The neo-open reading frame peptides that comprise the tumor framome are a rich source of neoantigens for cancer immunotherapy

Identification of immunogenic cancer neoantigens as targets for therapy is challenging. Here, we integrate cancer whole genome and long-read transcript sequencing to identify the collection of novel open reading frame peptides (NOPs) expressed in tumors, termed the framome. NOPs represent tumor-specific peptides that are different from wild-type proteins and may be strongly immunogenic. We describe an uncharacterized class of hidden NOPs, which derive from structural genomic variants involving an upstream protein coding gene driving expression and translation of non-coding regions of the genome downstream of a rearrangement breakpoint. NOPs represent a vast amount of possible neoantigens particularly in tumors with many (complex) structural genomic variants and a low number of missense mutations. We show that NOPs are immunogenic and epitopes derived from NOPs can bind to MHC class I molecules. Finally, we provide evidence for the presence of memory T-cells specific for hidden NOPs in lung cancer patient peripheral blood.

Immune microenvironment composition in non-small cell lung cancer and its association with survival

Objectives

In non-small cell lung cancer (NSCLC), the immune system and possibly its composition affect survival. In this in silico study, the immune infiltrate composition in NSCLC patients was evaluated.

Methods

Gene expression data of tumors from early NSCLC patients were obtained from Gene Expression Omnibus (GEO). With CIBERSORT, 22 immune cell fractions were estimated.

Results

The immune infiltrate of 1430 pretreatment NSCLC patients contained mostly plasma cells, macrophages and CD8 T cells. Higher fractions of resting mast and CD4 T-helper cells were associated with longer overall survival (OS) (HR = 0.95, P < 0.01; HR = 0.98, = 0.04, respectively) and higher fractions of M2 macrophages and active dendritic cells with shorter survival (HR = 1.02, P = 0.03; HR = 1.03, P = 0.05, respectively). Adenocarcinoma patients with survival data (n = 587) showed higher fractions of resting mast and resting CD4 T cells, and lower M0 macrophages than squamous cell carcinoma (n = 254), which were associated with OS (HR = 0.95, P = 0.04; HR = 0.97, P = 0.01; HR = 1.03, P = 0.01, respectively). Fractions of memory B cells, naïve CD4 T cells and neutrophils had different associations with survival depending on the subtype. Smokers had had higher fractions of regulatory T cell, follicular helper T cell, neutrophil and M2 macrophage, which were associated with shorter survival (HR = 1.3, P < 0.01; HR = 1.13, P = 0.02; HR = 1.09, P = 0.03; HR = 1.04, P = 0.02, respectively).

Conclusion

Pretreatment differences in immune cell composition in NSCLC are associated with survival and depend on smoking status and histological subtype. Smokers' immune composition is associated with lower survival.

First-line tyrosine kinase inhibitors in EGFR mutation-positive non-small-cell lung cancer: a network meta-analysis

Background

EGFR-tyrosine kinase inhibitors (EGFR-TKIs) including afatinib, dacomitinib, erlotinib, gefitinib, and osimertinib have proven efficacy in terms of progression-free survival (PFS) in patients with non-small-cell lung cancer (NSCLC) harboring EGFR mutations. However, an overall view for comparing efficacy and toxicity on a meta-level is lacking. This study compared efficacy and toxicity of first-line treatment with five different EGFR-TKIs by conducting a network meta-analysis (NMA).

Methods

A systematic review was performed, aiming to find eligible literature. Data of PFS, overall survival (OS), objective response rate (ORR), and adverse events were extracted. An NMA based on Bayesian statistics was established to synthesize the efficacy and toxicity of all treatments.

Results

Thirteen randomized controlled trials, including data from 3,539 patients with EGFR-mutated NSCLC, were analyzed. Rank probabilities showed that osimertinib had a potentially better efficacy in terms of PFS and OS compared to all other TKIs. For ORR, afatinib and osimertinib showed a trend of superiority compared to the other four TKIs. Furthermore, there was a high risk of diarrhea and rash for patients treated with afatinib or dacomitinib as well as a moderate risk for treatment with erlotinib, gefitinib, and osimertinib.

Conclusion

Our study showed a favorable efficacy of osimertinib in terms of PFS and OS compared to all other EGFR-TKIs in patients with NSCLC harboring activating EGFR mutations. Furthermore, gefitinib, erlotinib, and osimertinib were associated with fewer toxicities compared to the other TKIs. Therefore, osimertinib is indicated as a preferable first-line TKI in patients with activating EGFR-mutated NSCLC.

Evaluation of elastix-based propagated align algorithm for VOI- and voxel-based analysis of longitudinal (18)F-FDG PET/CT data from patients with non-small cell lung cancer (NSCLC)

Background

Deformable image registration allows volume of interest (VOI)- and voxel-based analysis of longitudinal changes in fluorodeoxyglucose (FDG) tumor uptake in patients with non-small cell lung cancer (NSCLC). This study evaluates the performance of the elastix toolbox deformable image registration algorithm for VOI and voxel-wise assessment of longitudinal variations in FDG tumor uptake in NSCLC patients.

Methods

Evaluation of the elastix toolbox was performed using ¹⁸F-FDG PET/CT at baseline and after 2 cycles of therapy (follow-up) data in advanced NSCLC patients. The elastix toolbox, an integrated part of the IMALYTICS workstation, was used to apply a CT-based non-linear image registration of follow-up PET/CT data using the baseline PET/CT data as reference. Lesion statistics were compared to assess the impact on therapy response assessment. Next, CT-based deformable image registration was performed anew on the deformed follow-up PET/CT data using the original follow-up PET/CT data as reference, yielding a realigned follow-up PET dataset. Performance was evaluated by determining the correlation coefficient between original and realigned follow-up PET datasets. The intra- and extra-thoracic tumors were automatically delineated on the original PET using a 41% of maximum standardized uptake value (SUV_max) adaptive threshold. Equivalence between reference and realigned images was tested (determining 95% range of the difference) and estimating the percentage of voxel values that fell within that range.

Results

Thirty-nine patients with 191 tumor lesions were included. In 37/39 and 12/39 patients, respectively, thoracic and non-thoracic lesions were evaluable for response assessment. Using the EORTC/SUV_max-based criteria, 5/37 patients had a discordant response of thoracic, and 2/12 a discordant response of non-thoracic lesions between the reference and the realigned image. FDG uptake values of corresponding tumor voxels in the original and realigned reference PET correlated well (R²=0.98). Using equivalence testing, 94% of all the voxel values fell within the 95% range of the difference between original and realigned reference PET.

Conclusions

The elastix toolbox impacts lesion statistics and therefore therapy response assessment in a clinically significant way. The elastix toolbox is therefore not applicable in its current form and/or standard settings for PET response evaluation. Further optimization and validation of this technique is necessary prior to clinical implementation.

Electronic supplementary material

The online version of this article (doi:10.1186/s13550-015-0089-z) contains supplementary material, which is available to authorized users.

Immunoglobulin-like transcript 3 is expressed by myeloid-derived suppressor cells and correlates with survival in patients with non-small cell lung cancer

Myeloid-derived suppressor cells (MDSCs) play an important role in immune suppression and accumulate under pathologic conditions such as cancer and chronic inflammation. They comprise a heterogeneous population of immature myeloid cells that exert their immunosuppressive function via a variety of mechanisms. Immunoglobulin-like transcript 3 (ILT3) is a receptor containing immunoreceptor tyrosine-based inhibition motifs (ITIMs) that can be expressed on antigen-presenting cells and is an important regulator of dendritic cell tolerance. ILT3 exists in a membrane-bound and a soluble form and can interact with a yet unidentified ligand on T cells and thereby induce T-cell anergy, regulatory T cells, or T suppressor cells. In this study, we analyzed freshly isolated peripheral blood mononuclear cells (PBMCs) of 105 patients with non-small cell lung cancer and 20 healthy controls and demonstrated for the first time that ILT3 is expressed on MDSCs. We show that increased levels of circulating MDSCs correlate with reduced survival. On the basis of ILT3 cell surface expression, an ILT3^low and ILT3^high population of polymorphonuclear (PMN)-MDSCs could be distinguished. Interestingly, in line with the immunosuppressive function of ILT3 on dendritic cells, patients with an increased proportion of PMN-MDSCs and an increased fraction of the ILT3^high subset had a shorter median survival than patients with elevated PMN-MDSC and a smaller ILT3^high fraction. No correlation between the ILT3^high subset and other immune variables was found. ILT3 expressed on MDSCs might reflect a previously unknown mechanism by which this cell population induces immune suppression and could therefore be an attractive target for immune intervention.

