Daniel S. Oh

Estrogen-Regulated Genes Predict Survival in Hormone Receptor–Positive Breast Cancers

PURPOSE The prognosis of a patient with estrogen receptor (ER) and/or progesterone receptor (PR) -positive breast cancer can be highly variable. Therefore, we developed a gene expression-based outcome predictor for ER+ and/or PR+ (ie, luminal) breast cancer patients using biologic differences among these tumors. MATERIALS AND METHODS The ER+ MCF-7 breast cancer cell line was treated with 17beta-estradiol to identify estrogen-regulated genes. These genes were used to develop an outcome predictor on a training set of 65 luminal epithelial primary breast carcinomas. The outcome predictor was then validated on three independent published data sets. Results The estrogen-induced gene set identified in MCF-7 cells was used to hierarchically cluster a 65 tumor training set into two groups, which showed significant differences in survival (P = .0004). Supervised analyses identified 822 genes that optimally defined these two groups, with the poor-prognosis group IIE showing high expression of cell proliferation and antiapoptosis genes. The good prognosis group IE showed high expression of estrogen- and GATA3-regulated genes. Mean expression profiles (ie, centroids) created for each group were applied to ER+ and/or PR+ tumors from three published data sets. For all data sets, Kaplan-Meier survival analyses showed significant differences in relapse-free and overall survival between group IE and IIE tumors. Multivariate Cox analysis of the largest test data set showed that this predictor added significant prognostic information independent of standard clinical predictors and other gene expression-based predictors. CONCLUSION This study provides new biologic information concerning differences within hormone receptor-positive breast cancers and a means of predicting long-term outcomes in tamoxifen-treated patients.

Mutation of GATA3 in human breast tumors

GATA3 is an essential transcription factor that was first identified as a regulator of immune cell function. In recent microarray analyses of human breast tumors, both normal breast luminal epithelium and estrogen receptor (ESR1)-positive tumors showed high expression of GATA3. We sequenced genomic DNA from 111 breast tumors and three breast-tumor-derived cell lines and identified somatic mutations of GATA3 in five tumors and the MCF-7 cell line. These mutations cluster in the vicinity of the highly conserved second zinc-finger that is required for DNA binding. In addition to these five, we identified using cDNA sequencing a unique mis-splicing variant that caused a frameshift mutation. One of the somatic mutations we identified was identical to a germline GATA3 mutation reported in two kindreds with HDR syndrome/OMIM #146255, which is an autosomal dominant syndrome caused by the haplo-insufficiency of GATA3. The ectopic expression of GATA3 in human 293T cells caused the induction of 73 genes including six cytokeratins, and inhibited cell line doubling times. These data suggest that GATA3 is involved in growth control and the maintenance of the differentiated state in epithelial cells, and that GATA3 variants may contribute to tumorigenesis in ESR1-positive breast tumors.

High intraepithelial eosinophil counts in esophageal squamous epithelium are not specific for eosinophilic esophagitis in adults.

OBJECTIVESThe histologic criterion of >20 eosinophils per high power field (hpf) is presently believed to establish the diagnosis of idiopathic eosinophilic esophagitis (IEE). This is based on data that the number of intraepithelial eosinophils in gastroesophageal reflux disease (GERD) is less than 20/hpf. This study tests this belief.METHODSPathology records were searched for patients who had an eosinophil count >20/hpf in an esophageal biopsy. This patient population was biased toward adults with GERD who had routine multilevel biopsies of the esophagus. The clinical, radiological, and manometric data and biopsies were studied.RESULTSForty patients out of a total of 3,648 reports examined had an eosinophil count >20/hpf in squamous epithelium of an esophageal biopsy. Analysis of these 40 cases indicated that 6 (15%) patients had IEE, 2 (5%) had coincident IEE and GERD, 28 (70%) had GERD, and 2 (5%) each had achalasia and diverticulum. There was no significant difference among these groups in terms of maximum eosinophil number, biopsy levels with >20 esoinophils/hpf, presence of eosinophilic microabscesses, involvement of surface layers by eosinophils, and severity of basal cell hyperplasia and dilated intercellular spaces.CONCLUSIONAll histologic features presently ascribed to IEE can occur in other esophageal diseases, notably GERD. As such, the finding of intraepithelial eosinophilia in any number is not specific for IEE. When a patient with GERD has an esophageal biopsy with an eosinophil count >20/hpf, it does not mean that the patient has IEE.

