Biomedical subjects

Brendan C Stack

Publications and source records attributed to Brendan C Stack.

At least 19 recordsLinked to original sources

PubMed2007

Using comorbidity indexes to predict costs for head and neck cancer.

OBJECTIVE: To determine whether the general Charlson Comorbidity Index (CCI) and the head and neck cancer-specific Washington University Head and Neck Cancer Comorbidity Index (WUHNCCI) were useful for predicting cost of treatment for elderly patients with head and neck cancer. DESIGN: Retrospective, observational study. PATIENTS: A total of 1780 Medicare patients with head and neck cancer, who were treated between 1984 and 1994, were analyzed using the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database. MAIN OUTCOME MEASURES: Total Medicare payments were accumulated for each patient up to 1 and 5 years. Linear regression was used to estimate the impact of the comorbidity indexes on costs, controlling for demographics, site, stage, and treatment modality. RESULTS: Neither the WUHNCCI nor the CCI was significantly associated with 1-year costs. However, the effect of the WUHNCCI on 5-year costs was statistically significant (P<.001). A 1-point increase in the WUHNCCI from 4 to 5 was associated with an increase in 5-year costs of $2105. A 1-point increase in the WUHNCCI from 9 to 10 was associated with an increase in 5-year costs of $2837. CONCLUSION: These results suggest that comorbidity indexes for head and neck cancer may be useful for prognostication of patient outcomes and predicting costs.

Aged↗

PubMed2006

Enhanced growth inhibition of squamous cell carcinoma of the head and neck by combination therapy of fusaric acid and paclitaxel or carboplatin.

Combination of a single dose of paclitaxel with three different dosages of FA resulted in significant (P<0.001) reductions in cell number from controls, paclitaxel alone, and FA treatments alone at four different time points. Combination of a single dose of carboplatin with three different dosages of FA resulted in significant (P<0.001) reductions in cell number from controls and carboplatin treatment alone at 72 and 96 h. Our data suggest that these combinations may provide an enhanced anti-tumor effect with respect to HNSCC. Since, FA can be administered orally, this regimen may introduce a paradigm change in chemotherapy for HNSCC.

Aged↗

PubMed2006

The cost-effectiveness of additional preoperative ultrasonography or sestamibi-SPECT in patients with primary hyperparathyroidism and negative findings on sestamibi scans.

OBJECTIVE: To determine whether the use of additional preoperative imaging was cost-effective compared with bilateral neck exploration (BNE) for the treatment of primary hyperparathyroidism in patients with negative findings on scans with technetium Tc 99m sestamibi. DESIGN: We performed a cost-effectiveness analysis. The decision whether to proceed to BNE or obtain additional preoperative imaging using ultrasonography (US) or single-photon emission computed tomography with technetium Tc 99m sestamibi (SPECT) was modeled using decision analysis. We obtained probabilities of cure, detection of pathologic glands, and the correct side of the neck from recent literature. MAIN OUTCOME MEASURES: Expected cost, cure rate, and the incremental cost per cured case using the preoperative imaging strategies compared with BNE. RESULTS: The US strategy dominated the SPECT and BNE strategies, with a lower expected cost (USD $6030 vs USD $7131 and $8384, respectively) and a greater expected cure rate (99.42% vs 99.26% and 97.69%, respectively). Threshold analysis suggests that the preoperative imaging strategies continued to dominate unless the cost of BNE was less than USD $5400 or the cost of unilateral neck exploration exceeded USD $6500. The US strategy dominated SPECT as a preoperative imaging strategy if the cost of SPECT exceeded $12 or the cost of a US test was less than $1300. CONCLUSIONS: For the treatment of primary hyerparathyroidism in the patient with negative findings on technetium Tc 99m sestamibi scans, a strategy that uses additional preoperative US imaging appears to be cost-effective compared with SPECT or BNE.

Cost-Benefit Analysis↗

PubMed2006

The cost-effectiveness of iodine 131 scintigraphy, ultrasonography, and fine-needle aspiration biopsy in the initial diagnosis of solitary thyroid nodules.

