Effect of recombinant human granulocyte-macrophage colony-stimulating factor on chemotherapy-induced myelosuppression

An increase in the dose of chemotherapy enhances the response of many experimental and clinical cancers, but the extent of dose escalation is often limited by myelosuppression. In preliminary trials, recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) has augmented leukocyte numbers and function, but the optimal dose is not established. We treated 16 adults who had inoperable or metastatic sarcomas with escalating doses of rhGM-CSF before and immediately after a first cycle of chemotherapy (cycle 1) to assess hematologic response and toxicity. A second cycle of chemotherapy (cycle 2) was given without rhGM-CSF. RhGM-CSF was tolerated well at doses of 4 to 32 micrograms per kilogram of body weight per day. At 64 micrograms per kilogram per day, edema and thrombi around a central venous catheter developed in two of four patients. Leukocyte and granulocyte counts increased significantly during the rhGM-CSF infusion. Neutropenia after cycle 1 was significantly less severe and shorter in duration than after cycle 2 (P less than 0.01). Mean total leukocyte and platelet nadirs were 1.0 and 101 x 10(9) per liter for cycle 1 and 0.45 and 44 x 10(9) per liter for cycle 2 (P less than 0.01), and the median intervals from day 1 of chemotherapy to neutrophil recovery (greater than 0.500 x 10(9) per liter) were 15 and 19 days, respectively (P less than 0.01). The duration of neutropenia was 3.5 days with cycle 1 and 7.4 days with cycle 2 (P less than 0.01). We conclude that rhGM-CSF is tolerated well at doses up to 32 micrograms per kilogram per day and is biologically active in leukopenic patients. It merits further evaluation for the prevention of morbidity from chemotherapy.

Recombinant human tumor necrosis factor administered as a 24-hour intravenous infusion. A phase I and pharmacologic study

Recombinant human tumor necrosis factor (rH-TNF) is a cytokine with direct antitumor properties. In a phase I trial we continuously infused rH-TNF for 24 hours. We gave a total of 115 courses of therapy to 50 patients. Doses ranged from 4.5 to 645 micrograms of rH-TNF/m2. Systemic toxicity, including fever, chills, fatigue, and hypotension, increased with the dose of rH-TNF administered. Doses greater than 454 micrograms/m2 frequently caused severe lethargy and fatigue, which precluded hospital discharge of the patient at the completion of therapy. The dose-limiting toxicity was hypotension, and five patients treated at the two highest dose levels required dopamine treatment. Other organ-specific toxicity was modest and spontaneously resolved after 48 hours. The 24-hour infusions of rH-TNF were associated with significant decreases in serum cholesterol and high-density lipoprotein levels. Pharmacokinetic studies using an enzyme-linked immunosorbent assay demonstrated peak plasma rH-TNF levels of 90-900 pg/mL. Despite continuous infusion of rH-TNF, no steady-state level was achieved. The recommended phase II dose for rH-TNF as a 24-hour continuous infusion is 545 micrograms/m2.

Influence of thiocompounds on the metabolism of N-nitrosodiethylamine

Diethyldithiocarbaminate (DDTC), mercaptoethanesulfonate (MESNA) and ethylxanthate (PEX) were tested for their influence on N-nitrosodiethylamine (NDEA) metabolism. The exhalation rate of 14CO2 released from [14C]NDEA was decreased by PEX, but not by MESNA or DDTC. The sulfur compounds led to an increased excretion of unchanged NDEA in urine in the order PEX greater than DDTC much greater than MESNA. The activity of NDEA-deethylase in liver microsomal system was decreased only after DDTC or PEX treatment. Glutathione content and glutathione-S-transferase activity were not affected significantly by any of the tested compounds. NDEA-induced single-strand breaks in liver cell DNA were inhibited after PEX treatment.

