Cost analysis of laparoscopic appendectomy in a large integrated healthcare system.

INTRODUCTION: Healthcare expenditure is on the rise placing greater emphasis on operational excellence, cost containment, and high quality of care. Significant variation is seen in operating room (OR) costs with common surgical procedures such as laparoscopic appendectomy. Surgeons can influence cost through the selection of instrumentation for common surgical procedures such as laparoscopic appendectomy. We aimed to quantify the cost of laparoscopic appendectomy in our healthcare system and compare cost variations to operative times and outcomes. METHODS AND PROCEDURES: We performed a retrospective review of laparoscopic appendectomies in a large regional healthcare system during one-year period (2018). Operating room supply costs and procedure durations were obtained for each hospital. The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) outcomes and demographics were compared to the costs for each hospital. RESULTS: A total of 4757 laparoscopic appendectomies were performed at 20 hospitals (27 to 522 per hospital) by 233 surgeons. The average supply cost per case ranged from $650 to $1067. Individual surgeon cost ranged from $197 to $1181. The average operative time was 41 min (range 33 to 60 min). There was no association between lower cost and longer operative time. The patient demographics and comorbidities were similar between sites. There were no significant differences in postoperative complications between high- and low-cost centers. The items with the greatest increase in cost were single-use energy devices (SUD) and endoscopic stapler. We estimate that a saving of over $417 per case is possible by avoiding the use of energy devices and may be as high as $ 984 by adding selective use of staplers. These modifications would result in an annual savings of $1 million for our health system and more than $ 125 million nationwide. CONCLUSION: Performing laparoscopic appendectomy with reusable instruments and finding alternatives to expensive energy devices and staplers can significantly decrease costs and does not increase operative time or postoperative complications.

A prospective audit on the use of prophylactic antiemetics and rates of CINV in patients receiving carboplatin AUC≥4 or combination anthracycline-cyclophosphamide.

BACKGROUND: Chemotherapy-induced nausea and vomiting (CINV) are two of the most frequently experienced and distressing side effects of cancer treatment. Recent updates by ESMO/MASCC and ASCO on guidelines for prevention of CINV have recommended the addition of a neurokinin-1 receptor antagonist to antiemetic regimens for patients receiving carboplatin-based chemotherapy area under the curve (AUC) ≥4 mg/mL per minute, and an addition of olanzapine for those receiving combination anthracycline/cyclophosphamide chemotherapy. AIMS: To assess current use of prophylactic antiemetics and rates of CINV in patients under the care of MidCentral Regional Cancer Treatment Service (MRCTS) receiving carboplatin AUC≥4 or combination anthracycline/cyclophosphamide. METHODS: Data was prospectively collected on patients under the care of MRCTS receiving carboplatin AUC≥4 or combination anthracycline/cyclophosphamide chemotherapy, including breast cancer patients receiving 5-fluorouracil, epirubicin and cyclophosphamide (FEC) and lymphoma patients receiving rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP). Questionnaires were given to eligible patients to be completed daily from day two to day six of first cycle of chemotherapy only. Data on each patient's gender, age, types of chemotherapies, types of malignancies, presence of nausea or vomiting, number of dry retching or vomiting episodes and anti-emetics were recorded. RESULTS: From 15 September 2018 to 10 August 2019, a total of 44 patients receiving carboplatin-based chemotherapy AUC≥4 and 30 patients receiving combination anthracycline/cyclophosphamide were included. Twenty-two patients (50%) had either emesis or significant nausea in the overall and delayed phase when treated with carboplatin AUC≥4, and only three (7%) in the acute phase. Fourteen patients (56%) had either emesis or significant nausea in the overall phase when treated with FEC chemotherapy, mostly in the acute phase (13 patients) rather than in the delayed phase (9 patients). CONCLUSION: The rates of CINV are high with the existing antiemetic regimens used at MidCentral Regional Cancer Treatment Service. Therefore, in accordance with international guidelines, we will add a neurokinin-1 antagonist to the antiemetic regimens for patients receiving carboplatin-based chemotherapy AUC≥4, and olanzapine for those receiving combination anthracycline/cyclophosphamide chemotherapy, in an attempt to improve the rates of CINV in these groups. Repeating this audit post-implementation of above recommendations will be important to assess for any improvement.