Strategies for patients with newly diagnosed oral squamous cell carcinoma and a positive chest CT. A cohort study on the effects on treatment planning and incidence

The purpose of this study was to establish how often routine CT scan of the chest yields positive findings in patients suffering from oral SCC and how it influences the treatment in terms of extra diagnostic procedures, treatment planning and treatment delay. Costs of this additional diagnostic approach for pulmonary tumors in a selected group were also calculated. A retrospective study was conducted of a group of 196 patients who were newly diagnosed with a squamous cell carcinoma of the oral cavity between January 2004 and July 2006; 142 hospital files were eligible for reviewing. In 20 (13%) patients chest abnormalities were observed on CT scan of the chest and in 6 (4%) patients malignancy was pathologically confirmed. Both pulmonary second primary tumors and pulmonary metastases were independent of stage of oral malignancy. We found that additional diagnostic procedures did not significantly lengthen the time interval between first consult and start of treatment. The cost of the screening for pulmonary malignancies in the group was € 8.214 per observed pulmonary malignancy. We advocate that CT imaging of the chest should be routinely performed in the diagnostic work up of all patients with a newly discovered SCC of the oral cavity, irrespective of the tumor stage of the oral malignancy.

Prognostic Classification with Laboratory Parameters or Imaging Techniques in Small-Cell Lung Cancer

PURPOSE

Our aim in this study was to compare prognostic models based on laboratory tests with a model including imaging information in small-cell lung cancer.

PATIENTS AND METHODS

A retrospective analysis was performed on 156 consecutive patients. Three existing models based on laboratory tests and performance status (PS) and a model based on disease stage assessed by imaging techniques and PS were tested with Cox regression analysis.

RESULTS

The 3 laboratory-based models and the imaging-based model were significant in predicting prognosis in our patient group, with hazard ratios of 1.6-3 for medium prognosis groups and 2.6-6.1 for poor prognosis groups compared with good prognosis groups. Models based on laboratory tests appear to predict survival probabilities at least as well as a model with information from imaging techniques.

CONCLUSION

Prognostic models using PS and laboratory tests provide a similar estimation of survival of patients with small-cell lung cancer as the combination of PS and disease stage assessed by imaging tests.

[The biopsying of at least 5 mediastinal lymph node stations for presurgical staging in patients with a non-small-cell lung carcinoma]

OBJECTIVE

To determine the additional value of mediastinoscopy/tomy in the pre-surgical staging of non-small-cell lung carcinoma.

DESIGN

Retrospective.

METHODS

Patients who underwent mediastinoscopy/tomy for staging of non-small-cell lung carcinoma from 1994 to 2000 at Groningen University Hospital, the Netherlands, were evaluated. Starting with data on history, physical examination, data imaging tests and bronchoscopy, the additional value of the mediastinoscopy was then evaluated using a logistic regression model. Not only was the additional value of a limited, routinely performed mediastinoscopy (whereby only lymph nodes at the site of the primary tumour are biopsied) examined, but also that of the comprehensive standard mediastinoscopy (conforming to the minimal requirements regarding number and localization of biopsied lymph nodes, i.e. lymph-node stations 2L, 2R, 4R, 4L, 7). The outcome against which all the test results were measured was the result of final pathological tumour staging.

RESULTS

A total of 176 evaluable patients were included. History, physical examination and bronchoscopy played a small but significant role in predicting the percentage of patients in which resection was possible, 58% (95% CI: 50-67). Age was an important predictor. The subsequent addition of the limited and routinely performed mediastinoscopy to the model increased the correct prediction to 69% (95% CI: 61-77), while adding the standard mediastinoscopy to the model showed a significantly higher correct prediction of 81% (95% CI: 75-88).

CONCLUSION

The standard mediastinoscopy involving a minimum of five different lymph node stations was of greater diagnostic value than limited mediastinoscopy.

[Factors involved in the etiology of hypomineralized first permanent molars]

Severe hypomineralized first permanent molars (cheese molars) can be found in children. The aetiology of this phenomenon is unknown. The aim of this study is to collect more information about the causes of such molars. Parents of 24 children with severe cheese molars and of 21 controls without cheese molars, matched for age, living area and sex were interviewed. The mean age of the 45 children was 9.9 year (; ssd: 2.02). A questionnaire about the medical data from birth to four years of age and the medical situation of the mother during pregnancy was sent to the parents. No significant differences were found concerning weight and length at the time of birth between the two groups. Also no significant differences were found for the period of breast-/and bottle-feeding and for problems of the mother during pregnancy and child delivery. The mothers were healthy during pregnancy. Compared to the control group the children with cheese molars were ill more often Significant differences were found for pneumonia, high fever and inflammation of the middle ear.

Factors involved in the aetiology of molar-incisor hypomineralisation (MIH)

AIM: This study aimed to collect more information on factors associated with molar-incisor hypomineralisation (MIH), which is a frequent developmental enamel defect with unknown aetiology. MATERIALS AND METHODS: A questionnaire was sent to the parents of 45 children (average age 9.9 years; SD+/-2.02), 24 with affected first molars and 21 controls. The two groups of children were similar in terms of age, gender and living conditions. Questions were asked about the health of mother and child during pregnancy, the birth and health of the child up to age four years. RESULTS: Birth weight and length in the two groups of children were similar, as was the duration of breast- and/or bottle-feeding and the incidence of complications during pregnancy and birth. The children with MIH were ill more frequently during the first four years of life. CONCLUSION: Knowledge of the type of disease that might be involved in the development of such molars is still inadequate, but there appears to be an association with pneumonia, otitis media and high fevers.

PNU-145156E, a novel angiogenesis inhibitor, in patients with solid tumors: a phase I and pharmacokinetic study

Our aim was to establish, in patients with solid tumors, the dose-limiting toxicity, maximum tolerated dose (MTD), and pharmacology of PNU-145156E, a new sulfonated distamycin A derivative that blocked circulating angiogenesis-promoting growth factors in animal studies and exhibited an antitumor effect in murine solid tumors. In a Phase I study, PNU-145156E was administered i.v. every 6 weeks. Included were patients with solid tumors; an Eastern Cooperative Oncology Group performance score </=1; and normal bone marrow, renal, and liver functions and blood clotting tests. Excluded were patients with brain metastases or on steroid medication. Toxicity was scored with the National Cancer Institute Common Toxicity Criteria. Plasma and urine PNU-145156E was measured for pharmacokinetic analysis. The effect of PNU-145156E on serum basic fibroblast growth factor (bFGF) was measured by sandwich ELISA. Twenty-nine patients (median age, 54 years; range, 33-71 years; 19 males and 10 females; median performance score = 1) were treated at dose levels of 100-1050 mg/m(2). We observed, during 47 treatment cycles, erratic but short-lasting decreases of antithrombin III levels (<75%) at all dose levels. Other clotting tests remained normal except during thromboembolic events. Dose-limiting toxicity was thrombophlebitis, pulmonary embolism, and grade 3 dyspnea. PNU-145156E disappeared from the circulation, decreasing triexponentially with a long terminal half-life of 1 month. No significant change in bFGF and no objective tumor responses were observed. Disease stabilization was achieved in four patients. In conclusion, the MTD of PNU-145156E was 1050 mg/m(2). Serum bFGF level was not affected by PNU-145156E up to the MTD.

