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Biomedical subjects

M L Rothenberg

Publications and source records attributed to M L Rothenberg.

17 recordsLinked to original sources

Tumor angiogenesis in advanced stage ovarian carcinoma.

Tumor angiogenesis has been found to have prognostic significance in many tumor types for predicting an increased risk of metastasis. We assessed tumor vascularity in 43 cases of advanced stage (International Federation of Gynecologists and Obstetricians stages III and IV) ovarian cancer by using the highly specific endothelial cell marker CD34. Microvessel counts and stage were associated with disease-free survival and with overall survival by Kaplan-Meier analysis. The plots show that higher stage, higher average vessel count at 200x (200x avg) and 400x (400x avg) magnification and highest vessel count at 400x (400x high) magnification confer a worse prognosis for disease-free survival. Average vessel count of less than 16 (400x avg, P2 = 0.01) and less than 45 (200x avg, P2 = 0.026) suggested a better survival. Similarly, a high vessel count of less than 20 (400x high, P2 = 0.019) conferred a better survival as well. The plots suggest that higher stage, higher average vessel count at 200x and 400x, and highest vessel count at 200x and 400x show a trend to worse overall survival as well. With the Cox proportional hazards model, stage was the best predictor of overall survival, however, the average microvessel count at 400x was found to be the best predictor of disease-free survival. These results suggest that analysis of neovascularization in advanced stage ovarian cancer may be a useful prognostic factor.

Adolescent

Multidrug resistance in cancer chemotherapy.

Resistance to chemotherapy is the single most important reason for treatment failure in cancer patients. Over the past 15 years, we have gained significant insight into one of the mechanisms responsible for this process: multidrug resistance (MDR). Far from being a phenomenon limited to the laboratory, multidrug resistance has been identified in a wide variety of newly diagnosed and recurrent human tumors. A number of compounds can block p-glycoprotein and overcome MDR in vitro and in vivo. Current strategies to block MDR are discussed in this review. Future research in this area will focus on the identification of more selective and potent MDR reversing agents and the development of entirely new approaches to overcoming multidrug resistance such as monoclonal antibodies, immunotoxins, and gene therapy.

ATP Binding Cassette Transporter, Subfamily B, Mem

A phase II trial of DaunoXome, liposome-encapsulated daunorubicin, in patients with metastatic adenocarcinoma of the colon.

CONTEXT: Liposomal encapsulation of drugs can potentially ameliorate toxicities and improve acute and chronic tolerance. The increased uptake of liposomes by colon adenocarcinoma cell lines may enable DaunoXome to circumvent the p-glycoprotein-mediated anthracycline resistance of colon cancer cells. PURPOSE: To determine if DaunoXome, liposome-encapsulated daunorubicin, has clinical activity in patients with adenocarcinoma of the colon who failed treatment with a 5-fluorouracil containing regimen. METHOD: In a Phase II trial, patients with metastatic adenocarcinoma of the colon, whose disease has progressed after receiving one 5-fluorouracil-containing regimen, were treated with DaunoXome 100 mg/m2 repeated every 3 weeks. RESULTS: In this trial 16 patients received 45 courses of therapy. No objective tumor responses were seen. Hematologic toxicities consisted of neutropenia (grade 3 and 4), grade 2 anemia, and grade 2 thrombocytopenia. Nonhematologic toxicities were mild and manageable. Of the 16 patients, 5 experienced flushing, shortness of breath, chest tightness, and back pain during DaunoXome infusion, which resolved with infusion interruption, diphenhydramine, and meperidine. CONCLUSIONS: DaunoXome is generally well tolerated at a dose of 100 mg/m2 every 3 weeks. Toxicities are mild and reversible. On this schedule DaunoXome does not have significant clinical activity in patients with metastatic adenocarcinoma of the colon who have progressed after one 5-fluorouracil-containing regimen.

Adenocarcinoma

Phase I and pharmacokinetic trial of weekly CPT-11.

