Ecteinascidin-743: evidence of activity in advanced, pretreated soft tissue and bone sarcoma patients

Purpose. To evaluate the activity and safety of ecteinascidin (ET-743) in pretreated patients with advanced or metastatic soft tissue and bone sarcoma. Patients or subjects. Eighty-nine patients received ET-743 as a 24-hour continuous infusion at a dose of 900-1500 mug/m(2) every 3 weeks. Results. We observed one complete remission, 5 partial remissions, one minimal response, and 16 patients with a disease stabilization of 6 months or more. The objective response rate was 6.7% and the clinical benefit rate at 3 and 6 months was 37.7% and 23.4%, respectively. Responses were noted in patients with lipo-, leiomyo-, osteo-, and myogenic sarcoma, with a median duration of 9.85 months. Toxicity mainly involved an asymptomatic elevation of transaminases and neutropenia. Estimated 1- and 2-year survival rates were 39.4% and 15.8%. Median overall survival was 8.25 months. Discussion. This retrospective analysis confirms that ET-743 induces objective responses and progression arrest in a clinically relevant proportion of patients.

DNA repair functionality modulates the clinical outcome of patients with advanced sarcoma treated with trabectedin (ET-743)

9522

Background and Methods: The sensitivity to trabectedin (Yondelis, ET-743) in experimental cancer models correlates with functional transcription-coupled nucleotide excision repair (TC-NER) and with deficient homologous recombination repair (HRR) activity. In order to assess the clinical relevance of this observation we have characterized the mRNA expression levels of ERCC1, XPD, BRCA1 and BRCA2 by RT-PCR in historical tumor samples from 92 sarcoma patients (pts) treated with the agent. Results: The overall objective response (CR+PR) rate to Yondelis in this group was 9%, which confirms the previous clinical experience with the compound in unselected, pre-treated patients with sarcoma. The Kaplan-Meier estimates for progression-free survival at 6 months (PFS6) was 23% and for median survival 8 months (mo). 26% of pts were alive at 24 mo. Correlative Study: Pts with high expression levels (> median) of ERCC1 had better PFS6 (32% vs 15%, p = 0.07) and better median survival (12 vs 7 mo) as compared to pts with low expression ( ≤ to median). Pts with low expression levels of BRCA1 had better PFS6 (33 vs 11%, p = 0.02) and superior median survival (15 vs 5 mo, p = 0.0003) than pts with high expression. Expression levels of XPD and BRCA2 (58 pts) had no significant impact on PFS and survival. The analysis of co-expression of ERCC1-BRCA1 identified a highly sensitive group of pts, characterized by high ERCC1 and low BRCA1 expression levels, with a PFS6 of 50% (p=0.0003) and median survival of 20.4 mo (p = 0.0005). A Cox regression analysis demonstrated that ERCC1 (HR=0.52, p = 0.02) and BRCA1 (HR=2.73, p = 0.0006) are independent variables for PFS, while BRCA1 (HR= 2.57, p = 0.0005) is also an independent variable for survival. Conclusion: This exploratory retrospective study supports the hypothesis that the sensitivity to Yondelis in pts with sarcoma correlates with a functional TC-NER and with deficient HRR. Prospective studies in sarcoma and other potentially sensitive tumor types are required to confirm and validate these findings.

[Table: see text]

Changing phenotype of gastrointestinal stromal tumours under imatinib mesylate treatment: a potential diagnostic pitfall

AIMS

The diagnosis of gastrointesinal stromal tumours (GISTs) is widely based on morphological features and KIT (CD117) immunoreactivity. Most patients with advanced GISTs show a major clinical response after treatment with imatinib mesylate. The histopathological features of GISTs in patients on prolonged imatinib treatment have, thus far, not been addressed in detail. In this report, we present three patients with metastatic GISTs, who received more than 1 year of therapy with imatinib, and whose tumours changed their morphological and immunohistochemical characteristics during continued treatment with the drug.

METHODS AND RESULTS

All three primary GISTs from these patients were classical spindle-type tumours, showing diffuse, strong CD117, CD34, and focal alpha-smooth muscle actin expression. During treatment, two clinically progressive and one clinically stable GIST revealed a diffuse epithelioid, or pseudopapillary epithelioid growth pattern, characterized by rounded cells with eosinophilic cytoplasm and uniform round-to-ovoid nuclei. In addition, GIST specimens from patients on therapy showed complete loss of CD117 immunoreactivity. Remarkably, two of these tumours also became CD34 immunonegative and in one case the progression was accompanied by desmin expression. KIT mutational analysis revealed the presence of distinct exon 11 mutant isoforms in all cases examined, while the same genotype was sustained in the base line and on-therapy tumour specimens, proving the common origin of analysed specimens.

CONCLUSIONS

GISTs subject to imatinib treatment can undergo striking (immuno)phenotypic changes, which are not necessarily corroborated by new genotypic modifications. Because these may mimic other tumour types, this feature creates a differential diagnostic challenge, of which the pathologist should be aware.

Real-time quantitative RT-PCR and detection of tumour cell dissemination in breast cancer patients: plasmid versus cell line dilutions

BACKGROUND

We previously developed a real-time quantitative RT-PCR technique to detect breast carcinoma cells in peripheral blood (PB). The aim of the current study was to improve cytokeratin 19 (CK19) quantification using plasmid dilutions of cloned PCR fragments to obtain a more reliable and reproducible quantification of CK19 transcripts.

MATERIALS AND METHODS

PB samples of 14 stage IV breast cancer patients and 23 healthy controls were examined with RT-PCR using plasmid quantification.

RESULTS

Median CK19+ copy numbers of one and 11 were detected in the control group and stage IV breast cancer patients, respectively (Mann-Whitney, P </=0.0001). When comparing the results obtained using cell line dilutions with those obtained using plasmid dilutions, a good correlation was observed (r(2) = 0.98).

CONCLUSIONS

Plasmid dilutions are more reliable than cell line dilutions for quantification of gene expression, and more objective criteria for positivity could be defined based on the characteristics of the standard curve (slope and intercept). A more universally accepted agreement on the definition of the cut-off value for positivity is needed.

