Molecular portraits of patients with intrahepatic cholangiocarcinoma who diverge as rapid progressors or long survivors on chemotherapy

OBJECTIVE

Cytotoxic agents are the cornerstone of treatment for patients with advanced intrahepatic cholangiocarcinoma (iCCA), despite heterogeneous benefit. We hypothesised that the pretreatment molecular profiles of diagnostic biopsies can predict patient benefit from chemotherapy and define molecular bases of innate chemoresistance.

DESIGN

We identified a cohort of advanced iCCA patients with comparable baseline characteristics who diverged as extreme outliers on chemotherapy (survival <6 m in rapid progressors, RP; survival >23 m in long survivors, LS). Diagnostic biopsies were characterised by digital pathology, then subjected to whole-transcriptome profiling of bulk and geospatially macrodissected tissue regions. Spatial transcriptomics of tumour-infiltrating myeloid cells was performed using targeted digital spatial profiling (GeoMx). Transcriptome signatures were evaluated in multiple cohorts of resected cancers. Signatures were also characterised using in vitro cell lines, in vivo mouse models and single cell RNA-sequencing data.

RESULTS

Pretreatment transcriptome profiles differentiated patients who would become RPs or LSs on chemotherapy. Biologically, this signature originated from altered tumour-myeloid dynamics, implicating tumour-induced immune tolerogenicity with poor response to chemotherapy. The central role of the liver microenviroment was confrmed by the association of the RPLS transcriptome signature with clinical outcome in iCCA but not extrahepatic CCA, and in liver metastasis from colorectal cancer, but not in the matched primary bowel tumours.

CONCLUSIONS

The RPLS signature could be a novel metric of chemotherapy outcome in iCCA. Further development and validation of this transcriptomic signature is warranted to develop precision chemotherapy strategies in these settings.

Impact of Testosterone Recovery on Clinical Outcomes of Patients Treated with Salvage Radiotherapy and Androgen Suppression: A Secondary Analysis of the NRG/RTOG 0534 Sport Phase 3 Trial

PURPOSE/OBJECTIVE(S)

Testosterone (T) kinetics and its relationship with clinical outcomes has not been studied in trials using salvage radiotherapy and androgen deprivation therapy (ADT). We performed a secondary analysis of the NRG Oncology/RTOG 0534 SPPORT trial, which compared prostate bed radiotherapy (PBRT) (arm 1), PBRT + short-term androgen deprivation therapy (ADT) (arm 2), or PBRT + pelvic lymph node radiotherapy (PLNRT) + short-term ADT (arm 3). We assessed longitudinal serum T levels and the impact of testosterone recovery (TR) on clinical outcomes.

MATERIALS/METHODS

ADT was given for 4-6 months in arms 2 and 3, starting 2 months prior to radiotherapy. The trial excluded patients with baseline T < 40% of the lower limit of normal. TR was defined in 3 ways: 1) return to non-castrate level (>50 ng/dL), 2) return to normal level (>300 ng/dL), and 3) return to baseline level. Time to TR was estimated using cumulative incidence and death without an event considered a competing risk. Unadjusted and adjusted hazard ratios and 95% confidence intervals (CIs) were calculated using Cox proportional hazards model. Freedom from progression (FFP) was defined as biochemical failure according to the Phoenix definition (PSA ≥2 ng/mL over the nadir PSA), clinical failure (local, regional, or distant), or death from any cause.

RESULTS

A total of 1699 patients with T at baseline and at least 1 follow-up assessment were included. The median age was 64 years (IQR 59 - 69), 12.8% were black, 14.9% had diabetes, and 54.1% were former or current smokers. Median baseline T in arms 1, 2 and 3 was 320 ng/dL (IQR 239 - 424), 319 ng/dL (IQR 237 - 438) and 330 ng/dL (IQR 252 - 446), respectively. At 6 months, median T in arms 1, 2 and 3 was 290 ng/dL (IQR 210 - 390), 190.4 ng/dL (IQR 66 - 296) and 191 ng/dL (IQR 40.5 - 313). At 2 years, in arms 2 and 3, TR to non-castrate, normal and baseline levels were 95%, 55% and 23%, respectively. At 5 years, in arms 2 and 3, TR to non-castrate, normal and baseline levels were 98%, 73% and 42%, respectively. FFP was superior in arms 2 and 3 vs. arm 1 in patients with TR by all three definitions. In patients with recovered T to normal levels by 2 years (n = 904), the 5-year FFP rates were 71.8% (95% CI 66.9-76.6) in arm 1, 77.2% (72.1-82.2) in arm 2, and 86.3% (82.3-90.3) in arm 3 (arm 2 vs arm 1: HR 0.74, 95% CI 0.56-0.98, p = 0.034; arm 3 vs arm 1: HR 0.54, 95% CI 0.40-0.72, p<.0001).

