A current review of U.S. beef flavor I: Measuring beef flavor

Historically, consumer acceptance of beef was determined by tenderness. Developments in genetics and management over the last couple of decades have improved tenderness to the point that it is secondary to other factors in beef's taste. Flavor, however, is an extraordinarily complex taste attribute dependent on biological sensors in the mouth, sinus cavity, and jaws. The culinary industry has recently focused on innovative ways to give consumers new products satisfying their curiosity about different foods, especially proteins. Competition from plant-based, cell-based, and even other animal-based proteins provides diversity in consumers' ability to select a protein that satisfies their desire to include unique products in their diet. Consequently, the beef industry has focused on flavor for the last 10 to 15 years to determine whether it can provide the guardrails for beef consumption in the future. The U.S. beef industry formed a Flavor Working Group in 2012 composed of the authors listed here to investigate new and innovative ways to manage and measure beef flavor. The results of this working group have resulted in dozens of papers, presentations, abstracts, and symposia. The objective of this manuscript is to summarize the research developed by this working group and by others worldwide that have investigated methodologies that measure beef flavor. This paper will describe the strengths of the research in beef flavor measurement and point out future needs that might be identified as technology advances.

A current review of U.S. beef flavor II: Managing beef flavor

Beef flavor continues to be one of the largest drivers of beef demand and a differentiation point of beef from other competing proteins. Tenderness has long been identified as the most important palatability trait for consumer satisfaction. However, as technological advancements and industry practices evolve and improve in response to tenderness management, flavor has emerged as a key driver of consumer satisfaction. In response, the beef industry has recently invested in research focused on beef flavor development, measurement, and management to better understand the factors impacting flavor and help beef maintain this advantage. The current review paper is the second of two such papers focused on summarizing the present knowledge and identifying knowledge gaps. While the other review focuses on current practices related to beef flavor measurement, this review will cover research findings related to beef flavor management. Numerous production and product management factors influence beef flavor. Pre-harvest factors including marbling level, animal genetics/cattle type, diet, and animal age, can influence beef flavor. Moreover, numerous post-harvest product management factors, including product type, aging length and conditions, cookery methods, product enhancement, muscle-specific factors, packaging, retail display factors, and antimicrobial interventions, have all been evaluated for their impact on beef flavor characteristics. Results from numerous studies evaluating many of these factors will be outlined within this review in order to present management and production chain factors that can influence beef flavor.

Evaluation of a novel computer vision-based livestock monitoring system to identify and track specific behaviors of individual nursery pigs within a group-housed environment

Animal behavior is indicative of health status and changes in behavior can indicate health issues (i.e., illness, stress, or injury). Currently, human observation (HO) is the only method for detecting behavior changes that may indicate problems in group-housed pigs. While HO is effective, limitations exist. Limitations include HO being time consuming, HO obfuscates natural behaviors, and it is not possible to maintain continuous HO. To address these limitations, a computer vision platform (NUtrack) was developed to identify (ID) and continuously monitor specific behaviors of group-housed pigs on an individual basis. The objectives of this study were to evaluate the capabilities of the NUtrack system and evaluate changes in behavior patterns over time of group-housed nursery pigs. The NUtrack system was installed above four nursery pens to monitor the behavior of 28 newly weaned pigs during a 42-d nursery period. Pigs were stratified by sex, litter, and randomly assigned to one of two pens (14 pigs/pen) for the first 22 d. On day 23, pigs were split into four pens (7 pigs/pen). To evaluate the NUtrack system’s capabilities, 800 video frames containing 11,200 individual observations were randomly selected across the nursery period. Each frame was visually evaluated to verify the NUtrack system’s accuracy for ID and classification of behavior. The NUtrack system achieved an overall accuracy for ID of 95.6%. This accuracy for ID was 93.5% during the first 22 d and increased (P < 0.001) to 98.2% for the final 20 d. Of the ID errors, 72.2% were due to mislabeled ID and 27.8% were due to loss of ID. The NUtrack system classified lying, standing, walking, at the feeder (ATF), and at the waterer (ATW) behaviors accurately at a rate of 98.7%, 89.7%, 88.5%, 95.6%, and 79.9%, respectively. Behavior data indicated that the time budget for lying, standing, and walking in nursery pigs was 77.7% ± 1.6%, 8.5% ± 1.1%, and 2.9% ± 0.4%, respectively. In addition, behavior data indicated that nursery pigs spent 9.9% ± 1.7% and 1.0% ± 0.3% time ATF and ATW, respectively. Results suggest that the NUtrack system can detect, identify, maintain ID, and classify specific behavior of group-housed nursery pigs for the duration of the 42-d nursery period. Overall, results suggest that, with continued research, the NUtrack system may provide a viable real-time precision livestock tool with the ability to assist producers in monitoring behaviors and potential changes in the behavior of group-housed pigs.

Beef Carcass Size and Aging Time Effects on Yield and Color Characteristics of Top Round Steaks

Variation in cut size and weight of fabricated subprimals is a challenge of increased beef carcass weights. Subsequently, variation in carcass size has resulted in consistency challenges during retail display. The objective of this study was to assess three aging periods of commercially available top rounds from varying carcass weights as it relates to yield and color characteristics. In the current study, 21 industry average weight (AW; 340 to 409 kg; no industry discount) beef carcasses and 21 oversized (OS; exceeding 454 kg; receive a discount) beef carcasses were evaluated. Carcasses were selected at a commercial beef packing plant, where the left and right (paired) top round subprimals of each carcass were procured. Paired top rounds were assigned to a short (8 d), average (23 d), or extended (42 d) postmortem aging period. After wet-aging, subprimals were fabricated into steaks for additional analysis. Steaks were evaluated as whole top round steaks or further fabricated into “ superficial ” and “ deep ” portions at 5.08 cm from the superficial edge of the Semimembranosus and the Adductor muscle. Top rounds and steaks from OS carcasses were larger (P < 0.01) than those from AW carcasses. Quantitative color of the anatomically deep locations of the OS steaks had the greatest mean L* (lightness; P < 0.01), a* (redness; P < 0.01) and b* (yellowness; P < 0.01) values. Extending the aging timeline increased L* (lightness; P < 0.01), decreased a* (redness; P < 0.01), and decreased b* (yellowness; P < 0.01). Alternative top round steak fabrication that separates the deep and superficial anatomical locations could be an effective means of providing more uniform steaks.