The impact of drug administration sequence and pharmacokinetic interaction in a phase I study of the combination of docetaxel and gemcitabine in patients with advanced solid tumors

Our objective was to determine the maximum tolerated dose (MTD) of two administration sequences of docetaxel and gemcitabine in cancer patients, and to describe the pharmacokinetics of both drugs. Patients were treated in a 4-weekly schedule at two dose levels: gemcitabine 800 mg/m2 on days 1, 8 and 15, and docetaxel 85 or 100 mg/m2 on day 15 (levels I and II). The protocol was amended to a 3-weekly schedule, testing gemcitabine 800 or 1000 mg/m2 on days 1 and 8, with docetaxel 85 mg/m2 on day 8 given initially (dose levels IIIa and IV). At the recommended dose, an extra cohort of patients initially received gemcitabine (dose level IIIb). Eleven patients were treated with the 4-week schedule; 29% of cycles were delayed predominantly because of hematological toxicity. Four patients developed dose-limiting toxicities (DLTs), predominantly hematological. In the 3-week schedule, 14 patients were treated. At level IV, three of four patients developed DLTs, defining the MTD. With the reverse sequence, three patients received a total of 10 cycles. Overall, nine partial remissions were observed. We conclude the recommended dose for phase II studies is gemcitabine 800 mg/m2 on days 1 and 8, combined with docetaxel 85 mg/m2 on day 8, on a 3-weekly schedule. Gemcitabine distribution is significantly altered upon docetaxel administration.

Phase II study of vincristine, bleomycin, mitomycin C and cisplatin (VBMP) in disseminated squamous cell carcinoma of the uterine cervix

The objective of this study was to study the antitumor activity of the vincristine, bleomycin, mitomycin C and cisplatin (VBMP) scheme in patients with disseminated squamous cell carcinoma of the uterine cervix and to document its toxicity. VBMP consisted of vincristine 1.4 mg/m2 (max. 2 mg) i.v. day 1, bleomycin 15 mg/day by continuous i.v. infusion on day 1 + 2, mitomycin C 6 mg/m2 i.v. day 3 and cisplatin 50 mg/m2 i.v. day 4, and was given every 4 weeks. Bleomycin was withdrawn from the schedule after a cumulative dose of 300 mg (210 mg in patients over 60). Thereafter VMP continued (V + M day 1, P day 2) with the same interval. A median number of 4.5 (range 2-13) treatment cycles was given to 50 fully evaluable patients, 26 with only distant metastases (group A) and 24 with pelvic disease also (23 previously irradiated) (group B). All patients were < 70 years old, had a Karnofsky index >/=60, and measurable metastatic lesions outside previously irradiated areas. They all had normal organ functions and gave informed consent. Response in group A was 54% (31% complete), in group B 25% (all partial), 40% in all. Median time to progression in group A was 20 weeks and in group B 15 weeks; median survival was 42 weeks in group A, 32 weeks in group B, 37 weeks for all patients. Hematologic toxicity was cumulative and the majority of patients needed blood transfusions. Nonhematologic toxicity was acceptable, but in one patient pulmonary toxicity might have contributed to death. Although it is active, it is unclear whether this regimen is superior to cisplatin alone.

Hodgkin's disease in a patient with Von Hippel-Lindau disease. A case report

Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited disorder with a predisposition to develop a wide variety of lesions: retinal, cerebellar, spinal and medullar hemangioblastomas, renal cell carcinomas, phaeochromocytomas, and renal, pancreatic and epididymal cysts are the most frequent manifestations of the disease. The prevalence of VHL disease has been estimated to be 1 per 36,000 persons. We report the case of a 68-year-old woman with Von Hipple-Lindau disease who developed high fever with pulmonary and hepatic lesions proven to be Hodgkin's disease on biopsy. To our knowledge, this is the first report of Hodgkin's disease in a patient with Von Hippel-Lindau.

Pharmacokinetics of ifosfamide are changed by combination with docetaxel: results of a phase I pharmacologic study

The pharmacokinetics of the combination of docetaxel and ifosfamide were studied in a phase I study. Docetaxel was given to cancer patients as a 1-hour infusion followed by a 24-hour infusion of ifosfamide (schedule A). After the dose-limiting toxicity of the combination was reached, ifosfamide was administered as a 24-hour infusion followed after 24 hours by a 1-hour infusion of docetaxel (schedule B). Cycle duration was 21 days. Docetaxel was determined by high-performance liquid chromatography, and ifosfamide and its metabolites, by gas chromatography-mass spectrometry. Twenty-seven patients were treated according to schedule A, and 6 according to schedule B. Combining the two drugs did not change their respective plasma half-lives. The sequence of drug administration did not affect the clearance and the area under the curve (AUC) of docetaxel. There was a decrease in the AUC of ifosfamide in schedule A compared with schedule B, resulting from an increase in the clearance of ifosfamide. The pharmacokinetics of docetaxel are not influenced by combination with ifosfamide, regardless of the drug sequence, but ifosfamide pharmacokinetics are changed by docetaxel, depending on the sequence of administration. The increase of clearance in schedule A may be due to the pretreatment with corticosteroids.

Quality control in multicentric clinical trials. An experience of the EORTC Gynecological Cancer Cooperative Group

Data Quality is a central requirement of scientific research and external monitoring is essential in multicentric clinical trials (MCT). A quality control (QC) study was conducted in the main Institutions participating in EORTC-GCCG Protocol number 55863 - randomised phase III trial of vindesine, cisplatin, bleomycin and mitomycin-C (BEMP) versus cisplatin (P) in disseminated squamous cell carcinoma of the uterine cervix - in order to assess the impact of variations in data quality on the conclusions of the trial. The reliability of the different centres in following the protocol was investigated by a questionnaire covering drug prescription, local facilities and the procedure for preparation and administration of chemotherapy. The 'treatment protocol adherence' was evaluated by recalculation of the ideal protocol dose and its comparison with the actual delivered dosage at each cycle of chemotherapy. 'Data quality control' was assessed by comparison of data on case report forms (CRFs) with the corresponding items in the medical records. Eleven centres participating in the trial were visited by the same team of reviewers. Striking differences were noted in the chemotherapy administration procedures and between the type and quality of hospital files. Overall, there was an acceptable level of data quality and protocol compliance. Data accuracy was 81.8% (range: 65. 6-97%) of the 4424 items checked. Incorrect data were found in 7.0% (2.3-14.5%), data were missing on the form in 3.6% of cases (0-12%) and data was on the form but not in the file in 7.6% of cases (0. 7-17.5%). Causes of inaccuracy were analysed. Both problems in data management but also in a lack of clarity of the protocol and/or CRFs were to blame. Training and supervision of data managers, precision in writing protocols, standardisation of some aspects of CRFs and the use of a checklist for chemotherapy data and treatment toxicities would have avoided many of these errors. The need for QC in all collaborative groups performing MCT is emphasised. A literature review on QC in MCT dealing with chemotherapy is included.

