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Purpose: The accessibility of cancer care faces challenges due to the rising prevalence of colorectal cancer (CRC) coupled with a shrinkage of healthcare professionals-known as the double aging phenomenon. To ensure sustainable and patient-centred care, innovative solutions are needed. This study aims to assess the needs of CRC patients regarding their follow-up care., Methods: This study uses a mixed-method approach divided in three phases. The initial phase involved focus group sessions, followed by semi-structured interviews to identify patients' needs during follow-up. Open analysis was done to define main themes and needs for patients. In the subsequent quantitative phase, a CRC follow-up needs questionnaire was distributed to patients in the follow-up., Results: After two focus groups (n = 14) and interviews (n = 5), this study identified six main themes. Findings underscore the importance of providing assistance in managing both physical and mental challenges associated with cancer. Participants emphasised the need of a designated contact person and an increased focus on addressing psychological distress. Furthermore, patients desire individualised feedback on quality of life questionnaires, and obtaining tailored information. The subsequent questionnaire (n = 96) revealed the priority of different needs, with the highest priority being the need for simplified radiology results. A possible approach to address a part of the diverse needs could be the implementation of a platform; nearly 70% of patients expressed interest in the proposed platform., Conclusions: CRC patients perceive substantial room for improvement of their follow-up care. Findings can help to develop a platform fulfilling the distinct demands of CRC patients during follow-up., (© 2024. The Author(s).)

The nitrogen mustards are powerful cytotoxic and lymphoablative agents and have been used for more than 60 years. They are employed in the treatment of cancers, sarcomas, and hematologic malignancies. Cyclophosphamide, the most versatile of the nitrogen mustards, also has a place in stem cell transplantation and the therapy of autoimmune diseases. Adverse effects caused by the nitrogen mustards on the central nervous system, kidney, heart, bladder, and gonads remain important issues. Advances in analytical techniques have facilitated the investigation of the pharmacokinetics of the nitrogen mustards, especially the oxazaphosphorines, which are prodrugs requiring metabolic activation. Enzymes involved in the metabolism of cyclophosphamide and ifosfamide are very polymorphic, but a greater understanding of the pharmacogenomic influences on their activity has not yet translated into a personalized medicine approach. In addition to damaging DNA, the nitrogen mustards can act through other mechanisms, such as antiangiogenesis and immunomodulation. The immunomodulatory properties of cyclophosphamide are an area of current exploration. In particular, cyclophosphamide decreases the number and activity of regulatory T cells, and the interaction between cyclophosphamide and the intestinal microbiome is now recognized as an important factor. New derivatives of the nitrogen mustards continue to be assessed. Oxazaphosphorine analogs have been synthesized in attempts to both improve efficacy and reduce toxicity, with varying degrees of success. Combinations of the nitrogen mustards with monoclonal antibodies and small-molecule targeted agents are being evaluated. SIGNIFICANCE STATEMENT: The nitrogen mustards are important, well-established therapeutic agents that are used to treat a variety of diseases. Their role is continuing to evolve., (Copyright © 2022 by The Author(s).)

Isolated limb perfusion (ILP) with melphalan and tumor necrosis factor (TNF)-α is used to treat bulky, locally advanced melanoma and sarcoma. However, TNF toxicity suggests a need for better-tolerated drugs. Cilengitide (EMD 121974), a novel cyclic inhibitor of alpha-V integrins, has both anti-angiogenic and direct anti-tumor effects and is a possible alternative to TNF in ILP. In this study, rats bearing a hind limb soft tissue sarcoma underwent ILP using different combinations of melphalan, TNF and cilengitide in the perfusate. Further groups had intra-peritoneal (i.p.) injections of cilengitide or saline 2 hr before and 3 hr after ILP. A 77% response rate (RR) was seen in animals treated i.p. with cilengitide and perfused with melphalan plus cilengitide. The RR was 85% in animals treated i.p. with cilengitide and ILP using melphalan plus both TNF and cilengitide. Both RRs were significantly greater than those seen with melphalan or cilengitide alone. Histopathology showed that high RRs were accompanied by disruption of tumor vascular endothelium and tumor necrosis. Compared with ILP using melphalan alone, the addition of cilengitide resulted in a three to sevenfold increase in melphalan concentration in tumor but not in muscle in the perfused limb. Supportive in vitro studies indicate that cilengitide both inhibits tumor cell attachment and increases endothelial permeability. Since cilengitide has low toxicity, these data suggest the agent is a good alternative to TNF in the ILP setting., (Copyright © 2012 UICC.)

Introduction: Nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to reduce the risk of colorectal cancer in cyclooxygenase-2 (COX-2) overexpressing colorectal cancers. The present study was designed to evaluate the inhibitory effects of the COX-2 inhibitor celecoxib on the growth of colorectal cancer liver metastases in a syngeneic rat model, CC531., Materials and Methods: The effects of celecoxib on cell viability in vitro were evaluated by treatment of CC531 tumor cell cultures with celecoxib. In vivo, Wag/Rij rats were inoculated with CC531 tumor cells at two sites in the liver and treated with celecoxib starting one week before, or directly after tumor inoculation. Control rats were inoculated without treatment. Three weeks after tumor inoculation rats were sacrificed. Tumor size, immune cell infiltration, caspase-3 activity, PGE(2) and celecoxib levels were determined., Results: CC531 tumors did not show COX-2 expression. Tumor growth was significantly inhibited by celecoxib treatment in a dose dependent manner. Immune cell infiltration was decreased after celecoxib treatment, indicating that the immune system was not involved in preventing tumor growth. Tumor caspase-3 levels were only significantly increased if treatment was started before tumor inoculation. Celecoxib serum concentration starting at 0.84 microg/ml significantly inhibited the outgrowth of CC531 liver tumors. In contrast, in vitro concentrations of celecoxib of at least 12 microg/ml were needed to affect tumor cell viability., Conclusion: These results suggest that the inhibitory effects of celecoxib on tumor growth are not by direct cytotoxicity, but by creating an unfavorable environment for tumor growth.