PURPOSE: We conducted a phase I and pharmacokinetic trial of CPT-11 (irinotecan) to characterize the maximum-tolerated dose (MTD), toxicities, pharmacokinetic profile, and antitumor effects in patients with refractory solid malignancies. PATIENTS AND METHODS: We treated 32 patients with CPT-11 administered as a 90-minute intravenous infusion every week for 4 consecutive weeks followed by a 2-week rest period. Dose levels ranged from 50 to 180 mg/m2/wk. We determined concentrations of the lactone (active) and total (lactone plus carboxylate) forms of CPT-11 and its metabolite, SN-38, in the plasma and urine of selected patients during and after drug infusion. RESULTS: Grade 4 diarrhea was the dose-limiting toxicity (DLT) at the 180-mg/m2/wk dose level. Other toxicities attributed to CPT-11 included dehydration, nausea, vomiting, and asthenia. Hematologic toxicity was mild in most patients. The terminal plasma half-life for CPT-11 (total) was 7.9 +/- 2.8 hours, for CPT-11 (lactone) 6.3 +/- 2.2 hours, for SN-38 (total) 13.0 +/- 5.8 hours, and for SN-38 (lactone) 11.5 +/- 3.8 hours. We observed significant correlations between drug dose and peak plasma concentration (Cpmax) and between drug dose and area under the concentration curve (AUC) for CPT-11, but not for SN-38. CONCLUSION: The MTD for CPT-11 in this patient population was 150 mg/m2/wk when administered on a weekly-times-four schedule repeated every 6 weeks. At dose levels greater than 150 mg/m2/wk, diarrhea is dose-limiting.

Adult

Dose-intensive induction therapy with cyclophosphamide, cisplatin, and consolidative abdominal radiation in advanced-stage epithelial ovarian cancer.

PURPOSE: The primary goal of this trial was to evaluate the clinical activity of a high-dose cisplatin-based induction regimen for women with advanced-stage ovarian cancer. A secondary goal was to assess the use of whole-abdominal radiation as consolidative therapy in the subset of women left with less than 5 mm residual disease after completion of chemotherapy. PATIENTS AND METHODS: Fifty consecutive patients with newly diagnosed, advanced-stage ovarian cancer received cisplatin 40 mg/m2/d and cyclophosphamide 200 mg/m2/d intravenously (IV) for 5 days, every 4 to 6 weeks. After three to four cycles of chemotherapy, patients who still had residual disease less than 5 mm in greatest diameter at second-look surgery were given whole-abdominal radiotherapy. RESULTS: The overall response rate in 49 patients assessable for response was 61.3% (24.5% pathologic complete responses [pCRs], 32.7% pathologic partial responses [pPRs], and 4.1% clinical partial responses [cPRs]). Median survival for all patients was 23.4 months, and actuarial 4-year survival was 33.7% (95% confidence interval [CI], 21.8% to 48.1%). Multivariate analysis showed stage III and serous histology as independent favorable prognostic factors for survival. Median survival for stage III patients was 36.5 months, with an actuarial 4-year survival of 41.6% (95% CI, 25.5% to 59.6%). Median survival for stage IV patients was 12.0 months, with actuarial 4-year survival of 22.9% (95% CI, 9.5% to 45.5%). The major acute toxicities encountered were myelosuppression and peripheral neuropathy. Patients who received consolidative radiotherapy were at increased risk of developing late-onset enteropathy. CONCLUSIONS: This regimen is active against advanced-stage ovarian cancer, but the associated toxicity is severe. Consolidative whole-abdominal radiation did not appear to prolong survival in the subset of women left with less than 5 mm residual disease after chemotherapy.

Adolescent

Clinical trials with the topoisomerase I inhibitors.

