Abstract P2-09-13: BRCA mutations in South Texas and the Rio Grande Valley among Hispanics with a personal or family history of breast cancer

South Texas, including regions along the US-Mexico border, is characterized by a predominantly Hispanic population, most of who are of Mexican decent. In the past decade, the discovery of Mexican-American founder mutations in BRCA1/2 has established the importance of large rearrangement testing in this population. Recent studies estimate that 15-25% of Mexican women with early-onset breast cancer carry a BRCA mutation, with the BRCA1 EX9-12 deletion accounting for 10% of all mutations. Here we review the BRCA1/2 pathogenic and unclassified variants in our South Texas Hispanic population who underwent cancer genetic risk assessment and testing between June 2013 and May 2015. All mutation carriers had either a personal history of early-onset breast cancer (before age 50), or early-onset breast cancer in a first-degree relative. A total of 23 unique mutations were identified in 28 kindreds. Three affected individuals harbored mutations that had not previously been reported in the literature at the time of testing (BRCA1 134+3A>T; BRCA2 428C>G; BRCA2 8265A>T). Pathogenic mutations in BRCA1 were the most common finding, accounting for 64.3% of identified variants. The BRCA1 EX9-12 deletion was only found in only family. We also identified a co-segregating pathogenic mutation (1793delA) and variant of uncertain significance (1149G>A) in BRCA1 in two unrelated kindreds, suggesting a possible founder mutation. Although previous studies have identified recurrent BRCA mutations in Hispanic families with breast cancer in the Southwestern United States, this was not seen in our sample of South Texas Hispanics. While only one (3.5%) of our families had the BRCA1 EX9-12 deletion, other large rearrangements, such as BRCA1 EX1-2 deletion, BRCA1 EX21-22 duplication and whole gene deletions demonstrate the continued importance of comprehensive BRCA1/2 analysis in Hispanics. This work was supported by CPRIT Grant PP120089 and NIH 2P30CA054174.

BRCA gene mutations in South Texas Hispanics with a personal or family history of breast cancerMutation (n%)FrequencyKindredsBRCA1 pathogenic (64.3%)2715delEX1-2631793delA*42EX12del41815_824deupAGCCATGTGG31delEX9-1221entire gene deletion213878delTA11IVS16+3G-T112806_2809delAAAC11188insAG114936delG11dup21-2211BRCA2 pathogenic (9.5%)44R2520X228377G>A118591G>A11BRCA1 variant of uncertain significance (16.7%)751149G>A*427819C>T115470A>G11134+3A>T11BRCA2 variant of uncertain significance (9.5%)44314+12A>G11428C>G113575T>G118265A>T11*co-segregating

Citation Format: Mette LA, Poullard NE, Pulido Saldivar AM, Torres IC, Seth SG, Seigler D, Jatoi I, Tomlinson GE. BRCA mutations in South Texas and the Rio Grande Valley among Hispanics with a personal or family history of breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-13.

Study of the effects of dietary fish intake on serum lipids and lipoproteins in two populations with different dietary habits

Increased concentrations of n-3 polyunsaturated fatty acids (PUFA), namely eicosapentaenoic acid (20:5; EPA) and docosahexaenoic acid (22:6; DHA), have been shown to be beneficial in coronary artery disease (CAD). In the present study, the relationships between fish intake and concentrations of serum EPA and DHA and the effects of these fatty acids on serum lipids and lipoproteins were investigated. Two groups of men, one living in a fishing village and the other in a farming village, participated in this study. The daily fish consumption was ten times greater in the fishing village group than in the rural village group and the mortality from IHD in the rural village was four times higher. Serum concentrations of EPA and DHA were significantly higher in the fishing village group (P < 0.001). In this group, the serum concentration of arachidonic acid (20:4; AA), was significantly lower (P < 0.001), and the ratio EPA:AA was twice that of the rural village (P < 0.001). Moreover, in the fishing village group, the serum triacylglycerol and total cholesterol levels were significantly lower than those observed in the rural village (P < 0.01 and P < 0.05 respectively). In the fishing village group the serum LDL-cholesterol concentration was also lower, although the difference was not significant. Our results reinforce the hypothesis that a high intake of n-3 PUFA provides protection against CAD.

Pharmacokinetics, biodistribution and dosimetry of 99mTc-labeled anti-human epidermal growth factor receptor humanized monoclonal antibody R3 in rats

The pharmacokinetics, biodistribution and dosimetry of 99mTc-labeled anti-human epidermal growth factor receptor (anti-hEGF-r) humanized monoclonal antibody (MAb) R3 was investigated following intravenous injection in normal Wistar rats. Serum disappearance curves were best fit by a two-compartment model having a mean distribution half-life (t 1/2alpha) of 0.250 h and a mean elimination (t 1/2beta) of 13.89 h. Among the various organs, a little accumulation of the radiolabeled antibody was found only in kidneys. Biodistribution and dosimetry studies in humans were performed by extrapolation of the animal data to humans. Absorbed dose to normal organs and the remainder of the whole body were estimated using the medical internal radiation dose formula, and dose contributions from radioactivity in transit through the gastrointestinal tract were estimated using a compartment model. Extrapolated values of radiation absorbed dose to normal organs in rads per millicurie administered were whole body, 0.0085; lower large intestine wall, 0.0898; small intestine, 0.0530; upper large intestine wall, 0.0731; and kidneys, 0.0455. The effective dose equivalent predicted was 0.0162 rem/mCi and the effective dose was found to be 0.015 rem/mCi. On the basis of the pharmacokinetics, biodistribution and internal radiation dosimetry information obtained in this study, a diagnostic phase I clinical trial with 99mTc-labeled humanized MAb R3 conjugate in patients should be supported.

A preliminary study of hypoglycemic activity of Lythrum salicaria

A study of the hypoglycemic activity of several extracts of Lythrum salicaria was made in normoglycemic and hyperglycemic rabbits. Circulating insulin variations were studied as well. The results of this study prove a hypoglycemic activity of the plant.