[Medicinal prevention of gastrointestinal tumors: aspirin, Helicobacter and more?]

Despite the huge number of drugs on the market and recent advances in pharmacotherapy, only a few substances are available for the prevention of gastrointestinal tumors--most of which are not approved for this indication or not validated in appropriately designed randomized trials. General recommendations include lifestyle modifications such as avoidance of smoking, only moderate consumption of alcohol, regular physical exercise and a nutrition rich in fresh fruits and vegetables with limited meat. A global eradication therapy for Helicobacter pylori would be desirable to prevent gastric carcinoma, but this does not seem feasible from the socio-economic point of view. Therefore, at least patients at high risk should be screened and this pathogen eradicated, preferentially in their youth. Hepatitis B vaccination of newborns to prevent the development of hepatocellular carcinoma has already been established in Germany; a specific antiviral therapy should be offered to all patients with hepatitis B or C infections, taking into consideration the risks associated with this treatment. The use of non-steroidal anti-inflammatory drugs (NSAIDs) to prevent gastrointestinal malignancies cannot generally be recommended and should be restricted to patients at high risk and to clinical studies. However, the appropriate substance, dose and duration of NSAID therapy are still being debated.

Bcl-2 expression in rituximab refractory cutaneous B-cell lymphoma

Rituximab has been established as an effective and safe therapy for cutaneous B-cell lymphoma (CBCL). Different survival pathways, that is the Raf/MEK/Erk- or the p38MAPK cascade, have been suggested as downstream mediators of rituximab and may be involved in treatment failure. Biopsies from four patients, suffering from different subtypes of CBCL, which were obtained at various time points of relapse during or after therapy with 375 mg rituximab per m² of body surface area, were analysed for the expression of CD20, CD3, Ki-67, Raf-kinase inhibitory protein (RKIP) and bcl-2 by immunohistochemistry. No CD20-loss variants, that is the suggested main tumour escape mechanism to rituximab therapy, were observed in any specimen of relapsing CBCL. Notably, the expression of proapoptotic RKIP remained increased in these tumour samples. This was concomitated by a constant to slightly reduced proliferation status as demonstrated by Ki-67 staining. However, relapsing CBCL exhibited a strong upregulation of the antiapoptotic molecule bcl-2 in comparison to pretherapeutic levels. The immunohistochemical analyses of this case series of rituximab refractory CBCL suggest that upregulation of bcl-2 may play a major role in therapy resistance.

Chemoimmunotherapy for cutaneous melanoma with dacarbazine and epifocal contact sensitizers: results of a nationwide survey of the German Dermatologic Co-operative Oncology Group

PURPOSE

To scrutinize published data from small mono-centric studies and case reports which implicated high response rates and promising survival times for a combination therapy consisting of epifocal dinitrochlorobenzene (DNCB) and dacarbazine (DTIC) for metastasized melanoma. This therapy merges the effects of an allergic contact dermatitis elicited at the site of a cutaneous metastasis, and systemic chemotherapy.

METHODS

We performed a retrospective survey with nine German centers and evaluated 72 patients treated from 1993 to 2005.

RESULTS

The objective response rate in stage III melanoma (n = 39) was 62%. In contrast, only 9% objective responses were observed in 33 stage IV patients. Interestingly, more than half of patients with objective remissions remained progression-free for more than 1 year irrespective of the stage of disease.

CONCLUSIONS

Epifocal DNCB combined with DTIC is effective in patients with regionally metastasized melanoma not amenable to surgery or isolated limb perfusion, whereas in stage IV disease in spite of few durable remissions the addition of DNCB does not improve the therapeutic efficacy of DTIC.

Erfolgreiche Dexamethason-Pulstherapie bei großflächig erosivem perianalen Lichen ruber

A 70-year-old man presented with a 6-month history of extensive, progressive perianal erosions. In addition, he had white reticulate striae and small erosions on the penis. The clinical diagnosis of erosive lichen planus was confirmed histologically. After several topical approaches failed and his ss-blocker was stooped, 3 pulses of dexamethasone (100 mg dexamethasone i.v. on 3 consecutive days every 4 weeks) led to complete and long-lasting remission.