CONCLUSION

This work represents the largest study of T kinetics in patients treated with salvage radiation and ADT. Approximately half of patients did not normalize their T levels by 2 years. Our data validate an incremental and meaningful FFP benefit of adding short-term ADT and PLNRT to PBRT independent of T recovery.

Validation of a Genomic Classifier in the NRG Oncology/RTOG 0521 Phase III Trial of Docetaxel with Androgen Suppression and Radiotherapy for Localized High-Risk Prostate Cancer

PURPOSE/OBJECTIVE(S)

Decipher is a prognostic genomic classifier (GC) validated in several prospective NRG Oncology Phase III trials. Herein, we validate the GC in pre-treatment biopsy samples for risk stratification in a cohort of high-risk men treated with definitive radiotherapy and androgen suppression with or without docetaxel chemotherapy.

MATERIALS/METHODS

As per a pre-specified and approved NCI analysis plan (Navigator #1061), we obtained available formalin-fixed paraffin-embedded tissue from biopsy specimens from the NRG biobank from patients enrolled on the NRG/RTOG 0521 randomized phase III trial. After central review, the highest-grade tumors were profiled on clinical-grade whole-transcriptome arrays (Veracyte, San Diego, CA) and GC scores were obtained. Pre-specified categorical GC scores, adjusted for archival tissue analysis, were used to define higher (>0.46) and lower (≤0.46) risk groups. The primary objective was to validate the independent prognostic ability of GC for metastasis-free survival (MFS) with Cox multivariable analyses (MVA).

RESULTS

Samples were obtained from 283 consented, evaluable patients with tissue (50% of trial) yielding 183 (65%) GC scores that passed quality metrics, 91 from control and 92 from the interventional arm. Median age was 66 years, median PSA was 19.3 ng/uL (IQR: 8.1-41.4), 81% had clinical stage ≥T2 and 80% had Gleason score ≥8 (47% ≥9). Median GC score was 0.55 (IQR: 0.38-0.78) and overall the arms were balanced for key covariates. With a median follow-up of 9.9 years (IQR: 9.3, 10.7), 67 MFS events including 34 distant metastases (DM) were observed. On MVA, only the GC (per 0.1 unit) was independently associated with MFS (HR 1.12, 95% CI 1.01-1.25) as well as DM (sHR 1.22, 95% CI 1.06-1.41), whereas the 4 pre-defined trial risk groups used for stratification (based on Gleason score, T-stage and PSA), randomization and patient age were not. For categorical GC, on MVA, higher-risk GC patients (65%) had worse DM (sHR 2.82, 95% CI 1.1-7.3) compared to those with lower GC. Cumulative incidence of DM at 10-years was 27% for higher GC vs 9% (95% CI 7-18%) for lower GC. No biomarker-by-treatment interaction with GC and the addition of docetaxel was detected.

CONCLUSION

In pre-treatment biopsy samples from a randomized Phase 3 trial cohort, GC demonstrated its ability to further risk stratify clinically high-risk men demonstrating an independent association of GC score with DM and MFS. High-risk prostate cancer is a heterogeneous disease state and GC can improve risk stratification to help personalize shared decision-making. NRG-GU009/PREDICT-RT (NCT04513717) aims to determine the optimal therapy based on GC score for high-risk prostate cancer.