Extending the Shelf Life of Beef Steaks Using Acerola Cherry Powder and Rosemary Extract

Improvements in retail shelf life of exported beef will help with merchandising and increase competitiveness in the worldwide market for United States beef products. The objective of this study was to determine the effect of topically applying acerola cherry powder or rosemary extract from various suppliers on beef bone-in short rib steak and chuck roll steak shelf life. USDA Choice beef bone-in short ribs (IMPS 123A) and chuck rolls (IMPS 116A) were aged (0°C) for 28 d postfabrication. Following aging, 1.02-cm-thick steaks were cut (N = 126) and systematically assigned to a treatment based on steak location within the subprimal. Treatments included untreated control (C), topically sprayed (2 mL) with an acerola cherry powder solution (0.05%) from 1 of 3 suppliers (C1, C2, C3), or topically sprayed (2 mL) with a rosemary extract solution (0.10%) from 1 of 3 suppliers (R1, R2, R3). Half of the steaks were assigned to day 0 lipid oxidation, metmyoglobin-reducing activity (MRA), and oxygen consumption; the remaining steaks were assigned to color evaluation over 4 d of retail display followed by day 4 lipid oxidation and MRA. Short rib steaks treated with antioxidants had a brighter oxygenated lean color than control steaks (P < 0.001). There was an interaction (P = 0.028) between time of retail display and MRA. Short rib steaks treated with C3 and R2 did not change in MRA between day 0 and 4 (P = 0.620, P = 0.428, respectively). Chuck roll steaks treated with C1, C2, C3, R2, and R3 all had a higher, or more desirable, MRA than the control steaks on day 0 (P < 0.001). Applying topical antioxidants improves the shelf-life stability of steaks from beef bone-in short ribs and chuck rolls aged for an extended period.

26 Extending the Shelf-life of Beef Bone-in Short Rib Steaks Using Acerola Cherry Powder and Rosemary Extract

Improving the shelf-life of beef bone-in short rib steaks, which are commonly exported, will increase beef export demand and subsequently producer profits. The objective was to determine the effect of the topical application of acerola cherry powder and rosemary extract from various suppliers on beef bone-in short rib shelf-life. Beef bone-in short ribs (IMPS 123A) (n = 18) from USDA Choice carcasses were aged for 28 days post-fabrication at 0°C. Steaks 1.02 cm-thick were systematically assigned based on location to treatments including: untreated control (C), topically sprayed (~2ml) with an acerola cherry powder solution (0.05%) from one of three suppliers (C1, C2, C3), or topically sprayed (~2ml) with a rosemary extract solution (0.10%) from one of three suppliers (R1, R2, R3). Steaks were assigned to day 0 lipid oxidation or 4 days of retail display followed by day 4 lipid oxidation. Steaks were weighed on day 0 and 4 to determine fluid loss. Throughout retail display, objective and subjective color were measured twice daily on the lean and bone marrow portions of the steaks. Data were analyzed using the Mixed Model procedure of the Statistical Analysis System. Lipid oxidation (P = 0.323) did not differ between treatments. However, treatments differed in fluid loss (P = 0.024), where steaks treated with C1, C2, C3, R2, and R3 had less fluid lost than control steaks. Subjective color evaluation of lean color (P < 0.0001) and uniformity (P < 0.001) differed between treatments. Steaks treated with C1, C2, C3, and R3 were a brighter red than control steaks. Treatments differed when measuring bone marrow L* (P < 0.001), a* (P < 0.001), and b* (P = 0.004), where R3 treated marrow was the darkest, reddest, and yellowest. Natural antioxidants, specifically acerola cherry powder and rosemary extract, improved steak color and water holding capacity of beef bone-in short ribs aged for an extended period.

32 Assessment of Dry-Aged Beef from Commercial Aging Locations Across the United States

Dry-aging is a practice that involves storing meat at refrigerated temperatures without protective packaging. Despite the increase in dry-aged beef popularity, relatively little is known about commercial dry-aging parameters. Thus, the objectives of this study were to determine dry-aging parameters of commercial aging facilities and their influence on eating quality (acceptability, flavor, tenderness, and juiciness) of dry-aged beef from locations across the United States. Sixty-six Certified Angus Beef® brand bone-in beef strip loins (IMPS #175) were randomly assigned to ten commercial dry-aging facilities across the United States. An additional six strip loins were wet-aged for 45-days as a negative control. Strip loins were shipped overnight to aging locations where a 45-day dry aging period transpired before being returned for subsequent analysis, upon completion of aging. Objective color, pH, and water activity were measured post aging, at the time of processing. Strip loins were then fabricated, and steaks were vacuum packaged and frozen until further analysis. Intrinsic quality parameters objective color (L*, a*, b*), pH, and water activity were not different (P > 0.05) between strip loins aged 45 days by location. Cooler conditions including temperature, percent relative humidity, and air speed were different (P < 0.01) across aging locations. Pacific Northwest consumer panelists indicated a difference in overall acceptability (P < 0.01), tenderness (P = 0.01), and flavor (P < 0.01) based on aging location. Additionally, consumers detected (P < 0.01) unique dry-aging flavors for individual aging locations including cheesy and nutty attributes. Research indicates individual dry-aging facility conditions aid in producing unique dry-aged beef products according to U.S. consumers from the Pacific Northwest Region.

