Activity of pirarubicin (4'-0-tetrahydropyranyladriamycin) in malignant mesothelioma

Eight patients with diffuse malignant mesothelioma of the pleura or peritoneum, previously untreated with chemotherapy, were treated with a new anthracycline 4'-0-tetrahydropyranyladriamycin (pirarubicin). Pirarubicin was given intravenously at the rate of 5 mg per minute, at doses ranging from 35 to 70 mg/m2 once every 21 days. On clinical evaluation, one patient had complete response lasting 4 months. On second-look laparotomy residual tumor was found and she was labelled a partial responder and changed to alternate chemotherapy. Another patient had a partial response of recurrent chest wall tumors lasting 11 months. A third patient had a partial response lasting 4+ months of a pleural-based tumor and resolution of pleural effusion. After the fifth course of chemotherapy, he developed severe granulocytopenia, pseudomonas sepsis, shock, and renal failure. Despite recovery of blood counts to normal within 3 days, renal failure proved fatal. Autopsy revealed only fibrosis and no gross or microscopic evidence of malignant mesothelioma. A fourth patient had improvement in evaluable disease lasting about 4 months; and the remaining four had stable disease for at least 2 months each. The authors conclude that, whenever feasible, noninvasive clinical assessment of tumor response should be supplemented by surgical-pathologic evaluation. Pirarubicin is active in malignant mesothelioma. This is the first report documenting complete tumor eradication after chemotherapy in an adult with malignant mesothelioma.

Correlation of in vitro clonogenic assay data with in vivo growth delays and cell cycle changes of a human melanoma xenograft

We have reported previously that, in a human melanoma xenograft line, plating efficiency and drug sensitivity in vitro were enhanced under hypoxic conditions. In the present study, we show that the in vitro chemosensitivity data using clonogenic assays at 5% oxygen also correlate better with the drug-induced in vivo growth delay. Tumors implanted in bilaterally symmetrical locations grew at different rates, and response to chemotherapy was also variable. Cell cycle changes in the xenograft, as monitored by flow cytometry, suggest that major changes in cell cycle traverse occur when a drug is active in vitro and also causes in vivo growth delay. These studies indicate the usefulness of the nude mouse human xenografts to study correlations between soft agar clonogenic assays, in vivo growth delay, and cell cycle traverse in response to chemotherapeutic manipulation.

Effect of cholesterol content on antitumor activity and toxicity of liposome-encapsulated 1-beta-D-arabinofuranosylcytosine in vivo

1-beta-D-Arabinofuranosylcytosine (ara-C) was encapsulated in anionic multilamellar liposomes prepared with different lecithin: cholesterol (L:C) ratios. The chemotherapeutic activity of encapsulated ara-C was compared with comparable doses of ara-C in 0.85% saline solution (single- and multiple-dose schedules) in mice bearing L1210 (i.p.) leukemia. Maximum survival was obtained in animals given injections of ara-C (40 mg/kg) encapsulated in liposomes with a L:C ratio of 1:1. The effect of L:C ratio on survival was not pronounced in multiple-dose schedules. Multiple doses (every 4.5 hr for 3 separate injections) of 40 mg/kg with L:C ratios of 1:1 and 1:0.5 were toxic, resulting in 83 and 50% mortality, respectively, of mice by Day 7. This study shows that drug efflux and in vivo antitumor activity and toxicity of encapsulated ara-C is influenced by the cholesterol content of the liposomal lipid bilayer.

Vincristine effect on methotrexate cerebrospinal fluid concentration

A 67-year-old man with malignant lymphoma, nodular, poorly differentiated lymphocytic type, developed meningeal lymphomatosis. Repeated high-dose methotrexate-citrovorum factor treatment (1 g/m2 in 24 hours) rendered the patient free of disease. The administration of vincristine at 23 hours consistently increased the concentration of methotrexate in the cerebrospinal fluid 2.5-fold above baseline values.

Selective toxicity of anticancer drugs: Presidential Address

In the chemotherapy of infectious diseases, selective toxicity has been achieved by designing curative regimens based on pharmacokinetic data. Selective toxicity of antitumor drugs has been demonstrated for rapidly growing large growth fraction tumors occurring in patients under age 30. In these tumors curative schedules have been achieved by application of animal data relating to cellular and drug kinetics. The attempts to improve chemotherapy of large and small growth fraction tumors by kinetic observations in vivo in humans have been disappointing. Recent evidence suggests that the heterogeneity of cells within tumors has prevented precise observations on the relation of cellular and drug kinetics to improved selective toxicity. The availability of xenografts, flow cytometry, and tumor markers presents an opportunity to isolate subpopulations of tumor cells; to characterize their cellular and drug kinetics; and to correlate these with values obtained in vivo in humans. It should then be possible at long last to examine the potential role of cellular and drug kinetics in devising drug schedules with greater selective toxicity for human cancer.

Combining talents for the management of cancer patients

The combination of talents required to bring to all patients the maximum benefits of combined modality treatment is examined in the following steps: devising treatment strategy, carrying out treatment, extension widely to the community, and treatment research. The devising of strategy should rest upon the theoretical principles of cell kinetics and pharmacokinetics, which in most instances combine local removal in the primary tumor and anticipatory chemotherapy of occult metastases. The delivery of treatment involves implementation of these principles for each individual patient, and its success depends upon continual consultation among the various members of the treatment team. Wide extension of best treatment to all patients with cancer in the community will involve the good will and effective liaison of many individuals in federal, state, and local government, and many professional and lay people. Many problems of treatment are still unsolved, so research must provide new knowledge. While future advances will come in unexpected ways, the three most needed are a quantitative marder for cancer cells, better drug combinations for carcinomas, and an effective was to diagnose and repair immune deficits.

Combinations of drugs in the treatment of acute leukemias

In the United States, the Acute Leukemia Task Force has been studying ways to achieve chemical control over the acute leukemias. It was found that L1210 mouse leukemia is an excellent predictive model for childhood acute leukemia. Examination of the kinetics of cell generation led to the conclusions that a single cell could multiply to a lethal number of cells in a relatively short time, and that therapy must destroy every cell. Extension of these hypotheses to childhood leukemia has permitted estimates of generation time of human leukemic cells; the size of the leukemic cell population at clinical relapse and the fractional destruction of cells by individual drugs. By the use of combinations of antileukemic drugs complete cell destruction has been approached in a few patients with early leukemia.