Long non-coding RNAs within the tumour microenvironment and their role in tumour-stroma cross-talk

Long non-coding RNAs (lncRNAs) are a diverse class of RNA transcripts which have limited protein coding potential. They perform a variety of cellular functions in health, but have also been implicated during malignant transformation. A further theme in recent years is the critical role of the tumour microenvironment and the dynamic interactions between cancer and stromal cells in promoting invasion and disease progression. Whereas the contribution of deregulated lncRNAs within cancer cells has received considerable attention, their significance within the tumour microenvironment is less well understood. The tumour microenvironment consists of cancer-associated stromal cells and structural extracellular components which interact with one another and with the transformed epithelium via complex extracellular signalling pathways. LncRNAs are directly and indirectly involved in tumour/stroma cross-talk and help stimulate a permissive tumour microenvironment which is more conducive for invasive tumour growth. Furthermore, lncRNAs play key roles in determining the phenotype of cancer associated stromal cells and contribute to angiogenesis and immune evasion pathways, extracellular-matrix (ECM) turnover and the response to hypoxic stress. Here we explore the multifaceted roles of lncRNAs within the tumour microenvironment and their putative pathophysiological effects.

What carcinoembryonic antigen level should trigger further investigation during colorectal cancer follow-up? A systematic review and secondary analysis of a randomised controlled trial

BACKGROUND

Following primary surgical and adjuvant treatment for colorectal cancer, many patients are routinely followed up with blood carcinoembryonic antigen (CEA) testing.

OBJECTIVE

To determine how the CEA test result should be interpreted to inform the decision to undertake further investigation to detect treatable recurrences.

DESIGN

Two studies were conducted: (1) a Cochrane review of existing studies describing the diagnostic accuracy of blood CEA testing for detecting colorectal recurrence; and (2) a secondary analysis of data from the two arms of the FACS (Follow-up After Colorectal Surgery) trial in which CEA testing was carried out.

SETTING AND PARTICIPANTS

The secondary analysis was based on data from 582 patients recruited into the FACS trial between 2003 and 2009 from 39 NHS hospitals in England with access to high-volume services offering surgical treatment of metastatic recurrence and followed up for 5 years. CEA testing was undertaken in general practice.

RESULTS

In the systematic review we identified 52 studies for meta-analysis, including in aggregate 9717 participants (median study sample size 139, interquartile range 72-247). Pooled sensitivity at the most commonly recommended threshold in national guidelines of 5 µg/l was 71% [95% confidence interval (CI) 64% to 76%] and specificity was 88% (95% CI 84% to 92%). In the secondary analysis of FACS data, the diagnostic accuracy of a single CEA test was less than was suggested by the review [area under the receiver operating characteristic curve (AUC) 0.74, 95% CI 0.68 to 0.80]. At the commonly recommended threshold of 5 µg/l, sensitivity was estimated as 50.0% (95% CI 40.1% to 59.9%) and lead time as about 3 months. About four in 10 patients without a recurrence will have at least one false alarm and six out of 10 tests will be false alarms (some patients will have multiple false alarms, particularly smokers). Making decisions to further investigate based on the trend in serial CEA measurements is better (AUC for positive trend 0.85, 95% CI 0.78 to 0.91), but to maintain approximately 70% sensitivity with 90% specificity it is necessary to increase the frequency of testing in year 1 and to apply a reducing threshold for investigation as measurements accrue.

LIMITATIONS

The reference standards were imperfect and the main analysis was subject to work-up bias and had limited statistical precision and no external validation.

CONCLUSIONS

The results suggest that (1) CEA testing should not be used alone as a triage test; (2) in year 1, testing frequency should be increased (to monthly for 3 months and then every 2 months); (3) the threshold for investigating a single test result should be raised to 10 µg/l; (4) after the second CEA test, decisions to investigate further should be made on the basis of the trend in CEA levels; (5) the optimal threshold for investigating the CEA trend falls over time; and (6) continuing smokers should not be monitored with CEA testing. Further research is needed to explore the operational feasibility of monitoring the trend in CEA levels and to externally validate the proposed thresholds for further investigation.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015019327 and Current Controlled Trials ISRCTN93652154.

FUNDING

The main FACS trial and this substudy were funded by the National Institute for Health Research Health Technology Assessment programme.