Malignant melanoma. Treatment with high-dose combination alkylating agent chemotherapy and autologous bone marrow support

Nineteen patients with metastatic malignant melanoma were treated with 20 courses of high-dose combination alkylating agent chemotherapy and autologous bone marrow support. All 20 treatment courses were evaluable for toxic reactions and 17 of 20 courses were assessable for response. Twelve of the 20 courses were given at the phase 2 dose per square meter of cyclophosphamide (5.625 g), cisplatin (165 mg), and carmustine (600 mg). Marrow reconstitution occurred with a median time to recovery of 21 and 24 days for more than 500 neutrophils and more than 20,000 platelets, respectively. The overall response rate was 65%, with one patient achieving a complete response with chemotherapy alone. Ten additional patients achieved partial responses following chemotherapy, of which three were subsequently rendered disease free by surgical resection of single areas of residual tumor. Two of these patients are alive and disease free more than 22 months following chemotherapy and one remains relapse free. The median survival for responding patients was 15.2 months and 8.6 months for the entire group.

Development of alkylating agent-resistant human tumor cell lines

Survival curves and dose escalation studies of four representative human tumor cell lines exposed to the various alkylating agents are presented. With HN2, at a level of one log of cell kill there was a fivefold range in drug concentration required to achieve this degree of cell kill among the cell lines, from 4.5 microM for the SL6 lung adenocarcinoma to 22 microM for the SW2 small-cell lung carcinoma. Four logs of SCC-25 squamous carcinoma cells were killed by 100 microM CDDP; however, there was only about one log of SL6 cells killed by 500 microM CDDP. To kill one log of G3361 melanoma cells required 24 microM 4-HC and to kill one log of SCC-25 cells required 24 microM, approximately a 16-fold difference. The curves for cell kill by L-PAM appeared to be biphasic, with a break at about 100 microM. There was about a threefold range in drug concentration required to achieve one log of cell kill with L-PAM, from 60 microM in the SCC-25 cell line to 18 microM in the SW2 line. To kill one log of SCC-25 cells required 295 microM BCNU and to kill one log of SW2 cell required 120 microM, about a 2.5-fold difference. The range of maximally tolerated HN2 concentrations were from 1200 microM for the SL6 cell line, 48 times the initial concentration, to 300 microM for the SCC-25 line, 16 times the initial concentration. The G3361 line tolerated the highest level of CDDP, 1900 microM, 48 times the initial concentration. The SCC-25 line, on the other hand, tolerated only 600 microM, 30 times the initial concentration. The SL6 cell line maximally tolerated 36 times the initial concentration of 4-HC (1450 microM), whereas the SCC-25 cell line tolerated only 18 times the initial concentration (720 microM). The G3361 melanoma tolerated 1555 microM, 30 times the initial concentration of L-PAM, and the SCC-25 cell line tolerated 700 microM, 14 times the initial concentration. The SL6 cell line tolerated the highest concentration of BCNU, 4200 microM, 24 times the initial concentration. The SCC-25 cell line tolerated 1450 microM, 8 times the initial concentration. In all cases, the SCC-25 cell line was least able to tolerate exposure to increasing concentrations of alkylating agents. The SL6 and G3361 cell lines showed the greatest tolerance for increasing concentrations of alkylating agents.(ABSTRACT TRUNCATED AT 400 WORDS)

Chemotherapeutic strategies in the multidisciplinary treatment of head and neck cancer