OBJECTIVE: To compare the cost-effectiveness of fine-needle aspiration biopsy, iodine 131 scintigraphy, and ultrasonography for the initial diagnostic workup of a solitary palpable thyroid nodule. DESIGN: A deterministic cost-effectiveness analysis was conducted using a decision tree to model the diagnostic strategies. SETTING: A single, mid-Atlantic academic medical center. MAIN OUTCOME MEASURES: Expected costs, expected number of cases correctly diagnosed, and incremental cost per additional case correctly diagnosed. RESULTS: Relative to the routine use of fine-needle aspiration biopsy, the incremental cost per case correctly diagnosed is 24,554 dollars for the iodine 131 scintigraphy strategy and 1212 dollars for the ultrasound strategy. CONCLUSIONS: A diagnostic strategy using initial fine-needle aspiration biopsy for palpable thyroid nodules was found to be cost-effective compared with the other approaches as long as a payor's willingness to pay for an additional correct diagnosis is less than 1212 dollars. Prospective studies are needed to validate these finding in clinical practice.

Biopsy, Needle↗

PubMed2006

The effect of single agent oral fusaric acid (FA) on the growth of subcutaneously xenografted SCC-1 cells in a nude mouse model.

OBJECTIVE: To determine whether oral administration of fusaric acid (FA) inhibits tumor growth in an animal model of head and neck cancer (HNSCC). DESIGN: In vivo murine model, two arm controlled study. METHODS: Thirty-eight (38) 5-week-old athymic nude mice were randomly assigned to a fusaric acid treatment group (1 mg/mL) (n = 19) or a sterile saline group (n = 19). A left, lateral flank subcutaneous injection of 2.0 x 10(6) UM-SCC-1 cells were administered to all mice on day 1. Both groups were gavaged daily with either 0.25 mLs of oral FA or sterile saline throughout the experiment (32 days). Latency to a measurable tumor (> or =65 mm3), and tumor volumes were recorded after tumor xenografting. Tumor weights were recorded at the conclusion of the experiment. Tumor volume growth curves were modeled as polynomial functions of time with treatment interaction effects. Survivorship functions for time to measurable tumor were estimated using the Kaplan-Meier product limit estimator. RESULTS: Survival analysis showed mice treated with FA developed measurable tumors after a significantly longer interval post-xenografting than control mice (p = 0.00451). By Day 9, all mice in the control group had developed measurable tumors in comparison to only 78% of mice in the FA group. Likewise, estimated growth curves for both groups suggested that mice receiving FA demonstrated significantly slower tumor growth rates throughout the entire study period (p < 0.0001). At the conclusion of the experiment, tumor weights from both the control and FA groups were also significantly different (p = 0.0142). CONCLUSIONS: Single agent oral fusaric acid (1 mg/mL) is an inhibitor of UM-SCC-1 in a murine model. As an orally active agent, it may have a potential role in the treatment of human squamous cell carcinoma of the head and neck.

Administration, Oral↗

PubMed2006

Successful recovery of esophageal patency in 2 patients with complete obstruction by using combined antegrade retrograde dilation procedure, needle knife, and EUS needle.

BACKGROUND: Esophageal occlusion is typically caused by cancer or postradiation changes; it is difficult to treat, with poor surgical outcomes. The combined antegrade retrograde dilation (CARD) method has been used to endoscopically restore the esophageal lumen after complete occlusion by cancer or postradiation changes, with good preliminary results. Reproducing this technique and improving its speed and convenience would be advances in treating this difficult clinical problem. OBJECTIVE: A demonstration of 2 alternative endoscopic techniques for treating complete esophageal obstructions. DESIGN: The CARD method was performed in 2 patients with unresectable cancer and complete esophageal occlusion. In the first patient, a needle knife was used to cut through the obstruction, instead of removing it piecemeal with biopsy forceps before over-the-wire dilation. In the second patient, an EUS needle was used to cross a particularly long obstruction, which allowed subsequent dilation and recanalization. SETTING: A tertiary referral center. PATIENTS: Two patients with complete esophageal obstruction secondary to head and neck cancer, with associated radiation therapy. RESULTS: In both cases, this method resulted in successful recanalization of the occluded lumen in a relatively short amount of time, without complications. LIMITATIONS: The small number of patients in this series. CONCLUSIONS: The CARD needle-knife method may be a safe, effective, and efficient approach to complete esophageal occlusion. In addition, the CARD-EUS needle method may be an preferable technique to cross long obstructions quickly; however, more experience will be required.