Impact of beef carcass size on chilling rate, pH decline, display color, and tenderness of top round subprimals

Beef carcass weights in the United States have continued to increase over the past 30 yr. As reported by the United States Department of Agriculture, grid-based carcass weight discounts begin when carcasses exceed 408 kg. Despite weight discounts, beef carcass weights continue to increase. At the same time, an increased prevalence of discoloration and color variability in top round subprimals has been observed throughout the industry which may be influenced by the increases in carcass weights. The objectives of this study were to assess the effects of beef carcass size and its relationship to chill time, color, pH, and tenderness of the beef top round. In the current study, eight industry average weight beef carcasses (AW, 341–397 kg) and eight oversized beef carcasses (OW, exceeding 432 kg) were evaluated. Temperatures and pH measurements were observed on both sides of all carcasses for the initial 48 h postharvest at a consistent superficial and deep anatomical location of the respective top rounds. Carcasses were fabricated into subprimals at 48 h and top rounds were aged at 2 °C for an additional 12 d. The superficial location of both AW and OW carcasses cooled at a faster rate (P < 0.01) than the deep locations. The deep location of OW carcasses had a lower pH and a more rapid (P < 0.01) initial pH decline. Quantitative color of steaks from OW carcasses had greater mean L* (lightness; P = 0.01) and initial b* (yellowness; P < 0.01) values. The delayed temperature decline and the accelerated pH decline of the deep location of the top round of OW carcasses occur at different rates than AW carcasses. Delayed rate of cooling leads to irreversible impacts on steak appearance of top round steaks fabricated from OW beef carcasses when compared with AW carcasses.

Using Genetic Panels to Predict Tenderness in Beef Cattle

Genetic panel use as a selection tool has grown in popularity in the beef industry. The objective of the study was to determine whether beef cattle genetically selected for tenderness generated a tender product. Igenity® (IT) panel results were provided by a cattle producer for 52 steers, which were harvested at a commercial harvest facility. Boneless strip loins (Institutional Meat Purchase Specifications #180; United States Department of Agriculture [USDA] Choice, n = 32; USDA Prime n = 20) were collected from the left side of each carcass and transported to the University of Idaho Meat Science Laboratory. Four steaks were cut from each subprimal and assigned to aging periods of 7, 14, and 21 d for Warner-Bratzler Shear Force (WBSF) analysis or 21 d for consumer sensory analysis. Carcasses were assigned to tenderness groups based on their IT tenderness indexes (Low IT, 3 – 6, n = 30; High IT, 7 – 10, n = 22). Data were analyzed using the mixed model procedure of SAS version 9.4 (SAS Institute Inc., Cary, NC). An interaction was observed between tenderness group and USDA quality grade (P = 0.015) when analyzing WBSF. All of the cattle had less than 4.14 kg of WBSF; however, USDA Prime steers that were in the High IT tenderness group produced more tender steaks than High IT USDA Choice, Low IT USDA Prime, and Low IT USDA Choice steers. Consumers were not able to detect tenderness differences between IT tenderness groups (P = 0.11) or USDA quality grades (P = 0.11), but they found USDA Prime steaks to be more acceptable (P = 0.01), juicier (P = 0.01), and more flavorful (P = 0.02) than USDA Choice steaks. In conclusion, regardless of tenderness group, USDA Prime steaks were preferred by consumers over USDA Choice steaks in terms of flavor, juiciness, and acceptability.

Assessing outcomes of genetic selection panels to predict marbling in crossbred beef cattle

The objective of this study was to evaluate the effectiveness of genetic panel marbling indexes [Igenity (IT) and PredicGEN (PG)] to predict marbling and tenderness of crossbred cattle. Steers (n = 23) were harvested at the University of Idaho Meat Science Laboratory, and blood samples were submitted to Neogen and Zoetis for genetic panel analysis. Forty-eight hours postharvest, one boneless strip loin was collected from each carcass, and six 2.54-cm thick steaks were cut from each strip loin. Steaks were aged for 14 and 21 d and assigned to consumer sensory evaluation or Warner–Bratzler Shear Force (WBSF) analysis. Results were analyzed using the Mixed Model procedure of the Statistical Analysis System (SAS Institute, Inc., Cary, NC). Carcasses were grouped by marbling index score into Low IT (IT indexes 3–6; n = 16; marbling score (MS) = 410), High IT (IT indexes 7–10; n = 7; MS = 496), Low PG (PG index <50; n = 9; MS = 398), or High PG (PG index ≥50; n = 14; MS = 458). Mean MS was observed to be greater in High IT steaks than Low IT (P < 0.01) and greater in High PG steaks than Low PG (P = 0.01). There was a trend observed in WBSF between IT marbling groups (P = 0.06); however, no difference in WBSF was observed between PG marbling groups (P = 0.83). Consumers did not report differences between IT marbling groups in terms of acceptability (P = 0.99) or tenderness (P = 0.24). Additionally, consumers could not detect differences between PG marbling groups in terms of acceptability (P = 0.75) or tenderness (P = 0.40). Consumers consistently preferred Choice steaks over Select steaks in terms of acceptability (P = 0.02) and tenderness (P = 0.02). In conclusion, though consumers were not able to tell the difference between steaks from each of the genetic panels, using genetic panels to predict marbling, in conjunction with proper nutrition and handling practices, could be a beneficial tool to producers making decisions about retaining ownership at the feedlot.

Abstract P1-10-01: Defining the spectrum of germline variants among African American patients with triple negative breast cancer

Background: African American (AA) women are more likely to have breast cancer at a younger age and be diagnosed with triple negative breast cancer (TNBC), which is as yet unexplained. We examined results of multi-gene panel testing in AA women with TNBC tested at a large commercial laboratory to assess the utility of gene panels and findings in this group.

Methods: We assessed individuals who had clinical hereditary cancer testing with a multi-gene panel between September 2013 and May 2018. Women were included for analysis if they had a personal history of TNBC and self-identified as having any AA ancestry (n=3,268) or only Caucasian (CA) ancestry (n=8,953). Clinical data was collected from provider-completed test request forms. Comparisons were performed using descriptive statistics, t-tests (continuous variables), and chi-square tests (categorical variables) adjusting for multiple testing when necessary.

