Jeffrey E. Boyd

Estrogen Resistance Caused by a Mutation in the Estrogen-Receptor Gene in a Man

BACKGROUND AND METHODS Mutations in the estrogen-receptor gene have been thought to be lethal. A 28-year-old man whose estrogen resistance was caused by a disruptive mutation in the estrogen-receptor gene underwent studies of pituitary-gonadal function and bone density and received transdermal estrogen for six months. Estrogen-receptor DNA, extracted from lymphocytes, was evaluated by analysis of single-strand-conformation polymorphisms and by direct sequencing. RESULTS The patient was tall (204 cm [80.3 in.]) and had incomplete epiphyseal closure, with a history of continued linear growth into adulthood despite otherwise normal pubertal development. He was normally masculinized and had bilateral axillary acanthosis nigricans. Serum estradiol and estrone concentrations were elevated, and serum testosterone concentrations were normal. Serum follicle-stimulating hormone and luteinizing hormone concentrations were increased. Glucose tolerance was impaired, and hyperinsulinemia was present. The bone mineral density of the lumbar spine was 0.745 g per square centimeter, 3.1 SD below the mean for age-matched normal women; there was biochemical evidence of increased bone turnover. The patient had no detectable response to estrogen administration, despite a 10-fold increase in the serum free estradiol concentration. Conformation analysis of his estrogen-receptor gene revealed a variant banding pattern in exon 2. Direct sequencing of exon 2 revealed a cytosine-to-thymine transition at codon 157 of both alleles, resulting in a premature stop codon. The patients parents were heterozygous carriers of this mutation, and pedigree analysis revealed consanguinity. CONCLUSIONS Disruption of the estrogen receptor in humans need not be lethal. Estrogen is important for bone maturation and mineralization in men as well as women.

Frequent Mutation of the PIK3CA Gene in Ovarian and Breast Cancers

Purpose: Activation of the phosphatidylinositol 3-kinase (PI3K)-AKT pathway, resulting in increased cell proliferation, survival, and motility, is believed to play an oncogenic role in many cancer types. The PIK3CA gene encodes the p110α catalytic subunit of PI3K, and is amplified in some ovarian cancers, whereas the AKT2 gene is amplified in some ovarian, breast, and pancreatic cancers. Recently, in a mutational screen of eight PI3K genes and eight PI3K-like genes, PIK3CA was found to be the only gene affected by somatic mutations, which were observed frequently in gastrointestinal and brain cancers. Here, we test whether PIK3CA is subject to mutation in ovarian and breast cancers. Experimental Design: Exons 9 and 20, encoding the highly conserved helical and kinase domains of PIK3CA, were subjected to sequence analysis in 198 advanced stage epithelial ovarian carcinomas and 72 invasive breast carcinomas (48 of ductal histology and 24 of lobular histology). Results: Somatic missense mutations were observed in 24 of 198 (12%) ovarian carcinomas, and in 13 of 72 (18%) breast carcinomas. Conclusions: These data indicate that mutations of PIK3CA play an oncogenic role in substantial fractions of ovarian and breast carcinomas, and in consideration of mutation of other components of the PI3K-AKT pathway in both tumor types, confirm the major oncogenic role of this pathway in ovarian and breast carcinomas.

Genome-wide association study provides evidence for a breast cancer risk locus at 6q22.33

We performed a three-phase genome-wide association study (GWAS) using cases and controls from a genetically isolated population, Ashkenazi Jews (AJ), to identify loci associated with breast cancer risk. In the first phase, we compared allele frequencies of 150,080 SNPs in 249 high-risk, BRCA1/2 mutation-negative AJ familial cases and 299 cancer-free AJ controls using χ2 and the Cochran–Armitage trend tests. In the second phase, we genotyped 343 SNPs from 123 regions most significantly associated from stage 1, including 4 SNPs from the FGFR2 region, in 950 consecutive AJ breast cancer cases and 979 age-matched AJ controls. We replicated major associations in a third independent set of 243 AJ cases and 187 controls. We obtained a significant allele P value of association with AJ breast cancer in the FGFR2 region (P = 1.5 × 10−5, odds ratio (OR) 1.26, 95% confidence interval (CI) 1.13–1.40 at rs1078806 for all phases combined). In addition, we found a risk locus in a region of chromosome 6q22.33 (P = 2.9 × 10−8, OR 1.41, 95% CI 1.25–1.59 at rs2180341). Using several SNPs at each implicated locus, we were able to verify associations and impute haplotypes. The major haplotype at the 6q22.33 locus conferred protection from disease, whereas the minor haplotype conferred risk. Candidate genes in the 6q22.33 region include ECHDC1, which encodes a protein involved in mitochondrial fatty acid oxidation, and also RNF146, which encodes a ubiquitin protein ligase, both known pathways in breast cancer pathogenesis.

