Helen Huang

BRCA Mutations and Risk of Prostate Cancer in Ashkenazi Jews

Purpose: The Breast Cancer Linkage Consortium and other family-based ascertainments have suggested that male carriers of BRCA mutations are at increased risk of prostate cancer. Several series looking at the frequency of BRCA mutations in unselected patients with prostate cancer have not confirmed this finding. To clarify this issue, we conducted a large case-control study. Experimental Design: Blood specimens from 251 unselected Ashkenazi men with prostate cancer were screened for the presence of one of the three common Ashkenazi founder mutations in BRCA1 and BRCA2. The incidence of founder mutations was compared with the incidence of founder mutations in 1472 male Ashkenazi volunteers without prostate cancer using logistic regression analysis after adjusting for age. Results: Thirteen (5.2%) cases had a deleterious mutation in BRCA1 or BRCA2 compared with 28 (1.9%) controls. After adjusting for age, the presence of a BRCA1 or BRCA2 mutation was associated with the development of prostate cancer (odds ratio, 3.41; 95% confidence interval, 1.64–7.06; P = 0.001). When results were stratified by gene, BRCA2 mutation carriers demonstrated an increased risk of prostate cancer (odds ratio, 4.78; 95% confidence interval, 1.87–12.25; P = 0.001), whereas the risk in BRCA1 mutation carriers was not significantly increased. Conclusions: BRCA2 mutations are more likely to be found in unselected individuals with prostate cancer than age-matched controls. These results support the hypothesis that deleterious mutations in BRCA2 are associated with an increased risk of prostate cancer.

Frequency of CHEK2*1100delC in New York breast cancer cases and controls

BackgroundThe 1100delC CHEK2 allele has been associated with a 1.4–4.7 fold increased risk for breast cancer in women carrying this mutation. While the frequency of 1100delC was 1.1–1.4% in healthy Finnish controls, the frequency of this allele in a North American control population and in North American breast cancer kindreds remains unclear.MethodsWe genotyped 1665 healthy New York volunteers and 300 cases of breast cancer for the CHEK2*1100delC.ResultsThe overall frequency of the 1100delC was 3/300 (1.0%) among all cases with either a family history of breast cancer (n = 192) or a personal history of breast cancer (n = 108, of which 46 were bilateral, 46 unilateral, and 16 were male breast cancer cases), compared to a frequency of 5/1665 (0.3%) in healthy controls (p = 0.1). There was no difference in allele frequency among Ashkenazi and non-Ashkenazi controls.ConclusionThe relatively low breast cancer penetrance of this allele, along with the low population frequency, will limit the clinical applicability of germline testing for CHEK2*1100delC in North American kindreds.

Estrogen Receptor Genotypes and Haplotypes Associated with Breast Cancer Risk

Nearly one in eight US women will develop breast cancer in their lifetime. Most breast cancer is not associated with a hereditary syndrome, occurs in postmenopausal women, and is estrogen and progesterone receptor-positive. Estrogen exposure is an epidemiologic risk factor for breast cancer and estrogen is a potent mammary mitogen. We studied single nucleotide polymorphisms (SNPs) in estrogen receptors in 615 healthy subjects and 1011 individuals with histologically confirmed breast cancer, all from New York City. We analyzed 13 SNPs in the progesterone receptor gene (PGR), 17 SNPs in estrogen receptor 1 gene (ESR1), and 8 SNPs in the estrogen receptor 2 gene (ESR2). We observed three common haplotypes in ESR1 that were associated with a decreased risk for breast cancer [odds ratio (OR), ∼ O.4; 95% confidence interval (CI), 0.2–0.8; P < 0.01]. Another haplotype was associated with an increased risk of breast cancer (OR, 2.1; 95% CI, 1.2–3.8; P < 0.05). A unique risk haplotype was present in ∼7% of older Ashkenazi Jewish study subjects (OR, 1.7; 95% CI, 1.2–2.4; P < 0.003). We narrowed the ESR1 risk haplotypes to the promoter region and first exon. We define several other haplotypes in Ashkenazi Jews in both ESR1 and ESR2 that may elevate susceptibility to breast cancer. In contrast, we found no association between any PGR variant or haplotype and breast cancer. Genetic epidemiology study replication and functional assays of the haplotypes should permit a better understanding of the role of steroid receptor genetic variants and breast cancer risk.