Results: In this cohort, AA women were significantly more likely than CA women to meet NCCN guidelines (97.5% vs. 96.6%, p=0.010) and significantly less likely to have an additional personal (16.2% vs. 21.8%, p&lt;0.001) or family (79.3% vs. 86.3%, p&lt;0.001) history of cancer. Overall, 11.5% of AA women were found to carry a pathogenic variant (PV) compared to 13.4% of CA women (p=0.004; Table 1). Compared to CA women, AA women with a PV were significantly younger at diagnosis (46.7 vs. 49.5 years of age; p&lt;0.001). The prevalence of PVs in BRCA1, CHEK2 and the Lynch syndrome genes was higher in CA women, whereas the prevalence of BRCA2 PVs was higher in AA women. While the prevalence of PVs in individual genes was not significantly different according to ancestry after adjusting for multiple comparisons, AA women were significantly less likely to have a PV in any breast cancer-related gene compared to CA women (p=0.048). AA women were significantly more likely to have a Variant of Uncertain Significance (VUS; 35.6% vs. 20.9%; p&lt;0.001) and to have &gt;1 VUS (8.6% vs. 2.6%, p&lt;0.001). Regardless of ancestry, patients diagnosed before age 40 were more likely to carry a PV (19.7% AA, 22.2% CA). However, the prevalence of PVs among patients diagnosed after age 60 was still striking (8.9% AA, 10.9% CA) and was similar to the PV prevalence among patients diagnosed between 40-60 (10.1% AA, 12.3% CA).

Conclusions: In the era of multi-gene panel testing, this large cohort of patients with TNBC supports the use of panel testing in AA women with TNBC regardless of age or additional personal/family history of cancer. While additional research to the rate and pathogenicity of VUS in AA women is needed, genetic counseling is necessary to explain the possibility and meaning of a VUS in this group.

Table 1.Distribution of PVs in BC-related genes according to ancestry AA WomenCA WomenGeneN (%)N (%)Any Breast Cancer-Related Gene347 (10.6)1104 (12.3)BRCA1132 (4.0)496 (5.5)BRCA297 (3.0)236 (2.6)ATM6 (0.2)25 (0.3)BARD119 (0.6)67 (0.7)BRIP120 (0.6)46 (0.5)CDH11 (&lt;0.1)1 (&lt;0.1)CHEK22 (0.1)33 (0.4)NBN2 (0.1)10 (0.1)PALB244 (1.3)138 (1.5)PTEN2 (0.1)4 (&lt;0.1)RAD51C20 (0.6)41 (0.5)STK1101 (&lt;0.1)TP532 (0.1)6 (0.1)Lynch Syndrome Genes10 (0.3)46 (0.5)Other Genes12 (0.4)24 (0.3)Multiple PVs6 (0.2)28 (0.3)Total (Any Gene)375 (11.5)1202 (13.4)

Citation Format: Pederson HJ, Heald B, Budd GT, Bernhisel R, Cummings S, Saam JR, Lancaster JM, Grobmyer SR, Eng C. Defining the spectrum of germline variants among African American patients with triple negative breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-10-01.

Modes of delivery of genetic testing services and the uptake of cancer risk management strategies in BRCA1 and BRCA2 carriers

BRCA testing services are now offered by various healthcare providers, thus it is important to evaluate whether the implementation of cancer risk management (CRM) strategies varies by service provider. Using a registry-based sample of 795 female BRCA mutation carriers, we explored the association between uptake of CRM strategies with duration of genetic counseling (GC) sessions, provider type, and other demographic and clinical variables. All participants completed a baseline questionnaire. Information about uptake of CRM strategies was collected for a subset of 438 participants who completed additional questions. Summary statistics and Pearson chi-squared analysis were used to examine the associations between demographic and clinical variables with service delivery factors and with the uptake of various CRM strategies. Overall uptake of CRM strategies was high across all provider types. However, GC sessions were longer when provided by a genetics professional than by another provider (p < 0.001). Furthermore, higher frequencies of uptake of most CRM strategies were associated with longer GC sessions and when testing was performed by a genetics professional. Identification of factors to optimize delivery of these specialized GC services is important to maximize implementation of CRM strategies in BRCA carriers.

In vitro analysis of ovarian cancer response to cisplatin, carboplatin, and paclitaxel identifies common pathways that are also associated with overall patient survival

Background:

Carboplatin and cisplatin, alone or in combination with paclitaxel, have similar efficacies against ovarian cancer (OVCA) yet exhibit different toxicity profiles. We characterised the common and unique cellular pathways that underlie OVCA response to these drugs and analyse whether they have a role in OVCA survival.

Methods:

Ovarian cancer cell lines (n=36) were treated with carboplatin, cisplatin, paclitaxel, or carboplatin–paclitaxel (CPTX). For each cell line, IC₅₀ levels were quantified and pre-treatment gene expression analyses were performed. Genes demonstrating expression/IC₅₀ correlations (measured by Pearson; P<0.01) were subjected to biological pathway analysis. An independent OVCA clinico-genomic data set (n=142) was evaluated for clinical features associated with represented pathways.

Results:

Cell line sensitivity to carboplatin, cisplatin, paclitaxel, and CPTX was associated with the expression of 77, 68, 64, and 25 biological pathways (P<0.01), respectively. We found three common pathways when drug combinations were compared. Expression of one pathway (‘Transcription/CREB pathway’) was associated with OVCA overall survival.

Conclusion:

The identification of the Transcription/CREB pathway (associated with OVCA cell line platinum sensitivity and overall survival) could improve patient stratification for treatment with current therapies and the rational selection of future OVCA therapy agents targeted to these pathways.

Defining practice patterns in Gynecologic Oncology to prevent pulmonary embolism and deep venous thrombosis

OBJECTIVE

The goal of venous thromboembolism (VTE) prophylaxis is to reduce the morbidity and mortality associated with the development of a deep venous thrombosis (DVT) or pulmonary embolism (PE). Because women with gynecologic cancers are at high risk to develop VTE, we sought to determine the present practice patterns of gynecologic oncologists regarding their use of VTE prophylaxis.

METHODS

1073 members of the Society of Gynecologic Oncologists (SGO) were mailed surveys that asked about preferred methods to prevent the development of VTE after gynecologic oncology surgery. Data were collected by online member entry and return mail. Frequency distributions were calculated and nonparametric test used for comparisons.