Gene expression patterns associated with p53 status in breast cancer

BackgroundBreast cancer subtypes identified in genomic studies have different underlying genetic defects. Mutations in the tumor suppressor p53 occur more frequently in estrogen receptor (ER) negative, basal-like and HER2-amplified tumors than in luminal, ER positive tumors. Thus, because p53 mutation status is tightly linked to other characteristics of prognostic importance, it is difficult to identify p53s independent prognostic effects. The relation between p53 status and subtype can be better studied by combining data from primary tumors with data from isogenic cell line pairs (with and without p53 function).MethodsThe p53-dependent gene expression signatures of four cell lines (MCF-7, ZR-75-1, and two immortalized human mammary epithelial cell lines) were identified by comparing p53-RNAi transduced cell lines to their parent cell lines. Cell lines were treated with vehicle only or doxorubicin to identify p53 responses in both non-induced and induced states. The cell line signatures were compared with p53-mutation associated genes in breast tumors.ResultsEach cell line displayed distinct patterns of p53-dependent gene expression, but cell type specific (basal vs. luminal) commonalities were evident. Further, a common gene expression signature associated with p53 loss across all four cell lines was identified. This signature showed overlap with the signature of p53 loss/mutation status in primary breast tumors. Moreover, the common cell-line tumor signature excluded genes that were breast cancer subtype-associated, but not downstream of p53. To validate the biological relevance of the common signature, we demonstrated that this gene set predicted relapse-free, disease-specific, and overall survival in independent test data.ConclusionIn the presence of breast cancer heterogeneity, experimental and biologically-based methods for assessing gene expression in relation to p53 status provide prognostic and biologically-relevant gene lists. Our biologically-based refinements excluded genes that were associated with subtype but not downstream of p53 signaling, and identified a signature for p53 loss that is shared across breast cancer subtypes.

Does routine serial computed tomography of the head influence management of traumatic brain injury? A prospective evaluation.

BACKGROUND Computed tomography (CT) of the head is the current standard for diagnosing intracranial pathology following blunt head trauma. It is common practice to repeat the head CT to evaluate any progression of injury. Recent retrospective reviews have challenged the need for serial head CT after traumatic brain injury (TBI). This study intends to prospectively examine the value of routine serial head CT after TBI. METHODS Consecutive adult blunt trauma patients with an abnormal head CT admitted to an urban, Level I trauma center from January 2003 to September 2003 were prospectively studied. Variables collected included: initial head CT results, indication for repeat head CT (routine versus neurologic change), number and results of repeat head CT scans, and clinical interventions following repeat head CT. RESULTS Over the 9-month period, there were 128 patients admitted with an abnormal head CT after sustaining blunt trauma. The 16 patients who died within 24 hours and the 12 patients who went directly to craniotomy were excluded. The remaining 100 patients make up the study population. Abnormal head CT findings were subarachnoid hemorrhage (47%), intraparenchymal hemorrhage (37%), subdural hematoma (28%), contusion (14%), epidural hematoma (11%), intraventricular hemorrhage (3%), and diffuse axonal injury (2%). Overall, 32 patients (32%) had only the admission head CT, while 68 patients (68%) underwent 90 repeat CT scans. Of the repeat head CT scans, 81 (90%) were performed on a routine basis without neurologic change. The remaining 9 (10%) were performed for a change in Glasgow Coma Scale (n = 5), change in intracranial pressure (n = 1), change in Glasgow Coma Scale and intracranial pressure (n = 1), change in pupil size (n = 1), or sudden appearance of a headache (n = 1). Three patients had their care altered after repeat head CT: two underwent craniotomy and one was started on barbiturate therapy. All three patients had their repeat head CT after neurologic change (decrease in Glasgow Coma Scale in 2 and increase in intracranial pressure in 1). CONCLUSIONS Serial head CT is common after TBI. Most repeat head CT scans are performed on a routine basis without neurologic change. Few patients with TBI have their management altered after repeat head CT, and these patients have neurologic deterioration before the repeat head CT. The use of routine serial head CT in patients without neurologic deterioration is not supported by the findings of this study.