Combined Genetic Assessment of Transforming Growth Factor-β Signaling Pathway Variants May Predict Breast Cancer Risk

There is growing evidence that common variants of the transforming growth factor-beta (TGF-beta) signaling pathway may modify breast cancer risk. In vitro studies have shown that some variants increase TGF-beta signaling, whereas others have an opposite effect. We tested the hypothesis that a combined genetic assessment of two well-characterized variants may predict breast cancer risk. Consecutive patients (n = 660) with breast cancer from the Memorial Sloan-Kettering Cancer Center (New York, NY) and healthy females (n = 880) from New York City were genotyped for the hypomorphic TGFBR1*6A allele and for the TGFB1 T29C variant that results in increased TGF-beta circulating levels. Cases and controls were of similar ethnicity and geographic location. Thirty percent of cases were identified as high or low TGF-beta signalers based on TGFB1 and TGFBR1 genotypes. There was a significantly higher proportion of high signalers (TGFBR1/TGFBR1 and TGFB1*CC) among controls (21.6%) than cases (15.7%; P = 0.003). The odds ratio [OR; 95% confidence interval (95% CI)] for individuals with the lowest expected TGF-beta signaling level (TGFB1*TT or TGFB1*TC and TGFBR1*6A) was 1.69 (1.08-2.66) when compared with individuals with the highest expected TGF-signaling levels. Breast cancer risk incurred by low signalers was most pronounced among women after age 50 years (OR, 2.05; 95% CI, 1.01-4.16). TGFBR1*6A was associated with a significantly increased risk for breast cancer (OR, 1.46; 95% CI, 1.04-2.06), but the TGFB1*CC genotype was not associated with any appreciable risk (OR, 0.89; 95% CI, 0.63-1.21). TGFBR1*6A effect was most pronounced among women diagnosed after age 50 years (OR, 2.20; 95% CI, 1.25-3.87). This is the first study assessing the TGF-beta signaling pathway through two common and functionally relevant TGFBR1 and TGFB1 variants. This approach may predict breast cancer risk in a large subset of the population.

Colorectal cancer risk in individuals with biallelic or monoallelic mutations of MYH.

Paolo Peterlongo, Nandita Mitra, Shaokun Chuai, Tomas Kirchhoff, Crystal Palmer, Helen Huang, Khedoudja Nafa, Kenneth Offit and Nathan A. Ellis* Cell Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY, USA Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY, USA Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY, USA

A636P is associated with early-onset colon cancer in Ashkenazi Jews

BACKGROUND Hereditary predisposition to colorectal cancer most often manifests itself as familial adenomatous polyposis from mutations of APC, or hereditary nonpolyposis colorectal cancer, resulting from mutations of MSH2, MLH1, MSH6, or other genes. Previously, we described a rare founder mutation MSH2*1906C > G in Ashkenazi Jews that was found in 8 of 1,345 individuals (0.6%) of Ashkenazi descent with colorectal cancer. This study seeks to characterize the proportion of individuals of Ashkenazi heritage with very early-onset colon cancer (diagnosed at age 40 or younger) that could be attributed to MSH2*1906C>G. STUDY DESIGN We analyzed the carrier frequency of MSH2*1906C>G in paraffin samples from 31 Jewish patients age 40 or less, diagnosed with colorectal cancer at Memorial Sloan-Kettering and lymphocyte-derived DNA from 10 patients. We did not select for family history. Genotyping for MSH2*1906C>G was performed by polymerase chain reaction and restriction enzyme digestion methods. RESULTS We detected the MSH2*1906G>C mutation in 3 of the 41 samples (7.14%) of patients who had colorectal cancer diagnosed at age 40 or younger. This incidence is significantly greater than the 8 in 1,345 (0.6%) we observed for cases of colorectal cancer in Ashkenazi Jews not selected for age (p = 0.004). CONCLUSION Although very rare in the population, MSH2*1906G>C is found at an increased frequency in young Jewish patients with colorectal cancer. These results suggest that testing for the MSH2*1906G>C mutation should be included in the evaluation of Ashkenazi Jewish individuals diagnosed with early-onset colon cancer.

The TP53 mutational spectrum and frequency of CHEK2*1100delC in Li-Fraumeni-like kindreds

Li–Fraumeni syndrome (LFS) is a dominantly inherited cancer predisposition syndrome characterized by a wide spectrum of neoplasms occurring at young age. Germline mutations in the TP53 tumor suppressor gene have been identified in approximately 71 of LFS patients and 22 of Li–Fraumeni-like (LFL) patients. Mutations within the cell cycle checkpoint gene CHEK2 have also been reported in some patients with LFS, LFL, and phenotypically suggestive of LFS (PS-LFS) not carrying a TP53 mutation. In this study, we show that 7 of the 23 patients with LFS/LFL tested positive for deleterious mutations in p53. Fifteen of the remaining sixteen were not found to carry the CHEK2* 1100delCmutation. These results indicate that CHEK2*1100delC is not a common cause of LFS, LFL, or PS-LFS in North American kindreds not carrying a TP53 mutation. Of note, two patients were found to carry p53*R72P, which is of unknown clinical significance. Lack of segregation of this allele in one of these kindreds provides strong evidence that the R72P allele is not disease-causing. While mutations in p53 account for a proportion of patients with LFS/LFL, future studies are needed to determine if other genes are responsible for LFS/LFL families not carrying germline p53 mutations.