RESULTS

343/1073 (34%) of SGO members and fellows responded. 142/343 (42%) preferred double prophylaxis consisting of external pneumatic compression (EPC) and an anticoagulant while 41% (n=141) preferred EPC with no additional anticoagulation. Of respondents choosing any anticoagulant, 40% preferred Enoxaparin pre- and/or postoperatively. Ovarian cancer patients were perceived by respondents to have the highest risk of developing a postoperative PE.

CONCLUSIONS

Most respondents agree that women with gynecologic cancers undergoing major surgery should receive VTE prophylaxis, though there is not agreement as to which method is optimal. While 42% of members preferred double prophylaxis, 41% chose no additional measures other than EPC. Randomized studies in gynecologic oncology should be initiated in the United States to determine the optimal practice pattern.

Cyclooxygenase-2 (COX-2) expression in human endometrial carcinoma and precursor lesions and its possible use in cancer chemoprevention and therapy

In recent years, the design of new antineoplastic agents that can halt the progression of human malignancies with minimal systemic damage has been at the forefront of cancer research, with cyclooxygenase-2 (COX-2) as a major target molecule. With an aim to demonstrate the expression and role of COX-2, the principal putative target of COX-2 inhibitor therapy, in endometrial adenocarcinoma (EACA) and precursor lesions, atypical complex hyperplasia (ACH) and endometrial hyperplasia (EH), an immunohistochemical (IHC) analysis of 22 primary human EACAs and 14 precursor lesions was carried out. Relevant clinicopathological data were tabulated from a random computer-generated sample of 22 primary EACA patients, treated by hysterectomy at our institution. Representative tumor sections including adjacent precursor lesions and normal endometrium (NE) were immunostained with human monoclonal anti-COX-2. Qualitative and semi-quantitative COX-2 IHC staining scores were determined based on the proportion of immunoreactive cells and the intensity of cytoplasmic COX-2 expression. Fisher's exact test and the Wilcoxon Rank Sum test were used for statistical analysis. Mean patient age was 68 years (range 51-93). All 22 EACAs were of endometrioid type, of which ten (45%) were grade I, eight (36%) grade II and four (18%) were grade III. Overall, four out of nine (44%) EHs, four out of five (80%) ACHs, and 18 out of 22 (88%) EACAs were COX-2 positive. The mean COX-2 IHC scores for EH and EACAs were 33 (SD 24.11) and 76 (SD 54.57), respectively (p = 0.022). Strong or moderate COX-2 expression was observed in 17 out of 22 (77%) adenocarcinomas as compared to two out of 14 (14%) of the precursor lesions (EH and ACH). The areas of adenomyosis were COX-2 positive, while myometrial smooth muscle and normal fallopian tube tissues stained negative for COX-2. The demonstration of frequent and strong expression of COX-2 in human EACAs supports a possible role for COX-2 inhibitors. Furthermore, an increasing expression of COX-2 from EH to invasive EACAs suggests potential usefulness of COX-2 inhibition to halt the progression of precursor lesions to invasive endometrial cancers.

High expression of insulin-like growth factor binding protein-2 messenger RNA in epithelial ovarian cancers produces elevated preoperative serum levels

The molecular etiology of epithelial ovarian cancer remains unclear. Using microarray expression analysis, we recently reported that expression of the insulin-like growth factor binding protein-2 (IGFBP-2) gene is elevated in advanced epithelial ovarian cancers. The aim of this study was to further delineate the role of IGFBP-2 in the pathoetiology of epithelial ovarian cancer and determine if elevated ovarian cancer IGFBP-2 gene expression is reflected in serum. Relative IGFBP-2 expression was measured using quantitative real-time polymerase chain reaction in 113 epithelial ovarian cancers and 6 normal ovarian surface epithelial samples. Preoperative serum IGFBP-2 levels were measured by radioimmunoassay in 84 women (42 ovarian cancers, 26 benign gynecological conditions, and 10 healthy female controls). Ovarian cancers demonstrated 38-fold higher mean IGFBP-2 expression than normal ovarian epithelium (P < 0.01). Serum IGFBP-2 levels were elevated in women with early- and advanced-stage ovarian cancer compared to controls and patients with benign gynecological conditions (P = 0.05 and P < 0.01, respectively). Epithelial ovarian cancers express high levels of IGFBP-2 relative to normal ovarian epithelium, and this is associated with elevated serum IGFBP-2 levels compared to both normal controls and patients with benign gynecological disease. Our findings provide further support that the insulin-like growth factor pathway plays a significant role in epithelial ovarian cancer pathogenesis. Further, IGFBP-2 may represent an additional serum biomarker with utility in detection and monitoring of epithelial ovarian cancer.

Identification of genes associated with ovarian cancer metastasis using microarray expression analysis

Although the transition from early- to advanced-stage ovarian cancer is a critical determinant of survival, little is known about the molecular underpinnings of ovarian metastasis. We hypothesize that microarray analysis of global gene expression patterns in primary ovarian cancer and metastatic omental implants can identify genes that underlie the metastatic process in epithelial ovarian cancer. We utilized Affymetrix U95Av2 microarrays to characterize the molecular alterations that underlie omental metastasis from 47 epithelial ovarian cancer samples collected from multiple sites in 20 patients undergoing primary surgical cytoreduction for advanced-stage (IIIC/IV) serous ovarian cancer. Fifty-six genes demonstrated differential expression between ovarian and omental samples (P < 0.01), and twenty of these 56 differentially expressed genes have previously been implicated in metastasis, cell motility, or cytoskeletal function. Ten of the 56 genes are involved in p53 gene pathways. A Bayesian statistical tree analysis was used to identify a 27-gene expression pattern that could accurately predict the site of tumor (ovary versus omentum). This predictive model was evaluated using an external data set. Nine of the 27 predictive genes have previously been shown to be involved in oncogenesis and/or metastasis, and 10/27 genes have been implicated in p53 pathways. Microarray findings were validated by real-time quantitative PCR. We conclude that gene expression patterns that distinguish omental metastasis from primary epithelial ovarian cancer can be identified and that many of the genes have functions that are biologically consistent with a role in oncogenesis, metastasis, and p53 gene networks.