KW-2149-induced pulmonary toxicity is not prevented by corticosteroids: a phase I and pharmacokinetic study

KW-2149 is a new, semisynthetic, C-7-N-Substituted, mitomycin C analog showing antitumor activity both in vitro and in vivo, equal or superior to mitomycin C. In a phase I study, KW-2149 was administered as an i.v. bolus injection every 21 days and at a dose of 100 mg/m2 pulmonary toxicity was dose limiting. Animal studies have indicated since that KW-2149-induced pulmonary toxicity can be prevented by pretreatment with corticosteroids. This paper presents the results of a further phase I study of KW-2149 with corticosteroid pretreatment. Patients were treated with oral dexamethasone 8 mg every 12 h, starting 24 h before KW-2149 administration, for 5 days. KW-2149 was given as an i.v. bolus injection every 21 days. Seventeen patients were treated with a total of 48 courses. Six patients received 60 mg/m2 and 11 patients 75 mg/m2. Two courses were not evaluable for toxicity. Significant lung toxicity was observed in at least three patients treated with a dose of 75 mg/m2 KW-2149 and pulmonary toxicity was therefore considered the dose-limiting toxicity at 75 mg/m2. No other important side effects were noted. One partial response was observed in a patient with colorectal cancer. Pretreatment with dexamethasone failed to suppress KW-2149-induced lung toxicity.

Soft tissue sarcoma in adults

Soft tissue sarcomas are a heterogeneous group of tumors, consisting of numerous histiotypes that all share a putative common mesenchymal origin. Although prognosis of these tumors is determined by clinical parameters (size, location, and resection margin status) and pathologic features (mitotic activity and necrosis), the histologic subtype has never been shown to be a consistent independent prognostic factor. Some relevant differences among these histiotypes are emerging, in specific biological parameters such as proliferation indices, in integrin expression profiles, and with regard to drug sensitivity. Several biological factors are considered to be prognostically important. Most attention is directed to regulators of cell-cycle progression. The significance of p53 dysregulation is confirmed by the inhibition of cellular proliferation, both in in-vitro and in in-vivo sarcoma models, after reintroduction of wild type p53. A multidisciplinary approach is essential for the optimal treatment of soft tissue sarcomas. Multimodality treatment has led to a patient-tailored approach with limb-sparing resections integrated with external and/or interstitial irradiation. The value of chemotherapy both in the neoadjuvant and the adjuvant setting, although of critical value in other sarcomas such as Ewing's sarcoma and osteosarcoma, remains to be established for soft tissue sarcomas.

Pharmacokinetics and bioavailability of oral 5'-deoxy-5-fluorouridine in cancer patients

AIMS

Oral administration of 5-fluorouracil (FUra), an important cytotoxic agent, is limited by a wide variation in bioavailability. 5'-deoxy-5-fluorouridine (dFUrd), a masked form of FUra, has shown promise clinically when given intravenously or orally as a solution or tablet. This study investigates the efficacy of an oral capsule formulation of dFUrd in generating continuous systemic levels of this compound in cancer patients.

METHODS

Six patients with advanced intestinal or ovarian malignancies were given three cycles of dFUrd, days 1-5, at intervals of 4 weeks. The doses of dFUrd were 600 mg m-2 three times daily, 800 mg m-2 three times daily, and 1000 mg m-2 three times daily, on cycles one, two and three, respectively (total dose 36 g m-2 ). The initial dose in each cycle was given as a slow intravenous injection over 10 min, and the remainder orally. Plasma and urine levels of dFUrd and two of its metabolites, FUra and 5,6-dihydro-5-fluorouracil (FUraH2 ), were monitored in six patients at each dose level.

RESULTS

All six patients completed the study, receiving three different doses over a 3 month period, following which one had achieved a partial response, one had stable disease, and four had developed progressive disease. Side-effects were negligible, and only two instances of transient diarrhoea WHO grade 1 were seen. Total body clearance (CLtot) of intravenous dFUrd decreased with increasing dose; 2.7, 2.0 and 1.3 l min-1 m-2, following doses of 600, 800 and 1000 mg m-2, respectively. The mean elimination half-life of intravenous dFUrd increased with the dose from 15 to 22 min. Oral dFUrd was rapidly absorbed with a lag time of less than 20 min. The mean elimination half-life (t1/2, z ) of oral dFUrd was 32-45 min in the dose range 600-1000 mg m-2. The AUC of FUra and FUraH2 increased overproportionally with increasing intravenous doses of dFUrd. The mean systemic bioavailability of oral dFUrd was 34-47%.

CONCLUSIONS

dFUrd, which selectively releases the antimetabolite FUra in tumour cells, can be given orally at doses of 600-1000 mg m-2 three times daily for 5 days. The systemic levels achieved are equivalent to those seen following continuous infusions of dFUrd or FUra. Toxicity is tolerable, and further clinical investigation of oral dFUrd is warranted.

Role of red blood cells in pharmacokinetics of chemotherapeutic agents

After oral or parenteral administration of chemotherapeutic agents, these drugs are transported to the tissues by the blood in different fractions: plasma water, plasma proteins or cells. In this review, the role of the red blood cell in storage, transport and metabolism of different anti-cancer drugs is described.

[Interactions of carboplatin, cisplatin, and ionizing radiation on a human cell line of ovarian cancer]

AIM OF THE STUDY

Cisplatin (CDDP) and radiotherapy are frequently used concomitantly in the treatment of various malignant conditions. Because of its toxicity, cisplatin tends to be replaced by carboplatin (CBDCA) in several indications. Available data regarding the combined effects of cisplatin and carboplatin with ionising radiation are contradictory.

MATERIALS AND METHODS

Various concentrations of cisplatin and carboplatin and various timing of association with radiation have been tested in vitro in a human ovarian cancer cell line. The parental cell line (AOvC-0) and a cisplatin-resistant stable subline (AOvC-CDDP/0) (De Pooter et al., Canc Res, 1991) were exposed to carboplatin (2.5, 5 and 10 M) and to CDDP (1, 2.5 and 5 M), 16 h and 4 h before and 4 h and 16 h after irradiation, respectively. Cell survival was evaluated by a classical clonogenic assay.