Purpose: The activity of imatinib in leukemia has recently been linked with expression of the organic cation transporter 1 (OCT1) gene SLC22A1. Here, we characterized the contribution of solute carriers to imatinib transport in an effort to further understand mechanisms involved in the intracellular uptake and retention (IUR) of the drug., Experimental Design: IUR of [3H]imatinib was studied in Xenopus laevis oocytes and HEK293 cells expressing OATP1A2, OATP1B1, OATP1B3, OCT1-3, OCTN1-2, or OAT1-3. Gene expression was determined in nine leukemia cell lines using the Affymetrix U133 array., Results: Imatinib was not found to be a substrate for OCT1 in oocytes (P = 0.21), whereas in HEK293 cells IUR was increased by only 1.20-fold relative to control cells (P = 0.002). Furthermore, in 74 cancer patients, the oral clearance of imatinib was not significantly altered in individuals carrying reduced-function variants in SLC22A1 (P = 0.99). Microarray analysis indicated that SLC22A1 was interrelated with gene expression of various transporters, including ABCB1, ABCC4, ABCG2 (negative), and OATP1A2 (positive). Imatinib was confirmed to be a substrate for the three efflux transporters (P < 0.05) as well as for OATP1A2 (P = 0.0001)., Conclusions: This study suggests that SLC22A1 expression is a composite surrogate for expression of various transporters relevant to imatinib IUR. This observation provides a mechanistic explanation for previous studies that have linked SLC22A1 with the antitumor activity of imatinib. Because of its high expression in the intestine, ciliary body, gliomas, and leukemia cells, OATP1A2 may play a key role in imatinib pharmacokinetics-pharmacodynamics.

Background: Isolated hepatic perfusion with high-dose chemotherapy is a treatment option for patients with irresectable metastases confined to the liver. Prolonged local control and impact on survival have been claimed. Major drawbacks are magnitude and costs of the procedure. We developed an isolated hypoxic hepatic perfusion (IHHP) with retrograde outflow without the need for a heart-lung machine., Patients and Methods: Twenty-four consecutive patients with irresectable metastases of various origins were treated. IHHP inflow was via the hepatic artery, outflow via the portal vein with occlusion of the retrohepatic caval vein. Radiolabeled albumine was used for leakage monitoring. Melphalan was used at 1-2 mg/kg. A 25-minute perfusion period was followed by a complete washout. Local and systemic melphalan concentrations were determined., Results: Compared with oxygenated classical IHP, the IHPP procedure reduced operation time from >8 h to 4 hours, blood loss from >4000 to 900 cc and saved material and personnel costs. Leakage was 0% with negligible systemic toxicity and 0% perioperative mortality. Tumor response: complete response (CR) in 4%, partial response (PR) in 58%, and stable disease (SD) in 13%. Median time to progression was 9 months (2-24 months); pharmacokinetics demonstrated intrahepatic melphalan concentrations more than 9 fold higher than postperfusion systemic concentrations., Conclusions: IHPP is a relatively simple procedure with reduced costs, reduced blood loss, no mortality, limited toxicity, and response rates comparable to classic IHP. The median duration of 9 months of tumor control should be improved. Hereto, vasoactive drugs, will be explored in further studies.

Histamine (Hi) combined to melphalan in a rat experimental model of isolated limb perfusion (ILP) for lower limb soft tissue sarcoma, resulted in overall response rates (OR) of 66%. Likewise, ILP with interleukin-2 (IL-2) resulted in OR of 67%, when combined to melphalan, in the same experimental model. In systemic immunotherapy, the combination of IL-2 and Hi has been used for solid tumor treatment based on immunomodulatory effects. In this study, we used our well-established ILP experimental model to evaluate whether the synergistic effect between the two drugs seen in the systemic setting, could further improve response rates in a loco-regional setting. Histological evaluation was done directly and 24 h after ILP. Melphalan uptake by tumor and muscle were measured. Hi and IL-2 together, combined to melphalan in the ILP led to OR of only 28%. Histology of tumors demonstrated partial loss of Hi-induced hemorrhagic effect when IL-2 was present. Melphalan accumulation in the tumor when both Hi and IL-2 were added (3.1-fold) was very similar to accumulation with Hi only (2.8-fold), or IL-2 only (3.5-fold) combined to melphalan. In vitro there was no synergy between the drugs. In conclusion there was a negative synergistic effect between IL-2 and Hi in the regional setting.

Our objective was to determine the response to gemcitabine plus docetaxel in advanced urothelial transitional cell carcinoma in a phase II trial, and gemcitabine distribution between plasma and erythrocytes, following docetaxel administration. Patients with locally advanced or metastatic transitional cell carcinoma, following a maximum of one prior chemotherapy regimen, were given gemcitabine 800 mg/m on days 1 and 8 plus docetaxel 85 mg/m on day 8, every 21 days. Gemcitabine was measured in the plasma and erythrocytes of nine patients before and after docetaxel administration. Thirty-four patients (median 63 years; range 49-79 years), of whom seven had prior chemotherapy and 27 were chemotherapy-naive, received a median of six cycles (range 1-6). Complete and partial remissions were observed in two and 16 (including three pretreated) patients, respectively, for an overall response rate of 53%. Median response duration was 5 months (range 1-39+). Haematoxicity was manageable, despite grade 3 infections in 24% of patients, but other toxicities were mostly mild. An apparent shift of gemcitabine from plasma to erythrocytes occurred after docetaxel in five of six patients evaluable for this analysis. We conclude gemcitabine plus docetaxel is tolerable and highly active in treated and untreated patients with advanced transitional cell carcinoma.

A reversed phase high-performance liquid chromatographic (HPLC) method with UV detection was developed for the simultaneous determination of imatinib (Gleevec, Glivec, STI571) and AMN107 in cultured tumour cells, using clozapine as an internal standard. The compounds of interest were extracted by liquid-liquid extraction using TOXI-TUBES((R)) A extraction tubes. Chromatographic separation was performed on a Phenomenex Gemini C18 reversed phase column (150 mm x 2.0 mm, 5 microm particle size), using a mixture of 65% CH(3)OH (methanol) and 35% NH(4)Ac (Ammonium acetate) buffer (20mM, pH 10). Separation was achieved under isocratic conditions at a flow rate of 0.5 ml/min. Imatinib, clozapine and AMN107 are detected by UV detection at 260 nm. Calibration curves were linear from 50 to 7500 ng/ml with correlation coefficients (r(2)) better than 0.998. The limit of quantitation (LOD) was 50 ng/ml. The method has been successfully applied to a cellular kinetics study.

Recent years have seen the development of powerful technologies that have provided forensic scientists with new analytical capabilities, unimaginable only a few years ago. With liquid chromatography-mass spectrometry (LC-MS) in particular, there has been an explosion in the range of new products available for solving many analytical problems, especially for those applications in which non-volatile, labile and/or high molecular weight compounds are being analysed. The aim of this article is to present an overview of some of the most recent applications of LC-MS (/MS) to forensic analysis. To this end, our survey encompasses the period from 2002 to 2005 and focuses on trace analysis (including chemical warfare agents, explosives and dyes), the use of alternative specimens for monitoring drugs of abuse, systematic toxicological analysis and high-throughput analysis. It is not the intention to provide an exhaustive review of the literature but rather to provide the reader with a 'flavour' of the versatility and utility of the technique within the forensic sciences.