Allele loss on chromosome 1p36 in epithelial ovarian cancers

OBJECTIVES

Prior studies have shown that allelic loss on chromosome 1p36 occurs frequently in ovarian as well as several other types of cancer. This suggests that inactivation of gene(s) in this region may play a role in the pathogenesis of these cancers. The aim of this study was to further delineate the region of loss on chromosome 1p36 in ovarian cancers and to identify associated patient or tumor characteristics.

METHODS

Paired normal/cancer DNA samples from 75 ovarian cancers (21 early stage I/II and 54 advanced stage III/IV) were analyzed using microsatellite markers.

RESULTS

Forty-nine of 75 (65%) ovarian cancers had loss of at least one marker. The marker demonstrating the most frequent loss was D1S1597, which was lost in 29/57 (51%) informative cases. Allele loss on 1p36 was significantly more common in poorly differentiated ovarian cancers (73%) relative to well or moderately differentiated cases (48%) (P = 0.03). Evidence was obtained for two common regions of deletion: one flanked by D1S1646/D1S244 and another more proximally by D1S244/D1S228.

CONCLUSION

These findings further delineate regions on chromosome 1p36 proposed to contain tumor suppressor gene(s) that may play a role in the development and/or progression of epithelial ovarian carcinoma. Allele loss on 1p36 is associated with poor histologic grade.

Mutational analysis of the PTEN gene in human uterine sarcomas

OBJECTIVE

Uterine sarcomas are rare, lethal cancers, and little is known about their molecular etiology. The PTEN gene is located on chromosome 10q23.3, a region that displays frequent loss of heterozygosity in human uterine sarcomas. PTEN mutations have been described in 40% to 60% of uterine adenocarcinomas. To determine whether the PTEN gene is involved in the pathogenesis of uterine sarcoma, we analyzed deoxyribonucleic acid from uterine sarcomas and cell lines.

STUDY DESIGN

Single-strand conformation analysis and direct sequencing of deoxyribonucleic acid were used to screen for PTEN mutations.

RESULTS

Silent polymorphisms were detected in 2 of 36 primary uterine sarcomas. A 4-base pair deletion and a point mutation producing a stop codon were identified in 1 cell line.

CONCLUSIONS

Mutational inactivation of PTEN does not play a major role in uterine sarcoma tumorigenesis, and another gene or genes on chromosome 10q may be implicated as a cause of these cancers. Differences in the molecular alterations underlying the development of uterine sarcomas and adenocarcinomas are significant.

BRCA1 and BRCA2 in breast cancer families from Wales: moderate mutation frequency and two recurrent mutations in BRCA1

Mutations in the BRCA1/BRCA2 genes account for varying proportions of breast cancer families studied, and demonstrate considerable variation in mutational spectra coincident with ethnic and geographical diversity. We have screened for mutations in 17 families from Wales with two or more cases of breast cancer under age 50 and/or ovarian cancer. Eight out of 17 (47%) families had demonstrable mutations. Six out of 17 (35%) carried BRCA1 mutations and 2 out of 17 (12%) carried BRCA2 mutations. Two recurrent mutations in BRCA1 were identified, which appear to represent founder mutations in this population. These data support the existence of additional breast and ovarian cancer susceptibility genes.

Frequency of germline and somatic BRCA1 mutations in ovarian cancer

Germline mutations in the BRCA1 tumor suppressor gene are thought to be the most common cause of hereditary ovarian cancer. The aim of this study was to explore further the role of BRCA1 alterations in the development of ovarian cancers. We sought to determine whether somatic BRCA1 mutations are ever present in ovarian cancers and whether mutation is always accompanied by loss of the wild-type allele. The entire coding region and intronic splice sites of BRCA1 were sequenced using genomic DNA samples from 103 unselected ovarian cancers. Thirteen clearly deleterious BRCA1 mutations and two variants of uncertain significance were found. Blood DNA was available in all but two cases and demonstrated that 4 of 13 mutations and both variants of uncertain significance were germline alterations, whereas in seven cases the mutation was a somatic change present only in the cancer. Using four microsatellite markers, loss of heterozygosity at the BRCA1 locus was found in all 15 ovarian cancers with BRCA1 sequence alterations, compared with only 58% of ovarian cancers that did not have BRCA1 mutations. BRCA1-associated ovarian cancers were characterized by serous histology and moderate histological grade. These data confirm prior reports suggesting that germline mutations in BRCA1 are present in about 5% of women with ovarian cancer. In addition, somatic mutations in BRCA1 occur in the development of some sporadic cases. The finding that both germline and somatic BRCA1 mutations are accompanied by loss of heterozygosity, suggests that loss of this tumor suppressor gene is a critical event in the development of these cancers.

Aberrant splicing of the TSG101 tumor suppressor gene in human breast and ovarian cancers

OBJECTIVE

To determine whether large deletions or other alterations in the putative tumor suppressor gene TSG101 play a role in the molecular pathogenesis of breast and ovarian cancers.

METHODS

Expression of TSG101 transcripts was examined in breast and ovarian cancers using the reverse transcriptase-polymerase chain reaction (RT-PCR), and selected transcripts were sequenced. Southern blot analysis was performed to determine whether there were genomic deletions in the TSG101 gene, and Northern blot analysis was used to examine the relative abundance of various transcripts.

RESULTS

All the cancerous and normal breast tissue examined expressed full length 1145 base pair (bp) TSG101 transcripts. Additional truncated transcripts were seen using the RT-PCR in 57 (64%) of 89 primary breast cancers, 1 (20%) of 5 breast cancer cell lines, 3 (50%) of 6 normal breast tissues, 16 (64%) of 25 primary ovarian cancers and 1 (33%) of 3 ovarian cancer cell lines. Only the primary breast (21%) and ovarian (24%) cancers had three or more truncated transcripts. None of the normal tissues or cell lines examined had more than two aberrant transcripts. DNA sequencing revealed that the most commonly expressed truncated transcript arises because of loss of 902 bp between codons 153 and 1055. Only full length TSG101 transcripts were seen on Northern blot analysis of breast cancer cell lines, however. There was no evidence of genomic deletions in the TSG101 gene on Southern blot analysis.