A role for chemotherapy in the multidisciplinary treatment of patients with advanced squamous cell carcinoma of the head and neck (SCCHN) is yet to be defined. Results of uncontrolled studies indicate high response rates to induction chemotherapy and an association between a response to chemotherapy and either local-regional control or survival. Unfortunately, results of randomized, controlled trials have not confirmed an overall survival advantage with such treatment. From 1979 to the present, the Dana-Farber Cancer Institute has registered more than 224 patients on two trials of induction and adjuvant chemotherapy for patients with stage III to IV SCCHN. Protocol 80-016 (1979 to 1983) evaluated two cycles of induction cisplatin, bleomycin, and methotrexate/leucovorin (PBM) before local regional treatment in 114 patients. Eighty-nine (78%) patients responded to PBM, with 30 (28%) patients achieving a complete response (CR). After surgery and/or radiotherapy (RT), 46 responders to induction PBM entered a trial of the randomly assigned additional adjuvant PBM. Protocol 83-084 (1983 to present) randomly assigned patients to receive up to four cycles of either induction PBM or cisplatin and infusion 5-fluorouracil before local treatment. Adjuvant chemotherapy was not used in the latter study. Updated results from both trials will be presented, with their implications for future phase II and III multidisciplinary studies. Optimal approaches to the treatment of patients with advanced SCCHN can include planned reductions in the extent of surgery or RT offered to selected patients with a good response to induction chemotherapy but may require adjuvant chemotherapy for patients at high risk for recurrent disease. Until the rate of CR to induction chemotherapy is reproducibly over 50%, documentation of an improved overall survival with multidisciplinary treatment may be difficult.

Recombinant human tumor necrosis factor administered as a five-day continuous infusion in cancer patients: phase I toxicity and effects on lipid metabolism

Recombinant human tumor necrosis factor (rH-TNF) is a cytotoxic monokine with pleiotropic effects. A phase I trial of rH-TNF was initiated using a five-day continuous intravenous (IV) infusion repeated every 28 days. Thirty-eight courses of therapy were administered to 19 patients. The starting dose was 5 X 10(4) U/m2/d, with escalations to 1.0 X 10(5), 2.0 X 10(5), 2.4 X 10(5), and 3.0 X 10(5) U/m2/d. Systemic side effects, including fever, chills, hypotension, fatigue, anorexia, and headaches, were mild and self-limiting. At the maximum tolerated dose of 3.0 X 10(5) U/m2/d, dose-limiting hematologic toxicity was manifested by transient thrombocytopenia and leukopenia. Elevated bilirubin levels were also seen at the higher dose levels. Lipoprotein analysis demonstrated that the five-day treatment with rH-TNF was associated with decreases in high-density lipoproteins, as well as increases in triglycerides and very-low-density lipoproteins. Pharmacokinetic studies using an enzyme-linked immunosorbent assay (ELISA) test indicated plasma rH-TNF levels less than 0.2 U/mL. The recommended phase II dose of rH-TNF administered as a five-day continuous infusion is 2.4 X 10(5) U/m2/d.

Combination of N,N',N"-triethylenethiophosphoramide and cyclophosphamide in vitro and in vivo

In vitro and in vivo studies with the drug combination thioTEPA and cyclophosphamide (CPA) were carried out using the MCF-7 human breast carcinoma cell line and the EMT6 mouse mammary carcinoma cell line. In vitro, survival curves were essentially linear. The EMT6 cell line was less sensitive to thioTEPA than the MCF-7 cell line, with concentrations which reduce cell survival to 10% of 440 and 140 microM, respectively. The response of both cell lines to 4-hydroperoxycyclophosphamide was similar. Simultaneous and immediate sequential treatments with these drugs produced supraadditive cell killing of both cell lines, although the magnitude of the supraadditivity was greater in the MCF-7 cell line than in the EMT6 cell line. Both of these drugs appeared to be as effective as thiol-depleting agents as is diethyl maleate. By DNA alkaline elution, there was a pattern of increasing DNA cross-linking similar to the increasing levels of cytotoxicity of this drug combination with increasing thioTEPA concentrations. In the EMT6 tumor in vivo, the maximally tolerated combination therapy (5 mg/kg x 6 thioTEPA and 100 mg/kg x 3 CPA) produced about 25 days of tumor growth delay which was not significantly different than expected for additivity of the individual drugs. The survival of EMT6 tumor cells after treatment of the animals with various single doses of thioTEPA and CPA was assayed. Tumor cell killing by thioTEPA produced a very steep, linear survival curve through 5 logs. The tumor cell survival curve for CPA out to 500 mg/kg gave linear tumor cell kill through almost 4 logs. In all cases, the combination treatment tumor cell survivals fell well within the envelope of additivity. Both of these drugs are somewhat less toxic toward bone marrow cells by the granulocyte-macrophage colony-forming unit in vitro assay method than to tumor cells. The combination treatments were subadditive or additive in bone marrow granulocyte-macrophage colony-forming unit killing. When bone marrow is the dose-limiting tissue, there is a therapeutic advantage to the use of this drug combination.

