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Cisplatin is a potent DNA-damaging agent that has demonstrated anticancer activities against several tumors. However, manifestation of cellular resistance is a major obstacle in anticancer therapy that severely limits the curative potential of cisplatin. Therefore, understanding the molecular basis of cisplatin resistance could significantly improve the clinical efficacy of this anticancer agent. Here, we employed Saccharomyces cerevisiae as a model organism to study cisplatin resistance mechanisms and describe a one-step cisplatin selection to identify and characterize novel cisplatin resistance genes. Screening a multicopy yeast genomic library enabled us to isolate several yeast clones for which we could confirm that the cisplatin resistance phenotype was linked to the introduced fragment. In a first attempt, a number of open reading frames could be identified. Among these genes, PDE2 and ZDS2 were repeatedly identified as genes whose overexpression confers cellular resistance to cisplatin. PDE2, encoding cAMP-phosphodiesterase 2, is of particular interest because the overexpression of this yeast gene is known to induce cisplatin resistance in mammalian cells as well, providing proof of the principle of our experimental approach. In addition, the identification of PDE2 shows that our yeast screening system can directly be informative for drug resistance in mammalian cells.

A sensitive reversed-phase high-performance liquid chromatographic fluorescence method is described for the simultaneous determination of topotecan (I) and the hydrolysed lactone ring-opened product hydroxy acid (II) in plasma and for the determination of I in urine. To 250 microliters of plasma, a 750-microliters volume of cold methanol was added to stabilize the pH-dependent conversion of I into II. In plasma, the lower limit of quantitation (LLQ) for both compounds was 0.10 ng/ml. The between-day variation for I at the LLQ was 7.1% and for II was 5.5%. Prior to injection, urine samples were acidified with orthophosphoric acid and diluted with phosphate-buffered saline (PBS). In urine, the calibration curve for I was linear in the range of 10 to 250 ng/ml and the LLQ was 10 ng/ml. The assay was developed to enable pharmacological analysis of I, in on-going phase I and II studies, in patients with solid tumors.

Docetaxel is a new semi-synthetic taxoid, which acts as an antimicrotubule agent and is now clinically available. Clinical studies of docetaxel as a single agent and in combination with other cytotoxic drugs reveals favourable response rates in a number of solid tumor types. Docetaxel appears to have great potential in advanced breast cancer as first or secondline chemotherapy. The dose-limiting toxicity is an early and short-lasting neutropenia. Fluid retention is a cumbersome, sometimes disabling, side-effect. Other side-effects are usually mild and include alopecia, myalgia, mucostitis, neuropathy, hypersensitivity reaction, nail changes and cutaneous reactions.

Univariate and multivariate analyses were performed in 632 patients treated with cisplatin combination chemotherapy for metastatic non-seminomatous testicular germ cell tumours. Multivariately, the most important poor prognosis factors for the prediction of survival were: HCG greater-than-or-equal-to 10,000 IU/l, lung metastases greater-than-or-equal-to 10, abdominal metastases with a horizontal diameter of greater-than-or-equal-to 5 cm and the presence of supraclavicular metastases. If patients had 2 or more of these factors the death rates increased from 30% for patients with 2 factors to 65% for patients with 3 or 4 factors. The patients studied here are not a random sample of the metastatic testicular cancer patients in general, as the population studied comprised a large proportion of low volume metastatic disease patients. Therefore, the final analysis will include patients from all the recently completed trials.

From 1979 to 1983 the EORTC GU Group treated 239 patients with disseminated non-seminomatous testicular cancer with combination chemotherapy comprising cisplatin, vinblastine and bleomycin in a prospectively controlled trial. The protocol required complete resection of residual masses after induction chemotherapy, provided that serum tumour markers were normal. 102 patients were operated on. 27 patients had mature teratoma (teratoma differentiated) in the resected specimens and 23 had viable cancer. Follow-up data were available for 26 and 22 of these patients, respectively. 23 of 26 patients (88%) with mature teratoma are alive and disease free after a follow-up of 53-110 months (median 92 months). 3 patients developed progressive disease; 1 died. A peculiar case of growing mature teratoma on the forearm is described. 13 of 22 patients (59%) with residual carcinoma are alive and disease free after a follow-up of 74-112 months (median 95 months). The prognosis of patients with carcinoma is shown to be correlated with the completeness of surgery, which in turn is correlated with the initial tumour mass before chemotherapy.