CONCLUSION

Truncated TSG101 transcripts that probably represent splice variants are present in some breast and ovarian cancers, but there is no evidence to suggest that loss of this putative tumor suppressor gene plays a role in the molecular pathogenesis of these cancers.

Dideoxy fingerprinting assay for BRCA1 mutation analysis

Since the isolation of BRCA1, the familial breast/ovarian cancer predisposition gene, much effort has been invested in characterizing the mutation spectrum. The large size of the gene and the wide distribution of its more than 100 mutations has increased the challenge of this endeavor such that traditional mutation detection techniques are inadequate. We examined the sensitivity of dideoxy fingerprinting (DDF), which combine a Sanger sequencing reaction with multiple-fragment single-strand conformation analysis (SSCA), as a mutation detection technique to screen BRCA1. Here we describe the technique and compare its sensitivity with that of SSCA in detecting 21 previously described BRCA1 sequence variants. All the variants were detected by DDF, but only 17 of 21 (81%) were observed by SSCA under standard conditions. Three of four alterations missed by SSCA were base substitutions. As a BRCA1 mutation detection technique, DDF was more sensitive than SSCA and may prove to be a useful research tool in defining the mutation spectrum within this and other genes.

Microsomal epoxide hydrolase polymorphism as a risk factor for ovarian cancer

Microsomal epoxide hydrolase (EPHX) is one of many enzymes involved in the metabolism of endogenous and exogenous toxicants. Polymorphic forms of the human EPHX gene have been described that vary in enzymatic activity, and one, Tyr113His, has been associated with hepatocellular carcinoma susceptibility. We demonstrated that EPHX was highly expressed in the human ovary, and investigated whether specific EPHX genotypes are associated with ovarian cancer susceptibility. Seventy-three Caucasian patients with ovarian cancer and 75 Caucasian-female controls without cancer were genotyped for the Tyr113His polymorphism by a polymerase chain reaction-restriction fragment length polymorphism assay. The frequency of the homozygous high-activity genotype was 41% in the control population and 64% in the ovarian cancer patients. The odds ratio for ovarian cancer with this genotype was 2.6 (95% confidence interval 1.3, 5.0; P < 0.01). The increased ovarian cancer risk associated with the high-activity genotype could reflect differences in metabolic activation of endogenous or exogenous carcinogens.

Microsomal epoxide hydrolase polymorphism as a risk factor for ovarian cancer

Microsomal epoxide hydrolase (EPHX) is one of many enzymes involved in the metabolism of endogenous and exogenous toxicants. Polymorphic forms of the human EPHX gene have been described that vary in enzymatic activity, and one, Tyr113His, has been associated with hepatocellular carcinoma susceptibility. We demonstrated that EPHX was highly expressed in the human ovary, and investigated whether specific EPHX genotypes are associated with ovarian cancer susceptibility. Seventy-three Caucasian patients with ovarian cancer and 75 Caucasian-female controls without cancer were genotyped for the Tyr113His polymorphism by a polymerase chain reaction-restriction fragment length polymorphism assay. The frequency of the homozygous high-activity genotype was 41% in the control population and 64% in the ovarian cancer patients. The odds ratio for ovarian cancer with this genotype was 2.6 (95% confidence interval 1.3, 5.0; P < 0.01). The increased ovarian cancer risk associated with the high-activity genotype could reflect differences in metabolic activation of endogenous or exogenous carcinogens.

Microsomal epoxide hydrolase polymorphism as a risk factor for ovarian cancer

Microsomal epoxide hydrolase (EPHX) is one of many enzymes involved in the metabolism of endogenous and exogenous toxicants. Polymorphic forms of the human EPHX gene have been described that vary in enzymatic activity, and one, Tyr113His, has been associated with hepatocellular carcinoma susceptibility. We demonstrated that EPHX was highly expressed in the human ovary, and investigated whether specific EPHX genotypes are associated with ovarian cancer susceptibility. Seventy-three Caucasian patients with ovarian cancer and 75 Caucasian-female controls without cancer were genotyped for the Tyr113His polymorphism by a polymerase chain reaction-restriction fragment length polymorphism assay. The frequency of the homozygous high-activity genotype was 41% in the control population and 64% in the ovarian cancer patients. The odds ratio for ovarian cancer with this genotype was 2.6 (95% confidence interval 1.3, 5.0; P < 0.01). The increased ovarian cancer risk associated with the high-activity genotype could reflect differences in metabolic activation of endogenous or exogenous carcinogens.

Role of BRCA1 mutation screening in the management of familial ovarian cancer

Families with multiple cases of ovarian cancer have long been observed, and in the past prophylactic oophorectomy has been advocated for women with a history of ovarian cancer in two first-degree relatives. It is now thought that > 90% of familial ovarian cancer is due to inherited mutations in the BRCA1 breast-ovarian cancer susceptibility gene on chromosome 17q. BRCA1 testing is being performed in several academic medical centers on a research basis and is also now commercially available. With the ability to identify inherited mutations in BRCA1, prophylactic oophorectomy and other interventions intended to decrease cancer mortality can be offered specifically to women who carry a mutation, but the optimal strategy for decreasing cancer mortality in BRCA1 families has not yet been determined. To facilitate further clinical and basic research in this field, our group and others have established multidisciplinary hereditary breast-ovarian cancer clinics that offer a wide range of services including BRCA1 testing, genetic counseling, and cancer prevention and treatment.

BRCA2 mutations in primary breast and ovarian cancers

The second hereditary breast cancer gene, BRCA2, was recently isolated. Germline mutations of this gene predispose carriers to breast cancer, and, to a lesser extent, ovarian cancer. Loss of heterozygosity (LOH) at the BRCA2 locus has been observed in 30-40% of sporadic breast and ovarian tumours, implying that BRCA2 may act as a tumour suppressor gene in a proportion of sporadic cases. To define the role of BRCA2 in sporadic breast and ovarian cancer, we screened the entire gene for mutations using a combination of techniques in 70 primary breast carcinomas and in 55 primary epithelial ovarian carcinomas. Our analysis revealed alterations in 2/70 breast tumours and none of the ovarian carcinomas. One alteration found in the breast cancers was a 2-basepair (bp) deletion (4710delAG) which was subsequently shown to be a germline mutation, the other was a somatic missense mutation (Asp3095Glu) of unknown significance. Our results suggest that BRCA2 is a very infrequent target for somatic inactivation in breast and ovarian carcinomas, similar to the results obtained for BRCA1.