BRCA1 and BRCA2 Germline Mutations in Lymphoma Patients

Mutations in the BRCA1 and BRCA2 tumor suppressor genes are associated with an increased risk for breast and ovarian cancers as well as other types of malignancies. The observation of a germline BRCA1 mutation in an index case with a lymphoid neoplasm in the setting of a family history of breast cancer prompted us to explore the role of BRCA germline mutations as lymphoma susceptibility alleles. A panel of 286 DNA samples from Jewish lymphoma patients was analyzed for the three most frequent BRCA1 and BRCA2 germline mutations in those of Ashkenazi Jewish heritage, and compared to a cohort of 5010 DNA samples from healthy controls. Of the 286 cases, 2 patients carried a germline BRCA mutation; both were diagnosed at an early age with an intermediate grade non-Hodgkins lymphoma. This data indicate that germline BRCA mutations are not associated with an increased risk for lymphoid malignancies.

Erratum: Combined genetic assessment of transforming growth factor-β signaling pathway variants may predict breast cancer risk (Cancer Research (April 15, 2005) 65 (3454-3461))

Loss of RUNX3 expression is suggested to be causally related to gastric cancer as 45% to 60% of gastric cancers do not express RUNX3 mainly due to hypermethylation of the RUNX3 promoter. Here, we examined for other defects in the properties of RUNX3 in gastric cancers that express RUNX3. Ninety-seven gastric cancer tumor specimens and 21 gastric cancer cell lines were examined by immunohistochemistry using novel anti-RUNX3 monoclonal antibodies. In normal gastric mucosa, RUNX3 was expressed most strongly in the nuclei of chief cells as well as in surface epithelial cells. In chief cells, a significant portion of the protein was also found in the cytoplasm. RUNX3 was not detectable in 43 of 97 (44%) cases of gastric cancers tested and a further 38% showed exclusive cytoplasmic localization, whereas only 18% showed nuclear localization. Evidence is presented suggesting that transforming growth factor-beta is an inducer of nuclear translocation of RUNX3, and RUNX3 in the cytoplasm of cancer cells is inactive as a tumor suppressor. RUNX3 was found to be inactive in 82% of gastric cancers through either gene silencing or protein mislocalization to the cytoplasm. In addition to the deregulation of mechanisms controlling gene expression, there would also seem to be at least one other mechanism controlling nuclear translocation of RUNX3 that is impaired frequently in gastric cancer.

Incidence of ovarian cancer in BRCA-negative hereditary breast cancer families

9534 Background: Mutations in BRCA1 and BRCA2 account for the majority of hereditary breast/ovarian cancer (HBOC) and half of hereditary breast cancer (HBC). Sequence analysis, however, is known to be incompletely sensitive for detecting BRCA mutations associated with HBOC/HBC. Because of this, many centers recommend consideration of ovarian cancer risk-reduction strategies in BRCA-negative individuals with a strong family history of breast cancer. Limited data is available regarding the actual risk of ovarian cancer in these individuals. METHODS Pedigrees from all women who underwent BRCA mutation testing at the Clinical Genetics Service at MSKCC from 8/1/96 through 7/31/02 and consented to prospective follow-up were reviewed. 285 individuals who 1) had no deleterious BRCA mutation on either founder mutation testing or full sequencing; and 2) whose family history included ≥ 3 breast cancers in a single lineage with one being diagnosed at ≤50 were identified and sent a structured questionnaire asking about occurrence of new cancer. Number of cancers expected was calculated from the SEER database for 1975-2000 and the Connecticut Tumor Registry Study of Multiple Primary Cancers. Observed versus expected cancers were compared using the Exact Poisson Test. RESULTS 171 (60%) individuals returned a questionnaire. At baseline, 77% had a personal history of breast cancer and a mean of 4.2 breast cancers in the kindred. 22 kindreds also had ≥1 individual with ovarian cancer. During a mean 3.6 years follow-up, a single fallopian tube cancer was reported in an individual with a BRCA1 variant of uncertain significance. When the 11 patients with such variants were excluded, 8 breast, 4 non-melanoma skin, and one each of lymphoma, CML, uterine sarcoma and thyroid cancer were reported during 567 women years of follow-up. Breast cancer was seen significantly more than expected (8 vs 3.9 cases; p = 0.045). No ovarian cancers were observed vs 0.25 expected (p=0.78). CONCLUSIONS Individuals from HBC kindreds without a demonstrable BRCA mutation did not have an increased risk of ovarian cancer. If confirmed, these findings may have important implications for cancer screening in such kindreds. No significant financial relationships to disclose.