Activity of single-agent gemcitabine as second-line treatment after previous chemotherapy or radiotherapy in advanced non-small-cell lung cancer

The aim of the study was to evaluate activity, toxicity and health-related quality of life (HRQL) with gemcitabine as second-line treatment after previous chemo- or radiotherapy in non-small-cell lung cancer (NSCLC). Patients with previously treated NSCLC were treated with gemcitabine (1000 mg/m(2)) on days 1, 8 and 15 in a 28-day cycle. Eighty patients were included; median age was 57 years (range 38-77). Prior treatment consisted of platinum-containing chemotherapy in 29 patients and high-dose thoracic radiotherapy in 51 patients. Median number of cycles was three (range 1-6). Granulocytopenia CTC grade 3 and 4 occurred in 9% and thrombocytopenia CTC grade 3 and 4 in 9% of cycles. Non-haematological toxicity was mild. Tumour response was achieved in 13% of the patients (95% CI 7-20), median survival time was 26 weeks and 1-year survival was 22%. Tumour response to second-line gemcitabine could not be predicted from response to first-line therapy, first-line treatment modality or treatment interval. In a subset of 35 patients HRQL was assessed with the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 and QLQ-LC13 questionnaires and showed improvement or control of symptoms and functioning in approximately 30% of patients. We conclude that gemcitabine in second-line treatment has modest anti-tumour activity, is well tolerated, and may control tumour-related symptoms and improve HRQL in a significant minority of patients.

Prevalence of cheese molars in eleven-year-old Dutch children

In the Netherlands, first permanent molars with idiopathic enamel disturbances (IED) are called cheese molars. Though concern is expressed about their prevalence, adequate figures on the subject are missing. The porous enamel of cheese molars can be very sensitive to cold air and can decay rapidly. The aim of the present study was to investigate the prevalence in eleven-year-old Dutch children of cheese molars (IED). During an epidemiological study performed in four cities in the Netherlands, the first permanent molars and central incisors of eleven-year-old children were examined for hypoplasia, opacities, posteruptive enamel loss, premature extraction, and atypical restorations. The observation of a hypoplasia excluded the possibility of cheese molar. A total of 497 children were examined. Six percent (n = 128) of the molars (n = 1988) showed signs of IED (cheese molars), 10 percent of the children had cheese molars of which 8 percent two or more. Incisors (4 percent) with opacities were found in 3 percent in combination with two or more cheese molars. Among the four cities, no significant differences in occurrence were found. The results of this study showed that in 10 percent of the Dutch children eleven years of age, cheese molars (IED) were found. The cause for the phenomenon called cheese molars appears to be child centered. Further studies on prevalence, causes and prevention are mandatory.

Population pharmacokinetics of ifosfamide and its 2- and 3-dechloroethylated and 4-hydroxylated metabolites in resistant small-cell lung cancer patients

The aim of this study was to develop a population pharmacokinetic model that could describe the pharmacokinetics of ifosfamide. 2- and 3-dechloroethylifosfamide and 4-hydroxyifosfamide, and calculate their plasma exposure and urinary excretion. A group of 14 patients with small-cell lung cancer received a 1-h intravenous infusion of 2.0 or 3.0 g/m2 ifosfamide over 1 or 2 days in combination with 175 mg/m2 paclitaxel and carboplatin at AUC 6. The concentration-time profiles of ifosfamide were described by an ifosfamide concentration-dependent development of autoinduction of ifosfamide clearance. Metabolite compartments were linked to the ifosfamide compartment enabling description of the concentration-time profiles of 2- and 3-dechloroethylifosfamide and 4-hydroxyifosfamide. The Bayesian estimates of the pharmacokinetic parameters were used to calculate the systemic exposure to ifosfamide and its metabolites for the four ifosfamide schedules. Fractionation of the dose over 2 days resulted increased metabolite formation, especially of 2-dechloroethylifosfamide, probably due to increased autoinduction. Renal recovery was only minor with 6.6% of the administered dose excreted unchanged and 9.8% as dechloroethylated metabolites. In conclusion, ifosfamide pharmacokinetics were described with an ifosfamide concentration-dependent development of autoinduction and allowed estimation of the population pharmacokinetics of the metabolites of ifosfamide. Fractionation of the dose resulted in increased exposure to 2-dechloroethylifosfamide, probably due to increased autoinduction.

Dose-finding and pharmacological study of ifosfamide in combination with paclitaxel and carboplatin in resistant small-cell lung cancer

BACKGROUND

To find the maximum tolerated dose for ifosfamide in combination with paclitaxel and carboplatin in small-cell lung cancer patients (SCLC), who are resistant to cyclophosphamide, doxorubicin and etoposide (CDE).

PATIENTS AND METHODS

Different dose schedules of ifosfamide were combined with fixed doses of paclitaxel 175 mg/m2 and carboplatin AUC 6 mg/ml min. Included were 30 patients, with a median age of 60 years, and median time off prior cytotoxic treatment of 8 weeks. All patients were previously treated with CDE and 11 had received re-induction CDE.

RESULTS

Dose limiting toxicity of our schedule was persistent thrombocytopenia. None of the patients developed neutropenic fever. Non-haematological toxicity was mild, although two treatment-related deaths occurred. Fifty-four percent of patients had a partial response and median survival time was twenty-five weeks.

CONCLUSIONS

The maximum tolerated dose of this combination for patients with resistant SCLC is ifosfamide 2000 mg/m2 in combination with paclitaxel 175 mg/m2 and carboplatin AUC 6 mg/ml min administered on the first day of a 21-day cycle.

L-3-[123I]iodo-alpha-methyl-tyrosine SPECT in non-small cell lung cancer: preliminary observations

L-3-[123I]iodo-alpha-methyl-tyrosine (IMT) is a modified amino acid that is avidly taken up by many tumors. Uptake is based on the increased transmembrane transport of amino acids in malignancies. IMT is the only amino acid tracer suitable for SPECT. The aim of this study was to determine the feasibility of IMT SPECT in the detection, staging, and treatment evaluation of non-small cell lung cancer.

METHODS

We evaluated 44 IMT SPECT studies in 17 patients with histologically proven non-small cell lung cancer, stage III. IMT SPECT and planar imaging of the chest was performed before, 2 wk after, and 3 mo after 60 Gy radiotherapy. Staging was based on the findings of bronchoscopy, chest CT, mediastinoscopy, or explorative thoracotomy. After radiotherapy, CT and bronchoscopy were repeated to assess tumor response.

RESULTS

In 15 of 16 evaluable primary tumors, avid IMT uptake was present (sensitivity, 94%), with a mean (+/-SD) tumor-to-background ratio (T/B) of 2.95 +/- 0.78 (range, 1.7-4.9). In 12 of 14 patients (86%) with mediastinal involvement, IMT SPECT detected one or more mediastinal metastases. However, only 13 of 20 mediastinal metastases were detected in lesion analysis (lesion-based sensitivity, 65%). For lesions < 2 cm in diameter, sensitivity was 42%. FDG PET (available for 5 patients) detected more known and unknown lesions than did IMT SPECT. After radiotherapy, T/B had fallen to 1.84 +/- 0.29 (P < 0.001 vs. baseline), and 3 mo later to 1.61 +/- 0.41 (not statistically significant vs. second study). Considerable nonspecific uptake was found in irradiated normal lung tissue (mean ratio to nonirradiated tissue, 1.79 +/- 0.53), persisting for > 3 mo. No relationship was observed between various IMT uptake parameters and the presence of residual viable tumor tissue or survival.

CONCLUSION

IMT SPECT has a high sensitivity for the detection of primary non-small cell lung cancer. Although patient-based sensitivity in detecting mediastinal spread was adequate, sensitivity for individual lesions, especially for small metastases (<2 cm in diameter) was too low to be clinically helpful. Radiotherapy caused considerable nonspecific IMT uptake, which also limits applicability in evaluating the results of treatment.

Single-agent gemcitabine in patients with resistant small-cell lung cancer

OBJECTIVE

This study was conducted to assess the activity and toxicity ofgemcitabine in patients with resistant small-cell lung cancer (SCLC). PATIENTS TAND METHODS: Forty-one patients with limited- or extensive-stage SCLC, who were previously treated with at least one chemotherapeutic regimen and progressed during or within three months of finishing the last regimen, were treated with 1000 mg/m2 gemcitabine on days 1, 8, and 15 of a four-week cycle.