Mutation analysis of the BRCA2 gene in 49 site-specific breast cancer families

The hereditary breast cancer gene BRCA2 was recently cloned and is believed to account for almost half of site-specific breast cancer families and the majority of male breast cancer families. We screened 49 site-specific breast cancer families for mutations in the BRCA2 gene using single strand conformation analysis (SSCA) followed by direct sequencing. We found mutations in eight families, including all four families with male breast cancer. The eight mutations were small deletions with the exception of a single nonsense mutation, an all were predicted to interrupt the BRCA2 coding sequence and to lead to a truncated protein product. Other factors which predicted the presence of a BRCA2 mutation included a case of breast cancer diagnosed at age 35 or below (P = 0.01) and a family history of pancreatic cancer (P = 0.03). Two mutations were seen twice, including a 8535delAG, which was detected in two French Canadian families. Our results suggest the possibility that the proportion of site-specific breast cancer families attributable to BRCA2 may be overestimated.

An inevitable dilemma: prenatal testing for mutations in the BRCA1 breast-ovarian cancer susceptibility gene

The BRCA1 breast-ovarian cancer susceptibility gene was identified recently. Germline mutations in BRCA1 may be responsible for as many as 5% of breast and ovarian cancers. Inherited alterations confer up to a 94% risk of developing breast and/or ovarian cancer by age 70. With the discovery of BRCA1, there will be a heavy demand for genetic testing. Because of the large size of the gene and the distribution of reported mutations, scientists face considerable technical problems in developing widely available screening tests; clinicians will face even greater ethical problems in applying them. In the context of research programs, women with BRCA1 mutations are already being identified, and their physicians are confronted with a number of complex medical, ethical, legal, and social issues. Obstetricians will be faced with counseling parents regarding prenatal testing for specific BRCA1 mutations. Although it is difficult to formulate straightforward guidelines regarding prenatal BRCA1 testing, clinicians and health care providers must be familiar with the nuances of the debate so that these issues can be discussed wisely with patients. As with many ethically challenging problems in medicine, individual clinicians and their patients will have to work together to determine the course of action with which they are most comfortable. Although elective termination of a pregnancy with a germline mutation in BRCA1 is an option, experience with other adult-onset diseases suggests that only a minority of parents will choose this option.

Carbamazepine inhibits NMDA-induced depolarizations in cortical wedges prepared from DBA/2 mice

There is some doubt as to the mechanism of action of the widely-used anticonvulsant drug, carbamazepine. In cortical wedges prepared from genetically epilepsy-prone DBA/2 mice, carbamazepine at therapeutic concentrations (1-10 microM) markedly reduced the depolarization produced by N-methyl-D-aspartate (NMDA). The NMDA sub-type of glutamate receptor has been implicated in the pathogenesis of epilepsy and the inhibitory action of carbamazepine on this response suggests that the anticonvulsant action of the drug may be due to its blockade of NMDA receptor-mediated events.

Desmethylimipramine potentiates NMDA responses in a mouse cortical slice preparation

Desmethylimipramine (DMI) has been shown to interact with the N-methyl-D-aspartate (NMDA) receptor complex. Its probable action is through blockade of the cationic channel at the phencyclidine site and as a result it has potential anticonvulsant action. In this present study we have investigated the effects of DMI and ketamine on both NMDA-induced and spontaneous depolarizing shifts in cortical wedges prepared from genetically epilepsy-prone mice (DBA/2). Contrary to published reports, DMI potentiated the effects of NMDA and increased the frequency of spontaneous depolarizations. The actions of ketamine were inhibitory and these were reversed by DMI. Presynaptic mechanisms may be involved in the DMI-induced potentiation and this may explain the lowering of convulsive thresholds seen clinically with tricyclic antidepressants.

Pathologic fractures of the humerus

In a study of 57 actual or impending pathologic fractures of the humerus in 52 patients with inoperable cancer treated between 1972 and 1982, we retrospectively reviewed the charts for analysis and comparison of the functional result and pain relief afforded by the various treatments used. Function of the extremity and relief of pain were each graded as excellent, good, fair, or poor using a modification of Perez's rating system. Seven pathologic fractures were treated nonoperatively. These patients generally had only fair pain relief and a poor functional result. Forty-six pathologic fractures were treated with intramedullary fixation using a Rush rod (n = 16), a Küntscher rod (n = 29), or an Ender rod (n = 1); the Neer endoprosthesis was used in four patients. Thirty-one patients received radiation to the humerus. There were seven operative complications, the most common (n = 3) being prominence of an intramedullary rod at the insertion site which required a second minor procedure for advancement of the rod. From this series, we conclude that any patient who has a pathologic fracture or impending fracture of the humerus and a predicted survival of six weeks or more is likely to benefit from rigid internal fixation with an appropriately selected device, adjunctive use of methylmethacrylate, and postoperative local irradiation therapy as needed.

Intraspinal pathways taken by sublaminar wires during removal. An experimental study

The neurological complications of segmental sublaminar stabilization that have been reported by other authors led us to perform a cineradiographic study of the pathways in the spinal canal that were taken by wires as they were being removed. The single wires were removed by pulling on the wire while keeping the wire perpendicular to the lamina; by winding the wire on the wire-extractor, with the wire being kept as nearly parallel with the lamina as possible (the roll-up technique); or by pulling on the wire while keeping the wire parallel with the lamina. During removal, thirty-four single wires conformed to the lamina and forty-one single wires compressed the dura. The roll-up technique caused the most erratic pathways. Double wires, although they were removed together, assumed independent pathways unless a wire-extractor guide was used. These findings suggest that the removal of sublaminar wires may cause dural compression in the clinical situation.