Pimasertib Versus Dacarbazine in Patients With Unresectable NRAS-Mutated Cutaneous Melanoma: Phase II, Randomized, Controlled Trial with Crossover.

This study investigated the efficacy and safety of pimasertib (MEK1/MEK2 inhibitor) versus dacarbazine (DTIC) in patients with untreated NRAS-mutated melanoma. Phase II, multicenter, open-label trial. Patients with unresectable, stage IIIc/IVM1 NRAS-mutated cutaneous melanoma were randomized 2:1 to pimasertib (60 mg; oral twice-daily) or DTIC (1000 mg/m2; intravenously) on Day 1 of each 21-day cycle. Patients progressing on DTIC could crossover to pimasertib. Primary endpoint: investigator-assessed progression-free survival (PFS); secondary endpoints: overall survival (OS), objective response rate (ORR), quality of life (QoL), and safety. Overall, 194 patients were randomized (pimasertib n = 130, DTIC n = 64), and 191 received treatment (pimasertib n = 130, DTIC n = 61). PFS was significantly improved with pimasertib versus DTIC (median 13 versus 7 weeks, respectively; hazard ratio (HR) 0.59, 95% confidence interval (CI) 0.42-0.83; p = 0.0022). ORR was improved with pimasertib (odds ratio 2.24, 95% CI 1.00-4.98; p = 0.0453). OS was similar between treatments (median 9 versus 11 months, respectively; HR 0.89, 95% CI 0.61-1.30); 64% of patients receiving DTIC crossed over to pimasertib. Serious adverse events (AEs) were more frequent for pimasertib (57%) than DTIC (20%). The most common treatment-emergent AEs were diarrhea (82%) and blood creatine phosphokinase (CPK) increase (68%) for pimasertib, and nausea (41%) and fatigue (38%) for DTIC. Most frequent grade ≥3 AEs were CPK increase (34%) for pimasertib and neutropenia (15%) for DTIC. Mean QoL scores (baseline and last assessment) were similar between treatments. Pimasertib has activity in NRAS-mutated cutaneous melanoma and a safety profile consistent with known toxicities of MEK inhibitors. Trial registration: ClinicalTrials.gov, NCT01693068.

Neoadjuvant chemotherapy in non-metastatic breast cancer: a study on practice trends in a regional cancer treatment service.

BACKGROUND: Neoadjuvant chemotherapy (NACT) is increasingly used for managing locally advanced and high risk non-metastatic breast cancer. AIMS: To describe trends in NACT use, assess compliance to best practice recommendations and determine treatment response rates in a regional cancer treatment service. METHODS: In this retrospective cross- sectional study, electronic records of patients who underwent NACT in centres covered by the MidCentral Regional Cancer Treatment Service in 2013 and 2017 were reviewed. Data pertaining to patient demographics, disease status, compliance to best practice recommendations and treatment outcomes were extracted and analysed. RESULTS: Of a total of 502 referrals for non-metastatic breast cancer, 34 underwent NACT with the estimated NACT rate rising from 3.85% (2013) to 9.92% (2017). Compliance to practice recommendations improved in all domains (pre-treatment tumour and axillary evaluation, marker placement, multidisciplinary discussion). Overall, NACT was well tolerated with only three patients experiencing treatment limiting toxicity. Response rates mirror published data (complete response: 29.4%, partial: 61.8%) with higher responses registered in HER2 positive and triple negative subtypes. Discordance between radiological and pathological response was 28%, with imaging overestimating response in five out of seven cases. Of the 11 (32%) patients who initially underwent breast conserving surgery, six required a second surgery. CONCLUSION: NACT is increasingly used in the Regional Cancer Treatment Service, with improving compliance to practice recommendations. These results are reassuring and can be used to help patients develop a realistic expectation towards NACT.

Regional cost analysis for laparoscopic cholecystectomy.