Addition of high-dose tumor necrosis factor-alpha to melphalan-based isolated limb perfusion enhances anti-tumor effects impressively. Unfortunately, the mechanism of action of tumor necrosis factor-alpha is still not fully understood. Here, we investigated the effects of tumor necrosis factor-alpha on the tumor microenvironment and on secondary immunological events during and shortly after isolated limb perfusion in soft-tissue sarcoma-bearing rats. Already during isolated limb perfusion, softening of the tumor was observed. Co-administration of tumor necrosis factor-alpha in the isolated limb perfusion with melphalan induced a six-fold enhanced drug accumulation of melphalan in the tumor compared with isolated limb perfusion with melphalan alone. In addition, directly after perfusion with tumor necrosis factor-alpha plus melphalan, over a time-frame of 30 min, vascular destruction, erythrocyte extravasation and hemorrhage was detected. Interstitial fluid pressure and pH in the tumor, however, were not altered by tumor necrosis factor-alpha and no clear immune effects, cellular infiltration or cytokine expression were observed. Taken together, these results indicate that tumor necrosis factor-alpha induces rapid damage to the tumor vascular endothelial lining resulting in augmented drug accumulation. As other important parameters were not changed (e.g. interstitial fluid pressure and pH), we speculate that the tumor vascular changes, and concurrent hemorrhage and drug accumulation are the key explanations for the observed synergistic anti-tumor response.

Background: Isolated lung perfusion (ILuP) is an experimental technique for the treatment of pulmonary metastases. We hypothesized that part of the drug taken up by the lung during ILuP is washed out during the flush procedure. Therefore, we investigated gemcitabine uptake at different inflow concentrations, and the effect of delayed clamp release after ILuP on lung levels was studied., Methods: Thirty rats had ILuP during 30 minutes using gemcitabine perfusate levels of 1.3, 2.7, 4.0, 5.3, and 6.7 mg/mL. Another 37 rats underwent ILuP with gemcitabine perfusate levels of 6.7 mg/mL during 6 minutes followed by a 5-minute flush and 30 or 60 minutes of reperfusion, while two other groups had ILuP and delayed clamp release for 30 or 60 minutes followed by a 5-minute flush. All effluent and lung samples were stored for later analysis. Results were evaluated using Friedmann two-way analysis and two-way analysis of variance., Results: At 6 minutes, steady-state of gemcitabine uptake was achieved for all inflow concentrations and a linear relation (r = 0.933, p < 0.0001) between effluent and lung levels was observed. Delayed clamp release resulted in significantly higher lung levels compared with immediate restoration of blood circulation after ILuP (456% at 30 minutes and 828% at 60 minutes)., Conclusions: Effective gemcitabine lung levels are already achieved after 6 minutes of ILuP with 6.7 mg/mL followed by delayed clamp release during 30 minutes instead of the clinically applied 30 minutes ILuP.

The signal transduction inhibitor imatinib is one of the latest breakthroughs in cancer pharmacotherapy. It is administered orally over prolonged periods of time for the treatment of gastro-intestinal stromal tumours. Routine therapeutic drug monitoring of blood plasma versus red blood cells over several years by liquid chromatography coupled tandem mass spectrometry has high-lighted a very intriguing phenomenon. Imatinib plasma availability decreases dramatically owing to a significant shift in the partition ratio of red blood cells versus plasma. The shift is enforced by combination with everolimus, another signal transduction inhibitor. These data warrant routine erythrocyte versus plasma monitoring to prevent unexpected alterations in drug efficacy during long-term treatment.

Objective: Our objective was to explore the relationships between imatinib pharmacokinetics and 9 allelic variants in 7 genes coding for adenosine triphosphate-binding cassette transporters (ABCB1 and ABCG2) and enzymes (cytochrome P450 [CYP] 2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5) of putative relevance for imatinib., Methods: Imatinib transport in vitro was studied by use of human embryonic kidney 293 cells transfected with wild-type ABCG2 and an ABCG2 Q141K clone. Steady-state pharmacokinetics of imatinib was obtained in 82 patients with gastrointestinal stromal tumors treated with oral imatinib at doses ranging from 100 to 1000 mg/d. Genotyping was carried out via direct sequencing or restriction fragment length polymorphism-based techniques., Results: Human embryonic kidney 293 cells transfected with ABCG2 Q141K exhibited greater drug accumulation in vitro in comparison with cells expressing wild-type ABCG2 (P = .028). However, pharmacokinetic parameters of imatinib in vivo were not statistically significantly different in 16 patients who were heterozygous for ABCG2 421C>A compared with 66 patients carrying the wild-type sequence (P = .479). The apparent oral clearance of imatinib was potentially reduced in individuals with at least 1 CYP2D6*4 allele (median, 7.78 versus 10.6 L/h; P = .0695). Pharmacokinetic parameters were not related to any of the other multiple-variant genotypes (P >or= .230), possibly because of the low allele frequencies., Conclusions: This study indicates that common genetic variants in the evaluated genes have only a limited impact on the pharmacokinetics of imatinib. Further investigation is required to quantitatively assess the clinical significance of homozygous variant ABCG2 and CYP2D6 genotypes in patients treated with imatinib.