Abstract 1488: Altered skeletal muscle mitochondrial function and redox biology with chemotherapy and exercise in a colorectal cancer mouse model

Background: Chemotherapy improves outcomes for patients with gastrointestinal cancer, but carries associated morbidity. Platinum-based chemotherapy adversely impacts fitness, invivo mitochondrial function, and cellular redox status in humans, however the mechanisms are poorly understood. Exercise interventions mitigate against this, but interactions between the effect of the cancer, chemotherapy, and exercise intervention are poorly understood. Using a colorectal cancer (CRC) mouse model we investigated changes in skeletal muscle oxidative phosphorylation (OxPhos) capacity and redox biology with chemotherapy and exercise.

Method: SCID mice (n=48) were randomized to laparotomy with (Ca) or without (NCa) orthotopic caecal injection of DLD-1 CRC cells. CRC established over 8 weeks then mice were randomized to 1) 3 cycles of intra-peritoneal (IP) chemotherapy (Chemo; 5FU 5mg/kg, Oxaliplatin 10mg/kg and Leucovorin 90mg/kg) followed by interval exercise-training 2) Chemo and no exercise 3) IP saline sham (Sal) with exercise or 4) Sal with no exercise. Blood was collected pre and post-Chemo and at death (post-exercise), and markers of oxidative stress measured. Soleus muscle mitochondrial function was analyzed using high-resolution respirometry. Measurements included maximum OxPhos capacity (PI+II+β), Complex I and II capacities and the ratio of octanoyl-carnitine to pyruvate-supported respiration (FAO). Histopathological caecal examination was undertaken to determine cancer response.

Results: Chemotherapy alone resulted in 37% lower OxPhos capacities in sham mice (p=0.011), whilst FAO was 40% lower (p=0.004). Cancer alone resulted in 38% lower OxPhos capacities (p=0.012). In combination with cancer, chemotherapy resulted in OxPhos capacities that were 42% lower than in mice with cancer but no chemotherapy (p=0.007), along with 51% lower Complex I (p&lt;0.001) and 42% lower Complex II (p=0.007) capacities. In sham mice (NCaSal), exercise resulted in 33% greater Complex II activities (p=0.042), but exercise did not alter mitochondrial function in any other group. Total plasma protein content (TPPC) increased with time in the CaSal (+32%) and the NCaSal mice (+23%), whilst it decreased with chemotherapy (CaChemo -20%, NCaChemo -10%). Oxidative stress increased with chemotherapy and exercise, however exploratory interaction analyses are ongoing. Complete histopathological response was seen in 2 of 6 CaChemoEx animals. No other complete response was seen.

Conclusion: Chemotherapy and cancer alone were associated with a loss of oxidative capacity, with a greater reduction when combined. Chemotherapy alone and with cancer caused a shift away from FAO and reduction in TPPC. Though we demonstrated an exercise effect in sham mice, exercise did not increase OxPhos capacity, nor did it ameliorate the effects of cancer and chemotherapy. A more intense exercise intervention may be required.

Citation Format: Malcolm Andrew West, Alexandrina Roman, Ronan Astin, Sian Pugh, Bernadette Fernandez, Annette Hayden, Judith Cave, Eleanor Jaynes, John N. Primrose, Sandy Jack, Michael P. Grocott, Andrew Murray, Martin Feelisch, Alexander Mirnezami, Timothy Underwood. Altered skeletal muscle mitochondrial function and redox biology with chemotherapy and exercise in a colorectal cancer mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1488. doi:10.1158/1538-7445.AM2017-1488

The diagnostic accuracy of a single CEA blood test in detecting colorectal cancer recurrence: Results from the FACS trial

OBJECTIVE

To evaluate the diagnostic accuracy of a single CEA (carcinoembryonic antigen) blood test in detecting colorectal cancer recurrence.

BACKGROUND

Patients who have undergone curative resection for primary colorectal cancer are typically followed up with scheduled CEA testing for 5 years. Decisions to investigate further (usually by CT imaging) are based on single test results, reflecting international guidelines.

METHODS

A secondary analysis was undertaken of data from the FACS trial (two arms included CEA testing). The composite reference standard applied included CT-CAP imaging, clinical assessment and colonoscopy. Accuracy in detecting recurrence was evaluated in terms of sensitivity, specificity, likelihood ratios, predictive values, time-dependent area under the ROC curves, and operational performance when used prospectively in clinical practice are reported.