RESULTS

Exposure of AOvC-0 to 5 M CBDCA and of AOvC-CDDP/0 to 10 M CBDCA, before or shortly after radiation exposure, increased cell lethality in a clear supra-additive way, with the highest DEF in the shoulder region of the survival curve and at radiation doses relevant to clinical radiotherapy. In the sensitive cell line, 5 M carboplatin resulted in an additional lethality equivalent to 4.5 Gy; in the resistant cells, 10 M carboplatin was equivalent to 3.6 Gy. Replacing carboplatin by cisplatin in an identical set-up demonstrated exclusively simple additivity (DEF = 1).

CONCLUSION

These data suggest that carboplatin and cisplatin delivered at equitoxic doses interact with radiation in a different way and that, in the present set-up, only carboplatin enhanced the effects of radiation. Carboplatin might consequently be a better candidate than cisplatin in some concomitant combinations with radiotherapy.

A Phase I study of capecitabine in combination with oral leucovorin in patients with intractable solid tumors

Capecitabine (Xeloda) is a novel rationally designed fluoropyrimidine carbamate. It passes through the intestinal mucosal membrane intact and is subsequently activated by a cascade of three enzymes resulting in preferential release of 5-fluorouracil (5-FU) at the tumor site. Preclinical studies indicated an enhancement of the therapeutic index when capecitabine was combined with leucovorin. This Phase I trial was designed to determine the safety profile, maximal tolerated dose, and pharmacokinetic profile of the combination of capecitabine plus a fixed dose of p.o. leucovorin (60 mg/day) during administration to patients with refractory advanced cancers. The intention was to administer both drugs continuously, but the starting dose of capecitabine was also the maximum tolerated dose (1004 mg/m2/day) in six patients treated with this regimen. A cycle of treatment was then redefined as leucovorin and capecitabine given p.o., twice daily for 2 consecutive weeks followed by a 1-week rest period. Capecitabine doses from 1004 mg/m2/day to 2510 mg/m2/day were evaluated with the intermittent schedule over approximately 80 courses in an additional 25 patients. The dose-limiting toxicities that defined the maximum tolerated dose at 2000 mg/m2/day were diarrhea, nausea, vomiting, and palmar plantar erythrodysesthesia. The recommended Phase II dose using this schedule was 1650 mg/m2/day of capecitabine plus leucovorin 60 mg/day. Plasma concentrations of capecitabine, intermediate metabolites, and 5-FU were measured in 26 patients on days 1 and 14 of therapy. The pharmacokinetics of capecitabine were characterized by rapid GI absorption, with Cmax at 1 h, followed by conversion to active drug. The coadministration of leucovorin had no effect on the pharmacokinetics of capecitabine. Two patients with colorectal cancer, both previously treated with 5-FU, had partial responses. Phase II studies have confirmed the promising antitumor activity of this drug, and capecitabine is currently in Phase III evaluation.

Late relapse of a non-seminomatous germ cell tumour from residual mature teratoma

A patient with a late relapse of non-seminomatous germ cell tumour in a localisation of residual mature teratoma in the lung is reported. The mechanisms for late relapse and the therapeutic options, as reported in the literature, are discussed.

Activated oxazaphosphorines are transported predominantly by erythrocytes

PURPOSE

Oxazaphosphorines are metabolised by a variety of pathways, one of which leads to activation and the formation of alkylating compounds. However, the transport forms conveying activated oxazaphosphorines to the tumour cell have not been fully characterised. There is increasing recognition of the importance of the erythrocyte as a carrier of compounds in the circulation, and we have recently described higher concentrations of 4-hydroxycyclophosphamide within the erythrocyte compartment compared to plasma. We have now determined the concentrations of ifosfamide and seven of its metabolites in the plasma and erythrocytes of patients receiving a six-hour intravenous infusion of ifosfamide.

PATIENTS AND METHODS

Red cells from five patients, receiving a total of eight cycles of ifosfamide, were separated from plasma using the MESED instrument, and analysis of red cells and plasma performed using Gas Chromatography-Mass Spectrometry (GC/MS).

RESULTS

The concentration of all compounds in the erythrocyte compartment was higher than or equal to those in plasma, and isophosphoramide mustard and carboxyifosfamide showed a particular affinity for the erythrocyte. The red cell fraction can contain as much as 77% of the total blood concentration of isophosphoramide mustard.

CONCLUSIONS

Erythrocyte associated isophosphoramide mustard is an important transport form of activated ifosfamide. Red cells may have a role in the delivery of activated oxazaphosphorines to tissues.

In vitro toxicity studies with mitomycins and bleomycin on endothelial cells

Pulmonary side effects are increasingly observed as dose-limiting toxicity (DLT) of cancer treatment. The available preclinical models have a limited predictive value for lung toxicity in humans. We have attempted to elucidate potential mechanisms involved in these reactions, by studying the effects on cells, possibly involved in these reactions after in vitro exposure to drugs with known lung toxic effects. We have investigated the effects of bleomycin (BLM), mitomycin C (MMC), KW-2149 and its two known metabolites, M16 and M18, on oxygen radical production by granulocytes, on cytokine production: interleukin (IL)-6, transforming growth factor (TGF)-beta, tumor necrosis factor (TNF)-alpha by a human macrophage cell line (THP-1), by human endothelial cells (HVEC and HMEC) and a human colorectal cancer cell line (DLD-1), and on the cytotoxicity on endothelial cells in both confluent and non-confluent culture. The generation of oxygen radicals by normal and pre-stimulated granulocytes was not increased after preincubation with any of the drugs, at the concentrations tested. None of the cytokines (IL-6, TNF-alpha or TGF-beta) was found significantly increased in culture medium after exposure to any of the mitomycins. This was in contrast with the effect of BLM incubation, causing a rise in TGF-beta concentration. Both types of endothelial cells showed a dose-dependent, exposure duration-dependent, proliferation inhibition for all agents tested. This inhibitory effect was clearly proliferation dependent as shown by the increased inhibition in semi-confluent as opposed to confluent endothelial cell cultures. Both mitomycins tested were more cytotoxic than BLM to both confluent and proliferating endothelial cells.