Three murine tumor lines, B16 melanoma, C38 colon cancer and M2661 breast cancer, were used to evaluate the therapeutic efficacy of the drug combination ACNU and ifosfamide. For each tumor type five treatment groups of 12 mice each were studied, which respectively received 16.5 mg/kg ACNU, 150 mg/kg ifosfamide, 33 mg/kg ACNU, 300 mg/kg ifosfamide or 16.5 mg/kg ACNU + 150 mg/kg ifosfamide. One group served as controls. Growth delay was measured as the endpoint. In the B16 and C38 tumor lines both drugs were active and showed additive antitumor effects. However, no synergism was observed. Neither ACNU or ifosfamide or the combination of both had any activity against the M2661 tumor line.

Summary We initiated a phase II study with combination chemotheraphy consisting of cisplatin, etoposide and bleomycin in a subset of patients with carcinomas of unknown primary site characterized by the presence of at least one of the following criteria: 1) age below 50 years; 2) clinical evidence of rapid tumor growth; 3) tumour located predominantly in a mid-line distribution; 4) good response to previous administered radiotheraphy. In 34 evaluable patients an objective response rate of 53% (95% confidence limits 35%–70%) was achieved. For patients with poorly differentiated adenocarcinomas the response rate was 35%, and, in most instances, of short duration. A response rate of 79% including complete responses and long-term survivals was achieved in patients with undifferentiated carcinomas. This difference in response rate was statistically significant (p = 0.02). No supplementary prognostic factors predicting response to chemotherapy could be identified. One patient with an initial diagnosis of undifferentiated carcinoma proved to have a malignant lymphoma after additional immunohistochemical investigation. Untila better characterization of this syndrome is possible patients with undifferentiated carcinomas of unknown primary site should be challenged with cisplatin-based chemotherapy.

Following a previous EORTC GU-Group study, in which linomide showed some activity in poor prognosis patients, this study was initiated to determine the effect of linomide in more favourable patients. 35 patients with metastatic renal cell carcinoma with good prognostic factors, i.e. good performance status, prior nephrectomy, no prior systemic therapy, and no liver, bone or brain metastases, were treated with linomide, a quinoline derivative with immunomodulating properties, at a dose of 10 mg daily, after an initial dose escalation during the first 4 weeks of treatment. In 29 evaluable patients, no responses were observed (95% confidence interval 0-10%). Best overall response was no change in 9 patients, for a median duration of 4 months. Linomide in this schedule was poorly tolerated, with 17% (6 patients) of patients being withdrawn and 23% (8 patients) having dose reductions due to adverse events, mostly influenza-like symptoms of myalgia, arthralgia and fatigue. Several cases of pericarditis and neuropathy were observed. In spite of selection of favourable prognosis patients and an optimal daily dosing schedule, linomide was not an effective treatment in renal cell carcinoma. In view of toxicity and lack of efficacy, there is no rationale in further testing the drug in this disease. (C) 1997 Published by Elsevier Science Ltd.

47 patients with advanced urothelial cancer and no prior chemotherapy were randomly assigned to therapy with either carboplatin or iproplatin. Both platinum analogues were administered intravenously every 28 days at doses of 400 mg/m 2 carboplatin and 300 mg/m 2 iproplatin. None of 14 evaluable patients treated with carboplatin responded. Therefore, this arm was closed and from then on all eligible patients were registered on the iproplatin arm. 5 of 29 evaluable patients treated with iproplatin achieved a partial response (17%) for a median duration of 27 weeks (range 22–37). Iproplatin did not induce renal function disturbance. Gastrointestinal toxicity was mild to moderate. Bone marrow toxicity predominantly consisted of thrombocytopenia and required platelet transfusions in 13% of patients. 2 patients developed hypersensitivity reactions. It is concluded that the bone marrow toxicity and the chance of hypersensitivity render iproplatin an unattractive alternative to cisplatin.

Eighteen patients with progressive disseminated, platinum-resistant germ cell tumors were treated with epirubicin 135 mg/m2, every 3 weeks. One patient had stable disease, 17 developed progression. Myelosuppression was dose-limiting. One patient died of neutropenic septicemia. High-dose epirubicin is not active against platinum-resistant germ cell cancer.

Mitomycin C (MMC) is rarely used in first-line chemotherapy for advanced breast cancer, although the drug is reported to be active. Treatment with MMC is usually reserved for second- or third-line treatment. We have given MMC as second- or third-line treatment to 59 patients. Fifty-six patients were evaluable for response. No complete and only 3 partial responses were observed for an overall response rate of 5%. The median time to progression was 2 months and median survival time was 6 months. In this retrospective study MMC is demonstrated to be inactive in third-line chemotherapy.

Vindesine at a dose of 3 mg/m2 i.v. once a week failed to produce responses in 24 adequately treated patients with measurable advanced renal carcinoma. Leukopenia and peripheral neurotoxicity were the most often observed side-effects. On the basis of the negative result, the application of vindesine in this disease is not recommended.