BACKGROUND: Laparoscopic cholecystectomy is the most common procedure performed by general surgeons in the United States, with approximately 600,000 procedures performed annually. As the cost of care rises, there is increasing emphasis on utilization and quality. Our objective was to evaluate the cost of laparoscopic cholecystectomy in our health system and to compare the operative times and outcomes at high- and low-cost centers. METHODS: We evaluated all laparoscopic cholecystectomies performed in our system over a 1-year period. The operating room supply costs and procedure durations were obtained for each of the hospitals. The American College of Surgeons National Surgical Quality Improvement Program outcomes and demographics were compared to the costs for each hospital. RESULTS: During the study period, 7601 laparoscopic cholecystectomies were performed at 20 hospitals (170-759/hospital) by 227 surgeons. The average cost per case ranged from $296 at the lowest cost center to $658 at the highest cost center. The average operative time varied between sites from 46 to 95 min. There was no association between cost and operative time or case volume. There was a slight trend toward increased cost with higher number of emergency procedures, but this was not well correlated (R2 = 0.03). The patient demographics and comorbidities were similar between sites. There were no significant differences in postoperative complications between high- and low-cost centers. The items with the greatest increase in cost were disposable trocars, disposable hook cautery, disposable endoscissors, and disposable clip appliers. We estimate that a savings of over $300/case is possible by using reusable instruments, which would result in an annual savings of $1.3 million for our health system, and $285 million nationwide. CONCLUSION: Performing laparoscopic cholecystectomy with reusable instruments can significantly decrease costs and does not increase operative time or postoperative complications.

Identification of compounds acting as negative allosteric modulators of the LPA1 receptor.

The Lysophosphatidic Acid 1 Receptor (LPA1 receptor) has been linked to the initiation and progression of a variety of poorly treated fibrotic conditions. Several compounds that have been described as LPA1 receptor antagonists have progressed into clinical trials: 1-(4-{4-[3-methyl-4-({[(1R)-1-phenylethoxy]carbonyl}amino)-1,2-oxazol-5-yl]phenyl}phenyl)cyclopropane-1-carboxylic acid (BMS-986202) and 2-{4-methoxy-3-[2-(3-methylphenyl)ethoxy]benzamido}-2,3-dihydro-1H-indene-2-carboxylic acid (SAR-100842). We considered that as LPA1 receptor function is involved in many normal physiological processes, inhibition of specific signalling pathways associated with fibrosis may be therapeutically advantageous. We compared the binding and functional effects of a novel compound; 4-({(Cyclopropylmethyl)[4-(2-fluorophenoxy)benzoyl]amino}methyl}benzoic acid (TAK-615) with BMS-986202 and SAR-100842. Back-scattering interferometry (BSI) was used to show that the apparent affinity of TAK-615 was enhanced in the presence of LPA. The binding signal for BMS-986202 was not detected in the presence of LPA suggesting competition but interestingly the apparent affinity of SAR-100842 was also enhanced in the presence of LPA. Only BMS-986202 was able to fully inhibit the response to LPA in calcium mobilisation, ß-arrestin, cAMP, GTPγS and RhoA functional assays. TAK-615 and SAR-100842 showed different inhibitory profiles in the same functional assays. Further binding studies indicated that TAK-615 is not competitive with either SAR-100842 or BMS-986202, suggesting a different site of binding. The results generated with this set of experiments demonstrate that TAK-615 acts as a negative allosteric modulator (NAM) of the LPA1 receptor. Surprisingly we find that SAR-100842 also behaves like a NAM. BMS-986202 on the other hand behaves like an orthosteric antagonist.

Staged Definitive Repair after Carotid Blowout: A Case Report.

Carotid blowout syndrome is a highly morbid complication of head and neck cancer. We present the case of a 51-year-old woman with common carotid artery blowout, initially temporized with an endovascular stent graft and ultimately reconstructed using autologous superficial femoral artery. The patient recovered without sequelae and continues to be asymptomatic at 1 year. We present the modern hybrid management of this complex case.

SIRFLOX: Randomized Phase III Trial Comparing First-Line mFOLFOX6 (Plus or Minus Bevacizumab) Versus mFOLFOX6 (Plus or Minus Bevacizumab) Plus Selective Internal Radiation Therapy in Patients With Metastatic Colorectal Cancer.