Soft tissue sarcoma in adults

The importance of a multidisciplinary group in the treatment of soft tissue sarcomas is well established. This approach has led to a major shift in treatment from a single-modality radical surgery to a more sophisticated approach with limb-sparing resections integrated with external irradiation, interstitial irradiation, or both. The increasing knowledge of both the molecular mechanisms of sarcoma development and the biological characteristics (tumor cell proliferation, hypoxia, necrosis, angio-genesis) will enable us to predict prognosis on a more individual basis and thus allow for more selective treatment strategies. Studies relating these molecular markers and biological characteristics to treatment results obtained with surgery, radiotherapy, and chemotherapy are eagerly awaited.

Evaluation of tumour angiogenesis as a prognostic marker in malignant mesothelioma

Angiogenesis plays an important role in the growth, progression, and metastasis of solid tumours. Malignant mesothelioma (MM) of the pleura is a highly invasive tumour with a poor prognosis. In the present study, microvascular quantification was undertaken on 25 specimens of mesothelioma and 15 specimens of non-neoplastic mesothelium (NNM), by staining for the antigens CD34 and CD31. Areas of highest intratumoural microvascular density (IMD) were identified and counted either manually (mIMD) or on a computerized image analysis system (CIAS; iIMD). The two IMDs were significantly correlated with each other (r = 0.736; P < 0.001). The average IMD for MM was significantly (P < 0.001) higher than in NNM. Moreover, each unit increment in iIMD for MM, when regarded as a continuous variable, was significantly (P = 0.001) associated with an increased hazard of about 4 per cent. When regarded as a categorical variable, the patients in the highest tertile (> 58 vessels/field) had a significantly (P < 0.01; log-rank test) shorter survival than patients in the lowest tertile (< 45 vessels/field). This association was independent of the age of the patient and of the histological type or grade of the MM. No association was noted with p53 immunoexpression. Although the mean vascular area of blood vessels measured on the CIAS did not correlate with survival, assessment of IMDs can be an important independent prognostic indicator in malignant mesothelioma.

Comparison of daunorubicin and Fluo-3 for detection of multidrug resistance in human tumor cells

The detection of multidrug resistance (MDR) in clinical samples is still a topic for discussion. One method, proven extremely useful for detection of membrane proteins in patients with hematological malignancies is the flow cytometrical analysis of individual tumor cells. Recently an assay was described based on the labeling of the P-glycoprotein (P-gp) with the monoclonal antibody MRK16, combined with detection of active daunorubicin (DNR) extrusion. In order to improve the specificity of the assay, on line with the results obtained by Wall et al., we exploited staining with Fluo-3. Both assays prove to be able to discriminate between drug-resistant and drug-sensitive cells. A major drawback of labeling with Fluo-3 in combination with the monoclonal antibody MRK16 is the important overlap of emission spectra of both fluorochromes. Moreover, using Fluo-3 for the detection of MDR might be complicated by the fact that differences in fluorescence intensities are not solely dependent on the presence of P-gp, but also on the activity of cytosolic esterases and the intracellular calcium concentration. Combination of the detection of structural and functional aspects of the MDR-associated protein may lead to a more precise detection of the MDR-positive patient.

Phase IB study of doxorubicin in combination with the multidrug resistance reversing agent S9788 in advanced colorectal and renal cell cancer

S9788 is a new triazineaminopiperidine derivate capable of reversing multidrug resistance (MDR) in cells resistant to chemotherapeutic agents such as doxorubicin. It does not belong to a known class of MDR revertants, but its action involves the binding of P-glycoprotein. Thirty-eight evaluable patients with advanced colorectal or renal cell cancer were treated with doxorubicin alone (16 patients) followed after disease progression with combination treatment of doxorubicin plus S9788 (12 patients) or upfront with the combination of doxorubicin plus S9788 (22 patients). S9788 was given i.v. as a loading dose of 56 mg m-2 over 30 min followed by doxorubicin given at 50 mg m-2 as a bolus infusion. Thereafter, a 2-h infusion of S9788 was administered at escalating doses ranging from 24 to 120 mg m-2 in subsequent cohorts of 4-10 patients. Pharmacokinetic analysis demonstrated that concentrations of S9788 that are known to reverse MDR in vitro were achieved in patients at non-toxic doses. Compared with treatment with doxorubicin alone, treatment with the combination of doxorubicin and S9788 produced a significant increase in the occurrence of WHO grade 3-4 granulocytopenia. Treatment with S9788 was cardiotoxic as it caused a dose-dependent and reversible increase in corrected QT intervals as well as clinically non-significant arrhythmias on 24- or 48-h Holter recordings. Although clinically relevant cardiac toxicities did not occur, the study was terminated as higher doses of S9788 may increase the risk of severe cardiac arrhythmias. Twenty-nine patients treated with S9788 plus doxorubicin were evaluable for response, and one patient, who progressed after treatment with doxorubicin alone, achieved a partial response. We conclude that S9788 administered at the doses and schedule used in this study results in relevant plasma concentrations in humans and can safely be administered in combination with doxorubicin.

Elevated levels of the angiogenic cytokines basic fibroblast growth factor and vascular endothelial growth factor in sera of cancer patients

The concentration of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) was determined in the serum of 90 untreated and 42 treated metastatic cancer patients, including patients with colorectal, breast, ovarian and renal carcinomas, with an enzyme-linked immunosorbent assay (ELISA). Levels higher than the 95th percentile of the concentrations of a control group, i.e. 7.5 pg ml(-1) for bFGF and 500 pg ml(-1) for VEGF, were identified as 'elevated'. One measurement during follow-up was included into the analysis per patient. For 19 treated patients, consecutive serum samples were analysed. Fifty-seven per cent of all untreated patients had elevated serum levels of one or both angiogenic factors. The fraction of patients with elevated serum levels of bFGF and/or VEGF was similar in the different tumour types. Agreement of bFGF levels and VEGF levels, classified in relation to their respective cut-off values, was present in 67% of all patients. Fifty-eight per cent of the patients with progressive disease during treatment compared with 15% of the patients showing response to treatment (chi-squared test P < 0.05) had elevated bFGF and/or VEGF serum levels. When consecutive serum samples were analysed, two-thirds of the patients showing progressive disease had increasing serum levels of the angiogenic factors compared with less than one-tenth of the patients showing response (chi-squared test P < 0.05). The lack of association between the serum bFGF and VEGF levels and the tumour type may suggest an aspecific host reaction responsible for solid tumour-related angiogenesis. The main determinants of the serum bFGF and VEGF concentration are the progression kinetics of the metastatic carcinomas.

