = 3 × 10-6) and increasing age at first birth (P = 2 × 10-9) were less frequent in ER-than in ER+tumors. Obesity (body mass index [BMI] ≥ 30 kg/m2) in younger women (≤50 years) was more frequent in ER-/PR-than in ER+/PR+tumors (P = 1 × 10-7), whereas obesity in older women (>50 years) was less frequent in PR-than in PR+tumors (P = 6 × 10-4). The triple-negative (ER-/PR-/HER2-) or core basal phenotype (CBP; triple-negative and cytokeratins [CK]5/6+and/or epidermal growth factor receptor [EGFR]+) accounted for much of the heterogeneity in parity-related variables and BMI in younger women. Case-control analyses showed that nulliparity, increasing age at first birth, and obesity in younger women showed the expected associations with the risk of ER+or PR+tumors but not triple-negative (nulliparity vs parity, odds ratio [OR] = 0.94, 95% confidence interval [CI] = 0.75 to 1.19, P =. 61; 5-year increase in age at first full-term birth, OR = 0.95, 95% CI = 0.86 to 1.05, P =. 34; obesity in younger women, OR = 1.36, 95% CI = 0.95 to 1.94, P =. 09) or CBP tumors. Conclusion sThis study shows that reproductive factors and BMI are most clearly associated with hormone receptor-positive tumors and suggest that triple-negative or CBP tumors may have distinct etiology.

Missense variants in ATM in 26,101 breast cancer cases and 29,842 controls (Article)

2010-09-01T00:00:00Z

Background: Truncating mutations in ATM have been shown to increase the risk of breast cancer but the effect of missense variants remains contentious. Methods: We have genotyped five polymorphic (minor allele frequency, 0.9-2.6%) missense single nucleotide polymorphisms (SNP) in ATM (S49C, S707P, F858L, P1054R, and L1420F) in 26,101 breast cancer cases and 29,842 controls from 23 studies in the Breast Cancer Association Consortium. Results: Combining the data from all five SNPs, the odds ratio (OR) was 1.05 for being a heterozygote for any of the SNPs and 1.51 for being a rare homozygote for any of the SNPs with an overall trend OR of 1.06 (Ptrend= 0.04). The trend OR among bilateral and familial cases was 1.12 (95% confidence interval, 1.02-1.23; Ptrend= 0.02). Conclusions: In this large combined analysis, these five missense ATM SNPs were associated with a small increased risk of breast cancer, explaining an estimated 0.03% of the excess familial risk of breast cancer. Impact: Testing the combined effects of rare missense variants in known breast cancer genes in large collaborative studies should clarify their overall contribution to breast cancer susceptibility.