Four patients with myelodysplastic syndrome with translocation (1;7)(p11;p11) including one patient with independent clones del(7)q22) [corrected] and t(1;7)(q21;q11)

A translocation involving the short arm of chromosome #1 and the short arm of chromosome #7, [t(1;7)(p11;p11)] was present in four patients with myelodysplastic syndrome (MDS). Two of these patients had prior lymphoproliferative disorders and developed MDS following prolonged therapy with alkylating agents. One of the patients with prior therapy history has two additional independent abnormal clones: one with a partial deletion of the long arm of #7 and the other with t(1;7)(q21;q11). A third patient had a family history of leukemia in both the father and a brother, both of whom developed acute nonlymphocytic leukemia following an MDS phase. The last patient was an elderly woman with no predisposing features.

Molecular characterization of spalt, a homeotic gene required for head and tail development in the Drosophila embryo

The isolation, identification and structure of the spalt gene is described. This novel homeotic gene of Drosophila is required for the establishment of the posterior-most head and the anterior-most tail segments of the embryo. It encodes a small mRNA of 0.8 kb which is under the control of over 15 kb of upstream sequences as indicated by the phenotype of transformed embryos. The putative spalt protein contains internal repeats and other interesting structural motifs but no homeo box. The spalt transcript accumulates motifs but no homeo box. The spalt transcript accumulates to high levels in the segmental anlagen affected in mutant embryos but is also found in regions of the embryo where no functional requirement has been demonstrated.

Dihydrofolate reductase-activity in brain tissue. Effect of X-irradiation

The mechanism responsible for the toxic late effects of cranial irradiation, followed by the administration of systemic methotrexate (MTX) on brain tissue, is still under discussion. We studied the influence of X-irradiation on dihydrofolate reductase (E.C. 1.5.1.3) activity (DHFR), the enzyme inhibited by MTX. New Zealand white rabbits, 6-9 weeks old, underwent 24 Gy fractionated or 20 Gy single-dose brain irradiation using a 60Co source. Before, immediately following, and 1, 2, 4, 12 weeks after irradiation, DHFR was measured in brain and liver tissue by a photometric assay. DHFR in brain tissue was 11.9 +/- 2.9 mU/g wet weight (ww) X h and in liver tissue 121.8 +/- 24.2 mU/g ww X h. Fractionated brain irradiation with 2 Gy per day produced no significant changes in brain DHFR. Single-dose cranial irradiation significantly decreased brain DFHR (7.3 +/- 0.6 mU/g ww X h). Suppression of the developmental increase of DHFR by X-irradiation in young rabbits could be excluded by determining the unchanged brain-to-liver ratios of DHFR in the animals with fractionated brain irradiation.