Porous hydroxyapatite scaffold with three-dimensional localized drug delivery system using biodegradable microspheres

In this study, ionic immobilization of dexamethasone (DEX)-loaded poly(lactic-co-glycolic acid) (PLGA) microspheres was performed on the hydroxyapatite (HAp) scaffold surfaces. It was hypothesized that in vivo bone regeneration could be enhanced with HAp scaffolds containing DEX-loaded PLGA microspheres compared to the use of HAp scaffolds alone. In vitro drug release from the encapsulated microspheres was measured prior to the implantation in the femur defects of beagle dogs. It was observed that porous, interconnected HAp scaffolds as well as DEX-loaded PLGA microspheres were successfully fabricated in this study. Additionally, PEI was successfully coated on PLGA microsphere surfaces, resulting in a net positive-charged surface. With such modification of the PLGA microsphere surfaces, DEX-loaded PLGA microspheres were immobilized on the negatively charged HAp scaffold surfaces. Release profile of DEX over a 4week immersion study indicated an initial burst release followed by a sustained release. In vivo evaluation of the defects filled with DEX-loaded HAp scaffolds indicated enhanced volume and quality of new bone formation when compared to defects that were either unfilled or filled with HAp scaffolds alone. This innovative platform for bioactive molecule delivery more potently induced osteogenesis in vivo, which may be exploited in implantable bone graft substitutes for stem cell therapy or improved in vivo performance. It was thus concluded that various bioactive molecules for bone regeneration might be efficiently incorporated with calcium phosphate-based bioceramics using biodegradable polymeric microspheres.

A Comparison of Pancreaticogastrostomy and Pancreaticojejunostomy Following Pancreaticoduodenectomy

This retrospective study compares the results of pancreaticogastrostomy (PG) and pancreaticojejunostomy (PJ) in our institution, which has extensive experience in both techniques. Between the years of June 1995 and June 2001, 214 patients underwent pancreaticoduodenectomy (PD) at our institution. Of these 177 had PG and 97 had pancreatojejunostomy (PJ). There were 117 (54.6%) males and 97 (45.3%) females with a mean age of 64.2 ± 12.4 years. Indications for surgery were pancreatic adenocarcinoma in 101 (47.2%), ampullary adenocarcinoma in 36 (16.9%), distal bile duct adenocarcinoma in 22 (10.2%), duodenal adenocarcinoma in 9 (4.2%), and miscellaneous causes in 46 (21.4%) of patients. Preoperatively, significant differences in the groups were that the patients undergoing PJ were significantly younger than those undergoing PG. Also noted preoperatively, was that the patients undergoing PG had a significantly lower direct bilirubin than those undergoing PJ. With regard to intraoperative parameters, operative time was significantly shorter in the PJ group when compared to the PG group. When the patients who did not develop fistula (N = 186) were compared to those who developed fistula (N = 28) the significant differences were that the patients who developed fistula were more likely to have hypertension preoperatively and a higher alkaline phosphatase. They also showed a significantly higher drain amylase and were likely to have surgery for ampullary, distal bile duct or duodenal carcinoma rather than pancreatic adenocarinoma. In addition, those patients who developed fistula had a significantly longer postoperative stay, a larger number of intraabdominal abscesses and leaks at the biliary anastomosis. Thirty-day mortality was significantly higher in the PJ group compared to the PG (4 vs. 0, P = 0.041). There was a significantly larger number of bile leaks in the PJ group when compared to the PG (6 vs. 1, P = 0.048). In addition, the PJ group required a significantly larger number of new CT guided drains to control infection (8 vs. 2,P = 0.046) and the PJ group required a larger number of re-explorations to control infection or bleeding (5 vs. 0, P = 0.018). However, the pancreatic fistula rate was not different between the two groups (12% [PG] vs. 14% [PJ]). This retrospective analysis shows that safety of PG can be performed safely and is associated with less complications than PJ and proposes PG as a suitable and safe alternative to PJ for the management of the pancreatic remnant following PD.