Abatacept improves both the physical and mental health of patients with rheumatoid arthritis who have inadequate response to methotrexate treatment

OBJECTIVE

To examine the impact of added abatacept treatment on health related quality of life (HRQoL) in patients with rheumatoid arthritis (RA) who have inadequate response to methotrexate (MTX).

METHODS

The impact of abatacept treatment on HRQoL was examined in a longitudinal, randomised double blind, placebo controlled clinical trial. Effects of treatment on HRQoL were examined using repeated measures analysis of covariance and comparing rates of change in HRQoL across treatment groups. The relationship between American College of Rheumatology (ACR) clinical markers and disease duration with changes in HRQoL indicators was also examined. Finally, a responder analysis was used to examine the percentage of patients who improved by 0.5 SD in 12 months or who reached the normative levels seen in the US general population.

RESULTS

Statistically significant improvements in the abatacept group relative to controls were observed across a range of HRQoL measures, including physical function, fatigue, all eight domains of the SF-36, and the physical and mental component summaries (PCS and MCS). Improvements were seen as early as day 29 for fatigue and for five out of eight SF-36 domains. By day 169, all HRQoL measures were significantly better with abatacept than with placebo. HRQoL gains were associated with greater ACR clinical improvement, and the effects were consistent for patients with different disease duration. A significantly greater percentage of patients treated with abatacept reached normative levels of PCS, MCS, physical functioning, and fatigue compared with patients treated with MTX alone.

CONCLUSION

Combined abatacept and MTX treatment produces significant improvements across a wide range of HRQoL domains in patients with RA.

Safety of the selective costimulation modulator abatacept in rheumatoid arthritis patients receiving background biologic and nonbiologic disease-modifying antirheumatic drugs: A one-year randomized, placebo-controlled study

OBJECTIVE

To assess the safety of abatacept, a selective costimulation modulator, in patients with active rheumatoid arthritis (RA) who had been receiving > or =1 traditional nonbiologic and/or biologic disease-modifying antirheumatic drugs (DMARDs) approved for the treatment of RA for at least 3 months prior to entry into the study.

METHODS

This was a 1-year, multicenter, randomized, double-blind, placebo-controlled trial. Patients were randomized 2:1 to receive abatacept at a fixed dose approximating 10 mg/kg by weight range, or placebo.

RESULTS

The abatacept and placebo groups exhibited similar frequencies of adverse events (90% and 87%, respectively), serious adverse events (13% and 12%, respectively), and discontinuations due to adverse events (5% and 4%, respectively). Five patients (0.5%) in the abatacept group and 4 patients (0.8%) in the placebo group died during the study. Serious infections were more frequent in the abatacept group than in the placebo group (2.9% versus 1.9%). Fewer than 4% of patients in either group experienced a severe or very severe infection. The incidence of neoplasms was 3.5% in both groups. When evaluated according to background therapy, serious adverse events occurred more frequently in the subgroup receiving abatacept plus a biologic agent (22.3%) than in the other subgroups (11.7-12.5%).

CONCLUSION

Abatacept in combination with synthetic DMARDs was well tolerated and improved physical function and physician- and patient-reported disease outcomes. However, abatacept in combination with biologic background therapies was associated with an increase in the rate of serious adverse events. Therefore, abatacept is not recommended for use in combination with biologic therapy.

Acetylsalicylic acid enhances antiproliferative effects of the EGFR inhibitor gefitinib in the absence of activating mutations in gastric cancer

The epidermal growth factor receptor (EGFR) is highly expressed in gastric cancer indicating its suitability as a target for receptor tyrosine kinase (RTK) inhibitors. In the current study we explored the role of EGFR and its potential use as a therapeutic target in gastric cancer. First we analyzed 66 gastric cancer samples of Asian and Caucasian patients for the presence of EGFR mutations. No activating EGFR mutations were found and gefitinib alone was only weakly effective in gastric cancer cell lines. However, acetylsalicylic acid (ASA) significantly enhanced the inhibitory effects of gefitinib indicating synergistic action. Whole genome expression profiling indicated significant regulation of 120 genes in the case of co-administration of gefitinib and ASA (32 induced, 88 repressed) in gastric adenocarcinoma cells. Further analyses indicated that several important signalling pathways were effectively inhibited by simultaneous exposure to gefitinib and ASA. Our findings indicate that although gastric cancer does not seem to harbour mutations which render the cancer cells constitutively susceptible to gefitinib, the co-administration of ASA can strengthen RTK inhibitor activity in adenocarcinoma cells by EGFR activation. This is the first report of effective modulation of EGFR-inhibition activity in cancer.