RESULTS

Thirty-eight patients were evaluable for response. Five partial and no complete responses were seen, for an overall response rate of 13% (95% confidence interval (CI): 6%-27%). Time to progression varied from 4 to 20 weeks, with a median of 8 weeks. Median survival was 17 weeks (range 4-84 weeks). Hematological toxicity mainly consisted of NCI-CTC grade 3 thrombocytopenia (29% of patients) and, to a lesser extent, grade 3 leukopenia (18% of patients). Non-hematological toxicity was mild, with nausea being the most commonly reported event.

CONCLUSIONS

Gemcitabine has modest activity in patients with resistant SCLC. There is some non-cross resistance to most agents against SCLC.

Clinical pharmacokinetics and pharmacodynamics of ifosfamide and its metabolites

This review discusses several issues in the clinical pharmacology of the antitumour agent ifosfamide and its metabolites. Ifosfamide is effective in a large number of malignant diseases. Its use, however, can be accompanied by haematological toxicity, neurotoxicity and nephrotoxicity. Since its development in the middle of the 1960s, most of the extensive metabolism of ifosfamide has been elucidated. Identification of specific isoenzymes responsible for ifosfamide metabolism may lead to an improved efficacy/toxicity ratio by modulation of the metabolic pathways. Whether ifosfamide is specifically transported by erythrocytes and which activated ifosfamide metabolites play a key role in this transport is currently being debated. In most clinical pharmacokinetic studies, the phenomenon of autoinduction has been observed, but the mechanism is not completely understood. Assessment of the pharmacokinetics of ifosfamide and metabolites has long been impaired by the lack of reliable bioanalytical assays. The recent development of improved bioanalytical assays has changed this dramatically, allowing extensive pharmacokinetic assessment, identifying key issues such as population differences in pharmacokinetic parameters, differences in elimination dependent upon route and schedule of administration, implications of the chirality of the drug and interpatient pharmacokinetic variability. The mechanisms of action of cytotoxicity, neurotoxicity, urotoxicity and nephrotoxicity have been pivotal issues in the assessment of the pharmacodynamics of ifosfamide. Correlations between the new insights into ifosfamide metabolism, pharmacokinetics and pharmacodynamics will rationalise the further development of therapeutic drug monitoring and dose individualisation of ifosfamide treatment.

The blood-brain barrier and oncology: new insights into function and modulation

The efficacy of chemotherapy for malignant primary or metastatic brain tumours is still poor. This is at least partly due to the presence of the blood-brain barrier (BBB). The functionality of the BBB can be explained by physicochemical features and efflux pump mechanisms. An overview of the literature is presented with emphasis on oncology. The BBB consists of capillary endothelial cells that lack fenestrations and are connected together with continuous tight junctions, with a high electrical resistance. Permeability of tight junctions can be increased in vitro by contraction of the cytoskeleton, caused by bradykinin agonists. Different efflux pumps are present in the BBB. Examples are P-glycoprotein (P-gp), organic anion transporters, (OAT) and multidrug-resistance-associated proteins (MRP)(1 and 3). These pumps act as a multi-specific efflux pump for various chemotherapeutic drugs. Experiments have shown that P-gp can be inhibited by different non-chemotherapeutic substrates such as cyclosporin A. The functionality in vivo of P-gp can be measured with positron emission tomography and [(11)C]-verapamil or with single photon emission computer tomography and(99m)Tc-sestamibi. MRP(1)and MRP(3)act as organic anion transporters that in vitro act as efflux pumps for substances that are conjugated or co-transported with glutathione and glucuronide, respectively. Methotrexate has been recently demonstrated to be transported by MRP(1)and MRP(3). Results of studies which demonstrate the clinical relevance and applicability of BBB modulators are eagerly awaited.

Prolonged demand breast-feeding and nursing caries

The aim of this study was to study the characteristics and to explore risk factors within a group of Dutch children breast-fed on demand over a prolonged period, whose mothers attended the meetings of La Leche League. Ninety-six children, 55 boys and 41 girls (mean age 28.8 months, SD 8.8), were examined. Most of the parents belong to a higher socio-economic working class. The examination included a questionnaire and dietary sheet, combined with the caries status of the child. On average the children were breast-feed for 21.5 months (SD 9.8). The mean age at which the parents started brushing the children's teeth was 11.7 months (SD 5.1). Fluoridated toothpaste (250 ppm fluoride) was used by 70% of the children. The children were divided into three groups according to their caries pattern: 1 caries-free; 2 caries, and 3 nursing caries. Dentine caries was found in 14 (14.5%) of the children, of which 9 (9.3%) met the criteria of nursing caries. The mean dmfs of all children examined was 1.2 (SD 4.8). Up to 18 months of age the breast was given significantly more frequently during the night and up to 24 months during the day time, to the children of the nursing caries group compared to the children in the other two groups. The children still being breast-fed at the time of investigation more frequently slept in their parents' bed. The children of the nursing-caries group used fluoridated dentifrices less often. The majority of children of the caries and nursing-caries groups did not receive fluoride from other sources. The results of the present study demonstrate that prolonged demand breast-feeding does not lead to a higher caries prevalence although comparison between the groups demonstrates that frequent breast-feeding and low additional fluoride use should be considered as contributing factors in the process of nursing caries.

Treatment of brain metastases of small-cell lung cancer: comparing teniposide and teniposide with whole-brain radiotherapy--a phase III study of the European Organization for the Research and Treatment of Cancer Lung Cancer Cooperative Group

PURPOSE

Approximately 60% of patients with small-cell lung cancer (SCLC) develop brain metastases. Whole-brain radiotherapy (WBRT) gives symptomatic improvement in more than 50% of these patients. Because brain metastases are a sign of systemic progression, and chemotherapy was found to be effective as well, it becomes questionable whether WBRT is the only appropriate therapy in this situation.

PATIENTS AND METHODS

In a phase III study, SCLC patients with brain metastases were randomized to receive teniposide with or without WBRT. Teniposide 120 mg/m(2) was given intravenously three times a week, every 3 weeks. WBRT (10 fractions of 3 Gy) had to start within 3 weeks from the start of chemotherapy. Response was measured clinically and by computed tomography of the brain.

RESULTS

One hundred twenty eligible patients were randomized. A 57% response rate was seen in the combined-modality arm (95% confidence interval [CI], 43% to 69%), and a 22% response rate was seen in the teniposide-alone arm (95% CI, 12% to 34%) (P<.001). Time to progression in the brain was longer in the combined-modality group (P=.005). Clinical response and response outside the brain were not different. The median survival time was 3.5 months in the combined-modality arm and 3.2 months in the teniposide-alone arm. Overall survival in both groups was not different (P=.087).

CONCLUSION

Adding WBRT to teniposide results in a much higher response rate of brain metastases and in a longer time to progression of brain metastases than teniposide alone. Survival was poor in both groups and not significantly different.

A phase I study of a new polyamine biosynthesis inhibitor, SAM486A, in cancer patients with solid tumours

Because tumour cell proliferation is highly dependent upon up-regulation of de-novo polyamine synthesis, inhibition of the polyamine synthesis pathway represents a potential target for anticancer therapy. SAM486A (CGP 48664) is a new inhibitor of the polyamine biosynthetic enzyme S-adenosylmethionine decarboxylase (SAMDC), more potent and specific than the first-generation SAMDC inhibitor methylglyoxal (bis) guanylhydrazone (MGBG). Preclinical testing confirmed promising antiproliferative activity. In this phase I study, SAM486A was given 4-weekly as a 120 h infusion. 39 adult cancer patients were enrolled with advanced/refractory disease not amenable to established treatments, PS </= 2, adequate marrow, liver, renal and cardiac function. Doses were escalated in 100% increments without toxicity in 24 pts from 3 mg m(-2)cycle(-1)up to 400 mg m(-2)cycle(-1). At 550 and 700 mg m(-2)cycle(-1)reversible dose-limiting neutropenia occurred. Other toxicities included mild fatigue, nausea and vomiting. No objective remission was seen. Pharmakokinetic analysis showed a terminal half-life of approximately 2 days. AUC and Cmax were related to dose; neutropenia correlated with AUC. The recommended dose for further phase II studies on this schedule is 400 mg m(-2)cycle(-1).