Aged↗

PubMed2006

Color doppler ultrasonography is a reliable predictor of free tissue transfer outcomes in head and neck reconstruction.

OBJECTIVE: The purpose of our investigation was to report our experience with a color flow doppler (CFD) ultrasonography for postoperative monitoring of free tissue transfers. METHODS: A retrospective analysis of head and neck free tissue transfers at a single institution between 2000 and 2005 (n = 84; 80 successful, 4 failures). CFD measured blood flow velocity (cm/sec) and resistance to flow in the pedicle vein and artery on postoperative days 1, 3, and 7. RESULTS: Analysis of artery/vein ratio revealed vascular congestion by postoperative day 3 which later resolved. In flap failures, there was a significant reduction (P < 0.05) in venous blood flow by postoperative day 3. Waveform morphology representing vascular resistance and origin of donor flap did not correlate with flap outcome (r(2) = 0.23 and 0.44 respectively). CONCLUSION: Postoperative monitoring of free tissue transfers may allow for detection of poor perfusion. CFD is an objective method of studying blood flow postoperatively. EBM RATING: C-4.

Blood Flow Velocity↗

PubMed2006

Endoscopic extruded screw removal after anterior cervical disc fusion: technical case report.

OBJECTIVE AND IMPORTANCE: Symptomatic complications related to screw migration and extrusion after anterior cervical disc fusion are uncommon. CLINICAL PRESENTATION: We report a case of significant dysphagia owing to late screw migration. INTERVENTION: An endoscopic transpharyngeal removal was performed without pharyngeal closure and with relief of symptoms. CONCLUSION: A transpharyngeal endoscopic approach to remove loose anterior cervical hardware is feasible and warrants further evaluation.

Bone Screws↗

PubMed2005

Opioid growth factor enhances tumor growth inhibition and increases the survival of paclitaxel-treated mice with squamous cell carcinoma of the head and neck.

Paclitaxel is used as a single agent, and in combination with other drugs, as a standard of care in the treatment of squamous cell carcinoma of the head and neck (SCCHN). However, the use of paclitaxel for therapy of SCCHN may be accompanied by serious side effects. Paclitaxel is a known cytotoxic inhibitor of cell proliferation that acts by stabilizing microtubules and inducing apoptosis. Opioid growth factor (OGF), [Met(5)]-enkephalin, is an endogenous peptide that has tonically active inhibitory effects on the growth of SCCHN in vitro and in vivo. OGF action is rapid, reversible, mediated by the nuclear-associated OGF receptor (OGFr), and is not cytotoxic (nor apoptotic related). The present study was designed to examine whether a combination of chemotherapy with paclitaxel and biotherapy with OGF is more effective than either agent alone in inhibiting tumor growth. Moreover, focus was placed on whether there are changes in the side effects known to occur with paclitaxel alone, following this combined therapy. Human SCC-1 cells, derived from a well differentiated SCCHN, were transplanted into athymic mice. The mice were randomized to receive intraperitoneal (i.p.) injections of sterile saline (controls), OGF (10 mg/kg, daily), paclitaxel (8 mg/kg, every other day), or both paclitaxel (8 mg/kg, every other day) and OGF (10 mg/kg, daily) beginning on the day of tumor inoculation. OGF, but not paclitaxel, delayed measurable and visible tumor appearance of mice with SCCHN. Treatment with paclitaxel, but not with other agents, had a marked effect on the body weights. Survival only was reduced in the paclitaxel group, with an average life span of 34.3+/-3.1 days recorded, in comparison to the 50-day survival (date of termination) for all other groups. Beginning after week 4 of tumor inoculation and drug treatment, the tumor weight of the paclitaxel/OGF group was significantly reduced from the control, OGF, and paclitaxel-exposed mice. The OGFr number of the SCCHN tumors was 2.1-fold greater in the animals exposed to OGF or paclitaxel, and elevated 38% in the paclitaxel/OGF group; significant differences from the control group were found for the OGF and paclitaxel groups. These data suggest that combined chemotherapy (i.e., paclitaxel) and biotherapy (OGF) provides a valuable alternative to the standard of care for SCCHN patients.

