Prognostic value and kinetics of circulating endothelial cells in patients with recurrent glioblastoma randomised to bevacizumab plus lomustine,bevacizumab single agent or lomustine single agent. A report from the Dutch Neuro-Oncology Group BELOB trial

Background:

Angiogenesis is crucial for glioblastoma growth, and anti-vascular endothelial growth factor agents are widely used in recurrent glioblastoma patients. The number of circulating endothelial cells (CECs) is a surrogate marker for endothelial damage. We assessed their kinetics and explored their prognostic value in patients with recurrent glioblastoma.

Methods:

In this side study of the BELOB trial, 141 patients with recurrent glioblastoma were randomised to receive single-agent bevacizumab or lomustine, or bevacizumab plus lomustine. Before treatment, after 4 weeks and after 6 weeks of treatment, CECs were enumerated.

Results:

The number of CECs increased during treatment with bevacizumab plus lomustine, but not during treatment in the single-agent arms. In patients treated with lomustine single agent, higher absolute CEC numbers after 4 weeks (log₁₀CEC hazard ratio (HR) 0.41, 95% CI 0.18–0.91) and 6 weeks (log₁₀CEC HR 0.16, 95% CI 0.05–0.56) of treatment were associated with improved overall survival (OS). Absolute CEC numbers in patients receiving bevacizumab plus lomustine or bevacizumab single agent were not associated with OS.

Conclusion:

CEC numbers increased during treatment with bevacizumab plus lomustine but not during treatment with either agent alone, suggesting that this combination induced the greatest vascular damage. Although the absolute number of CECs was not associated with OS in patients treated with bevacizumab either alone or in combination, they could serve as a marker in glioblastoma patients receiving lomustine single agent.     

Prognostic value of circulating tumour cells for early recurrence after resection of colorectal liver metastases

Background:

Despite good outcomes for many, a substantial group of patients undergoing metastasectomy for isolated liver metastases from colorectal cancer (CRC) experience early recurrence. We have investigated whether circulating tumour cell (CTC) detection can identify patients developing disease recurrence within 1 year after liver metastasectomy.

Methods:

In CRC patients undergoing liver metastasectomy, 30 ml peripheral blood was withdrawn preoperatively. CTCs were detected by the CellSearch system after a density-gradient-based enrichment step.

Results:

One hundred and seventy-three samples from 151 individual patients were analysed. In 75 samples (43%), CTCs were detected, 16% had ⩾3 CTCs/7.5 ml of blood. Eighty-two patients (47%) experienced early disease recurrence (<1 year). The 1-year recurrence rate between patients with or without detectable CTCs were similar (47% vs 48%) or with a low or high CTC count (<3 or ⩾3 CTCs/7.5 ml of blood) (50% vs 47%). Also disease-free and overall survival were similar between patients with or without CTCs.

Conclusions:

The presence of CTCs in preoperative peripheral blood samples does not identify patients at risk for early disease recurrence after curative resection of colorectal liver metastases. Other parameters are needed to better identify patients at high risk to relapse after liver metastasectomy for CRC.     

Comparative assessment of leflunomide and methotrexate for the treatment of rheumatoid arthritis, by dynamic enhanced magnetic resonance imaging

OBJECTIVE: Ethical constraints on the conduct of placebo-controlled trials evaluating new therapies for serious chronic diseases, such as rheumatoid arthritis (RA), indicate the need for discerning methods to assess treatment effect in active-controlled clinical trials. Dynamic gadolinium-enhanced magnetic resonance imaging (DEMRI) is a sensitive technique for the detection of synovial inflammation in RA. Therefore, this investigation was undertaken to evaluate DEMRI as an efficacy assessment tool for differentiating treatment effect in a randomized, active-controlled trial comparing leflunomide and methotrexate. METHODS: Patients with active RA (n = 39) were randomized in a 2-center, prospective, double-blind clinical trial to receive either leflunomide (n = 18) or methotrexate (n = 21) therapy for 4 months. DEMRI scans were obtained at baseline and at 4 months, and the initial rate of enhancement (IRE) and the maximal signal intensity (SI) enhancement (ME) were calculated from the SI curves. Clinical improvement was assessed by conventional outcome measures. RESULTS: Thirty-four patients (17 treated with leflunomide and 17 with methotrexate) had usable baseline and end point DEMRI scans. Leflunomide treatment was associated with a significantly greater improvement in IRE compared with methotrexate treatment (P < 0.05). Average values of ME indicated reduction of inflammation with both leflunomide and methotrexate. The improvement in clinical signs and symptoms, as measured by traditional assessments, was comparable for both active treatments. CONCLUSION: Results of this study validate the sensitivity of DEMRI in detecting inflammatory changes in active RA in response to treatment. Improvement in synovial inflammation as measured by IRE was significantly better with leflunomide than with methotrexate over 4 months of therapy.     