Bacterial counts in carious dentine under restorations: 2-year in vivo effects

Little is known about the long-term effects of fluoride-releasing materials on carious dentine in vivo. The aim was to investigate the 2-year influence of a resin-modified glass ionomer cement (RM-GIC) and amalgam on the bacteriological counts of carious dentine that remained under class I restorations. To enable a split-mouth design, 33 molar pairs in 33 patients (mean age 15.1 years, SD 1.4) were selected, based on clinically and radiographically diagnosed occlusal dentine caries. The enamel of the carious molars was removed, and the carious dentine was sampled under aseptic conditions just beneath the dentinoenamel junction. The molars were alternately restored with RM-GIC or amalgam without further removal of carious dentine. The samples were processed for microbiological determination of total viable counts (TVC), mutans streptococci (MS), and lactobacilli (LB). The molar pairs of 25 patients were reevaluated after 2 years using the same clinical techniques and were permanently restored after complete caries removal. Both materials showed a substantial decrease in numbers of TVC and LB of the carious dentine after the 2-year period. Compared to amalgam, the decrease in the numbers of LB was significantly more pronounced for RM-GIC. No microorganisms were detected in only 11 molars (6 RM-GIC and 5 amalgam) after the 2-year period. Based on this study, we suggest that complete removal of carious dentine is still the best conservative treatment, irrespective of the restorative material used.

Diffusion capacity and haemodynamics in primary and chronic thromboembolic pulmonary hypertension

The transfer factor of the lung for carbon monoxide (TL,CO) is decreased in patients with pulmonary hypertension. The pulmonary membrane diffusion capacity (Dm) and pulmonary capillary blood volume (Vc), were studied to establish: 1) the relative contribution of the components of the transfer factor to the decrease in TL,CO; 2) whether differences exist between primary pulmonary hypertension (PPH) and chronic thromboembolic pulmonary hypertension (CTEPH); and 3) the relationship between these parameters and haemodynamic parameters. Dm and Vc were determined in 19 patients with PPH and in eight patients with CTEPH. The patients had been referred for consideration for lung transplantation. Haemodynamic parameters were assessed by heart catheterization. In the PPH group, Vc was reduced in 12 of 19 patients (mean+/-SD Vc 72+/-14% of the predicted value) and Dm in 17 of 19 patients (60+/-22% pred). In the CTEPH group, Vc was reduced in six of eight patients and Dm in seven of eight patients. The mean TL,CO Dm and Vc values were similar to those in the PPH group. The reduction in pulmonary membrane diffusion capacity was significantly greater than that in pulmonary capillary blood volume. No differences in pulmonary and cardiovascular functional values were found between the groups. Right atrial pressure showed a significant negative correlation with pulmonary capillary blood volume and an increased pulmonary vascular resistance was associated with a decrease in pulmonary membrane diffusion capacity. These results suggest pronounced functional impairment of the alveolocapillary membrane in these patients.

Preoperative staging of non-small-cell lung cancer with positron-emission tomography

BACKGROUND

Determining the stage of non-small-cell lung cancer often requires multiple preoperative tests and invasive procedures. Whole-body positron-emission tomography (PET) may simplify and improve the evaluation of patients with this tumor.

METHODS

We prospectively compared the ability of a standard approach to staging (computed tomography [CT], ultrasonography, bone scanning, and, when indicated, needle biopsies) and one involving PET to detect metastases in mediastinal lymph nodes and at distant sites in 102 patients with resectable non-small-cell lung cancer. The presence of mediastinal metastatic disease was confirmed histopathologically. Distant metastases that were detected by PET were further evaluated by standard imaging tests and biopsies. Patients were followed postoperatively for six months by standard methods to detect occult metastases. Logistic-regression analysis was used to evaluate the ability of PET and CT to identify malignant mediastinal lymph nodes.

RESULTS

The sensitivity and specificity of PET for the detection of mediastinal metastases were 91 percent (95 percent confidence interval, 81 to 100 percent) and 86 percent (95 percent confidence interval, 78 to 94 percent), respectively. The corresponding values for CT were 75 percent (95 percent confidence interval, 60 to 90 percent) and 66 percent (95 percent confidence interval, 55 to 77 percent). When the results of PET and CT were adjusted for each other, only PET results were positively correlated with the histopathological findings in mediastinal lymph nodes (P<0.001). PET identified distant metastases that had not been found by standard methods in 11 of 102 patients. The sensitivity and specificity of PET for the detection of both mediastinal and distant metastatic disease were 95 percent (95 percent confidence interval, 88 to 100 percent) and 83 percent (95 percent confidence interval, 74 to 92 percent), respectively. The use of PET to identify the stage of the disease resulted in a different stage from the one determined by standard methods in 62 patients: the stage was lowered in 20 and raised in 42.

CONCLUSIONS

PET improves the rate of detection of local and distant metastases in patients with non-small-cell lung cancer.

Effects of dental treatment and single application of a 40% chlorhexidine varnish on mutans Streptococci in young children under intravenous anaesthesia

Clinical studies suggest that application of a highly concentrated chlorhexidine varnish results in a decrease in the number of mutans streptococci and thereby a decrease in the caries risks. The aim of this study was to determine the effect of dental treatment on the levels of mutans streptococci (MS) and lactobacilli (LB) and the additional effect of a single application of 40% chlorhexidine varnish (EC40) on the level of MS. Twenty-three children under the age of 5 years scheduled for full dental treatment were selected. Of these 23 children (mean dmf-s 27.1, SD 19.3), 11 children had nursing bottle caries. The mean sugar exposure was 6.4. Subjects were randomly distributed into two groups of approximately equal size. One group received an EC40 application after dental treatment, while the other group received only full dental treatment, both with intravenous anaesthesia with propofol as a single drug. An unstimulated saliva sample and a plaque sample were taken prior to dental treatment. The saliva and plaque sampling of the subjects was repeated after 6 weeks. MS and LB were isolated and counted. The number of children harbouring more than 10(6) MS in a pooled plaque sample decreased significantly from 8 to 2 children 6 weeks after dental treatment. No additional effect of EC40 was found. The number of salivary MS did not change significantly between the groups or before and after treatment. The figures for LB remained at a high level of more than 10(4)/ml saliva before (21 children) and 6 weeks after treatment (17 children). The results of this study indicate that dental treatment results in a significant suppression of plaque MS, while a single application of EC40 showed no significant additional suppression after 6 weeks.

TGF-beta, radiation-induced pulmonary injury and lung cancer

PURPOSE

To determine whether changes in TGF-beta plasma levels during radiation therapy may be useful in predicting radiation-induced pulmonary injury and tumour response in non-small-cell lung cancer (NSCLC) patients.

MATERIALS AND METHODS

Plasma TGF-beta was investigated in 27 patients with stage III NSCLC, who were treated with 60 Gy (2Gy/day) radiotherapy with or without carboplatin. TGF-beta was measured prior to beginning radiotherapy and weekly during treatment; evaluated as a ratio between TGF-beta levels obtained during treatment and the pretreatment TGF-beta level. The endpoints of the study were development of symptomatic radiation pneumonitis and tumour response.

RESULTS

Nine of the 27 patients developed pneumonitis. The patients who developed pneumonitis had high persistent TGF-beta levels throughout the course of treatment (TGF-beta ratio>1), whereas the TGF-beta levels in patients who did not develop pneumonitis were unchanged or declined towards normal (TGF-beta ratio < 1). Patients who responded to treatment had low or normal TGF-beta levels during treatment compared with patients who failed to respond. Other parameters such as pretreatment TGF-beta values, carboplatin treatment or field size did not appear to have a significant effect, which is probably due to the small number of patients entered in the study.

CONCLUSION

This pilot study, with a limited number of patients, suggests the hypothesis that elevated TGF-beta levels during radiotherapy may not only indicate patients with a higher risk of developing pulmonary toxicity but also patients with a higher risk of treatment failure. This remains to be tested in a larger clinical study.