Jak3- and JNK-dependent vascular endothelial growth factor expression in cutaneous T-cell lymphoma

Biopsies from patients with cutaneous T-cell lymphoma (CTCL) exhibit stage-dependent increase in angiogenesis. However, the molecular mechanisms responsible for the increased angiogenesis are unknown. Here we show that malignant CTCL T cells spontaneously produce the potent angiogenic protein, vascular endothelial growth factor (VEGF). Dermal infiltrates of CTCL lesions show frequent and intense staining with anti-VEGF antibody, indicating a steady, high production of VEGF in vivo. Moreover, the VEGF production is associated with constitutive activity of Janus kinase 3 (Jak3) and the c-Jun N-terminal kinases (JNKs). Sp600125, an inhibitor of JNK activity and activator protein-1 (AP-1) binding to the VEGF promoter, downregulates the VEGF production without affecting Jak3 activity. Similarly, inhibitors of Jak3 inhibit the VEGF production without affecting JNK activity. Downregulation of Stat3 with small interfering RNA has no effect, whereas curcumin, an inhibitor of both Jak3 and the JNKs, almost completely blocks the VEGF production. In conclusion, we provide evidence of VEGF production in CTCL, which is promoted by aberrant activation of Jak3 and the JNKs. Inhibition of VEGF-inducing pathways or neutralization of VEGF itself could represent novel therapeutic modalities in CTCL.

Role of receptor tyrosine kinases in gastric cancer: New targets for a selective therapy

Receptor tyrosine kinases (RTKs) such as the epidermal growth factor receptor family participate in several steps of tumor formation including proliferation and metastatic spread. Several known RTKs are upregulated in gastric cancer being prime targets of a tailored therapy. Only preliminary data exist, however, on the use of the currently clinically available drugs such as trastuzumab, cetuximab, bevacizumab, gefitinib, erlotinib, and imatinib in the setting of gastric cancer. Preclinical data suggest a potential benefit of their use, especially in combination with “conventional” cytostatic therapy. This review summarizes the current knowledge about their use in cancer therapy as well as new approaches and drugs to optimize treatment success.

CD28-mediated costimulation impacts on the differentiation of DC vaccination-induced T cell responses

Costimulatory signals such as the ones elicited by CD28/B7 receptor ligation are essential for efficient T cell activation but their role in anti-tumour immune responses remains controversial. In the present study we compared the efficacy of DC vaccination-induced melanoma specific T cell responses to control the development of subcutaneous tumours and pulmonary metastases in CD28-deficient mice. Lack of CD28-mediated costimulatory signals accelerated tumour development in both model systems and also the load of pulmonary metastases was strongly increased by the end of the observation period. To scrutinize whether lack of CD28 signalling influences priming, homing or effector function of Trp-2(180-188)/K(b)-reactive T cells we investigated the characteristics of circulating and tumour infiltrating T cells. No difference in the frequency of Trp-2(180-188)/K(b)-reactive CD8+ T cells could be demonstrated among the cellular infiltrate of subcutaneous tumours after DC vaccination between both genotypes. However, the number of IFN-gamma-producing Trp-2-reactive cells was substantially lower in CD28-deficient mice and also their cytotoxicity was reduced. This suggests that CD28-mediated costimulatory signals are essential for differentiation of functional tumour-specific CD8+ T-effector cells despite having no impact on the homing of primed CD8+ T cells.

Dacarbazine (DTIC) versus vaccination with autologous peptide-pulsed dendritic cells (DC) in first-line treatment of patients with metastatic melanoma: a randomized phase III trial of the DC study group of the DeCOG

BACKGROUND

This randomized phase III trial was designed to demonstrate the superiority of autologous peptide-loaded dendritic cell (DC) vaccination over standard dacarbazine (DTIC) chemotherapy in stage IV melanoma patients.