PURPOSE: SIRFLOX was a randomized, multicenter trial designed to assess the efficacy and safety of adding selective internal radiation therapy (SIRT) using yttrium-90 resin microspheres to standard fluorouracil, leucovorin, and oxaliplatin (FOLFOX)-based chemotherapy in patients with previously untreated metastatic colorectal cancer. PATIENTS AND METHODS: Chemotherapy-naïve patients with liver metastases plus or minus limited extrahepatic metastases were randomly assigned to receive either modified FOLFOX (mFOLFOX6; control) or mFOLFOX6 plus SIRT (SIRT) plus or minus bevacizumab. The primary end point was progression-free survival (PFS) at any site as assessed by independent centralized radiology review blinded to study arm. RESULTS: Between October 2006 and April 2013, 530 patients were randomly assigned to treatment (control, 263; SIRT, 267). Median PFS at any site was 10.2 v 10.7 months in control versus SIRT (hazard ratio, 0.93; 95% CI, 0.77 to 1.12; P = .43). Median PFS in the liver by competing risk analysis was 12.6 v 20.5 months in control versus SIRT (hazard ratio, 0.69; 95% CI, 0.55 to 0.90; P = .002). Objective response rates (ORRs) at any site were similar (68.1% v 76.4% in control v SIRT; P = .113). ORR in the liver was improved with the addition of SIRT (68.8% v 78.7% in control v SIRT; P = .042). Grade ≥ 3 adverse events, including recognized SIRT-related effects, were reported in 73.4% and 85.4% of patients in control versus SIRT. CONCLUSION: The addition of SIRT to FOLFOX-based first-line chemotherapy in patients with liver-dominant or liver-only metastatic colorectal cancer did not improve PFS at any site but significantly delayed disease progression in the liver. The safety profile was as expected and was consistent with previous studies.

Dose-intense capecitabine, oxaliplatin and bevacizumab as first line treatment for metastatic, unresectable colorectal cancer: a multi-centre phase II study.

BACKGROUND: Dose intense chemotherapy may improve efficacy with acceptable toxicity. A phase II study was conducted to determine the feasibility of a dose-intense two weekly schedule of capecitabine, oxaliplatin, and bevacizumab in metastatic colorectal cancer (mCRC). METHODS: 49 patients with previously untreated mCRC were recruited. Nineteen received capecitabine (1750 mg/m(2) oral BD days 1-7)oxaliplatin (85 mg/m(2)i.v. day 1) and bevacizumab (5 mg/kg i.v. day 1) using a 14-day cycle (C1750). Following toxicity concerns capecitabine was reduced to 1500 mg/m2oral BD (C1500) and 30 further patients recruited. RESULTS: Over 80% of patients received at least 75% of planned chemotherapy doses over the first two cycles. At C1750 Grade 3 or higher toxicity occurred in 74% (95% CI 49% to 91%) and on C1500 in 70% (95% CI 51% to 85%). The median progression-free survival was 6.9 months (95% CI 4.7 to 8.7) for C1750 dose and 8.9 months (95% CI 4.1 to 12.4) for C1500. 3 treatment-related deaths occurred. CONCLUSIONS: Dose intense capecitabine and oxaliplatin with bevacizumab does not show additional efficacy and has potentially significant toxicity. Its use outside of clinical trials is not recommended. TRIAL REGISTRATION: ISRCTN41540878.

Evidence That GRIN2A Mutations in Melanoma Correlate with Decreased Survival.

Previous whole-exome sequencing has demonstrated that melanoma tumors harbor mutations in the GRIN2A gene. GRIN2A encodes the regulatory GluN2A subunit of the glutamate-gated N-methyl-d-aspartate receptor (NMDAR), involvement of which in melanoma remains undefined. Here, we sequenced coding exons of GRIN2A in 19 low-passage melanoma cell lines derived from patients with metastatic melanoma. Potential mutation impact was evaluated in silico, including within the GluN2A crystal structure, and clinical correlations were sought. We found that of 19 metastatic melanoma tumors, four (21%) carried five missense mutations in the evolutionarily conserved domains of GRIN2A; two were previously reported. Melanoma cells that carried these mutations were treatment-naïve. Sorting intolerant from tolerant analysis predicted that S349F, G762E, and P1132L would disrupt protein function. When modeled into the crystal structure of GluN2A, G762E was seen to potentially alter GluN1-GluN2A interactions and ligand binding, implying disruption to NMDAR functionality. Patients whose tumors carried non-synonymous GRIN2A mutations had faster disease progression and shorter overall survival (P < 0.05). This was in contrast to the BRAF V600E mutation, found in 58% of tumors but showing no correlation with clinical outcome (P = 0.963). Although numbers of patients in this study are small, and firm conclusions about the association between GRIN2A mutations and poor clinical outcome cannot be drawn, our results highlight the high prevalence of GRIN2A mutations in metastatic melanoma and suggest for the first time that mutated NMDARs impact melanoma progression.