RESULTS

Of 582 patients, 104 (17.9%) developed recurrence during the 5 year follow-up period. Applying the recommended threshold of 5μg/L achieves at best 50.0% sensitivity (95% CI: 40.1-59.9%); in prospective use in clinical practice it would lead to 56 missed recurrences (53.8%; 95% CI: 44.2-64.4%) and 89 false alarms (56.7% of 157 patients referred for investigation). Applying a lower threshold of 2.5μg/L would reduce the number of missed recurrences to 36.5% (95% CI: 26.5-46.5%) but would increase the false alarms to 84.2% (924/1097 referred). Some patients are more prone to false alarms than others-at the 5μg/L threshold, the 89 episodes of unnecessary investigation were clustered in 29 individuals.

CONCLUSION

Our results demonstrated very low sensitivity for CEA, bringing to question whether it could ever be used as an independent triage test. It is not feasible to improve the diagnostic performance of a single test result by reducing the recommended action threshold because of the workload and false alarms generated. Current national and international guidelines merit re-evaluation and options to improve performance, such as making clinical decisions on the basis of CEA trend, should be further assessed.

Resorbable Synthetic Bone Grafts Formed From a Silicon Stabilized Calcium Phosphate Bioceramic

Synthetic bone grafts resistant to random dissolution at physiological pH, yet capable of being gradually resorbed in vitro by osteoclasts have been created. Bulk ceramics and ceramic coatings formed from an additive stabilized colloidal sol possess two characteristic features: a phase mixture of calcium hydroxyapatite (HA) and a silicon stabilized tricalcium phosphate, and a microporous morphology based on inter-connected particles (0.2-1.0 μm). The characteristic phase composition arises during sintering through substitution reactions where silicon enters the calcium phosphate lattice under conditions of high chemical reactivity. Evidence for in vitro resorption lacunae on bulk ceramics is presented.

Thin Film Phosphate Based Bioactive Substrates

Calcium phosphate based thin films prepared by colloidal sol-gel slow draw dipping of quartz substrates are bioactive to both osteoclast resorption and osteoblast deposition. The bioactivity is related to the presence of mixed crystalline phases in the films generated under different sintering conditions. As the sintering temperature was increased from 800°C to 1000°C, a transition in film composition from calcium hydroxylapatite to alpha-tricalcium phosphate is achieved.

A survey of infection prevention and control resources in acute care facilities across British Columbia

BACKGROUND

To determine the gaps in infection prevention and control (IPAC) resources and the disparities between rural and urban areas, the Provincial Infection Control Network surveyed the current resources in British Columbia (BC).

METHODS

Acute care facilities (ACF) in six health authorities (HA) were surveyed for IPAC staff; distribution of work; infection prevention and control professional (ICP) to bed ratios; and teaching activities. HAs were designated as either urban or rural.

RESULTS

Responses represented 54 (68%) of the ACF in BC. Rural HAs showed a significantly higher number of inexperienced ICPs (68% vs. 17%; p < 0.001). Only 22 (60%) of eligible ICPs were Certification Board of Infection Control certified. Five out of six HAs (83%) reported having an IPAC physician. Acute care ICP to bed ratios ranged from one per 67 to one per 175 and combined acute and long-term care ICP to bed ratios ranged from one per 270 beds to one per 525 beds. The number of ICPs who reported working overtime on a consistent basis ranged from 20 to 100%.

CONCLUSIONS

ACFs surveyed did not meet the recommended standards for staffing and IPAC resources in order to function as an effective program. Surveys of infection control resources are valuable tools to identify needs and assist in acquiring the resources to fill the identified gaps within a health authority.

Clinical trial: oral prednisolone metasulfobenzoate (Predocol) vs. oral prednisolone for active ulcerative colitis

BACKGROUND

Systemic corticosteroids are effective in ulcerative colitis but commonly cause side effects.

AIM

To compare the safety and efficacy of a sparingly absorbed formulation of prednisolone metasulfobenzoate (Predocol) with a conventional tapering course of oral prednisolone.