PATIENTS AND METHODS

DTIC 850 mg/m2 intravenously was applied in 4-week intervals. DC vaccines loaded with MHC class I and II-restricted peptides were applied subcutaneously at 2-week intervals for the first five vaccinations and every 4 weeks thereafter. The primary study end point was objective response (OR); secondary end points were toxicity, overall (OS) and progression-free survival (PFS).

RESULTS

At the time of the first interim analysis 55 patients had been enrolled into the DTIC and 53 into the DC-arm (ITT). OR was low (DTIC: 5.5%, DC: 3.8%), but not significantly different in the two arms. The Data Safety & Monitoring Board recommended closure of the study. Unscheduled subset analyses revealed that patients with normal serum LDH and/or stage M1a/b survived longer in both arms than those with elevated serum LDH and/or stage M1c. Only in the DC-arm did those patients with (i) an initial unimpaired general health status (Karnofsky = 100) or (ii) an HLA-A2+/HLA-B44- haplotype survive significantly longer than patients with a Karnofsky index <100 (P = 0.007 versus P = 0.057 in the DTIC-arm) or other HLA haplotypes (P = 0.04 versus P = 0.57 in DTIC-treated patients).

CONCLUSIONS

DC vaccination could not be demonstrated to be more effective than DTIC chemotherapy in stage IV melanoma patients. The observed association of overall performance status and HLA haplotype with overall survival for patients treated by DC vaccination should be tested in future trials employing DC vaccines.

Lack of clinical efficacy of imatinib in metastatic melanoma

This two-centre phase-II trial aimed at investigating the efficacy of imatinib in metastasised melanoma patients in correlation to the tumour expression profile of the imatinib targets c-kit and platelet-derived growth factor receptor (PDGF-R). The primary study end point was objective response according to RECIST, secondary end points were safety, overall and progression-free survival. In all, 18 patients with treatment-refractory advanced melanoma received imatinib 800 mg day(-1). In 16 evaluable patients no objective responses could be observed. The median overall survival was 3.9 months, the median time to progression was 1.9 months. Tumour biopsy specimens were obtained from 12 patients prior to imatinib therapy and analysed for c-kit, PDGF-Ralpha and -Rbeta expression by immunohistochemistry. In four cases, cell lines established from these tumour specimens were tested for the antiproliferative effects of imatinib and for functional mutations of genes encoding the imatinib target molecules. The tumour specimens stained positive for CD117/c-kit in nine out of 12 cases (75%), for PDGF-Ralpha in seven out of 12 cases (58%) and for PDGF-Rbeta in eight out of 12 cases (67%). The melanoma cell lines showed a heterogenous expression of the imatinib target molecules without functional mutations in the corresponding amino-acid sequences. In vitro imatinib treatment of the cell lines showed no antiproliferative effect. In conclusion, this study did not reveal an efficacy of imatinib in advanced metastatic melanoma, regardless of the expression pattern of the imatinib target molecules c-kit and PDGF-R.

Clinical evaluation of in vitro chemosensitivity testing: the example of uveal melanoma

PURPOSE

Results from in vitro chemosensitivity testing recommend treosulfan/gemcitabine chemotherapy for the treatment of stage IV uveal melanoma.

METHODS

Twenty patients received treosulfan 3,500 mg/m2 followed by gemcitabine 1,000 mg/m2 on day 1 and day 8 repeated on day 29. In cases of prior chemotherapy only 75% of these dosages were used.

RESULTS

Without any patient achieving an objective response, 25% of patients (95% confidence interval, 8.6-49.1%) had stabilisation of disease. This stabilisation was associated with a prolonged median overall survival of 17 months compared with 7 months for the patients with progressive disease. First-line treatment was not associated with better response or survival although prognostic parameters did not significantly differ from that of other patients.

CONCLUSIONS

The results are disappointing and question the value of individualized chemotherapy based on in vitro assays.