Background: Oral administration of irinotecan (CPT-11) should allow sustained exposure to the drug without the inconvenience of intravenous delivery and with fewer side-effects., Patients and Methods: The present phase I trial of CPT-11, administered orally as a powder-filled capsule for 5 consecutive days every 3 weeks at doses ranging from 30 to 90 mg/m(2)/day, was conducted in 47 patients for whom a satisfactory standard treatment option was no longer available (24 males/23 females; median age 51 years, range 26-85). Tumour types included melanoma (11), colorectal (4), urinary tract (3), lung/pleura (4), thyroid (3), liver (3), gallbladder (2), cervix/uterus (3), breast (2), pancreas (2), carcinoma and other cancer types (10)., Results: A total of 171 cycles were administered (median 3, range 1-11). Dose limiting toxicities (DLTs) occurred during the first cycle in five of 31 patients in the dose-escalation part of the study: one patient at the 50 mg/m(2)/day dose level (diarrhoea grade 4); one patient at the 80 mg/m(2)/day dose level (prolonged neutropenia grade 4 and diarrhoea grade 3); and three patients at the 90 mg/m(2)/day dose level (diarrhoea, vomiting and neutropenia). The 80 mg/m(2)/day dose level was expanded, as a feasibility study, to include 16 additional patients, five of whom had received extensive prior pelvic irradiation. A further three patients in this cohort experienced DLTs, two of whom had received extensive prior pelvic irradiation. One patient died on study day 15 during the first cycle of oral CPT-11 following grade 3 diarrhoea, febrile neutropenia and a necrotic enterocolitis. Overall the grade 3/4 toxicities in 47 patients were asthenia (19%), anorexia (17%), neutropenia (14.9 %), diarrhoea (13%), nausea (12.7%), vomiting (8.5%) and thrombocytopenia (8.5%). Partial responses were observed in two melanoma patients and disease stabilisation was noted in 17 (36.1%) patients. Pharmacokinetic parameters were recorded for 46 patients., Conclusions: At the maximum tolerated dose, defined as 80 mg/m(2)/day for 5 days every 3 weeks, oral CPT-11 was shown to be well tolerated and safe with few of the haematological toxicities associated with the intravenous formulation.

With the human genome sequence now determined, the field of molecular medicine is moving beyond genomics to proteomics, the large-scale analysis of proteins. It is now possible to examine the expression of more than 1000 proteins using mass spectrometry technology coupled with various separation methods. Microarray technology is a new and efficient approach, for extracting relevant biomedical data and has a wide range of applications. It provides a versatile tool to study protein-protein, protein-nucleic acid, protein-lipid, enzyme-substrate and protein-drug interactions. This review paper will explore the key themes in proteomics and their application in clinical cancer research.

The analysis of the signal transduction inhibitor imatinib in patient tumour tissue using LC and MS/MS is described. The anticancer agent is eluted over RP-C18 within 2 mm together with its internal standard STI571-d8. Calibration curves were prepared in red blood cells (RBC). For quantitative isolation of the RBC, measurement of sediment was applied. There were no indications of signal suppression by substances originating in the biological matrix. The limit of determination in tumour tissue was in the range of those recorded for RBC and plasma. The assay is selective and sensitive, with its robustness favouring the experimental application in clinical oncology and its routine use in animal experiments. The LOD was 4.5 ng per gram in tumour tissue.

Aims: To review the development and current status of balloon catheter mediated hypoxic perfusion of abdomen, pelvis and liver for treatment of locally advanced malignancies. Within this context we focus on the addition of tumour necrosis factor-alpha (TNF) to these minimal invasive perfusion procedures., Methods: A literature search on these topics was carried out in PubMed for indexed articles and in all issues of Regional Cancer Treatment. The findings were related to our own experiences., Results: Hypoxic abdominal (HAP) and hypoxic pelvic perfusion (HPP) using balloon catheters, are currently applied modalities for treatment of a wide variety of abdominal and pelvic tumours, yet scientific validation of these procedures is poor. Following the results of several Phase I-II trials, both treatments are associated with severe systemic toxicity, significant morbidity and even mortality. The degree of systemic leakage associated with these procedures prohibits addition of TNF. For leakage free liver perfusion surgery is still required, as with current balloon catheter techniques it is not possible to perform leakage free isolated hypoxic hepatic perfusion (IHHP), using either orthograde or retrograde hepatic flow. Experimental and clinical observations suggest that within any perfusion setting, the utilization of TNF is only indicated for treatment of highly vascularised tumours and not for treatment of colorectal tumours., Conclusion: Balloon catheter technology in its present form does not provide adequate leakage control in any of these settings and is therefore associated with considerable toxicity. It is associated with poor response rates and cannot be considered in any setting as a standard of care.

Aims: To investigate the feasibility of hypoxic pelvic perfusion (HPP), using balloon catheter techniques as treatment modality for locally advanced pelvic malignancies., Methods: In a phase I--II study, 16 patients with various non-resectable pelvic tumours were treated with two HPP with MMC and melphalan, followed by radiotherapy (25 Gy) and surgical resection if feasible. Toxicity and procedure related complications were documented. Tumour responses were assessed by MRI or CT. Pain reductive effects were assessed by evaluation of pain registration forms., Results: HPP resulted in augmented regional drug concentrations with relatively low systemic levels. Some severe systemic toxicity was observed. One procedure related death occurred. Pain reduction effects were short-lived. Ten patients had radiological NC, two PD and one PR. In 11 patients surgical resection was performed, which was microscopically radical in six cases. Mean survival was 26.8 months (range 1--86)., Conclusion: The seemingly favorable pharmacokinetic profiles observed with HPP in this and other studies can still lead to severe systemic toxicity. In terms of survival, local (re-)recurrence and pain reduction there seems no benefit of addition of HPP to pre-operative radiotherapy. HPP with MMC and melphalan, does not seem a therapeutic option in patients with locally advanced pelvic tumours.

We have performed in vitro incubations of blood from male and female volunteers with gemcitabine and docetaxel alone, and in combination, at different concentration gradients in order to investigate changes in partition between red blood cells (RBCs), total plasma and the free fraction. After extraction and sample pre-treatment, a validated high-performance liquid chromatography method followed by UV detection was used to determine the concentrations of both drugs in the different blood constituents. The partition ratio [the concentration in the erythrocytes divided by the concentration in plasma (E/P)] was calculated. The partition ratio of docetaxel varied from 0.02 to 1.44 (mean 0.35), reflecting its relatively low affinity for RBCs, probably because of its high plasma protein binding (more than 98%). For gemcitabine, the partition ratio varied from 1 to 5, reflecting a high affinity for RBCs (less than 10% plasma protein bound). The partition ratios of both drugs increased significantly with higher whole-blood concentrations, favoring uptake in the erythrocytes when plasma protein binding is saturated. Combination incubations showed a complex and unexplained interaction between gender and the influence of docetaxel on the partition of gemcitabine. We conclude that the incorporation of drugs into the RBC pool may be important for transportation to tumor tissue and efficacy. In combination, one anti-cancer agent can alter the partition ratios of other anti-cancer agents.