A gene signature predicting for survival in suboptimally debulked patients with ovarian cancer.

Despite the existence of morphologically indistinguishable disease, patients with advanced ovarian tumors display a broad range of survival end points. We hypothesize that gene expression profiling can identify a prognostic signature accounting for these distinct clinical outcomes. To resolve survival-associated loci, gene expression profiling was completed for an extensive set of 185 (90 optimal/95 suboptimal) primary ovarian tumors using the Affymetrix human U133A microarray. Cox regression analysis identified probe sets associated with survival in optimally and suboptimally debulked tumor sets at a P value of <0.01. Leave-one-out cross-validation was applied to each tumor cohort and confirmed by a permutation test. External validation was conducted by applying the gene signature to a publicly available array database of expression profiles of advanced stage suboptimally debulked tumors. The prognostic signature successfully classified the tumors according to survival for suboptimally (P = 0.0179) but not optimally debulked (P = 0.144) patients. The suboptimal gene signature was validated using the independent set of tumors (odds ratio, 8.75; P = 0.0146). To elucidate signaling events amenable to therapeutic intervention in suboptimally debulked patients, pathway analysis was completed for the top 57 survival-associated probe sets. For suboptimally debulked patients, confirmation of the predictive gene signature supports the existence of a clinically relevant predictor, as well as the possibility of novel therapeutic opportunities. Ultimately, the prognostic classifier defined for suboptimally debulked tumors may aid in the classification and enhancement of patient outcome for this high-risk population.

BRCA1, BRCA2, and hereditary nonpolyposis colorectal cancer gene mutations in an unselected ovarian cancer population: Relationship to family history and implications for genetic testing

OBJECTIVE Our purpose was to determine the prevalence of BRCA1, BRCA2, and hereditary nonpolyposis colorectal cancer gene mutations in a large, unselected population of ovarian cancer patients and to evaluate the relationship between mutation status and a routinely obtained family history of cancer. STUDY DESIGN One hundred sixteen consecutive ovarian cancer patients seen for routine clinical care were examined for BRCA1, BRCA2, hMSH2, and hMLH1 gene mutations with use of the polymerase chain reaction, single-strand conformation polymorphism analysis, and direct gene sequencing. Fishers exact test was used to evaluate possible associations between BRCA1 and BRCA2 mutation status and specific familial characteristics. RESULTS Among 116 unselected ovarian cancer patients we identified a total of 13 germline mutations in 12 patients: 10 in BRCA1, one each in hMSH2 and hMLH1, and a single BRCA2 mutation, which occurred in a patient also carrying a BRCA1 mutation. More than half the patients with BRCA1 mutations had family histories that would generally be considered unremarkable. Of 22 family history variables analyzed, only two (maternal family history of breast or ovarian cancer, p=0.037, and maternal family history of any cancer, p=0.020) conferred a significantly increased risk of carrying a BRCA1 mutation compared with ovarian cancer patients without such a history. However, the majority of ovarian cancer patients with these family histories and other suggestive histories tested negative for mutations. CONCLUSIONS Approximately 10% of ovarian cancers occur in association with genetic mutations known to predispose to the disease. A routinely obtained family history is an unreliable way to identify patients who might harbor mutations. The majority of ovarian cancer patients with suggestive family histories test negative for known gene mutations, perhaps suggesting the existence of additional undiscovered genes predisposing to ovarian cancer.

Automated diagnosis and image understanding with object extraction, object classification, and inferencing in retinal images

Medical imaging is shifting from film to electronic images. The STARE (structured analysis of the retina) system is a sophisticated image management system that will automatically diagnose images, compare images, measure key features in images, annotate image contents, and search for images similar in content. The authors concentrate on automated diagnosis. The images are annotated by segmentation of objects of interest, classification of the extracted objects, and reasoning about the image contents. The inferencing is accomplished with Bayesian networks that learn from image examples of each disease. This effort at image understanding in fundus images anticipates the future use of medical images. As these capabilities mature, the authors expect that ophthalmologists and physicians in other fields that rely in images will use a system like STARE to reduce repetitive work, to provide assistance to physicians in difficult diagnoses or with unfamiliar diseases, and to manage images in large image databases.