Gastric Electrical Stimulation Results in Improved Metabolic Control in Diabetic Patients Suffering From Gastroparesis

AIMS/HYPOTHESIS

Symptoms of gastroparesis possess a heavy impact on the quality of life; delayed gastric emptying may result in poor metabolic control in diabetics. Gastric electrical stimulation (GES) has recently been introduced as a treatment option in patients with drug refractory gastroparesis to increase the quality of life by alleviating nausea and vomiting frequencies. However, the effect of GES on metabolic control has not been assessed yet.

METHODS

We performed a prospective single center study on the long-term effect (12 months) of continuous high-frequency/low-energy GES on symptoms, gastric emptying (measured scintigraphically), and metabolic control (HbA1c) in insulin-dependent diabetic subjects suffering from drug-refractory gastroparesis for more than one year.

RESULTS

Seventeen (12 female, 5 male) patients entered the study; all were available for analysis at all time points. No therapy-associated adverse events occurred. Weekly vomiting and nausea frequencies decreased significantly at 6 and 12 months. Gastric retention rates improved significantly from 83 % (2 h) and 38 % (4 h) to 35 % (2 h)/14 % (4 h) and 25 % (2 h)/17 % (4 h) at 6 and 12 months, respectively. HbA1c values were lowered in all 17 subjects; initially, all HbA1c values were above 7.5 %; at 6 and 12 months, mean values had significantly decreased from 8.6 % to 6.2 % and 6.5 %, respectively.

CONCLUSIONS/INTERPRETATION

Gastric electrical stimulation offers symptom control in diabetics with drug-refractory gastroparesis and decreases gastric retention. This study, for the first time, documents a positive effect of this therapy on metabolic control as indicated by HbA1c, a surrogate marker of the risk of diabetic complications.

Loss of nonclassical MHC molecules MIC-A/B expression during progression of uveal melanoma

Uveal melanoma differs from cutaneous melanoma with respect to aetiology, metastatic behaviour and immune biology. The notion that loss of classical MHC class I molecules in uveal melanoma lesions is associated with an improved prognosis suggests that NK cells act as the predominant cells responsible for immune surveillance of this tumour. Consequently, immune escape mechanisms of uveal melanoma should impair the innate immunity. To this end, expression of the ligand for the NK receptor NKG2D, that is, MIC-A/B was expressed by 50% of primary tumours, but none of the metastatic lesions. MIC⁺ tumours were characterised by a NKG2D⁺ infiltrate, which was absent in MIC⁻ lesions subsequent to chemoimmune therapy. Strikingly, MIC-A/B expression in metastatic lesions was observed subsequent to chemotherapy with fotemustine in one case. In summary, MIC/NKG2D interactions seem to be involved in the immune surveillance of primary uveal melanomas, whereas for metastatic tumours this ligand/receptor system seems not to be relevant, thus, suggesting an immune selection of MIC negative tumour cells.

Biological in vitro effects of fibrin glue: fibroblast proliferation, expression and binding of growth factors

BACKGROUND

Fibrin glue is used in the endoscopic therapy of bleeding ulcerations. Accelerated closure of ulcers has been documented for this treatment in comparison with other injection techniques; the biological reason, however, remains unclear.

METHODS

In an in vitro model the effects of fibrin glue on the expression and secretion of growth factors by gastric epithelial (AGS, KATO III) and mesenchymal cells (fibroblasts) as well as their proliferative response and their interaction were compared with those of other matrices.

RESULTS

Native fibrin glue does not release vascular endothelial growth factor (VEGF) but is able to bind this growth factor in biologically relevant concentrations of 152.6 pg/mL. The addition of fibrin glue to a collagen type I matrix led to an increased proliferation rate of gastric wall fibroblasts. The transcription of VEGF and platelet-derived growth factor (PDGF) mRNA was significantly increased in epithelial cells. Co-culture of fibroblasts grown on fibrin glue containing matrix and epithelial cells resulted in an increased secretion of VEGF by both cell lines.

CONCLUSIONS

Fibrin glue leads to increased proliferation of fibroblasts and local accumulation of VEGF. These findings might at least partly explain the accelerated closure of bleeding ulcers treated by fibrin glue injection.