METHOD

In a double-blind randomized study, 59 active ulcerative colitis patients received Predocol 40 mg/day for 6 months, 61 received Predocol 60 mg/day for 6 months and 61 received prednisolone 40 mg/day for 2 weeks, tapered to week 8, followed by placebo until 6 months.

RESULTS

Steroid-related side effects assessed using a 10-cm visual analogue scale were fewer at 2 months with Predocol 40 mg [VAS 8.1 cm (2.6), mean (s.d.)], or 60 mg [8.1 (2.1)] compared with prednisolone [6.7 (2.7); P = 0.01]. Mood changes affected 43% receiving prednisolone at 4 weeks vs. 8% for Predocol 40 mg (P = 0.001). Remission rates (Powell-Tuck < or =2) at 2 months were Predocol 40 mg 46%, Predocol 60 mg 28% and tapering prednisolone 41% (P = 0.13). Visual analogue scale for efficacy also showed non-inferiority for Predocol 40 mg/day. Remission rates at 6 months were Predocol 40 mg 51%, Predocol 60 mg 38% and tapering prednisolone 32% (P = 0.08).

CONCLUSION

Predocol 40 mg/day has similar efficacy but markedly fewer side effects than a conventional tapering prednisolone regimen (ISRCTN14133410).

Sentinel laboratory surveillance of hepatitis C antibody testing in England: understanding the epidemiology of HCV infection

This paper describes sentinel laboratory surveillance of hepatitis C antibody testing in England. Demographic and test result data were supplemented by follow-up questionnaires sent to the requesting clinician. Between October 2002 and September 2003 almost 75000 anti-HCV tests were performed in eight sentinel centres. More males were tested than females and over half of those tested were aged 25-44 years. Overall 5.7% (3333/58144, range 2.8-7.7%) individuals tested positive. Follow-up questionnaire data showed that 82% (1043/1277) of the positives had injecting drug use reported as the main risk exposure. The majority of negative individuals were undergoing routine screening as recommended for specific patient groups. Most individuals were asymptomatic. Antibody prevalence was estimated to be 34% in current injecting drug users and 42% in former injectors. Comparing positives to routine national surveillance suggests that only 53% (1782/3333) of diagnosed cases were reported. Sentinel laboratory data can provide valuable supplementary data to national surveillance.

Clinical pathways for patients with newly diagnosed hepatitis C - what actually happens

Management of hepatitis C virus (HCV)-infected individuals requires referral to specialist care. To determine whether patients newly diagnosed as anti-HCV positive are appropriately referred for further investigation and management, and if not, to determine why not. We studied patients tested for antibodies to HCV by Nottingham Public Health Laboratory in a 2-year period (2000-2002). The progress of newly diagnosed anti-HCV positive patients into specialist clinics for further management was documented. For patients not referred for specialist care, a questionnaire was sent to the clinician requesting the initial anti-HCV test, to identify reasons for nonreferral. Eleven thousand one hundred and seventy-seven patients were tested for anti-HCV. Two hundred and fifty-six (2.3%) were newly diagnosed as being anti-HCV positive. Two per cent of samples sent from primary care were anti-HCV positive, compared to 18.8, 18.9 and 1.3% sent from prison, drug and alcohol units, and secondary care, respectively. About 64.3% of positive patients diagnosed in primary care were referred to specialist care, compared to 18.4, 42.4 and 62.6% of patients diagnosed in the other three settings. One hundred and twenty-five (49%) newly diagnosed patients were referred appropriately for further management. 68 of these attended clinic, 45 underwent liver biopsy and 26 (10%) began treatment. One hundred and thirty-one patients (51%) were not referred. In 54 cases, there was no evidence that the anti-HCV positive result reached the patient. In 15, referral was considered but rejected, and 20 patients were referred to non-HCV-specialists (their general practitioners or to genito-urinary medicine). Hence less than 50% of newly diagnosed anti-HCV positive patients are referred to an appropriate clinic for further investigation and management. Reasons for this are multifarious and complex, reflecting both systems failure and patient choice. Unless these are understood and addressed, the Department of Health Hepatitis C Strategy (2002) and Action Plan for England (2004) will fail to achieve their intended objectives.