Collateral methotrexate resistance in cultured human head and neck carcinoma cells selected for resistance to cis-diamminedichloroplatinum(II)

A human head and neck squamous cell carcinoma line (SCC25) derived from a patient with no prior history of radiotherapy or chemotherapy was made resistant to cis-diamminedichloroplatinum(II) (CDDP) by continuous escalation of weekly 30-min pulses of the CDDP from 0 to 0.2 mM over 20 months and then cloned and pulsed weekly with 0.2 mM CDDP for another 20 months. This afforded a resistant subline, SCC25/CP[1], with an IC50 for CDDP 12-fold higher than that of the parental cells. The SCC25/CP[1] cells unexpectedly proved to be cross-resistant to methotrexate (MTX) (24-fold for 30-min treatment and 8-fold for continuous treatment). Resistance was associated with a modest (about 2-fold) increase in the dihydrofolate reductase (DHFR) content according to radioligand-binding assay, and in the rate of cell division. In addition there was a 4-fold decrease in the fraction of long-chain MTX polyglutamates MTX(G4-6) in the cell after 24 h exposure to either 0.2 or 2.0 microM MTX. When the SCC25/CP[1] cells were kept out of CDDP for 8-9 months and 12 months to give the sublines SCC25/CP[2] and SCC25/CP[3], respectively, MTX sensitivity to continuous exposure returned to normal. The SCC25/CP[3] cells still exhibited a slightly elevated DHFR level, but their generation time became shorter than that of the parental SCC25 line. In addition the SCC25/CP[3] cells had an initial uptake velocity (V0) for MTX that was 9-fold greater than the V0 of the SCC25 or SCC25/CP[1] cells, while its ability to form MTX(G4-6) was comparable to that of the SCC25 cells. When SCC25/CP[2] cells were rechallenged with weekly 0.2 mM CDDP pulses for 4-6 months, a MTX-resistant line, SCC25/CP[4], was produced. The SCC25/CP[4] cells retained a slightly elevated DHFR content and a high proliferation rate, but the V0 for MTX influx was intermediate between SCC25 and SCC25/CP[3] cells. The ability to form the longer-chain polyglutamates MTX(G4-6) was again impaired. Thus, MTX cross-resistance can develop in cultured head and neck carcinoma cells when CDDP is used as the selecting agent for primary resistance. MTX resistance is multifactorial, as it is when MTX itself is used as the selecting agent, and appears to involve various combinations of altered growth rate, DHFR content, MTX uptake, and ability to form noneffluxing long-chain MTX polyglutamate species. These results are potentially of clinical relevance, since CDDP and MTX are often used in combination with other drugs or with radiation to treat patients with squamous cell carcinoma of the head and neck.

Weekly high-dose methotrexate and doxorubicin for osteosarcoma: the Dana-Farber Cancer Institute/the Children's Hospital--study III

Weekly high-dose methotrexate with leucovorin rescue and vincristine (HDMTX) and doxorubicin was administered as adjuvant postoperative therapy to 46 patients with a diagnosis of conventional high-grade nonmetastatic osteosarcoma of an extremity between July 1976 and December 1981. The primary lesions were managed by wide or radical amputation (26 patients) or by limb-sparing resection in 20 selected patients. The margins of the resections were retrospectively classified as marginal in three, wide in 16, and radical in one. The 5-year relapse-free survival (RFS) for all patients is 59% (95% confidence interval [CI], 43%, 74%) and overall survival is 78% (95% CI, 65%, 91%). The RFS for patients initially having a limb resection procedure is 55% (95% CI, 32%, 77%) compared with 62% (95% CI, 43%, 81%) for those initially having amputations (P = .52). Using multivariate analysis, the only significant prognostic variables that predicted RFS of greater than or equal to 3 years, were the presence of moderate to marked lymphocytic infiltration of the primary tumor (P less than .002), primary site outside of the proximal humerus (P less than .005), and the absence of a predominance of osteoblastic pattern in the primary tumor (P less than .03).