We have performed in vitro incubations of blood from male and female volunteers, smokers and non-smokers, with irinotecan at a gradient of different concentrations in order to investigate changes of partition between red blood cells (RBCs), total plasma and the free fraction. Since irinotecan (CPT-11) is not metabolized in vitro, there is no data available on its active metabolite SN-38. After extraction and sample pre-treatment, a validated high-performance liquid chromatography method followed by fluorescence detection was used to determine the concentration of the drug in the different blood constituents. The partition ratio [the concentration in the erythrocytes divided by the concentration in plasma (E/P)] was calculated. The partition ratio of CPT-11 varied from 0.7 to 2.8, reflecting its relatively high affinity for the erythrocyte, probably because of its only moderate plasma protein binding (65%). The partition ratios increased significantly with higher whole-blood concentrations, favoring uptake in the erythrocytes when plasma protein binding is saturated. No gender difference was detected, but we found relatively more CPT-11 in the erythrocytes of non-smokers compared to smokers. The incorporation of drugs into the RBC pool may be important for transportation to tumor tissue and efficacy. Smoking can have a significant influence on drug partition in the blood.

The development of an on-column focusing gradient capillary LC method coupled to tandem mass spectrometry (quadrupole-linear ion trap) for the quantitative determination of the anticancer agent ZD1839 (Gefitinib, Iressa) in blood plasma is described. Plasma samples (0.2 ml) were extracted with methyl tert-butyl ether. The analytes of interest, ZD1839 and the internal standard [(2)H8]ZD1839 (ZD1839-d8) were eluted on a 50 mm x 1 mm, 5 microm particle size, capillary ODS Hypersil column using an aqueous ammonium acetate gradient at 40 microl/min. Mass spectrometric detection was performed by a Q-Trap tandem mass spectrometer with electrospray positive ionisation, and monitored in the multiple reaction monitoring transitions 447 >128 and 455 >136, respectively. The limit of quantification of ZD18395 was 0.1 ng/ml. The method proved to be robust, allowing quantification of ZD1839 with sufficient precision, accuracy and sensitivity.

Imatinib mesylate is a selective tyrosine kinase inhibitor that is successfully used in the treatment of Philadelphia-positive chronic and acute leukaemia's, and gastrointestinal stromal tumors. We investigated whether the intended chronic oral administration of imatinib might lead to the induction of the intestinal ABC transport proteins ABCB1, ABCC1 (MRP1), ABCC2 (MRP2) and ABCG2. Using Caco2 cells as an in vitro model for intestinal drug transport, we found that continuous exposure (up to 100 days) with imatinib (10 microM) specifically upregulates the expression of ABCG2 (maximal approximately 17-fold) and ABCB1 (maximal approximately 5-fold). The induction of gene expression appeared to be biphasic in time, with a significant increase in ABCG2 and ABCB1 at day 3 and day 25, respectively, and was not mediated through activation of the human orphan nuclear receptor SXR/NR1I2. Importantly, chronic imatinib exposure of Caco2 cells resulted in a approximately 50% decrease in intracellular accumulation of imatinib, probably by enhanced ABCG2- and ABCB1-mediated efflux, as a result of upregulated expression of these drug pumps. Both ABCG2 and ABCB1 are normally expressed in the gastrointestinal tract and it might be anticipated that drug-induced upregulation of these intestinal pumps could reduce the oral bioavailability of imatinib, representing a novel mechanism of acquired pharmacokinetic drug resistance in cancer patients that are chronically treated with imatinib.

Objective: Isolated lung perfusion (ILuP) is an experimental technique currently tested to increase the 5-year survival of 40% after surgical resection of pulmonary metastases from certain solid tumors. The standard technique of anterograde perfusion was compared with retrograde isolated lung perfusion in which the drug is introduced through the pulmonary veins while the effluent is collected from the pulmonary artery. Since the lung has a dual arterial circulation through the pulmonary artery and bronchial circulation, perfusion through the pulmonary veins can result in a more homogeneous distribution throughout the lung with subsequent higher melphalan concentration., Methods: We randomized 20 rats into two groups. Group one underwent anterograde isolated left lung perfusion while group two underwent retrograde isolated left lung perfusion. A dose of 2 mg/kg melphalan (MN) was administered to the lung at a flow of 0.5 mL/min during 30 min, followed by a 5-min washout with buffered hetastarch (BHE). The final melphalan lung concentration (FMLC) was determined in the hilum, at the apex, the mid-periphery and the base of the lung. Statistical analysis was done with an unpaired student's t-test., Results: Retrograde left ILuP resulted in a higher FMLC in the hilum (P<0.0001) and in the base of the lung (P=0.03), while anterograde ILuP induced a higher concentration at the apex of the lung (P=0.04). No difference was seen in the mid-peripheral area of the lung (P=0.92)., Conclusions: In this experimental study, retrograde perfusion seems to increase final melphalan lung concentration in hilar and basal regions of the lung compared to anterograde perfusion.

The cytokine interleukin 2 (IL-2) is a mediator of immune cell activation with some antitumor activity, mainly in renal cell cancer and melanoma. We have previously shown that tumor necrosis factor (TNF)-alpha has strong synergistic antitumor activity in combination with chemotherapeutics in the isolated limb perfusion (ILP) setting based on a TNF-mediated enhanced tumor-selective uptake of the chemotherapeutic drug followed by a selective destruction of the tumor vasculature. IL-2 can cause vascular leakage and edema and for this reason we examined the antitumor activity of a combined treatment with IL-2 and melphalan in our well-established ILP in soft tissue sarcoma-bearing rats (BN175). ILP with either IL-2 or melphalan alone has no antitumor effect, but the combination of IL-2 and melphalan resulted in a strong synergistic tumor response, without any local or systemic toxicity. IL-2 enhanced significantly melphalan uptake in tumor tissue. No signs of significant vascular damage were detected to account for this observation, although the tumor sections of the IL-2- and IL-2 plus melphalan-treated animals revealed scattered extravasation of erythrocytes compared with the untreated animals. Clear differences were seen in the localization of ED-1 cells, with an even distribution in the sham, IL-2 and melphalan treatments, whereas in the IL-2 plus melphalan-treated tumors clustered ED-1 cells were found. Additionally, increased levels of TNF mRNA were found in tumors treated with IL-2 and IL-2 plus melphalan. These observations indicate a potentially important role for macrophages in the IL-2-based perfusion. The results in our study indicate that the novel combination of IL-2 and melphalan in ILP has synergistic antitumor activity and may be an alternative for ILP with TNF and melphalan.

Gastrointestinal stromal tumors (GISTs) arise from the interstitial cells of Cajal through gain of function mutations of the oncogene KIT. Imatinib offers the first effective treatment for patients with GISTs, but the therapeutic outcome strongly depends on the type of KIT mutation. We used ProteinChip technology to investigate whether GISTs with different KIT mutations express different proteins. In total, 154 proteins were significantly differentially expressed in GISTs with exon 9 KIT mutation compared to GISTs with exon 11 KIT mutation.