Clinicopathologic Significance of Defective DNA Mismatch Repair in Endometrial Carcinoma

PURPOSE Defective DNA mismatch repair is commonly present in sporadic manifestations of gastrointestinal, endometrial, and other cancers. The pathognomonic molecular manifestation of this repair defect is microsatellite instability (MSI). Here, we test the hypothesis that MSI predicts the clinicopathologic features of endometrial carcinoma. PATIENTS AND METHODS A retrospective cohort of 473 patients treated for endometrial carcinoma at this institution was identified. All cases were reviewed by a gynecologic pathologist, and clinical information was abstracted from medical records. Using consensus criteria, DNA samples from nontumor and tumor tissue pairs were genotyped for MSI. Associations between MSI status and pathologic and clinical variables were assessed. RESULTS Ninety-three (20%) of 473 tumors were MSI+. In the MSI+ tumor group compared with the MSI- tumor group, the proportion of advanced compared with early-stage tumors was higher (92% v 81%; P = .01), as was the proportion of tumors of endometrioid compared with nonendometrioid histologic subtype (94% v 23%; P = .001), and the proportion of tumors with myometrial invasion compared with those with none (92% v 78%; P = .01). By multivariate analyses, disease-free survival (hazard ratio, 0.3; 95% CI, 0.2 to 0.7) and disease-specific survival (hazard ratio, 0.3; 95% CI, 0.1 to 0.8) were significantly improved in patients with MSI+ tumors. CONCLUSION In endometrial carcinoma, the presence of MSI was independently associated with a more favorable clinical outcome.

A Phase II Trial of Erlotinib in Combination with Bevacizumab in Patients with Metastatic Breast Cancer

Purpose: To evaluate the efficacy and toxicity of erlotinib plus bevacizumab in patients with metastatic breast cancer (MBC), targeting the epidermal growth factor receptor (EGFR/HER1) and the vascular endothelial growth factor (VEGF) pathway. Experimental Design: Thirty-eight patients with MBC were enrolled and treated at two institutions with erlotinib, a small molecule EGFR tyrosine kinase inhibitor (150 mg p.o. daily) plus bevacizumab, an anti-VEGF antibody (15 mg/kg i.v. every 3 weeks). Patients had one to two prior chemotherapy regimens for metastatic disease. The primary end point was response rate by Response Evaluation Criteria in Solid Tumors criteria using a Simon 2-stage design. Secondary end points included toxicity, time to progression, response duration, and stabilization of disease of ≥26 weeks. Correlative studies were done on tumor tissue, including EGFR expression and mutation analysis. Results: One patient achieved a partial response for 52+ months. Fifteen patients had stable disease at first evaluation at 9 weeks; 4 of these patients had stable disease beyond 26 weeks. Median time to progression was 11 weeks (95% confidence interval, 8-18 weeks). Diarrhea of any grade was observed in 84% of patients (grade 3 in 3%); 76% experienced grade 1 or 2 skin rash, and 18% developed hypertension (grade 3 in 11%). The level of EGFR expression was not predictive of response to therapy. Conclusions: The combination of erlotinib and bevacizumab was well-tolerated but had limited activity in unselected patients with previously treated MBC. Biomarkers are needed to identify those MBC patients likely to respond to anti-EGFR/HER1 plus anti-VEGF therapy.

Current understanding of the epidemiology and clinical implications of BRCA1 and BRCA2 mutations for ovarian cancer.

Genetic testing for susceptibility to ovarian cancer is rapidly becoming integrated into the clinical practice of oncology. Genetic testing for BRCA1 and BRCA2 is now recommended to most women with invasive ovarian cancer. Approximately 10% of these women will have a positive test, including 4% of women without a family history of cancer. Currently, the treatment of hereditary ovarian cancer is the same as for non-hereditary ovarian cancer. It appears that women with ovarian cancer and a BRCA mutation experience better survival than women without a mutation, possibly due to enhanced susceptibility to chemotherapy. Strategies for prevention of ovarian cancer among carriers include oral contraceptives, tubal ligation and prophylactic oophorectomy.

Describing motion for recognition

Our goal is to describe motion of a moving human figure in order to recognize individuals by variation in the characteristics of the motion description. We begin with a short sequence of images of a moving figure, taken by a static camera, and derive dense optical flow data for the sequence. We determine a range of scale-independent features of each how image as a whole, ranging from the motion of the centroid of the moving points (assuming a static background), to the integral of the torque relative to the centroid. We then analyze the periodic structure of these sequences. All elements are multiples of the fundamental period of the gait, but they differ in phase. The phase is time-invariant, since it is independent of the sampling period. We show that there are several regularities in the phase differences of the signals. Moreover, some scalar measures of the signals may be useful in recognition. The representation is model-free, and therefore could be used to characterize the motion of other non-rigid bodies.