Intraoperative Assessment of Perfusion of the Gastric Graft and Correlation With Anastomotic Leaks After Esophagectomy.

Anastomotic complications are a major source of morbidity after esophagectomy with gastric pull-up and are often related to poor graft perfusion. The aim of this study was to evaluate the use of laser-assisted fluorescent-dye angiography to assess perfusion in gastric grafts and determine the relationship between perfusion and anastomotic leaks.

The Impact of Reflux Composition on Mucosal Injury and Esophageal Function

The components of refluxed gastric juice are known to cause mucosal injury, but their effect on esophageal function is less appreciated. Our aim was to determine the effect of acid and/or bile on mucosal injury and esophageal function. From 1993–2004, 402 patients with reflux symptoms had 24-hour pH and Bilitec monitoring, manometry, and endoscopy with biopsies. Mucosal injury (esophagitis or Barrett’s esophagus) and esophageal function (lower esophageal sphincter [LES] characteristics and body contractility) in patients with acid reflux, bile reflux, or both were compared with patients without reflux. Reflux was present in 273/402 patients; of these, 37 (13.5%) had increased exposure to bile, 82 (30.0%) had increased exposure to acid, and 154 (56.4%) had increased exposure to both. Mucosal injury was most common with increased mixed acid and bile exposure, followed by acid alone, and was uncommon with bile alone (P<0.0001). Functional deterioration paralleled mucosal injury (P<0.0001). Mixed acid and bile exposure was present in more than half of patients with reflux and was associated with the most severe mucosal injury and the greatest deterioration of esophageal function. This suggests that composition of gastric juice is the primary determinant of inflammatory mucosal injury and subsequent loss of esophageal function.

Alimentary satisfaction, gastrointestinal symptoms, and quality of life 10 or more years after esophagectomy with gastric pull-up

OBJECTIVE The aim of this study was to evaluate alimentary satisfaction, gastrointestinal symptoms, and quality of life ≥10 years after esophagectomy with gastric pull-up. METHODS Patients who had undergone esophagectomy with gastric pull-up before 2003 were interviewed regarding their alimentary function and completed the Gastrointestinal Quality of Life and RAND short-form, 36-item, questionnaires. RESULTS We identified 67 long-term survivors after esophagectomy and gastric pull-up. Of these, 40 were located, and all agreed to participate. The median age was 75 years, and the median follow-up period was 12 years (interquartile range, 10-19). Most patients (88%) had no dysphagia, 90% were able to eat ≥3 meals/day, and 93% finished ≥50% of a typical meal. The mean alimentary comfort rating was 9 of 10. Dumping, diarrhea ≥3 times/day, or regurgitation occurred in 33% of patients. Six patients (15%) had aspiration episodes requiring hospitalization. The median weight loss after surgery was 26 lbs, and the current median body mass index was 25 kg/m(2). Only 2 patients were underweight (body mass index, <18.5 kg/m(2)). The median Gastrointestinal Quality of Life score was 2.9 of 4. The RAND scores were at the population mean in 1 category (physical function) and above the normal mean in the remaining 7 categories. CONCLUSIONS Long-term nutritional status, quality of life, and satisfaction with eating were excellent after esophagectomy with gastric pull-up. Gastrointestinal side effects were common, but serious complications such as aspiration were uncommon. Pessimism regarding the long-term ability to enjoy a meal and live with a good quality of life after esophagectomy is unwarranted.