Metabolism of methotrexate and gamma-tert-butyl methotrexate by human leukemic cells in culture and by hepatic aldehyde oxidase in vitro

The cellular uptake and metabolism of methotrexate (MTX) and gamma-tert-butyl methotrexate (TBM) were compared in CEM human leukemic lymphoblasts and a highly MTX-resistant subline (CEM/MTX) in which MTX uptake is defective. The CEM/MTX cells were found previously to be as sensitive as the parent line to TBM. While MTX was polyglutamylated extensively in the CEM cells, giving abundant levels of non-effluxing conjugates, polyglutamylation in CEM/MTX cells was reduced severely, even after exposure to a high MTX concentration (100 microM) in the medium. This treatment provided free intracellular MTX in greater than 100-fold excess over the dihydrofolate reductase level. In contrast to MTX, the ester TBM was unmetabolized in either cell line. Uptake levels after incubation of CEM and CEM/MTX cells with 2 microM TBM for 24 hr were 17 and 15 pmol/mg protein respectively. Thus, TBM accumulated equally in both cells and was well retained despite the lack of polyglutamylation. These results, together with the previously observed affinity of the drug for dihydrofolate reductase, provide a plausible rationale for the comparable sensitivity of CEM and CEM/MTX cells to TBM. Experiments were also performed to determine the susceptibility of TBM to metabolic detoxification by hepatic aldehyde oxidase. Km values were 8-fold lower for TBM than for MTX in assays using an enzyme preparation from rabbit liver, and Vmax values were 8-fold higher. Neither MTX nor TBM was oxidized to its 7-hydroxy derivative in intact CEM or CEM/MTX cells. Because TBM is capable of overcoming at least one of the modalities of MTX resistance, defective polyglutamylation, and may be more efficiently detoxified than MTX by the action of hepatic aldehyde oxidase, it has the potential to be a useful agent for the treatment of MTX-resistant tumors.

Response of drug-sensitive and -resistant L1210 leukemias to high-dose chemotherapy

Alkylating agent-sensitive and -resistant L1210 leukemia cell lines were used to determine the tumor response to dose levels of drugs that exceeded conventional doses up to a factor of 10. Since those dose levels were lethal to the host mice, tumor response was based on the results of in vivo bioassays of spleen and/or tumor from drug-treated and control mice. When mice bearing about 10(8) drug-sensitive leukemic cells were treated with a single, conventional (approximately 10% lethal) dose of cis-diamminedichloroplatinum, L-phenylalanine mustard (melphalan), or 1,3-bis(2-chloroethyl)-1-nitrosourea, 10(1) to 10(4) tumor cells were recovered by bioassay. Treatment at doses that were 2 to 8 times the 10% lethal dose of either of those drugs resulted in no recoverable cells and survival of all bioassay recipient mice. Mice bearing advanced L1210 leukemia resistant to cis-diamminedichloroplatinum (L1210/DDPt), 1,3-bis-(2-chloroethyl)-1-nitrosourea (L1210/BCNU), cyclophosphamide (L1210/CPA), or melphalan(L1210/L-PAM) also were treated with a 10% lethal dose and greater doses of the drug to which the tumor line was resistant. Bioassay results indicated a direct correlation between dose intensity and tumor cell kill, the response being linear. Similarly, when mice with L1210/BCNU were treated with high doses of N-(2-chloroethyl)-N''-(2,6-dioxo-3-piperidinyl)-N-nitrosourea or 1,1',1''-phosphinothioylidynetrisaziridine (thioTEPA) and when mice with L1210/DDPt were treated with cyclophosphamide, an increasing, linear cell kill resulted throughout the high-dose range. Overall, these results indicate that resistance to these alkylating agents can be overcome by dose intensification and that the tumor response is linear in relation to increasing dose level.