Prevalent mutations in the GALC gene of patients with Krabbe disease of Dutch and other European origin

Sixty-four unrelated patients with infantile Krabbe disease (globoid cell leukodystrophy, GLD) of Dutch (n=41) or other European origin (n=23) were screened for the presence of a large 30kb deletion starting in intron 10 (IVS 10del30kb), a base substitution 1538T(T513M) and a polymorphism, 502T. The deletion and the T513M mutation were present in 52% and 8.5%, respectively, of the 82 GALC alleles of the Dutch patients. The 502T polymorphism, which had an allele frequency of 5.3% in a Dutch control panel, occurred in 65% of the GLD alleles. Analysis of patients and both parents in 26 of the families showed that del30kb was invariably associated with 502T. However, 502T was also present on 40% of the GLD alleles with an as yet unidentified mutation, which is 7.5 times higher than its frequency in controls. This suggests that besides del30kb at least one other relatively frequent mutation has arisen on the 502T GALC allele. A relatively high incidence of del30kb was also found in 23 other European (non-Dutch) patients (allele frequency 35%), but T513M did not occur in this group. Practical examples described in this report illustrate the potential usefulness of mutation analysis in many families with Krabbe disease for heterozygote detection and prenatal diagnosis.     

Correlation of the size of type II transforming growth factor beta (TGF-beta) receptor with TGF-beta responses of isolated bovine articular chondrocytes.

OBJECTIVES--Transforming growth factor beta (TGF-beta) is a multipotent regulator of cell proliferation and extracellular matrix production. The effect of TGF-beta on chondrocyte matrix production was studied in relation to the expression of TGF-beta binding proteins. The effect of TGF-beta on proteoglycan synthesis of isolated articular chondrocytes depended on the culture period. Proteoglycan synthesis of chondrocytes which were cultured for one day was inhibited by TGF-beta whereas proteoglycan synthesis of chondrocytes cultured in monolayer for seven days or longer was stimulated by TGF-beta. To investigate if this differential response is related to a distinct expression of TGF-beta receptors, this parameter was studied by affinity labelling. METHODS--Chondrocytes were incubated with 100 pM TGF-beta labelled with iodine-125. Crosslinking was performed using 0.25 mM disuccinimidyl suberate. Membrane proteins were extracted and analysed by denaturating sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE) and autoradiography. RESULTS--Freshly isolated and cultured chondrocytes expressed types I, II, and III TGF-beta receptors. The type II TGF-beta receptor of cultured chondrocytes appeared to be about 15 kilodaltons smaller than the type II TGF-beta receptor expressed on freshly isolated chondrocytes, however. CONCLUSIONS--As the type II TGF-beta receptors appears to be involved in signal transduction, this change in size of the type II TGF-beta receptor might be related to the differential effect of TGF-beta on proteoglycan synthesis of freshly isolated and cultured bovine articular chondrocytes.     

Chondrocyte behavior in fibrin glue in vitro

To test fibrin glue as a vehicle in chondrocyte transplantation, chondrocytes, isolated from articular cartilage of young rabbits, were mixed with Tissucol®, a highly concentrated fibrin glue, and cultured for 7 days. Histology, autoradiography (35-S) and electron microscopy were used to study chondrocyte behavior and phenotypic expression. Chondrocytes multiplied, retained their morphology, and produced matrix in fibrin glue as long as the cells were surrounded by the glue. Glue disintegration started after 3 days and was accelerated by higher cell concentrations.     

Laxity characteristics of normal and pathological murine knee joints in vitro

The aim of this study was to validate a device developed previously to measure laxity of murine knee joints and to investigate whether experimentally induced pathological conditions result in measurable laxity. The laxity characteristics of normal murine knee joints were derived from measurements of 25 left knees of normal mice. Reporducible, nonlinear s-shaped load-displacement curves were determined, and parameters of anterior-posterior translation, varus-valgus rotation, and compliance were calculated from the curves. No differences were found between the left and right knee joints of eight mice. The average displacement between 0.8 N of anterior force and 0.8 N of posterior force was 0.47 ± 0.10 mm. The endpoint compliances for anterior and posterior displacements were 0.16 ± 0.03 and 0.16 ± 0.04 mm/N, respectively. The average rotation between a 4 Nmm valgus moment and a 4 Nmm varus moment was 17.4 ± 3.3°. The endpoint compliances for varsus and valgus rotations were 1.1 ± 0.7 and 1.0 ± 0.3°/Nmm, respectively. Storage of the joints at ?70°C had no effect on laxity. We also studied the parameters of laxity after pathology of the knee joint was induced. Zymosan-induced or antigen-induced arthritis did not increase laxity of the joint. In an osteoarthritis model induced by injection of collagenase, laxity was markedly increased. In conclusion, laxity in the knees of mice can be measured reproducibly, and changes in the characteristics of laxity due to pathological conditions can be quantified.