En bloc resection of a multilevel high-cervical chordoma involving C-2: new operative modalities: technical note.

En bloc resection of cervical chordomas has led to longer survival rates but has resulted in significant morbidities from the procedure, especially when the tumor is multilevel and located in the high-cervical (C1-3) region. To date, there have been only 5 reported cases of multilevel en bloc resection of chordomas in the high-cervical spine. In this technical report the authors describe a sixth case. A complete spondylectomy was performed at C-2 and C-3 with spinal reconstruction and stabilization, using several new modalities that were not used in the previous cases. The use of 1) preoperative endovascular sacrificing of the vertebral artery, 2) CT image-guidance, 3) an ultrasonic aspirator for skeletonizing the vertebral artery, and 4) the custom design of an anterior cage all contributed to absence of intraoperative or long-term (20 months) hardware failure and pseudarthrosis.

Treatment with the PARP-inhibitor PJ34 causes enhanced doxorubicin-mediated cell death in HeLa cells.

Adjuvant therapies can incorporate a number of different drugs to minimize the cardiotoxicity of cancer chemotherapy, decrease the development of drug resistance and increase the overall efficacy of the treatment regime. Topoisomerase IIα is a major target of many commonly used anticancer drugs, where cell death is brought about by an accumulation of double-strand DNA breaks. Poly (ADP-ribose) polymerase (PARP)-1 has been extensively studied for its role in the repair of double-strand DNA breaks, but its ability to add highly negative biopolymers (ribosylation) to target proteins provides a vast number of pathways where it can also be important in mediating cell death. In this study, we combine the classical topoisomerase IIα poison doxorubicin with the PARP inhibitor PJ34 to investigate the potentiation of chemotherapeutic efficiency in HeLa cells. We demonstrate that PJ34 treatment has the capacity to increase endogenous topoisomerase IIα protein by about 20%, and by combining doxorubicin treatment with PJ34, we observed a 50% improvement in doxorubicin-mediated cell death in HeLa cells. These results were correlated with the ribosylation of transcription factor specificity factor 1 after doxorubicin treatment, thereby altering its affinity for binding to known regulatory elements within the human topoisomerase IIα promoter. Taken together, these results highlight the synergistic potential of combining PARP inhibitors with classical topoisomerase IIα-targeting drugs.

Simultaneous on-chip DC dielectrophoretic cell separation and quantitative separation performance characterization.

Through integration of a MOSFET-based microfluidic Coulter counter with a dc-dielectrophoretic cell sorter, we demonstrate simultaneous on-chip cell separation and sizing with three different samples including 1) binary mixtures of polystyrene beads, 2) yeast cells of continuous size distribution, and 3) mixtures of 4T1 tumor cells and murine bone marrow cells. For cells with continuous size distribution, it is found that the receiver operator characteristic analysis is an ideal method to characterize the separation performance. The characterization results indicate that dc-DEP separation performance degrades as the sorting throughput (cell sorting rate) increases, which provides insights into the design and operation of size-based microfluidic cell separation.

Down-regulation of human topoisomerase IIalpha expression correlates with relative amounts of specificity factors Sp1 and Sp3 bound at proximal and distal promoter regions.