Histamine release during adult cardiopulmonary bypass

Histamine, an inflammatory mediator in its own right, may also be a marker for a more widespread systemic inflammatory process. In this study we have examined variations in plasma histamine concentrations produced during the course of cardiac surgery involving cardiopulmonary bypass, the relationship between these variations and intra-operative events. By assays of serum tryptase and CD-63 expression we have also attempted to identify the source of histamine. Histamine concentrations that were significantly raised from baseline level were demonstrated. These were elevated from the time of aortic cross-clamping and continued to be raised for 24 h postoperatively (p < 0.00625). This was associated with an increase in CD-63 expression (p < 0.025) (but not an increase in tryptase concentration) following aortic cross-clamping and protamine administration, suggesting that basophils are the source of histamine. 41% of patients had arrhythmias in the post bypass period. The rise in histamine levels was not related to the incidence of cardiac arrhythmias.

Who is being tested for genital chlamydia in primary care?

OBJECTIVES

To explore current patterns of testing for genital chlamydial infection in primary care, and to identify practice characteristics influencing testing rates.

METHOD

Aggregate numbers of chlamydia tests and results for each practice in Nottingham Health District were matched to practice characteristics. Age specific testing rates and diagnosed prevalence were calculated, and characteristics of the practice tested for association with chlamydia testing rates.

RESULTS

Most tests (63.1%) were performed on women over the age of 25, but the proportion of positive tests was highest in 15-19 year olds (13.3%) followed by 20-24 year olds (8.2%). A higher ratio of GP principals to female practice population was associated with higher testing rates and more chlamydia isolations, but the ratio of female GP principals to patients was associated with higher testing rates only in 20-24 year olds. Diagnosed incidence was greatest in more socioeconomically deprived practice populations, and this was not explained by higher testing rates. Men were rarely tested.

CONCLUSION

Current testing practice in primary care does not reflect the known epidemiology of genital chlamydia infection. Practices with lower doctor-patient ratios do less testing, and measures to enable their active participation in the envisaged screening programme will be important in reaching all at-risk groups.

Vital capacity inhalation induction with sevoflurane: an alternative to standard intravenous induction for patients undergoing cardiac surgery

OBJECTIVE

To determine the respiratory and cardiovascular effects of a high concentration vital capacity induction with sevoflurane compared with an intravenous induction with etomidate in patients scheduled for elective coronary artery bypass graft (CABG) surgery.

DESIGN

Prospective, randomized, double-blind, controlled clinical trial.

SETTING

Cardiothoracic unit at a university hospital referral center.

PARTICIPANTS

Twenty-two patients undergoing elective CABG surgery.

INTERVENTIONS

The study group (group S) received a vital capacity gaseous induction with sevoflurane 8% (n = 12) and the control group (group E) were given etomidate, 0.2 to 0.3 mg/kg (n = 10). Anesthesia was supplemented with fentanyl, 8 microg/kg, and vecuronium, 0.1 mg/kg, in both groups.

MEASUREMENTS AND MAIN RESULTS

The speed of induction of anesthesia was comparable between the groups. There was a significant increase in minute ventilation after induction of anesthesia in both groups. This increase was associated with a small reduction in PaCO2. There were no clinically significant changes in pH and PaO(2). The incidence of breath-holding and the need for an oropharyngeal airway were similar between the groups. Both groups had similar reductions in mean arterial pressure and cardiac output during the study period; however, a downward trend in mean pulmonary artery pressure was noted in group S, whereas in group E it remained unchanged. Absolute plasma epinephrine and norepinephrine values were low during the precardiopulmonary bypass period in both groups.

CONCLUSIONS

The technique of vital capacity inhalation induction with 8% sevoflurane offers a rapid onset of anesthesia, satisfactory airway control, and a good hemodynamic profile. Consideration should be given to the benefits of single-agent anesthesia and lowered pulmonary artery pressure during the precardiopulmonary bypass period. In addition to CABG surgery, this technique could be considered in patients with coronary artery disease undergoing noncardiac surgery, particularly for procedures in which spontaneous ventilation is preferred.