Animals↗

PubMed2005

Relationship of technetium Tc 99m sestamibi scans to histopathological features of hyperfunctioning parathyroid tissue.

OBJECTIVE: To investigate the histopathological features of pathologic parathyroid specimens associated with negative preoperative technetium Tc 99m sestamibi scans. DESIGN: Retrospective study. SETTING: Tertiary care center. PATIENTS: One hundred fourteen patients who underwent sestamibi scans before surgical exploration for primary hyperparathyroidism between 1996 and 2001. INTERVENTIONS: Surgical exploration and removal of parathyroid adenomas. MAIN OUTCOME MEASURES: Histopathological characteristics associated with true-positive and false-negative sestamibi scans, including parathyroid specimen weight, size, relative oxyphil and chief cell content, parathyroid hormone staining patterns, cellular architecture, and various immunohistochemical staining patterns. RESULTS: Twenty-three (24%) of 98 patients with parathyroid adenomas had negative sestamibi scan results. Among 20 age- and sex-matched patients with false-negative results vs 20 patients with true-positive results, tumor size (P = .04) and oxyphil cell content (P = .03) were found to be significantly different. CONCLUSION: Parathyroid gland size and oxyphil content are descriptive and predict differences between sestamibi properties of parathyroid adenomas but have no current therapeutic implications for parathyroid surgery.

Adenoma↗

PubMed2005

A systematic review of the diagnosis and treatment of primary hyperparathyroidism from 1995 to 2003.

OBJECTIVE: To systematically review the current preoperative diagnostic modalities, surgical treatments, and glandular pathologies associated with primary hyperparathyroidism. STUDY DESIGN: A systematic literature review. RESULTS: Of the 20,225 cases of primary hyperparathyroidism reported, solitary adenomas (SA), multiple gland hyperplasia disease (MGHD), double adenomas (DA), and parathyroid carcinomas (CAR) occurred in 88.90%, 5.74%, 4.14%, and 0.74% of cases respectively. Tc 99m -sestamibi and ultrasound were 88.44% and 78.55% sensitive, respectively, for SA, 44.46% and 34.86% for MGHD, and 29.95% and 16.20% for DA, respectively. Postoperative normocalcemia was achieved in 96.66%, 95.25%, and 97.69% of patients offered minimally invasive radio-guided parathyroidectomy (MIRP), unilateral, and bilateral neck exploration (BNE). Intraoperative PTH assays (IOPTH) were helpful in approximately 60% of bilateral neck exploration conversion (BNEC) surgeries. CONCLUSION: The overall prevalence of multiple gland disease (MGD and DA) was lower than often suggested by conventional wisdom. Furthermore, preoperative imaging was less accurate than it is often perceived for accurately imaging MGD. MIRP and UNE were more successful in achieving normocalcemia than is typically quoted. IOPTH was a helpful but not "fool-proof" adjunct in parathyroid exploration surgery. SIGNIFICANCE: These results support a greater role for the treatment of primary hyperparathyroidism using less invasive approaches. EMB rating: B-3.

Humans↗

PubMed2005

Is routine frozen section necessary for parathyroid surgery?

OBJECTIVE: Successful parathyroidectomy requires identification and excision of 1 or more abnormal parathyroid glands. The pathologist confirms or refutes the intraoperative presence of parathyroid tissue in excised material. With the advent of radionuclide scanning and rapid parathyroid hormone assays, the role of routine frozen section (FS) has once again been called into question. Our aim was to assess the need for routine FS in tissue identification during parathyroidectomy in a series of 50 consecutive cases. METHODS: We analyzed 50 consecutive parathyroidectomies performed by a single surgeon from December 2002 to August 2003. Diagnoses on gross examination (GE) of both the surgeon and the pathologist were recorded, cytologic smears made, and FSs performed. A cost analysis was also performed. RESULTS: Of the 50 parathyroidectomies performed (35 adenoma and 15 hyperplasia), both surgeon and pathologist's opinions on GE were concordant. Incorrect gross identification occurred by both in 6% (3) of the cases. GE is a cost-effective means of identifying parathyroid tissue. CONCLUSIONS: Experienced parathyroid surgeons need not routinely request FS examination. The decision to omit intraoperative FS examination must be balanced against the potential implications of misdiagnosis and a repeat operative procedure.