Characterization of a human squamous carcinoma cell line resistant to cis-diamminedichloroplatinum(II)

We have developed a human head and neck squamous cell carcinoma cell line (SCC-25/CP) which is relatively stably resistant to cis-diamminedichloroplatinum(II) (CDDP) after repeated exposure to escalating doses of the drug. The studies reported elucidate the mechanism(s) by which the SCC-25/CP cell line is resistant to CDDP. The SCC-25/CP cell line is approximately 30-fold resistant to CDDP, approximately 10-fold resistant to carboplatin, and about 9-fold resistant to iproplatin. Using [195mPt]CDDP, we examined the levels of platinum in whole cells and cellular fractions of both the SCC-25 and SCC-25/CP cells after 1 h exposure to 100 microM drug. The SCC-25 cells took up 30 pmol of platinum/10(6) cells in 1 h; 64% of the drug was in the nucleus and 21% in the cytosol. The SCC-25/CP cells took up 7 pmol of platinum/10(6) cells; of this, 41% was in the nucleus and 33% in the cytosol. The SCC-25 cell nuclei contained 331 pmol of platinum/mg protein and the cytosol 21 pmol of platinum/mg protein, whereas the SCC-25/CP cell nuclei contained 47 pmol of platinum/mg protein and the cytosol 8.1 pmol/mg protein. The release of drug from both cell lines followed a very similar course and was most rapid over the first 6 h. There was no difference in the non-protein sulfhydryl content of the cell lines. The protein sulfhydryl content, as measured by Ellman's procedure, indicated that the SCC-25/CP cell line has approximately a 2-fold increase in protein sulfhydryl content compared to the SCC-25 cell line. The SCC-25/CP cell line is about 2-fold resistant to cadmium chloride at 50% cell kill and about 2.5-fold resistant at 1 log kill compared to the SCC-25 cell line. Glutathione transferase activity in crude cytoplasmic extracts was measured and found to be approximately 2- to 3-fold higher in the CDDP resistant cells. The isoelectric point of the glutathione transferase isozyme was 4.8 in both the sensitive and resistant cell lines, suggesting induction of the predominant isozyme present in the parent cell line. By alkaline elution there was greater cross-link formation by CDDP in the SCC-25 cell line than in the SCC-25/CP cell line at the same drug concentrations. In conclusion, the mechanism of resistance of the SCC-25/CP cell line to CDDP is multifactorial, involving plasma membrane changes, increased cytosolic binding, and decreased DNA cross-linking.

Prediction of the optimal timing of bone marrow reinfusion after high dose chemotherapy

Autologous bone marrow transplantation allows the use of high dose chemotherapy by obviating dose limiting myelosuppression. The pharmacology of high dose chemotherapy has been inadequately explored, yet this information is critical to determine the timing of marrow infusion and assure that engraftment is not compromised. We have used the Salmonella mutagenesis test (SMT) and colony forming unit-granulocyte, erythrocyte, monocyte, megakaryocyte assay to evaluate the optimal time for marrow infusion after therapy with high dose combinations of alkylating agents (Solid Tumor Autologous Marrow Support Program) in seven patients. The SMT is sensitive, rapidly performed, and has been used to detect mutagenic activity in urine following administration of cyclophosphamide, cisplatin, and 1,3-bis(2-chloroethyl)-1-nitrosourea. In parallel, determination of colony forming ability of the patients own bone marrow (colony forming unit-granulocyte, erythrocyte, monocyte, megakaryocyte assay), when cocultured with autologous serum obtained before and after treatment, provided an assay for circulating marrow toxic drugs or metabolites. The onset of mutagenic activity in the SMT and the in vitro appearance of myelotoxicity by autologous serum in the colony forming unit-granulocyte, erythrocyte, monocyte, megakaryocyte assay were concurrent, and these activities returned to base line at the time of marrow infusion (72 h posttreatment). One patient of the seven was excreting mutagens (TA100 strain only) at the time of marrow reinfusion; he developed hepatic venoocclusive disease, and delayed engraftment. These observations suggest that as high dose regimens evolve the SMT may serve as a rapid, sensitive indicator of the circulation and excretion of toxic compounds, and thereby assist in predicting the optimum time of bone marrow reinfusion.