Preclinical efficacy of thioxanthone SR271425 against transplanted solid tumors of mouse and human origin

A highly active and broadly active thioxanthone has been identified: N-[[1-[[2-(Diethylamino)ethyl]amino]-7-methoxy-9-oxo-9H-thioxanthen++ +-4-yl] methylformamide (SR271425, BCN326862, WIN71425). In preclinical testing against a variety of subcutaneously growing solid tumors, the following %T/C and Log10 tumor cell kill (LK) values were obtained: Panc-03 T/C = 0, 5/5 cures; Colon-38 (adv. stage) T/C = 0, 3/5 cures, 4.9 LK; Mam-16/C T/C = 0, 3.5 LK; Mam-17/0 T/C = 0, 2.8 LK; Colon-26 T/C = 0, 1/5 cures, 3.2 LK; Colon-51 T/C = 0, 2.7 LK; Panc-02 T/C = 0, 3.1 LK; B16 Melanoma T/C = 13%, 4.0 LK; Squamous Lung-LC12 (adv. stage) T/C = 14%, 4.9 LK; BG-1 human ovarian T/C = 16%, 1.3 LK; WSU-Brl human breast T/C = 25%, 0.8 LK. The agent was modestly active against doxorubicin (Adr)-resistant solid tumors: Mam-17/AdrT/C =23%, 0.8 LK; and Mam-16/C/Adr T/C = 25%, 1.0 LK, but retained substantial activity against a taxol-resistant tumor: Mam-16/C/taxol T/C = 3%, 2.4 LK. SR271425 was highly active against IV implanted leukemias, L1210 6.3 LK and AML1498 5.3 LK. The agent was equally active both by the IV and oral routes of administration, although requiring approximately 30% higher dose by the oral route. Based on its preclinical antitumor profile, it may be appropriate to evaluate SR271425 in clinical trials.

Preclinical antitumor efficacy of analogs of XK469: sodium-(2-[4-(7-chloro-2-quinoxalinyloxy)phenoxy]propionate

A series of quinoxaline analogs of the herbicide Assure was found to have selective cytotoxicity for solid tumors of mice in a disk-diffusion-soft-agar-colony-formation-assay compared to L1210 leukemia. Four agents without selective cytotoxicity and 14 agents with selective cytotoxicity were evaluated in vivo for activity against a solid tumor. The four agents without selective cytotoxicity in the disk-assay were inactive in vivo (T/C > 42%). Thirteen of the fourteen agents with selectivity in the disk-assay were active in vivo (T/C < 42%). Five of the agents had curative activity. These five agents had a halogen (F, Cl, Br) in the 7-position (whereas Assure had a CI in the 6 position). All agents with curative activity were either a carboxylic acid, or a derivative thereof, whereas Assure is the ethyl ester of the carboxylic acid. All other structural features were identical between Assure and the curative agents. Assure had no selective cytotoxicity for solid tumors in the disk-assay, and was devoid of antitumor activity. The analog XK469 is in clinical development.

Discovery of cryptophycin-1 and BCN-183577: examples of strategies and problems in the detection of antitumor activity in mice

Historically, many new anticancer agents were first detected in a prescreen; usually consisting of a molecular/biochemical target or a cellular cytotoxicity assay. The agent then progressed to in vivo evaluation against transplanted human or mouse tumors. If the investigator had a large drug supply and ample resources, multiple tests were possible, with variations in tumor models, tumor and drug routes, dose-decrements, dose-schedules, number of groups, etc. However, in most large programs involving several hundred in vivo tests yearly, resource limitations and drug supply limitations have usually dictated a single trial. Under such restrictive conditions, we have implemented a flexible in vivo testing protocol. With this strategy, the tumor model is dictated by in vitro cellular sensitivity; drug route by water solubility (with water soluble agents injected intravenously); dosage decrement by drug supply, dose-schedule by toxicities encountered, etc. In this flexible design, many treatment parameters can be changed during the course of treatment (e.g., dose and schedule). The discovery of two active agents are presented (Cryptophycin-1, and Thioxanthone BCN 183577). Both were discovered by the intravenous route of administration. Both would have been missed if they were tested intraperitoneally, the usual drug route used in discovery protocols. It is also likely that they would have been missed with an easy to execute fixed protocol design, even if injected i.v.