BACKGROUND: Topoisomerase IIalpha has been shown to be down-regulated in doxorubicin-resistant cell lines. The specificity proteins Sp1 and Sp3 have been implicated in regulation of topoisomerase IIalpha transcription, although the mechanism by which they regulate expression is not fully understood. Sp1 has been shown to bind specifically to both proximal and distal GC elements of the human topoisomerase IIalpha promoter in vitro, while Sp3 binds only to the distal GC element unless additional flanking sequences are included. While Sp1 is thought to be an activator of human topoisomerase IIalpha, the functional significance of Sp3 binding is not known. Therefore, we sought to determine the functional relationship between Sp1 and Sp3 binding to the topoisomerase IIalpha promoter in vivo. We investigated endogenous levels of Sp1, Sp3 and topoisomerase IIalpha as well as binding of both Sp1 and Sp3 to the GC boxes of the topoisomerase IIalpha promoter in breast cancer cell lines in vivo after short term doxorubicin exposure. RESULTS: Functional effects of Sp1 and Sp3 were studied using transient cotransfection assays using a topoisomerase IIalpha promoter reporter construct. The in vivo interactions of Sp1 and Sp3 with the GC elements of the topoisomerase IIalpha promoter were studied in doxorubicin-treated breast cancer cell lines using chromatin immunoprecipitation assays. Relative amounts of endogenous proteins were measured using immunoblotting. In vivo DNA looping mediated by proteins bound at the GC1 and GC2 elements was studied using the chromatin conformation capture assay. Both Sp1 and Sp3 bound to the GC1 and GC2 regions. Sp1 and Sp3 were transcriptional activators and repressors respectively, with Sp3 repression being dominant over Sp1-mediated activation. The GC1 and GC2 elements are linked in vivo to form a loop, thus bringing distal regulatory elements and their cognate transcription factors into close proximity with the transcription start site. CONCLUSION: These observations provide a mechanistic explanation for the modulation of topoisomerase IIalpha and concomitant down-regulation that can be mediated by topoisomerase II poisons. Competition between Sp1 and Sp3 for the same cognate DNA would result in activation or repression depending on absolute amounts of each transcription factor in cells treated with doxorubicin.

Differential regulation of DNA repair protein Rad51 in human tumour cell lines exposed to doxorubicin.

Radiotherapy and chemotherapy often induce DNA double-strand breaks in both normal and malignant cells. The proteins involved in the repair of such lesions are central to cancer prognosis and treatment, as they can be overexpressed in many cancers, accelerating malignant transformation and increasing repair capacity, potentially leading to cellular resistance. If malignant cells can be selectively targeted repair proteins could also be candidates for targeted therapy. In this study, two keyplayers in eukaryotic DNA double-strand break repair, Rad51 and DNA-dependent protein kinase catalytic subunit, were analysed in noncancerous human breast cells (MCF12A) and the breast cancer cell lines (MDA MB 231 and MCF7) in response to treatment with doxorubicin. A cell cycle-independent increase in Rad51 protein levels (a recombinase involved in homologous recombination repair) was observed 24 and 48 h after treatment in MDA MB 231 and MCF12A when exposed to low levels of doxorubicin, whereas MCF7 cells displayed a continuous decrease in Rad51 protein with increasing drug concentration. DNA-dependent protein kinase catalytic subunit, which is involved in nonhomologous end joining of DNA lesions, remained unaltered under all conditions tested. Topoisomerase II-alpha protein, the primary target of doxorubicin, was upregulated at low concentrations of doxorubicin in all cell lines tested. Here we show that Rad51 protein levels can be differentially regulated in normal and malignant breast cell lines in response to doxorubicin, independent of cell cycle state. These observations have direct relevance to chemosensitivity and add an additional prognostic factor that could be taken into account when designing targeted therapeutic regimes.

Application of liquid chromatography-mass spectrometry to monitoring plasma cyclophosphamide levels in phase I trial cancer patients.