Topoisomerase I represents a unique new target that can be exploited for development of new antineoplastic agents. There are now two new topoisomerase I inhibitors that are in early clinical trials that have generated a tremendous amount of interest. Topotecan (SKF 104864-A) is a topoisomerase I inhibitor that has been explored in phase I trials using a variety of dosages and schedules. The dose-limiting toxicity of the agent is neutropenia. Other toxicities include alopecia, very mild nausea and vomiting, anemia, and occasional fever. Responses have already been noted in patients with advanced, refractory ovarian cancer and non--small-cell lung cancer. The drug is currently undergoing intense phase II testing. Irinotecan (CPT-11) is also a topoisomerase I inhibitor, which has already undergone extensive phase I and early phase II clinical testing in both Japan and the United States. Dose-limiting toxicities of the agent have included neutropenia and diarrhea. Responses have been noted in patients with refractory colorectal cancer, non--small-cell lung cancer, lymphoma, ovarian cancer, head and neck cancer, pancreatic cancer, and breast cancer. There is no doubt both of these agents will be important additions to our chemotherapy armamentarium.

Animals

Commentary concerning demonstration of safety and efficacy of investigational anticancer agents in clinical trials.

Expeditious clinical development and approval of new drugs that are beneficial to patients are matters of high priority. There has been a great deal of discussion within the oncology community about what should constitute evidence of effectiveness of new anticancer agents for purposes of drug approval. This commentary is intended to illustrate a variety of end points that can lead to approval of new anticancer agents for specific clinical situations. Although the ultimate hope of antineoplastic therapy is prolongation of life, there are other effects of anticancer drugs that constitute clear clinical benefit and represent evidence of effectiveness. The guiding principle is that the beneficial effects obtained from a new drug should sufficiently outweigh the adverse effects such that the potential risk:benefit ratio achieved by an individual patient is favorable. The assessment of a new drug should flexibly evaluate safety and efficacy in the context of the specific clinical condition being treated. Early discussions with the Food and Drug Administration (FDA) and the National Cancer Institute (NCI) are recommended to identify prospectively the end points and trial designs needed to demonstrate effectiveness of a new drug. The general principles discussed will likely apply to the drug approval process for other medical disciplines as well.

Antineoplastic Agents

Expression of the mdr-1/P-170 gene in patients with acute lymphoblastic leukemia.

Increased expression of the multidrug resistance gene (mdr-1/P-170) and the dihydrofolate reductase (DHFR) gene have been implicated in the development of in vitro drug resistance. Overexpression, with or without gene amplification, is seen in the development of drug resistance in culture and it has been postulated that genetic modulation of mdr-1/P-170 and DHFR may also be involved in the development of clinical drug resistance. We screened lymphoblasts from 28 patients with acute lymphoblastic leukemia (ALL) for evidence of overexpression of mdr-1/P-170 using RNAse protection, RNA in situ hybridization and immunohistochemistry. Overexpression of mdr-1/P-170 without gene amplification was detected in samples from four patients (three after multiple relapses, one at presentation). Overexpression of mdr-1/P-170 was heterogeneous within the population of malignant lymphoblasts as demonstrated by RNA in situ hybridization, immunohistochemistry, and drug uptake using daunomycin autofluorescence analysis. There was no evidence of overexpression of DHFR in any of the eight patient samples tested by RNAse protection nor was there any evidence of gene amplification in 11 patient samples on Southern blot analysis. From these observations it appears that overexpression without gene amplification of mdr-1/P-170 may be one mechanism of clinical drug resistance in ALL.

Adolescent

High-dose carboplatin with diethyldithiocarbamate chemoprotection in treatment of women with relapsed ovarian cancer.

Diethyldithiocarbamate (DDTC) has been found to protect the bone marrow, kidneys, and gastrointestinal tract from the toxic effects of cisplatin and carboplatin (CBDCA) in animal models. In an attempt to minimize the toxic effects of high-dose CBDCA (800 mg/m2), a pilot study was undertaken in which women with relapsed or refractory epithelial ovarian cancer were treated with high-dose CBDCA, which was followed 3 hours later with DDTC (4 g/m2). There were four partial responses and no complete response in 21 patients who could be evaluated (overall response rate, 19%). Significant toxic effects, including three treatment-related deaths, were associated with the regimen. This study suggests that while high-dose CBDCA plus DDTC may be active in relapsed or refractory ovarian cancer, it is associated with clinically significant hematologic and autonomic toxic effects.

Adult