Influence of investigator experience and microscopic field size on microvessel density in node-negative breast carcinoma

In this study on the determination of intratumoral microvessel density (MVD) in breast cancer, we have investigated the influence of the observer experience and the microscopic field size. We have used the sample set reported on earlier in the J Natl Cancer Inst 87: 1797-1798, 1995. This case-control study has shown a positive association of high MVD and unfavorable outcome when comparing node-negative pT1-2 breast carcinoma (NNBC) patients with a disease-free period of over ten years with those with an early distant relapse. Tumor sections of both outcome groups (favorable: n = 19; unfavorable: n = 19) were immunostained for factor VIII related-antigen (FVIII r-Ag). Microvessels were counted in the areas of most intense vascularization ('hot spots'), both at magnification x 200 (field size of 0.61 square mm) and x 400 (field size of 0.15 square mm), by one inexperienced and three experienced observers. Microphotographs of individual vascular hot spots were analyzed using overlays resembling the two field sizes. The main results obtained are: i) a confirmation of the prognostic value of microvessel density in the case-control sample set (n = 38) was established by all experienced but not by the unexperienced investigator; ii) both at x 200 and x 400 magnification, angiogenesis quantification in vascular hot spots contained prognostic information. The results of this study indicate that the selection of vascular hot spots in tumor sections immunostained for an antigen expressed on endothelial cells is more prone to inter-observer variability and more dependent on training than the counting of the microvessels within predefined hot spots itself. The microscopic magnification and resulting field size do not influence the prognostic significance of MVD in NNBC. This information validates the development of more objective methods of measuring the amount of angiogenesis within malignant tissue. This will allow more accurate implementation of the angiogenesis parameter in multiparametric and prospective prognostic factor studies in NNBC.

Serum basic fibroblast growth factor and vascular endothelial growth factor and tumour growth kinetics in advanced colorectal cancer

BACKGROUND

The development of new microvessels in the surrounding stroma is a prerequisite for tumour progression. Basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) are angiogenic factors expressed in a broad range of human tumours. We have measured the concentrations of both cytokines in the serum of patients with advanced colorectal cancer. We questioned whether these levels are related to the number of tumour sites, the volume of liver and/or lung involvement and the growth kinetics.

PATIENTS AND METHODS

44 untreated colorectal adenocarcinoma patients who had developed metastatic and/or recurrent disease were evaluated. Serum levels of bFGF and VEGF were repeatedly measured using ELISA. The extent of target organ involvement and the kinetics of tumour volume growth were determined on consecutive computer tomography (CT) images.

RESULTS

Patients with a tumour volume doubling time of less than 6 months showed a higher bFGF and VEGF serum level than others, independent of the number of sites involved and the extent of the metastatic disease.

CONCLUSIONS

The data suggest a predictive value of serum bFGF and VEGF levels for the progression of disease in patients with untreated metastatic colorectal cancer. The results corroborate the importance of angiogenesis in the process of tumour growth. The serum levels might prove a useful tool in the quantification of angiogenesis and might be of valuable information in the decision process of initiating palliative chemotherapy. It will be of considerable importance to investigate whether the serum bFGF and VEGF levels have a predictive value on the probability of response to cytotoxic therapy.

Deep cerebral invasion by basal cell carcinoma of the scalp

We report recurrent basal cell carcinoma of the scalp with deep cerebral invasion in an 82-year-old man. Plain films and CT showed extensive, full thickness, skull destruction at the vertex. Gadolinium-enhanced MRI revealed neoplastic invasion of the meninges and left cerebral hemisphere, down to the lateral ventricle. We postulate that tumour extended into the brain along perivascular spaces of transcerebral vessels. This hypothesis is supported by the cleft-like contrast enhancement on MRI.

The influence of hypoxia on the cytotoxicity of concomitant KW-2149 and ionizing irradiation in Chinese hamster fibroblasts

7-N-((2-((2-(gamma-L-glutamylamino)ethyl)dithio)ethyl))-mitomycin C (KW-2149) is a newly synthesized water-soluble mitomycin C (MMC) analog. Preclinical testing showed an interesting activity profile and a superior hematological tolerance in murine models. The aim of this study was to investigate the interaction of this compound with ionizing radiation, both under normoxic and hypoxic conditions, in Chinese hamster fibroblasts (V79). V79 cells were irradiated both under normoxic conditions and after a 1 h period of hypoxia. Paired irradiation dose-response curves confirmed the significance of radioresistance under hypoxia with an oxygen enhancement ratio of approximately 3. In contrast to MMC, KW-2149 showed no increased cytotoxic effect on hypoxic V79 cells. The cytotoxic effect of KW-2149 increased with increasing concentration, irrespective of the ambient oxygen pressure. When KW-2149 was combined with irradiation under hypoxic conditions, cytotoxicity was significantly enhanced under these conditions. The difference in survival between normoxic and hypoxic conditions was statistically significant (p < 0.004). These data suggest a radiosensitizing effect of KW-2149, more pronounced under hypoxic conditions. This effect increases with radiation dose. It also corroborates earlier suggestions of a different mode of action of KW-2149 as compared to MMC.

Correlation of the response to cisplatin of human ovarian cancer cell lines, originating from one tumor but with different sensitivity, with the recovery of DNA adducts

Cis-Diamminedichloroplatinum(II) (CDDP) is used in the treatment of various cancers, with or without ionizing radiation. During treatment, resistance may develop, and cross-resistance can also occur. DNA is the main target for CDDP and ionizing radiation, and we therefore evaluated the correlation between the amount of CDDP-DNA adducts and the cytotoxic activity of CDDP in human ovarian cancer cell lines with different platinum sensitivities. DNA-adduct levels were investigated 18 hr after CDDP exposure in three cell lines originating from the same human ovarian cancer. The least sensitive cells appeared to have the largest amounts of CDDP-DNA adducts, while the most sensitive had higher adduct levels than the parental cells. The proportion of the four adducts measured (i.e., Pt-G, Pt-AG, Pt-GG, and G-Pt-G) was comparable in all cell lines, with a preference for Pt-GG adduct formation (> 50% of the adducts). Intracellular CDDP concentrations were higher in sensitive than in resistant cells, in contrast to the degree of CDDP adduct formation. Data obtained following continuous exposure of CDDP-resistant cells to CDDP suggest that DNA repair is partly responsible for resistance to CDDP. We conclude that the amount of CDDP-DNA adduct formation in cancer cells is not a predictor of CDDP cytotoxicity.