Angiogenesis is a hallmark of wound healing, the menstrual cycle, cancer, and various ischemic and inflammatory diseases. A rich variety of pro- and antiangiogenic molecules have already been discovered. Vascular endothelial growth factor (VEGF) is an interesting inducer of angiogenesis and lymphangiogenesis, because it is a highly specific mitogen for endothelial cells. Signal transduction involves binding to tyrosine kinase receptors and results in endothelial cell proliferation, migration, and new vessel formation. In this article, the role of VEGF in physiological and pathological processes is reviewed. We also discuss how modulation of VEGF expression creates new therapeutic possibilities and describe recent developments in this field.

We have developed a rapid method that enables the simultaneous analysis of gamma-hydroxybutyrate (GHB) and its precursors, i.e. gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) in urine. The method comprised a simple dilution of the urine sample, followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Chromatographic separation was achieved using an Atlantis dC18 column, eluted with a mixture of formic acid and methanol. The method was linear from 1-80 mg/L for GHB and 1,4-BD and from 1-50 mg/L for GBL. The limit of quantification was 1 mg/L for all analytes. The procedure, which has a total analysis time (including sample preparation) of less than 12 min, was fully validated and applied to the analysis of 182 authentic urine samples; the results were correlated with a previously published GC-MS procedure and revealed a low prevalence of GHB-positive samples. Since no commercial immunoassay is available for the routine screening of GHB, this simple and rapid method should prove useful to meet the current increased demand for the measurement of GHB and its precursors.

Background: We have previously shown how tumor response of isolated limb perfusion (ILP) with melphalan was improved when tumor necrosis factor alpha (TNF-alpha) was added. Taking into account that other vasoactive drugs could also improve tumor response to ILP, we evaluated histamine (Hi) as an alternative to TNF-alpha., Methods: We used a rat ILP model to assess the combined effects of Hi and melphalan (n = 6) on tumor regression, melphalan uptake (n = 6), and tissue histology (n = 2) compared with Hi or melphalan alone. We also evaluated the growth of BN-175 tumor cells as well as apoptosis, necrosis, cell morphology, and paracellular permeability of human umbilical vein endothelial cells (HUVECs) after Hi treatment alone and in combination with melphalan., Results: The antitumor effect of the combination of Hi and melphalan in vivo was synergistic, and Hi-dependent reduction in tumor volume was blocked by H1 and H2 receptor inhibitors. Tumor regression was observed in 66% of the animals treated with Hi and melphalan, compared with 17% after treatment with Hi or melphalan alone. Tumor melphalan uptake increased and vascular integrity in the surrounding tissue was reduced after ILP treatment with Hi and melphalan compared with melphalan alone. In vitro results paralleled in vivo results. BN-175 tumor cells were more sensitive to the cytotoxicity of combined treatment than HUVECs, and Hi treatment increased the permeability of HUVECs., Conclusions: Hi in combination with melphalan in ILP improved response to that of melphalan alone through direct and indirect mechanisms. These results warrant further evaluation in the clinical ILP setting and, importantly, in organ perfusion.

Background: Addition of tumour necrosis factor-alpha (TNF) to hypoxic abdominal perfusion (HAP) and hypoxic pelvic perfusion (HPP) with chemotherapeutic agents for treatment of un-resectable malignancies may lead to similar enhanced anti-tumour effects as are observed when TNF is added to isolated limb perfusions (ILP) with Melphalan. Here, we validate the methodology of HAP and HPP using balloon catheter techniques, and investigate the distribution of TNF, Melphalan and Mitomycin C (MMC) over the regional and systemic blood compartments when applying these techniques., Materials and Methods: Twelve pigs underwent HAP or HPP with TNF, Melphalan and MMC for 20 min. Throughout and after the procedures blood samples were obtained from hepatic, portal and systemic blood compartments and plasma concentrations of perfused agents were determined., Results: We demonstrated that HAP and HPP result in temporary loco-regional concentration advantages of all perfused agents, although from start of perfusion significant systemic leakage occurred., Conclusion: On basis of these results it seems that the advantage in terms of regional plasma concentration of TNF may be insufficient for TNF-mediated effects to occur, making future addition of this cytokine to these procedures in the clinical setting questionable. The observed regional concentration advantages of MMC and Melphalan, however, warrant further studies on clinical application of these agents in both settings.

Background: Developments in balloon catheter methodology have made hypoxic abdominal perfusion (HAP) with anti-tumour agents possible with only minimal invasive surgery. The initial reports on this modality and celiac axis stop-flow infusion for treatment of pancreatic cancer were very promising in terms of tumour response, median survival and pain reduction. Recent reports, however, have not been able to confirm these results and some have disputed the efficacy of these currently still applied treatment modalities., Methods: Twenty-one patients with advanced pancreatic carcinoma were included in a phase I-II trial of HAP with MMC and Melphalan followed by celiac axis infusion (CAI) with the same agents six weeks later. Tumour response was assessed by abdominal-CT and by determining tumour markers. Effect on pain reduction was assessed by evaluation of pain registration forms., Results: HAP resulted in augmented regional drug concentrations. One patient died after CAI due to acute mesenterial ischaemia. One agent-toxicity related death was observed in the phase-I study. Significant hematological toxicity was observed after HAP and CAI at MTD. No patients were considered resectable after treatment. Median survival after HAP was 6 months (range 1-29). Pain reduction was experienced by only 5/18 patients and was short-lived., Conclusion: In contrast to earlier reports HAP and CAI with MMC and Melphalan did not demonstrate any benefit in terms of tumour response, median survival and pain reduction, compared to less invasive treatment options. As this treatment was associated with significant toxic side-effects and even one procedure related death, we do not consider this a therapeutic option in patients with advanced pancreatic cancer.