Neuroblastoma in adults. Three case reports and a review of the literature

Three adult patients with neuroblastoma have been treated recently at the Dana-Farber Cancer Institute. One adult neuroblastoma patient experienced two distinct paraneoplastic syndromes that have not been reported previously in association with neuroblastoma. The clinical data on our three patients are presented in detail and the important features of 27 cases that have been described in the literature are summarized. This study suggests that the distribution of primary neuroblastoma sites in adults is similar to that seen in pediatric cases but that the natural history of the disease may be longer. Furthermore, this study suggests that neuroblastoma in adults may be less sensitive to chemotherapy than is the childhood disease.

Alkylating agents: in vitro studies of cross-resistance patterns in human cell lines

The alkylating agents represent one of the most important classes of antitumor agents and play a major role in combination with other agents in the curative chemotherapy of selected human cancers. By repeatedly exposing cells to escalating doses of an alkylating agent, we have developed four human tumor cell lines which are relatively stably resistant to the drug with which the culture was treated. The response of these cell lines to a variety of alkylating agents was compared to the response of the parent cell lines to the same drug. The Raji/HN2 line was 7-fold resistant to nitrogen mustard and about 3-fold resistant to 4-hydroxyperoxycyclophosphamide, but it was not resistant to N,N'-bis(2-chloroethyl)-N-nitrosourea (BCNU), melphalan (MEL), busulfan, trimethyleneiminethiophosphoramide, 4-hydroperoxyifosfamide, or cisplatin [cis-diamminedichloroplatinum(II)] (CDDP). The Raji/BCNU line was 5.3-fold resistant to BCNU and 4-fold resistant to both MEL and CDDP. The Raji/CP line was 7-fold resistant to CDDP and 3-fold resistant to both nitrogen mustard and BCNU, but it was not resistant to busulfan, trimethyleneiminethiophosphoramide, or 4-hydroperoxyifosfamide. The SCC-25/CP line, which was 12-fold resistant to CDDP, was 5-fold resistant to MEL and 3-fold resistant to 4-hydroxyperoxycyclophosphamide. The SCC-25/CP line was almost 24-fold resistant to methotrexate after 30-min treatment and about 7-fold resistant to methotrexate after continuous treatment. None of the other cell lines was resistant to methotrexate. The survival of SCC-25 and SCC-25/CP cells exposed to several antineoplastic agents was examined over several logs of survival. The SCC-25/CP cells are highly resistant to CDDP; the ratio of the slopes of the survival curves (SCC-25/CP to SCC-25) of the two lines was 43. At survivals of 1%, resistance to MEL and BCNU became evident in the SCC-25/CP line. At survivals of 0.1%, resistance to mitomycin C and, to a lesser degree, to Adriamycin and vincristine was evident. It is more difficult to produce resistance to alkylating agents, even with extended selection pressure, than to other antineoplastic drugs such as antimetabolites and natural products. We found no evidence of pleiotropic resistance in any alkylating agent-resistant cell line. Our results suggest that a judicious choice of alkylating agents given in sequential or concurrent combination may be a rational treatment strategy with potential applications in the clinic.

Immunohistochemical identification of squamous carcinoma of the head and neck with monoclonal antibody SQM1

Frozen tissue sections of biopsies from head and neck squamous cancer lesions were examined for immunohistochemical staining with a recently developed monoclonal antibody, designated as SQM1 antibody and directed against the surface membrane of squamous carcinoma cells. SQM1 antibody stained selectively squamous carcinoma, while normal mucosa and cells of the stroma were non-reactive. Positive staining of tumor was found in 33/35 specimens obtained from several major sites of the head and neck area and was observed in primary manifestations and lymph node metastases as well as in recurrences. The most consistent reactivity was seen with carcinomas of the tongue. Well differentiated squamous carcinomas contained a higher proportion of SQM1 positive tumor cells than poorly differentiated carcinomas. We suggest that the SQM1 antibody may aid in the immunohistochemical identification of squamous carcinoma of the head and neck area.