Clinical and radiographic judgement of occlusal caries in adolescents

In this study, the clinical and radiographic material of two groups of 17- and 20-yr-old adolescents, born either in 1970 or in 1976, was compared to study changes in the prevalence of occlusal dentine caries and to determine the additional value of the bitewing radiographs. The first and second molars of 478 participants were included. Clinical data were derived from an epidemiological project. Two examiners judged the bitewing radiographs, of which about 10% was examined by both. The overall Cohen's kappa for interexaminer agreement was 0.87. The prevalence of occlusal caries had not changed for the two age groups; after clinical and radiographic examination, around 33% of the occlusal surfaces of the 17 yr olds and around 25% of the 20 yr olds exhibited dentine caries. The clinical prevalence of occlusal caries in first and second molars was highly underestimated when compared with the radiographs. In the 1976 group, more sealants were recorded during the clinical examination. On the bitewing radiographs, radiolucencies were found underneath one-half of the sealants of the 17 yr olds and underneath one quarter of the sealants present in the 20 yr olds.

Superior vena cava obstruction caused by radiation induced venous fibrosis

Superior vena cava syndrome is most often caused by lung carcinoma. Two cases are described in whom venous obstruction in the superior mediastinum was caused by local vascular fibrosis due to radiotherapy five and seven years earlier. The development of radiation injury to greater vessels is discussed, together with the possibilities for treatment of superior vena cava syndrome.

A prolonged methoxymorpholino doxorubicin (PNU-152243 or MMRDX) infusion schedule in patients with solid tumours: a phase 1 and pharmacokinetic study

The aim of this phase I study was to assess feasibility, pharmacokinetics and toxicity of methoxymorpholino doxorubicin (MMRDX or PNU-152243) administered as a 3 h intravenous infusion once every 4 weeks. Fourteen patients with intrinsically anthracycline-resistant tumours received 37 cycles of MMRDX. The first cohort of patients was treated with 1 mg m(-2) of MMRDX. The next cohorts received 1.25 mg m(-2) and 1.5 mg m(-2) respectively. Common toxicity criteria (CTC) grade III/IV nausea and vomiting were observed in 1/18 cycles at 1.25 mg m(-2) and in 2/11 cycles at 1.5 mg m(-2). Transient elevation in transaminases up to CTC grade III was observed in 2/16 cycles at 1.25 mg m(-2) and 4/11 cycles at 1.5 mg m(-2). No cardiotoxicity was observed. At 1.25 mg m(-2) CTC grade IV neutropenia occurred in 1/17 cycles. At 1.5 mg m(-2) CTC grade III neutropenia was seen in 2/7 and grade IV in 3/7 evaluable cycles. Thrombocytopenia grade III was observed in 2/9 and grade IV in 1/9 evaluable cycles. One patient treated at 1.5 mg m(-2) died with neutropenic fever. Therefore, dose-limiting toxicity was reached and 1.25 mg m(-2) was considered the maximum tolerated dose for MMRDX as 3 h infusion. No tumour responses were observed. Pharmacokinetic parameters showed a rapid clearance of MMRDX from the circulation by an extensive tissue distribution. Renal excretion of the drug and its metabolite was negligible. In conclusion, prolongation of MMRDX infusion to 3 h does not improve the toxicity profile as compared with bolus administration.

Activity of high-dose epirubicin combined with gemcitabine in advanced non-small-cell lung cancer: a multicenter phase I and II study

The aim of the study was to evaluate efficacy and tolerance of epirubicin and gemcitabine as first-line chemotherapy in patients with advanced non-small-cell lung cancer. A phase I study was performed with the combination of escalating doses of epirubicin intravenously on day 1 and a fixed dose of gemcitabine on days 1 and 8 of a 21 -day cycle. Eighteen patients were included in the phase I part of the study before the maximum tolerated dose was found. Dose-limiting toxicity was febrile neutropenia. The phase II part of the study was continued with epirubicin 100 mg m(-2) on day 1 and gemcitabine 1125 mg m(-2) on days 1 and 8 of a 21-day cycle. Forty-three chemotherapy-naive patients were included. The median age of the patients was 60 years (range 26-75). Most patients (74%) were in stage IV. Granulocytopenia CTC grade 4 occurred in 32.5% and thrombocytopenia grade 4 in 11.6% of cycles. Febrile neutropenia occurred in six patients. Non-haematological toxicity was mainly mucositis CTC grade 2 and 3 in 35% of patients. The tumour response rate was 49% (95% confidence interval (CI) 35-63%). The median survival time for the patients was 42 weeks (95% CI 13-69).

Lack of nephrotoxicity of new oral platinum drug JM216 in lung cancer patients

PURPOSE

The purpose of this study was to assess renal function in patients treated with the oral platinum drug JM216 [bisacetato-ammine-dichloro-cyclohexylamine-platinum(IV)], since the effects of JM216 on renal function have only partly been investigated using serum parameters or 51Cr-EDTA clearance. We used a sensitive method that assessed glomerular filtration rate (GFR), effective renal plasma flow (ERPF), and indicators of tubular and glomerular damage.

METHODS

A group of 24 patients with either non-small-cell lung cancer (NSCLC) stage IIIb/IV or small-cell lung cancer (SCLC), limited disease (LD) or extensive disease (ED), treated with JM216 were studied. All patients had no prior chemotherapy, a performance score < 2, a life expectancy of more than 3 months and normal liver, renal and bone marrow functions before treatment. All patients received oral JM216 120 mg/m2 per day for 5 consecutive days, repeated every 21 days with a maximum of six cycles. In six SCLC patients the dose was escalated to 140 mg/m2 per day after the first cycle. Prior to treatment, after the first cycle and after the end of treatment renal function was assessed by 125I-sodium thalamate and 131-hippurate clearances to determine acute and cumulative changes in GFR and ERPF, respectively. Furthermore, tubular and glomerular damage were assessed by urinary excretion of beta2-microglobulin, lactic dehydrogenase (LDH), alkaline phosphatase (ALP), gamma-glutamyltransferase (GT) and albumin.

RESULTS

In 20 evaluable patients no significant acute impairment of renal function was observed. Median (range) GFR, ERPF and filtration fraction (FF) before treatment were 101 ml/min (53-164 ml/min), 417 ml/min (227-719 ml/min), and 0.25 (0.19-0.33), respectively. After the first cycle values were 117 ml/min (71-189 ml/min), 418 ml/min (228-709 ml/ min) and 0.28 (0.21-0.33), respectively. Also, no indications of tubular or glomerular damage were found. In four patients renal function was evaluated at the end of treatment (one after three cycles, one after five cycles and two after six cycles). Median (range) GFR, ERPF and FF were 99 ml/min (74-139 ml/min), 401 ml/min (277-496 ml/min) and 0.26 (0.23-0.30), respectively, revealing no delayed nephrotoxicity.

CONCLUSION

We conclude that oral JM216 shows no nephrotoxicity.

Ketac Molar Versus Dyract Class II restorations in primary molars: twelve month clinical results

The aim of the present clinical study was an in vivo evaluation of an improved conventional glass ionomer cement Ketac Molar (ESPE), compared to a polyacid modified composite resin, Dyract (Dentsply/De Trey), used in primary molars. Fifty-three Ketac Molar and fifty-two Dyract restorations were placed in box-only preparations in primary molars. The application time for the chemically cured Ketac Molar, was longer compared to the light-cured Dyract. In comparing the materials, no differences were found, comparing both materials regarding secondary caries, marginal adaptation, wear and fracture toughness. One case of recurrent caries adjacent to a Ketac Molar restoration and two cases in the Dyract group were reported. Two Ketac Molar restorations and one Dyract showed bulk fracture at the time of evaluation. At the twelve-month evaluation, no difference between the investigated materials was registered, which indicates that Ketac Molar can be used as a proximal restoration in the primary dentition. It should be emphasized, however, that one-year data should not be extrapolated to indicate the long-term success of restorations.

Phase II study of oral platinum drug JM216 as first-line treatment in patients with small-cell lung cancer

PURPOSE

This multicenter phase II trial was performed to determine tumor efficacy and tolerance of the oral platinum drug JM216 in patients with small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Patients with SCLC limited disease unfit for intensive chemotherapy or those with extensive disease received JM216 120 mg/m(2)/d for 5 consecutive days every 3 weeks. Individual dose escalation to 140 mg/m(2)/d was allowed if toxicity was </= grade 2 according to the National Cancer Institute Common Toxicity Criteria. Tumor response was evaluated according to World Health Organization criteria.