Background: Isolated hepatic perfusion for irresectable metastases confined to the liver has reported response rates of 50% to 75%. Magnitude, costs, and nonrepeatability of the procedure are its major drawbacks. We developed a less invasive, less costly, and potentially repeatable balloon catheter-mediated isolated hypoxic hepatic perfusion (IHHP) technique., Methods: In this phase I and II study, 18 consecutive patients with irresectable colorectal or ocular melanoma hepatic metastases were included. Two different perfusion methods were used, both with inflow via the hepatic artery, using melphalan 1 mg/kg. In the first eight patients, the portal vein was occluded, and outflow was via the hepatic veins into an intracaval double-balloon catheter. This orthograde IHHP had on average 56% leakage. In next 10 patients, we performed a retrograde outflow IHHP with a triple balloon blocking outflow into the caval vein and allowing outflow via the portal vein. The retrograde IHHP still had 35% leakage on average., Results: Although local drug concentrations were high with retrograde IHHP, systemic toxicity was still moderate to severe. Partial responses were seen in 12% and stable disease in 81% of patients. The median time to local progression was 4.8 months., Conclusions: We have abandoned occlusion balloon methodology for IHHP because it failed to obtain leakage control. We are presently conducting a study using a simplified surgical retrograde IHHP method, in which leakage is fully controlled, which translates into high response rates.

We evaluated the effect of different intervals and sequences of the vascular targeting agent combretastatin A-4 disodium phosphate (CA4DP) and CPT-11 administration on tumour growth delay and intratumoral uptake of CPT-11 using a syngeneic rhabdomyosarcoma tumour model. Irrespective of the administration sequence, the combination of CA4DP and CPT-11 significantly increases tumour growth delay in comparison with both drugs alone (P<0.001). Intratumoral CPT-11 concentration generally decreased (up to 5-fold) in the combination groups, while SN-38, the active metabolite of CPT-11, increased up to 9-fold. However, the increased amount of intratumoral SN-38 trapping after CA4DP injection did not correlate with the observed tumour growth delay. In conclusion, CA4DP significantly enhances the antitumour effect of CPT-11, which is not greatly influenced by the administration sequence, and which lacks a correlation with the intratumoral trapping of CPT-11 or SN-38. Mechanisms other than trapping are likely to be involved in the chemosensitising capacity of CA4DP.

The shape of a normal human red blood cell (RBC) is well known: under resting conditions it is that of a biconcave discocyte. However, RBCs can easily undergo transformation to other shapes with stomatocytes and echinocytes as extremes. Various anticancer agents, generally reactive and labile substances, e.g., oxazaphosphorines and fluoropyrimidines, can induce severe deformation of shape. Shape changes in erythrocytes can induce rheological disturbances, which occasionally have pathophysiological consequences. It is difficult to estimate the impact of shape changes on the in vivo behavior of agents of biological interest. However, it has been demonstrated for various anticancer agents that erythrocytes fulfill an important role in their uptake, transport, and release. Moreover, some anticancer agents are capable of influencing important transporters such as MRP and GLUT-1. Monitoring of erythrocyte concentrations of certain cytotoxic agents is therefore of interest as the data generated can have a predictive outcome for therapeutic efficacy. This is true for cyclophosphamide, ifosfamide, lometrexol, and 6-mercaptopurine, as well as MRP and GLUT-1 mediated agents.

Therapeutic drug monitoring generally focuses on the plasma compartment only. Differentiation between the total plasma concentration and the free fraction (plasma water) has been described for a number of limited drugs. Besides the plasma compartment, blood has also a cellular fraction which has by far the largest theoretical surface and volume for drug transport. It is with anti-cancer drugs that major progress has been made in the study of partition between the largest cellular blood compartment, i.e., erythrocytes, and the plasma compartment. The aim of the present review is to detail the progress made in predicting what a drug does in the body, i.e., pharmacodynamics including toxicity and plasma and/or red blood cell concentration monitoring. Furthermore, techniques generally used in anti-cancer drug monitoring are highlighted. Data for complex Bayesian statistical approaches and population kinetics studies are beyond the scope of this review, since this is generally limited to the plasma compartment only.

An isocratic high-performance liquid chromatographic method coupled to tandem mass spectrometry for the quantification of the revolutionary and promising anticancer agent STI-571 (tradenames Gleevec, Glivec, Imatinib) in blood plasma and red blood cells (RBCs) is described. The method involves measurement of sediment technology for RBCs and a subsequent single protein precipitation step by the addition of acetonitrile to both the RBC isolate and plasma. The sample mixture was centrifuged (10 min, 3600 g), and the supernatant filtered through a HPLC filter (0.45 microm). The analytes of interest, STI-571 and the internal standard [2H8]STI-571 were eluted on a Waters Symmetry C18 column (50x2.1 mm I.D., 3.5 microm particle size) using a methanol-0.05% ammonium acetate (72:28, v/v) mixture. STI-571 and [2H8]STI-571 were detected by electrospray tandem mass spectrometry in the positive mode, and monitored in the multiple reaction monitoring transitions 494>394 and 502<394, respectively. The lower limit of quantitation of STI-571 was 2.1 ng/ml in RBCs and 1.8 ng/ml in plasma. The recovery from both plasma and RBCs was between 65 and 70%. The method proved to be robust, allowing simultaneous quantification of STI-571 in RBCs and plasma with sufficient precision, accuracy and sensitivity and is useful in monitoring the fate of this signal transduction inhibitor in whole blood of cancer patients.

Liquid chromatography-tandem mass spectrometry (LC-MS-MS) is emerging as the tool of choice for rapid analysis and the detection of biologically active compounds in complex mixtures. We describe the development of a sensitive method for the simultaneous quantitation of 10 benzodiazepines in Calliphora vicina (Diptera: Calliphoridae) larvae and puparia. The use of larvae for toxicological analyses offers some technical advantages over putrefied tissue. Four sample pretreatment methods for isolating the benzodiazepines out of larvae were evaluated. A simple homogenization, followed by acetonitrile precipitation yielded the highest recoveries. Puparia were pulverized and extracted by ultrasonification in methanol. All extracts were subsequently analyzed using reversed-phase LC-MS-MS. Larvae and puparia calibrators containing benzodiazepines at concentrations ranging from 25 to 750 pg/mg and 50 to 500 pg/mg, respectively, were prepared and analyzed. The method was demonstrated to be linear over the ranges investigated. Limits of detection were from 1.88 to 5.13 pg/mg larva and from 6.28 to 19.03 pg/mg puparium. The developed method was applied to the determination of nordiazepam and its metabolite oxazepam in larvae and puparia of the Calliphora vicina fly that had been reared on artificial foodstuff (beef heart) spiked with 1 microg/g nordiazepam. The larvae were harvested at day 5 for analysis of drug content. The method was sufficiently sensitive to allow the detection of nordiazepam and oxazepam in a single larva or puparium.