Biopsy↗

PubMed2005

Thyroid lymphoma: a single institution's experience.

BACKGROUND: Primary lymphoma of the thyroid gland is uncommon. METHODS: The tumor registry at the Penn State Milton S. Hershey Medical Center was searched for all patients carrying a diagnosis of thyroid lymphoma. All available records for these patients were examined and information regarding patient and tumor characteristics, clinical presentation, interventions, and survival were tabulated. RESULTS: The average age of patient in our series was 67.5 years. There was a 2.7:1 female to male preponderance. Thirteen (60%) patients presented with thyroid nodule(s). Eleven (50%) presented with aerodigestive tract obstructive symptoms. Sixteen (73%) patients had no pre-existing history of thyroid disease; none had known pre-existing Hashimoto's thyroiditis. CONCLUSIONS: The typical thyroid lymphoma patient is female and elderly with painless thyroid enlargement. Compressive symptoms of the aerodigestive tract are common at presentation and may require urgent intervention. Treatment modalities (XRT, CHOP chemotherapy) and outcomes are distinct from other thyroid malignancies.

Adult↗

PubMed2005

Perioperative parathyroid hormone assay for diagnosis and management of postthyroidectomy hypocalcemia.

OBJECTIVES/HYPOTHESIS: The purpose of this study was to assess the relationship between perioperative changes in parathyroid hormone (PTH) level and the likelihood of postthyroidectomy hypocalcemia. STUDY DESIGN: In a series of 78 patients undergoing total or completion thyroidectomy, PTH levels were measured before surgery and at 10 minutes after removal of the thyroid gland. METHODS: A prospective, nonrandomized collection of serum from 78 consecutive total or completion thyroidectomy procedures performed by a single surgeon was carried out over 18 months. Analysis is made of PTH levels, serum calcium values, need for calcium supplementation, and symptoms of hypocalcemia. RESULTS: Both a PTH change of 75% and an absolute postoperative PTH of 7 pg/mL are accurate standards for predicting symptomatic hypocalcemia after total or completion thyroid surgery. CONCLUSIONS: Perioperative PTH levels are a tool for the prediction of postoperative symptomatic hypocalcemia after thyroidectomy. A PTH level drawn 10 minutes after removal of the thyroid predicts the likelihood of postoperative hypocalcemia.

Adult↗

PubMed2005

Enhanced growth inhibition of squamous cell carcinoma of the head and neck by combination therapy of paclitaxel and opioid growth factor.

This study evaluated the effects of a combination of opioid growth factor (OGF) and paclitaxel on squamous cell carcinoma of the head and neck (SCCHN) using a tissue culture model of human SCCHN. The combination of OGF and paclitaxel was markedly inhibitory to SCCHN proliferation, reducing growth from control levels by 48 to 69% within 48 h. OGF in combination with carboplatin also depressed cell growth. The effect of a combination of OGF and paclitaxel or carboplatin on SCCHN growth was greater than either of the individual compounds. The efficacy of OGF, but not paclitaxel, was mediated by a naloxone-sensitive receptor and completely reversible. OGF, but no other endogenous or exogenous opioid, altered replication of SCCHN. OGF and paclitaxel depressed DNA synthesis, whereas only paclitaxel induced apoptosis. The combination of OGF and paclitaxel also had a supra-additive effect on the growth of another SCCHN, CAL-27, indicating the ubiquity of the combined drug activity. These data suggest that the combination of a biotherapy (OGF) and chemotherapy (paclitaxel and carboplatin) may provide an enhanced antitumor effect with respect to SCCHN.

Aged↗

PubMed2004

Metallopanstimulin as a marker for head and neck cancer.