RESULTS

Twenty-seven patients were assessable for toxicity and 26 for tumor response. Eighty-eight cycles were administered. Common Toxicity Criteria grade 3 and 4 hematologic toxicities were neutropenia in 15.9% and 3.7%, lymphocytopenia in 47.6% and 17.1%, and thrombocytopenia in 19.5% and 10.3% of cycles, respectively. One patient suffered from neutropenic fever. Nausea, vomiting, and diarrhea were the most common nonhematologic toxicities. Except for grade 4 diarrhea in one patient, no grade 4 nonhematologic toxicity was observed. No severe neurotoxicity or nephrotoxicity was observed. Tumor response rate was 10 of 26 (38%; 95% confidence interval, 19% to 58%), excluding five unconfirmed partial responses. No complete responses were observed. Median overall time to progression was 110 days (range, 5 to 624 days). Median overall survival time was 210 days (range, 5 to 624 days).

CONCLUSION

Oral JM216 is active in previously untreated patients with SCLC and shows mild toxicities.

The residual caries dilemma

Restorative dentistry is based on the assumption that bacterial infection of demineralized dentine should prompt operative intervention. One of the concepts of practical dentistry is to create a favourable environment for caries arrest with minimal operative intervention. The progress of remaining primary caries is key to any discussion of this concept. This discussion is important for the atraumatic restorative treatment (ART) approach, since the removal of all carious dentine is sometimes difficult using hand instruments only. In this paper the results of possible measures to guard against the effects of residual carious and its consequences are reviewed, in order to obtain an impression of the justification for (in)complete excavation of occlusal dentinal caries. Three types of measure are considered: isolating the caries process from the oral environment, excavating the carious dentine, and using a cariostatic filling material. Each of these measures contributes to the arrest of the caries process. However, none of these measures can arrest this process by itself. A combination of all three seems necessary. It is concluded that although residual caries does not seem to be the criterion for rerestoration, one has to strive for as complete caries removal as possible. If this cannot be fulfilled the sealing capacities of the filling material seem to be more important than its cariostatic properties.

Dyract versus Tytin Class II restorations in primary molars: 36 months evaluation

Due to the changed treatment approach of proximal caries and the amalgam controversy, clinicians are in search for new materials. The aim of the present study was to compare amalgam with an adhesive material in deciduous molars in a clinical, split-mouth design study. At baseline 30 polyacid modified composite (Dyract) and 30 amalgam (Tytin) restorations were placed in primary molars, of which 24 and 17 could be evaluated after 24 and 36 months, respectively. Modified USPHS criteria were used for clinical evaluation every 6 months. Annual bite-wing radiographs were taken for evaluation of recurrent caries and cervical gap formation. In the present study, for Dyract as well as for Tytin restorations, low rates of recurrent caries were found, while Dyract restorations showed a better marginal adaptation and surface texture compared to Tytin restorations. In the Dyract group more radiolucencies were found at baseline. In both groups no patient complaint or pain was reported related to the radiolucencies. After 3 years the colour of Dyract was not comparable to the original. For Dyract no excessive wear was noticed compared to enamel. During the study one Dyract (recurrent caries: 18 months) and two Tytin (pulpal aetiology: 6 months, recurrent caries: 36 months) restorations had to be replaced. Even though the restorations were placed in caries risk children, at the 36 months' evaluation of this clinical study, the results indicate that Dyract can be an alternative for Tytin in the primary dentition.

Evaluation of the experiences of fearful children at a Special Dental Care Centre

A representative sample of parents was interviewed one to two years after their children had been treated at a Dutch Special Dental Care Centre (SBT). Information was sought about the children's current behavior during visits to family dentists. Within one to two years after the experiences at SBT more than 90 percent of the children visited a family dentist, 60 percent of them required restorative treatment and 80 percent of this treatment was performed, using local anesthesia. Retrospectively, the parents report a decrease of their children's dental anxiety, when leaving the SBT. This level of anxiety is unchanged after one to two years visiting a family dentist. For the children there was a significant relationship between dental anxiety as reported by the parents and not visiting a family dentist. Results suggest that referring dentists arrange the initial treatment at the Special Dental Care Centre and that the children in this group referred for dental anxiety belong to a caries-risk group.

A Phase II study of gemcitabine in patients with malignant pleural mesothelioma. European Organization for Research and Treatment of Cancer Lung Cancer Cooperative Group

BACKGROUND

Gemcitabine has shown activity in patients with less chemosensitive solid tumors. Phase II screening of novel drugs is an accepted method with which to investigate new therapies in malignant mesothelioma. The European Organization for Research and Treatment of Cancer-Lung Cancer Cooperative Group has performed several sequential Phase II trials of new agents for the treatment of mesothelioma over the last 10 years.

METHODS

Twenty-seven chemotherapy-naive patients with histologically proven malignant mesothelioma were treated with gemcitabine as a 30-minute intravenous administration of 1250 mg/m2 on Days 1, 8, and 15 of a 28-day cycle. Therapy continued for up to ten cycles unless disease progression or excessive toxicity mandated discontinuation.

RESULTS

With a median relative dose intensity of 96%, toxicity was mild and neutropenia of > or = Grade 3 (according to National Cancer Institute criteria) occurred in 30% of patients, without episodes of febrile neutropenia. One case of hemolytic-uremic syndrome, most likely related to gemcitabine use, was observed. Overall, 2 objective responses were observed (response rate of 7%; 95% confidence interval, 1-24%). The median survival was 8 months.

CONCLUSIONS

At the prescribed dosage and schedule, single agent gemcitabine appears to have limited activity in chemotherapy-naive patients with malignant pleural mesothelioma.

99mTc-Sestamibi scanning with SDZ PSC 833 as a functional detection method for resistance modulation in patients with solid tumours

BACKGROUND

Our aim was to determine the value of 99mTc-Sestamibi scanning as functional detection method of P-glycoprotein (Pgp) blockade by PSC 833 in solid tumour patients.

PATIENTS AND METHODS

Day 1 and day 4 after 2,200 mg orally administered PSC 833 the tumour area was scanned after intravenous (i.v.) administration of 400 MBq 99mTc-Sestamibi. In tumours with net 99mTc-Sestamibi uptake and in the hepatic region K-efflux was determined. Whole blood was analyzed for 99mTc-Sestamibi, and PSC 833 levels.

RESULTS

Fourteen patients were included. In the only Pgp-positive tumour with positive 99mTc-Sestamibi scanning K-efflux of 99mTc-Sestamibi decreased significantly after PSC 833 intake. A net inhibition of liver efflux of Sestamibi after PSC 833 intake was observed in all evaluable patients. PSC 833 blood levels were all above 2 mg/L during scanning; 99mTc-Sestamibi blood levels post versus pre PSC 833 were unchanged.

CONCLUSIONS

PSC 833 induced modulation of K-efflux of 99mTc-Sestamibi in a Pgp positive tumour and in all patients in the liver.

Paclitaxel and carboplatin in the treatment of small-cell lung cancer patients resistant to cyclophosphamide, doxorubicin, and etoposide: a non-cross-resistant schedule

PURPOSE

To evaluate the efficacy of paclitaxel and carboplatin (PC) in small-cell lung cancer (SCLC) patients resistant to cyclophosphamide, doxorubicin, and etoposide (CDE).

PATIENTS AND METHODS

We performed a phase II study with PC in SCLC patients who relapsed within 3 months after first-line treatment with CDE. Paclitaxel administration (175 mg/m2 by a 3-hour intravenous infusion) was followed by a 30-minute infusion of carboplatin (area under the curve 7; Chatelut formula) once every 3 weeks for five cycles. Dexamethasone, clemastine, and ranitidine were standard premedication before every cycle.