We investigated the potential chemosensitizing effect of nicotinamide on CPT-11, and the relationship between nicotinamide and CPT-11, intratumoral drug uptake in syngeneic rhabdomyosarcoma tumors in rats. Pretreatment with nicotinamide, known to improve tumor oxygenation, perfusion and radiotherapy effect, only caused a minor increase in tumor growth delay. To our surprise, intratumoral uptake of CPT-11 and its active metabolite SN-38 decreased significantly between 19% and 43%. This discrepancy suggests that the potential chemosensitizing effect of nicotinamide, seen in other studies, is based on a direct effect on tumor cells rather than on an increased delivery of anticancer drugs. A second finding is that plasma levels of CPT-11 and SN-38 respectively increase and decrease after nicotinamide exposure, suggesting inhibition of carboxylesterase, which is necessary for the conversion of CPT-11 to its active metabolite SN-38. Great care is required when combining nicotinamide with anticancer drugs, since unexpected pharmacokinetic and pharmacodynamic alterations might occur.

Promising preclinical activity with agents blocking the function of vascular endothelial growth factor (VEGF) has been observed in various cancer types, especially with combination therapy. However, these drugs decrease microvessel density, and it is not known whether this reduced vessel density (VD) results in decreased delivery of concomitantly administered classical anticancer drugs. We designed an in vivo study to investigate the relation between VEGF-blocking therapy, tumoral blood vessels, and intratumoral uptake of anticancer drugs. Nude NMRI mice bearing colon adenocarcinoma (HT29) were treated with the anti-VEGFmAb A4.6.1 or placebo. After 1 week, CPT-11 was administered 1 h prior to killing the animals. In A4.6.1 treated tumours, there was a significant decrease in VD, more pronounced with potentially functional large vessels than endothelial cords. Interestingly, a trend to increased intratumoral CPT-11 concentration was observed (P=0.09). In parallel, we measured an increase in tumour perfusion, as estimated by high-performance liquid chromatography determination of intratumoural Hoechst 33342 concentration. In the growth delay study, CPT-11 was at least equally effective with or without pretreatment with A4.6.1. These data suggest that tumour vascular function and tumour uptake of anticancer drugs improve with VEGF-blocking therapy, and indicate the relevance for further investigations.

Target analysis of amphetamines in biological samples is of great importance for clinical and forensic toxicologists alike. At present, most laboratories analyze such samples by gas chromatography-mass spectrometry. However, this procedure is labor-intensive and time-consuming, particularly as a preliminary extraction and derivatization are usually unavoidable. Here we describe the development of an alternative method. Amphetamines were isolated from human plasma and oral fluid using a simple methanol precipitation step and subsequently analyzed using reversed-phase liquid chromatography-tandem mass spectrometry. Quantitation of the drugs was performed using multiple reaction monitoring. The developed method, which requires only 50 microL of biological sample, has a total analysis time of less than 20 min (including sample preparation) and enables the simultaneous quantitation of 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxyethylamphetamine, amphetamine, methamphetamine, and ephedrine in a single chromatographic run. Limits of detection of 2 microg/L or better were obtained. The method has been validated and subsequently applied to the analysis of plasma and oral fluid samples collected from current drug users.

Background: Toxicity and pharmacokinetics of gemcitabine (GCB) were evaluated in a rat model of isolated lung perfusion (ILuP) and compared to intravenous (iv) infusion., Materials and Methods: CC531S adenocarcinoma cells were incubated in vitro for 24 h with GCB. Cell survival was determined 4 days after GCB treatment with the sulforhodamine B test. In a first in vivo experiment, Wag/Rij rats underwent left ILuP with 20 mg/kg (n = 3), 40 mg/kg (n = 6), 80 mg/kg (n = 6), 160 mg/kg (n = 6), or 320 mg/kg (n = 6) of GCB and a control group (n = 6) with buffered starch. After 3 weeks, right pneumonectomy was performed. Furthermore, survival was determined for rats treated with iv infusion of 40 mg/kg (n = 10), 80 mg/kg (n = 10), 160 mg/kg (n = 10), or 320 mg/kg (n = 6) of GCB and a control group (n = 6) treated with saline (0.9% NaCl). In a second experiment lung and serum GCB levels were determined for rats treated with iv infusion (160 mg/kg, n = 6) and rats which had ILuP (160 mg/kg, n = 6; 320 mg/kg, n = 6)., Results: Incubation of the CC531S adenocarcinoma cells with GCB led to a 50% decrease (P < 0.05) in the number of cells compared to controls at a dose of 23.6 nM. After 90 days, the mortality for rats treated with 320 mg/kg iv GCB was 100% compared to 17% after ILuP for the same dose. ILuP with 160 and 320 mg/kg resulted in significantly higher lung levels of GCB compared to iv therapy without any systemic leakage., Conclusions: GCB ILuP is well-tolerated to a maximum dose of 320 mg/kg and results in significantly higher GCB lung levels with undetectable serum levels compared to iv treatment.

Isolated hepatic perfusion (IHP) with melphalan with or without tumour necrosis factor alpha (TNF-alpha) is currently performed in clinical trials in patients with hepatic metastases. Previous studies led to the hypothesis that the use of TNF-alpha in isolated limb perfusion causes specific destruction of tumour endothelial cells and thereby induces an increased permeability of tumour vasculature. However, whether TNF-alpha contributes to the therapeutic efficacy in IHP still remains unclear. In an in vivo rat liver metastases model we studied three different tumours: colon carcinoma CC531, ROS-1 osteosarcoma and BN-175 soft-tissue sarcoma which exhibit different degrees of vascularisation. IHP was performed with melphalan with or without the addition of TNF-alpha. IHP with melphalan alone resulted, in all tumour types, in a decreased growth rate. However in the BN-175 tumour addition of TNF-alpha resulted in a strong synergistic effect. In the majority of the BN-175 tumour-bearing rats, a complete response was achieved. In vitro cytoxicity studies showed no sensitivity (CC531 and BN-175) or only minor sensitivity (ROS-1) to TNF-alpha, ruling out a direct interaction of TNF-alpha with tumour cells. The response rate in BN-175 tumour-bearing rats when TNF-alpha was coadministrated with melphalan was strongly correlated with drug accumulation in tumour tissue, as only in these rats a five-fold increased melphalan concentration was observed. Secondly, immunohistochemical analysis of microvascular density (MVD) of the tumour showed a significantly higher MVD for BN-175 tumour compared to CC531 and ROS-1. These results indicate a direct relation between vascularity of the tumour and TNF-alpha mediated effects. Assessment of the tumour vasculature of liver metastases would be a way of establishing an indication for the utility of TNF-alpha in this setting.