BACKGROUND: Metallopanstimulin (MPS-1) is a ribosomal protein that is found in elevated amounts in the sera of patients with head and neck squamous cell carcinoma (HNSCC). We used a test, denoted MPS-H, which detects MPS-1 and MPS-1-like proteins, to determine the relationship between MPS-H serum levels and clinical status of patients with, or at risk for, HNSCC. PATIENTS AND METHODS: A total of 125 patients were prospectively enrolled from a university head and neck oncology clinic. Participants included only newly diagnosed HNSCC patients. Two control groups, including 25 non-smokers and 64 smokers, were studied for comparison. A total of 821 serum samples collected over a twenty-four month period were analyzed by the MPS-H radioimmunoassay. RESULTS: HNSCC, non-smokers, and smokers had average MPS-H values of 41.5 ng/mL, 10.2 ng/mL, and 12.8 ng/mL, respectively (p = 0.0001). CONCLUSION: We conclude that MPS-1 and MPS-1-like proteins are elevated in patients with HNSCC, and that MPS-H appears to be a promising marker of presence of disease and response to treatment in HNSCC patients.

Journal Article↗

PubMed2004

Serum protein profiles to identify head and neck cancer.

PURPOSE: New and more consistent biomarkers of head and neck squamous cell carcinoma (HNSCC) are needed to improve early detection of disease and to monitor successful patient management. The purpose of this study was to determine whether a new proteomic technology could correctly identify protein expression profiles for cancer in patient serum samples. EXPERIMENTAL DESIGN: Surface-enhanced laser desorption/ionization-time of flight-mass spectrometry ProteinChip system was used to screen for differentially expressed proteins in serum from 99 patients with HNSCC and 102 normal controls. Protein peak clustering and classification analyses of the surface-enhanced laser desorption/ionization spectral data were performed using the Biomarker Wizard and Biomarker Patterns software (version 3.0), respectively (Ciphergen Biosystems, Fremont, CA). RESULTS: Several proteins, with masses ranging from 2778 to 20800 Da, were differentially expressed between HNSCC and the healthy controls. The serum protein expression profiles were used to develop and train a classification and regression tree algorithm, which reliably achieved a sensitivity of 83.3% and a specificity of 100% in discriminating HNSCC from normal controls. CONCLUSIONS: We propose that this technique has potential for the development of a screening test for the detection of HNSCC.

Adult↗

PubMed2004

Identification of patients with head and neck cancer using serum protein profiles.

BACKGROUND: New and more consistent biomarkers of head and neck squamous cell carcinoma (HNSCC) are needed to improve early detection of disease and to monitor successful patient management. OBJECTIVE: To determine if a new proteomic technology can correctly identify protein expression profiles for cancer in patient serum samples as well as detect the presence of a known tumor marker. DESIGN: Direct proteomic analysis and comparison. METHODS: The surface-enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF) ProteinChip system was used to screen for differentially expressed proteins in serum samples from 99 patients with HNSCC, 25 "healthy" smokers, and 102 healthy (normal) controls. Protein peak clustering and classification analyses of the SELDI spectral data were performed. RESULTS: Several proteins, with masses ranging from 2778 to 20,800 Da, were differentially expressed between patients with HNSCC and the normal controls. The serum protein expression profiles were used to develop a classification tree algorithm, which achieved a sensitivity of 83.3% and a specificity of 90% in discriminating HNSCC from normal and healthy smoker controls. The positive and negative predictive values were 80% and 92%, respectively. A peak with an average mass of 10,068 Da was detected in sera from HNSCC patients and identified as the known biomarker metallopanstimulin-1 (MPS-1), based on mass. Peak relative intensity of the 10,068-Da protein correlated consistently with MPS-1 levels detected by radioimmunoassay in serum samples of HNSCC patients and controls. The 10,068-Da peak was provisionally identified as MPS-1 by SELDI immunoassay. CONCLUSION: We propose that this technique may allow for the development of a reliable screening test for the early detection and diagnosis of HNSCC, as well as the potential identification of tumor biomarkers.

Biomarkers, Tumor↗