Summary Electrochemotherapy (ECT) is a new therapeutic approach combining the effects of a low-permeant cytotoxic drug, bleomycin (BLM), administered i.v. and cell-permeabilizing electric pulses (EPs) locally delivered to tumours. The transient permeabilization of the cell membrane by the EPs allows free access of BLM to its intracellular targets, largely enhancing BLM's cytotoxic effects. ECT efficacy has been proved so far on transplanted subcutaneous murine tumours and on subcutaneous metastases in humans. Here, we present the first study of the effects of ECT on tumours transplanted to livers in rabbits. We used a recently developed EP applicator consisting of an array of parallel and equidistant needles to be inserted in tissues. Effects of EPs alone or of ECT were assessed by histological analysis, tumour growth rates and survival of the treated animals. A transient blood hypoperfusion was seen in the electropulsed areas, with or without BLM, related to EPdependent vasoconstriction but this had no major effects on cell survival. Long-term effects depended on the presence of BLM at the time of EP delivery. Almost complete tumour necrosis was observed after ECT, resulting from both BLM direct cytotoxic effects on electropermeabilized tumour cells and indirect effects on the tumour vessels. A large reduction in tumour growth rate and significantly longer survival times were scored in comparison with control rabbits. Moreover, ECT of liver tumours was well tolerated and devoid of systemic side-effects.When ECT was associated with a local interleukin 2-based immunotherapy, increased local anti-tumour effectiveness as well as a large decrease in the number of metastases were observed. Thus, ECT could become a novel treatment modality for liver tumours and other solid internal malignancies.Keywords: electrochemotherapy; bleomycin; electric pulse; liver tumour; immunotherapy; interleukin 2 Bleomycin (BLM), a non-permeant cytotoxic drug largely used in clinical oncology (Sikic, 1988;Mir et al, 1996), is a relatively large hydrophilic molecule that is carried into the cells by a lowefficiency mechanism . Consequently, very small amounts of BLM enter intact cells, limiting its cytotoxic effects (Orlowski et al, 1988;Poddevin et al, 1991). Brief and intense electric pulses (EPs) delivered in vitro or in vivo are known to induce changes in the plasma membrane of the pulsed cells, resulting in a transient and reversible cell permeabilization (Chang et al, 1992;Orlowski and Mir, 1993). One of the most innovative and promising biomedical applications of electropermeabilization is the therapeutic use of this technique to incorporate cytotoxic drugs into tumour cells (Mir et al, 1995a). In vitro cell electropermeabilization enhances BLM influx into electropulsed cells and thus greatly potentiates BLM cytotoxicity (Orlowski et al, 1988;Poddevin et al, 1991). Furthermore, in vivo experiments on tumour-bearing mice demonstrated that BLM potent anti-tumour effects were obtained by delivering transcutaneous EPs to subcutaneous t...
The aim of this study was to compare intra-arterial hepatic administration (IAH) versus i.v. administration of oxaliplatin and cisplatin in a VX2 tumor model in rabbits. VX2 tumors were implanted in the livers of White New Zealand female rabbits and 2 weeks later they received either cisplatin (4 mg/kg) or oxaliplatin (6 mg/kg) administered by IAH or i.v. Platinum pharmacokinetic parameters were measured by atomic absorption spectrometry at baseline, 2, 5 10, 20, 40 and 60 min, and then at 2, 4, 6 and 24 h after drug administration. Animals were sacrificed 24 h after drug administration to measure platinum concentrations in various tissues. After IAH oxaliplatin administration, we observed a significant decrease for total and filterable platinum in the Cmax compared with i.v. administration (12.4 versus 18.2 microg/l; p=0.02 and 11.2 versus 17.3 microg/l; p=0.02, respectively). Significant differences in various tissue concentrations were reported when comparing IAH and i.v. administration of oxaliplatin with IAH administration offering an advantage over i.v. administration. No differences in pharmacokinetic parameters or platinum tissue accumulation were apparent between the IAH and i.v. administration with cisplatin. We conclude that there is a significant pharmacokinetic advantage to using oxaliplatin for locoregional IAH chemotherapy compared with i.v. administration.
Pretherapeutic identification of patients likely to benefit from neoadjuvant chemotherapy for head and neck epidermoid cancer is of interest. We retrospectively analyzed the pretherapeutic computed tomographic (CT) scans of lymph nodes of 70 patients with head and neck cancer. All 70 patients were clinically classified as having stage IV disease. The purpose of our analysis was to compare the prognostic value of CT node density with that of the following factors: age, T and N categories, Eastern Cooperative Oncology Group performance status, tumor site, histopathologic type of disease [squamous cell carcinoma (SCC) or undifferentiated carcinoma of nasopharyngeal type (UNCT)], and type of local-regional treatment. A simple two-grade nodal density grading system was devised. The density of normal adjacent muscle was chosen as the density standard. A node was classified grade 1 if less than 33% of the node consisted of hypodense zones. A node was classified grade 2 if more than 33% of the node consisted of hypodense zones. Patients with grade 1 nodes had a complete response rate of 68% (21/31) compared with 8% (3/39) for those with grade 2 nodes (P less than .0001). The only other factor associated with complete node response was UCNT (P less than .03). However, node density remained the significant prognostic factor after adjustment for histopathologic type. Follow-up ranged from 16 to 44 months, with a median of 29 months. Patients with grade 1 nodes had a median survival time of 32 months versus 13 months for those with grade 2 nodes (P less than .01). A prospective study should validate the prognostic value of CT node density and its possible use in determining optimal multimodal therapy for advanced head and neck cancers.
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