RESULTS

Included were 35 patients (median age, 59 years; 16 with limited disease and 19 with extensive disease; Eastern Cooperative Oncology Group performance status of < or = 1; median time off treatment 6 weeks) who were previously treated with CDE (n = 33), oral etoposide (n = 2), and reinduction CDE (n = 15); only one patient had received three CDE treatments of five cycles. The CDE regimen was followed by local thoracic radiotherapy in seven patients. Hematologic toxicity of grade 3 or 4, for leukopenia was 27% and 6%, for thrombocytopenia 21% and 13%, and for anemia 17% and 0%, respectively, for a total of 132 cycles. Two patients had neutropenic fever; no toxic death occurred. Nonhematologic toxicity was paresthesia CTC grade 3, diarrhea grade 4, and myalgia grade 3 in one patient each. Reversible paresthesia (CTC grade 1 and 2) in toes and fingers was reported in 69% of patients. Thirty-four patients were assessable for response: complete response in two patients, partial response in 23 patients, stable disease in eight patients, and progressive disease in one patient (response rate, 73.5%; 95% confidence interval, 59% to 88%). One patient was found to have atypical carcinoid at pathologic review and was excluded. Median time to progression was 21 weeks (range, 3 to 40 weeks). Median survival was 31 weeks (range, 6 to 112 weeks). One-year survival was 9%.

CONCLUSION

Second-line PC in CDE-resistant SCLC patients yields a high response rate and seems non-cross-resistant to CDE. Toxicity was mild in these poor-prognosis patients.

A PCR-aided transcript titration assay (PATTY) to measure topoisomerase I gene expression in human tumor specimens

Topoisomerase I (topo I) inhibitors are promising anticancer agents with demonstrated activity against a wide range of solid tumors. Quantitative information on topol mRNA levels in tumor biopsies may predict response to topo I inhibitors.

MATERIALS AND METHODS

A polymerase chain reaction aided transcript titration assay (PATTY) was developed to allow quantitation of topol mRNA in small samples. Concentrations of topol mRNA in total RNA samples were estimated by RT-PCR analysis in a human small cell lung cancer (SCLC) cell line (GLC,) and its topotecan (GL2C/SK and F) and camptothecin (GL2C/Campt) resistant sublines, human non-small cell lung cancer (NSCLC) and ovarian carcinoma samples.

RESULTS

Topol PATTY showed a decreased topo I mRNA level in GLC2/SK and F (4.5 pg/100 ng total RNA) and GLC,/Campt (2.2 pg/100 ng total RNA), respectively, compared to the parent cell line GLC2 (5.4 pg/100 ng total RNA). Topol protein levels as measured by Western blotting were compatible with topol mRNA levels. Median (range) topol mRNA levels were 3.23 (2.33-5.10) pg/100 ng total RNA in resected NSCLC specimen (n = 6), and 2.03 (0.54-0.95) pg/100 ng total RNA in resected ovarian cancer specimen (n = 6).

CONCLUSION

We conclude that topol PATTY is a new assay that quantitates topol mRNA levels in cell lines and small tumor samples.

[What does the non-dentistry-trained person know about avulsion?]

The prognosis of an avulsed permanent incisor depends on a swift and correct emergency treatment. The chance of a favourable prognosis increases if the tooth is replanted as quickly as possible, preferably by the persons first present at the scene of the accident. Usually this person is a layman, therefore the aim of this study is to investigate the knowledge in this respect. To 48 schools and 15 swimming pools in Amsterdam, Arnhem and Nijmegen (the Netherlands), questionnaires were sent. Thirty-six schools and 15 swimming pools responded. Twenty-eight percent of the respondents had previous experience with an avulsion. Ten percent of the respondents would replant the incisor and 90% would store the incisor. Sixty-three percent would treat the tooth correctly. Respondents with previous experience had no more knowledge of the most effective treatment than persons without previous experience. Swimming instructors and physical health instructors knew significantly more about avulsion than teachers in primary schools. Since only 10% of the respondents would replant the incisor and 37% would handle this accident incorrectly, more information seems to be necessary.

Phase I and pharmacokinetic study of the topoisomerase II catalytic inhibitor fostriecin

We conducted a phase I and pharmacokinetic study of the topoisomerase II catalytic inhibitor fostriecin. Fostriecin was administered intravenously over 60 min on days 1-5 at 4-week intervals. Dose was escalated from 2 mg m(-2) day(-1) to 20 mg m(-2) day(-1) in 20 patients. Drug pharmacokinetics was analysed with high performance liquid chromatography with UV-detection. Plasma collected during drug administration was tested in vitro for growth inhibition of a teniposide-resistant small-cell lung cancer (SCLC) cell line. The predominant toxicities were elevated liver transaminases (maximum common toxicity criteria (CTC) grade 4) and serum creatinine (maximum CTC grade 2). These showed only a limited increase with increasing doses, often recovered during drug administration and were fully reversible. Duration of elevated alanine-amino transferase (ALT) was dose-limiting in one patient at 20 mg m(-2). Other frequent toxicities were grade 1-2 nausea/vomiting, fever and mild fatigue. Mean fostriecin plasma half-life was 0.36 h (initial; 95% CI, 0-0.76 h) and 1.51 h (terminal; 95% CI, 0.41-2.61 h). A metabolite, most probably dephosphorylated fostriecin, was detected in plasma and urine. No tumour responses were observed, but the plasma concentrations reached in the patients were insufficient to induce significant growth inhibition in vitro. The maximum tolerated dose (MTD) has not been reached, because drug supply was stopped at the 20 mg m(-2) dose level. However, further escalation seems possible and is warranted to achieve potentially effective drug levels. Fostriecin has a short plasma half-life and longer duration of infusion should be considered.

Feasibility of tumor imaging using L-3-[iodine-123]-iodo-alpha-methyl-tyrosine in extracranial tumors

L-3-[123I]-Iodo-alpha-methyl-tyrosine (IMT) is a modified amino acid. It is reported to be avidly taken up in brain tumors, reflecting amino acid transport and is suitable for SPECT.

METHODS

To determine whether tumors outside the brain can also accumulate this tracer, we injected 300-450 MBq IMT into 20 patients with different tumors [5 breast cancers, 4 lung tumors (1 benign), 2 carcinoid liver metastases, 4 soft-tissue tumors (1 benign), 3 malignant lymphomas and 2 primary brain tumors]. Tumor size ranged from 1-12 cm. Imaging was repeated after radiotherapy in two patients with breast cancer. Histology was available in all cases. Dynamic scans, whole-body imaging and SPECT were performed during the first hour and 3 hr after injection. Plasma samples were analyzed for IMT, free 1231 and other metabolites.

RESULTS

All primary tumors were visualized. Tumor-to-background ratios ranged from 1.1 to 3.8 on planar and from 1.3 to 6.2 on SPECT images. Tumor uptake peaked in the first hour. Two carcinoid lesions in the liver tumors exhibited no IMT uptake above liver background. Tumor-to-background ratios in a benign bone inflammatory process and a focal pulmonary vasculitis were less than 1.2 (planar) and 1.9 (SPECT) and could be differentiated from uptake in all malignant nonbrain tumors. IMT was rapidly cleared from the plasma [3.6% +/- 0.6% (mean +/- s.d.) injected dose/liter at 10 min postinjection]. Minor in vivo deiodination was present (<1% of injected dose 1 hr postinjection). No other metabolites were found. Normal distribution consists of some uptake in the brain, liver, spleen, muscles, pancreatic region and intestinal structures and massive uptake and excretion in the kidneys and bladder.

CONCLUSION

IMT has potential as a metabolic tracer in tumors outside the brain.

Brain-only metastases of small cell lung cancer; efficacy of whole brain radiotherapy. An EORTC phase II study

BACKGROUND AND PURPOSE

To evaluate the efficacy of WBRT as a single treatment modality in patients with brain metastases of small cell lung cancer.

PATIENTS AND METHODS

The patients had brain metastases of small cell lung cancer without any sign of tumour outside the brain and were treated with 10 x 3.0 Gy WBRT. Response and neurological functions were evaluated after 6, 18 and 36 weeks.

RESULTS

Twenty of 22 eligible patients were evaluable for response. In six patients a complete response was seen and in five patients a partial response was seen giving a response rate of 50% (95% CI 28-72%). Response duration was 5.4 months (range 63-260 days) and median survival was 4.7 months (range 14-743 days). In the majority of patients the first site of progression after WBRT was in the central nervous system. Twelve of the patients had stabilization or improvement of the neurological function.

CONCLUSION

WBRT for brain metastases of small cell lung cancer gives a 50% response rate with stabilization or improvement of neurological function. Response duration and survival are short.