Correlation of intratumoral microvessel density and p53 protein overexpression in human colorectal adenocarcinoma

A malignant cell population needs the development of microvessels in order to grow and metastasize. Recently, a role for the p53 gene in the regulation of this angiogenic process has been suggested. Wild-type p53 is involved in the secretion of Trombospondin-1 (TSP-1), an angiogenesis inhibitor. Mutations of the p53 gene cause a downregulation of TSP-1 mRNA in cell lines. Mutant p53 also upregulates the expression of vascular endothelial cell growth factor, a potent angiogenic factor. Together with the reported association of p53 protein overexpression and microvessel density (MVD) in head-and-neck squamous-cell carcinoma, these in vitro findings led us to investigate whether this association would also apply in colorectal adenocarcinomas. Structural changes of the p53 gene are the most frequent observed mutations in colorectal carcinoma and are suspected to be involved in the carcinogenesis at a relatively early stage. Parallel tissue sections from primary colorectal adenocarcinomas were immunostained for CD31, an endothelial cell marker, and with DO7, recognizing both mutant and wild-type p53 protein overexpression. The presence of p53 protein overexpression was found to be significantly associated with high MVD in the vascular hot spots. Our results are in accordance with the in vitro studies on the involvement of p53 in angiogenesis. Mutant p53 might stimulate tumor angiogenesis both indirectly, by augmenting the tumor cell proliferation, and directly, by upregulating angiogenic factors and downregulating angiogenic inhibitors.

Partitioning of ifosfamide and its metabolites between red blood cells and plasma

A recently developed GC-MS analytical method for the quantitative determination of oxazaphosphorines and their metabolites in blood plasma, using stable trifluoroacetyl derivatives and electron capture negative chemical ionization detection, was applied to measure the partitioning of the antitumor drug ifosfamide and its metabolites between plasma and red blood cells for four cancer patients. The separation of a constant volume of red blood cells was performed using a special instrument, MESED, through centrifugation of blood samples. The measured compounds were ifosfamide, 2- and 3-dechloroethylifosfamide, 4-ketoifosfamide, carboxyifosfamide, ifosfamide mustard, 2-chloroethylamine and 1,3-oxazolidin-2-one. Concentration-time profiles for the metabolites in the two blood fractions and partitioning factors between erythrocytes and plasma were obtained. For ifosfamide itself, and metabolites with an intact ring system, a partitioning factor between 1 and 2 was observed for the concentration ratio between red blood cells and plasma in the patients studied. However, for the compounds with an open structure, carboxyifosfamide and ifosfamide mustard, partitioning factors higher than 3 were obtained. The active antitumor metabolite ifosfamide mustard showed a strong preference for the red blood cells in the measured patient samples. This means that erythrocytes may play an important role in the transport and the subsequent release of the active alkylating agent to the tumor cells.

Long-term results of continuous treatment with recombinant interferon-alpha in patients with metastatic carcinoid tumors--an antiangiogenic effect?

This study investigated the efficacy of long-term continuous and dose-escalated interferon-alpha (IFN) treatment in patients with progressive carcinoid tumors. In this single-institution, phase II study 16 chemotherapy-naive, eligible patients were entered. Interferon treatment consisted on 5 MIU IFN three times weekly s.c. until radiologic progression. In case of progression the dose was increased to 10 MIU. Radiologic and biochemical evaluation was done monthly and thereafter 3 monthly. We have treated 16 patients of whom 15 are evaluable for tumor response. Calculated by standard response criteria, three patients experienced a partial response. Another three had an important minor response. Median response duration was 24 months (range 18-51 months). Biochemical responses were observed in nine out of 12 patients with an elevated 5-hydroxyindoleacetic acid excretion. The serum neuron-specific enolase proved a reliable marker for both response and progression. In the one patient progressive after 3 months, a dose increment to 10 MIU was without effect. In patients initially not progressing or responding to 5 MIU, escalation to 10 MIU had a short lasting beneficial effect in three cases. The radiological characteristics and the kinetics of these responses are compatible with an anti-angiogenic effect of IFN. This study of IFN in carcinoid tumors confirms the activity in this disease. Our results demonstrate the necessity of initiating treatment only in radiologically progressive patients and continuing this treatment until progression. We feel that currently the activity of IFN in metastatic carcinoid tumors compares favorably with that of systemic chemotherapy in patients with progressive disease.

Sternal resection for primary presternal and retrosternal mediastinal liposarcoma

In a 34-year-old patient, sternal resection was necessary for complete removal of a primary mediastinal myxoid liposarcoma grade I, which had grown around the right sternal border. Reconstruction was by the methylmethacrylate sandwich technique. Five months postoperatively part of the device had to be removed due to persistent inflammation. Two years after the initial operation there is no evidence of local recurrence or distant metastases.

[In vitro effects of piracetam on the radiosensitivity of hypoxic cells (adaptation of MTT assay to hypoxic conditions)]

This paper describes the adaptation of the MTT assay to hypoxic conditions in order to test the in vitro effect of piracetam on hypoxic cells and particularly on the radiosensitivity of hypoxic cells since this drug has shown clinical effect on acute and chronic hypoxia. The V79 cell line was selected by reference to preliminary hypoxic experiments using clonogenic assay and euoxic experiments using clonogenic and MTT assays. Cell growth and survival in our hypoxic conditions were assessed using MTT assay with an enclosure and special 48-well plates both made of glass. Growth curves on glass versus reference polystyrene plates were comparable and confirm the validity of using special glass plates. Growth curves on glass plates after 1-hour exposure to nitrogen versus air were comparable, so there is no bias effect due to gas composition. Survival curves using MTT versus reference clonogenic assay were comparable after radiation exposure in eu- and hypoxic conditions, and confirm the validity of our original technique for creating hypoxia. The Oxygen Enhancement Ratio was of about 3 for 1-hour hypoxic exposure. Piracetam gave no cytotoxic effect up to 10 mM of piracetam. Growth curves after continuous drug exposure and 1-hour euoxic versus hypoxic exposure gave no cytotoxic effect up to 10 mM of piracetam. Survival curves after continuous drug exposure to 10 mM of piracetam gave no significant effect on the radiosensitivity of hypoxic V79 cells using MTT or clonogenic assay. However, this does not preclude a potential in vivo effect of piracetam on the radiosensitivity owing to its action on microcirculation and its rheologic properties. The adaptation of the MTT assay to hypoxic irradiation conditions yields the easy screening of radiosensitizing drugs: shorter incubation, semi-automatic method and simultaneous analysis with different serial concentrations thanks to the special 48-well glass plates.