A specific and efficient liquid chromatography-mass spectrometry (LC-MS) method was established for monitoring patient plasma cyclophosphamide levels in a phase I trial of an oral cyclophosphamide-based combination chemotherapy regimen. An Agilent 1100 Series LC-MSD system (Agilent Technologies, Avondale, PA, USA), with a single quadrupole mass detector using a positive atmospheric pressure chemical ionization (APCI) interface and single ion monitoring at m/z 261, was used. Chromatography was performed using a LUNA C8 5 microm 30 x 4.6 mm stainless steel column (Phenomenex, Torrance, CA, USA) and a mobile phase of aqueous acetonitrile pumped at a flow rate of 0.7 mL/min. High-throughput solid-phase sample extraction was performed using a Gilson ASPEC XL4 system (Gilson Medical, Middleton, WI, USA) controlled by prestored programs. The standard curve for cyclophosphamide was linear over the concentration range 0.026-1.08 microg/mL (r(2) > 0.994). Intra- and interassay accuracy and precision were 97-107 and 3-10%, respectively. The limit of detection was determined to be 0.01 microg/mL. Single ion monitoring at m/z 261 provided a high degree of specificity without interference from the matrix or other chemotherapy drugs. Automated sample processing allowed the analysis of a large number of plasma samples from a clinical trial of repeated daily oral dosing of cyclophosphamide. One hour after dosing, cyclophosphamide was detected in 98 of 106 plasma specimens at concentrations ranging between 0.03 and 4.88 microg/mL. Twenty-four hours after dosing, cyclophosphamide was detected in 72 of 77 plasma specimens at concentrations ranging between 0.06 and 3.13 microg/mL. There were no time-dependent changes in cyclophosphamide concentration during the 43 day period of repeated daily oral dosing. There was no correlation between cyclophosphamide dose and plasma concentration, despite the wide range of doses given in the clinical trial (50-125 mg/m(2)). We conclude that a solid-phase extraction LC-MS technique was validated for determining cyclophosphamide in human plasma. Interoccasion variability in the rate of oral absorption and in the clearance of systemically available drug may have contributed to the wide range of cyclophosphamide concentrations found at 1 and 24 h after tablet ingestion.

Estimation of radiation-induced interphase cell death in cultures of human tumor material and in cell lines.

A short-term assay method able to estimate the radiation response of human cancer tissue samples would be of great advantage to the individualization of radiotherapy in cancer patients. However, the effect of radiation on [3H]thymidine incorporation by proliferating cells reflects a composite of cell cycle arrest and induced cell death pathways. Here we consider whether it is feasible to correct for cell cycle effects based on comparison of the effects of radiation and the mitotic inhibitor paclitaxel on [3H]thymidine incorporation. Sixty-two short-term (7-day) cultures of human tumor tissue from 61 patients with melanoma, gynecological cancer, brain cancer, and head and neck cancer, as well as 18 5-day cultures of low passage human tumor cell lines, were irradiated at doses from 2 to 9 Gy, or exposed to paclitaxel (200 nM). [3H]Thymidine incorporation was measured at the end of the incubation. Cell cycle times could be estimated from the paclitaxel data and were 2.7 to 18.6 days for melanomas, 2.5 to >40 days for carcinomas, 3.9 to 39 days for brain tumors, and 1.1 to 3.8 days for cell lines. The effects of radiation on [3H]thymidine incorporation varied widely (0-97% and 0-99% inhibition for 2 and 9 Gy, respectively), and in 23 of the clinical samples, but in none of the cell lines, radiation caused significantly greater inhibition of [3H]thymidine incorporation than paclitaxel (p < 0.05). We argue that that these differences reflect radiation-induced cell loss from G1 phase and/or S phase. Responses of short-term cultures of clinical tumor material to radiation, with appropriate correction for cell cycle effects, might have the potential to provide information on radiation-induced cell death in individual patients.

Esophageal stents in malignant dysphagia: a two-edged sword?

Dysphagia from mechanical esophageal obstruction in patients with advanced malignancy is a common and debilitating symptom in patients referred to palliative care services. Relief of such dysphagia is often attempted by insertion of an esophageal stent in the hope that this will improve the quality of life for these patients. We describe a series of 39 patients who had an esophageal stent inserted under radiologic guidance for malignant dysphagia over an 82-month period. While the stents were clearly effective at relieving dysphagia, they also induced significant comorbidity, in particular, moderate to severe chest pain occurring in 46% and reflux esophagitis in 26% of our non-selected patient group. In addition we found an eight percent mortality rate from esophageal bleeding following stent insertion. When discussing the potential role of esophageal stent insertion with patients under the care of palliative care teams, the frequency and severity of these significant secondary symptoms need to be considered.