Diagnosis and treatment of soft tissue sarcomas in adults

The optimal treatment of soft tissue sarcoma remains a challenge for the multidisciplinary approach in modern oncology. Only when a team of experienced clinicians, oncologists, radiotherapists, and oncologic orthopedic surgeons cooperates with the radiologist and the pathologist can optimal treatment be guaranteed. Recent advances in our knowledge of sarcomas have resulted from more detailed analysis of the cytogenetic and molecular changes in the different types of sarcoma. The prognostic significance of many biologic markers is still the subject of ongoing investigations, with sometimes conflicting results. The usefulness of adjuvant radiotherapy in the combined approach for optimal local control of both extremity and trunk sarcomas is confirmed in different studies. the discovery of antitumor activity of taxoids in this disease brings new chemotherapeutic combinations within reach.

Effects and systemic uptake of the new mitomycin C analogue KW-2149 in beagle dogs after intravesical administration

The present study was designed to evaluate the local effects of the new mitomycin C analogue KW-2149 after intravesical instillation, together with its penetration into the systemic circulation in healthy beagle dogs. Two reference dogs were treated with two instillations of mitomycin C (30 mg in 30 ml phosphate buffer). Four dogs were given two, three, four and six instillations, respectively, of KW-2149 (60 mg in 30 ml phosphate buffer). KW-2149 concentrations measured in the systemic circulation were very low and were frequently found to be below the limit of determination. The number of instillations had no influence on the KW-2149 concentrations measured in the systemic circulation. Blood analysis showed no systemic toxicity. The histopathological findings in the bladder were comparable in both groups. The number of instillations had no influence on the severity of the lesions found in the bladder wall. On the basis of its in vitro activity KW-2149 can be regarded as a promising agent for intravesical treatment of superficial bladder cancer.

Microvessel quantification in primary colorectal carcinoma: an immunohistochemical study

The vascularisation of human primary colorectal carcinomas was studied immunohistochemically using the endothelial cell markers CD31 and factor VIII-related antigen. Tumour sections were systematically scanned at a magnification of x 100 to find areas of intense neovascularisation. Microvessel counts within these vascular 'hotspots' were performed at magnification x 250. Regions in which tumour cords were surrounded by a collagen IV-positive basement membrane were compared with those in which this was absent and with normal mucosa. CD31 appeared to be a more sensitive marker for endothelial cells than factor VIII-related antigen (mean 185 +/- 59 and 120 +/- 38 microvessels mm-2). Within individual tumour sections microvessel counts in vascular hotspots with highest vessel density correlated significantly with microvessel counts in vascular hotspots with second highest vessel density (P < 0.01). Microvessel counts in tumour areas where collagen IV-positive basement membrane were absent exceeded those in areas where it was present (factor of 1.7) and those in normal mucosa (factor of 1.6). The differences in vessel density between individual tumours and the low variability in vessel density within individual tumours using this quantification technique allow us to investigate the prognostic value of vessel density in areas of intense neovascularisation in human primary colorectal carcinomas.

Cryptorchidism and extragonadal germ cell tumor

A patient with an extragonadal germ cell tumor and a history of bilateral cryptorchidism is reported. The rarity of this concurrence in a single patient is discussed. The necessity for thorough investigation of the cryptorchid testes in patients with metastatic germ cell cancer remains essential.

Microvessel density, endothelial cell proliferation and tumour cell proliferation in human colorectal adenocarcinomas

BACKGROUND

Thymidine incorporation studies performed in animal tumour models, revealed major differences in endothelial cell proliferation when tumour tissue was compared with normal tissue. The fraction of proliferating endothelial cells is reported to be increased by a factor of 30 to 40 in tumour tissue.

PATIENTS AND METHODS

To make it possible to analyze the endothelial cell proliferation in human tumours, an immunohistochemical double staining technique comprising CD31, an endothelial cell marker, and Ki-67, a proliferation marker, was developed. Endothelial cell proliferation was analysed in 21 primary human colorectal adenocarcinomas and in the adjacent mucosa.

RESULTS

Proliferating endothelial cells were found throughout the entire carcinoma. The mean overall endothelial cell labeling index (ECLI) was 9.9% (range, 5.4-18.0), and the labeling index of endothelial cells in areas of intense neovascularisation was even higher. Mean ECLI in the vascular hot spots was 21.0% (range, 6.8-35.0), and the mean tumour cell labeling index (TCLI) in the maximally Ki-67 immunostained areas was 78.3% (range 47.0-89.7). In 14 of 21 carcinomas, these areas were predominantly found at the luminal margin of the tumour, as were the vascular hot spots. A significant positive correlation was found between tumour vascularity, measured in the vascular hot spots, and tumour cell proliferation, measured in the maximally Ki-67 immunostained areas (p < 0.05). To analyse this relation in more detail, microvessel density (MVD), TCLI and ECLI were determined per x400 microscopic field by scanning in sequence from the luminal tumour margin to the invasive tumour base. In all tumours, the pattern of the MVD per x400 field, from the luminal margin to the tumour base, was similar to that of the TCLI and ECLI.

CONCLUSIONS

These findings confirm that the fraction of cycling endothelial cells is higher in human colorectal carcinoma than in the adjacent mucosa which suggests that endothelial cells are proliferating in most of the individual capillaries in tumour tissue. Regional differences in MVD correlate with differences in tumour cell proliferation in these tumours.

Diagnosis and treatment of soft tissue sarcomas in adults

Our knowledge of the molecular biology of sarcomas has progressed considerably over the past year, with major emphasis on the role of p53 and MDM2 gene mutations. Further studies on drug resistance mechanisms and the role of MDR1 expression in sarcomas have been reported. The investigations using different imaging techniques as ways of predicting tumor necrosis more accurately than our current response measurements after therapy have led to promising results. The many clinical phase II studies with new drugs led to the identification of taxotere as a new active agent against soft tissue sarcomas. Similar impressive results, such as those obtained with isolated limb perfusion in melanoma, have been reported in limb sarcomas with an identical regimen. The activity of ifosfamide in pretreated patients, administered at an increased dose, is suggestive of dose dependency. The improved results in phase II studies of dose-intensive chemotherapy with the support of colony-stimulating factors are encouraging and these regimens are now being investigated in the adjuvant setting.