Current status of etoposide in the management of small cell lung cancer

Temozolomide and oral etoposide in children with recurrent malignant brain tumors

Despite advances in the treatment of brain tumors, the prognosis of children with recurrent malignant brain tumors remains poor. Etoposide (VP-16), an inhibitor of nuclear enzyme deoxyribonucleic acid (DNA)-topoisomerase II, has shown activity in brain tumors. Its efficacy appears schedule dependent but, to date, the most effective schedule of administration has not been well defined. Temozolomide (TMZ), like VP-16, penetrates the blood–brain barrier and has activity against malignant brain tumors. This novel alkylating agent is rapidly absorbed and is highly bioavailable after oral administration. The antitumor activity of TMZ has been shown to be schedule dependent. Based on the evidence of different mechanisms of cytotoxicity, TMZ and VP-16 have been utilized in combination in patients with malignant brain tumors. This review evaluates the results derived from the combination use of TMZ and oral VP-16. The reported data suggest potential activity of oral VP-16 and TMZ alone or in combination. Further clinical trials are needed to explore and confirm their promising activity in relapsed brain neoplasms.

Selective Electrochemical Determination of Etoposide Using a Molecularly Imprinted Overoxidized Polypyrrole Coated Glassy Carbon Electrode

A simple and efficient new electrochemical sensor based on molecularly imprinted polymer has been developed for selective detection of an anticancer agent Etoposide (ETP). The sensor was prepared by electropolymerization via cyclic voltammetry (CV) of pyrrole onto a glassy carbon electrode (GCE) in the presence of ETP molecules. The extraction of ETP molecules embedded in the polymeric matrix was carried out by overoxidation in sodium hydroxide medium using CV. Various important parameters affecting the performance of the imprinted film (MIP) coated sensor were studied and optimized using differential pulse voltammetry (DPV). Under optimal conditions, the sensor response exhibited a linear dependence on ETP concentration (R2= 0.999) over the range 5.0×10−7M – 1.0×10−5M with a LOD (3σ/m) of 2.8×10−9M. The precision (% RSD, n=6) of the proposed sensor for intra- and interdays was found to be 0.84 and 2.46%, respectively. The selectivity of MIP/GCE sensor toward ETP was investigated in the presence of different interfering molecules including excipients and ETP metabolites. The developed sensor showed great recognition ability toward ETP and was successfully applied for its determination in injectable dosage forms and biological human fluids.

Successful cisplatin-etoposide chemotherapy-based treatment of a primary small cell neuroendocrine carcinoma of the tonsil with multiple metastases: a case report

Extrapulmonary small cell neuroendocrine carcinoma (SNEC) is an extremely rare and highly malignant tumor with a poor prognosis. Multiple metastases of SNEC are even more rare, and patients with locally advanced and metastatic disease generally face a poor outcome. To date, only a few cases of SNEC have been reported. Here, we describe a rare case of a 70-year-old female patient with SNEC of the tonsil who presented with multiple metastases and had achieved a complete response (CR) of the primary lesion and cervical lymph nodes for more than 1 year after receiving palliative chemotherapy. Initially, the patient presented with a 2-month history of throat pain. Magnetic resonance imaging and computed tomography revealed a soft mass with moderate enhancement on the left tonsil, which was confirmed by incisional aspiration biopsy. She was additionally sent for a positron emission tomography scan to evaluate small metastases in the left cervical lymph node, right lung, multiple mediastinal lymph nodes, and the fourth lumbar (L4) vertebra body metastases. Histopathological examination of the SNEC confirmed a nested, typical endocrine appearance with small round cells containing ovoid-shaped nuclei and high mitotic activity. Immunohistochemically, the tumor cells were positive for cytokeratin 8/18+, synaptophysin+, CD56+, and Ki-67 (<50%). The patient received 6 cycles of cisplatin combined with etoposide and was subsequently placed under close observation (<12 months). To date, she has achieved a CR of the primary lesion and cervical lymph nodes. In summary, we have described a case of successful treatment after chemotherapy for SNEC and have elucidated professional knowledge regarding the relevant aspects of SNEC.

Phase I trial of oral etoposide in combination with radiotherapy in head and neck squamous cell carcinoma - GORTEC 2004-02

PURPOSE

This study sought to determine the maximum tolerated dose (MTD) of oral etoposide in combination with radiotherapy in head and neck squamous cell carcinoma (HNSCC).

PATIENTS AND METHODS

Phase I, multicenter, open-labelled, non-comparative and dose escalating trial. Patients with locally advanced HNSCC were enrolled onto cohorts of escalating dose of etoposide. Oral etoposide was administered on five consecutive days every week for 7 weeks (7 treatment cycles) in combination with daily radiotherapy (70 Gy /35 fractions). Two dose levels (25 mg/day and 50 mg/day) of etoposide were planned and three to six patients were to be enrolled at each level according to the potential DLTs.

RESULTS

Fourteen patients were allocated to two dose levels: 25 mg/day (3) and 50 mg/day (11). Cisplatin was contra-indicated in all the patients included. Only one patient (50 mg/day) presents a grade 4 neutropenia (DLT), no other DLTs were observed. The most frequently adverse events (AEs) were radiomucositis. Two deaths before 3 months of end of treatment were not related to treatment. Seven patients were still alive with a median follow-up of 30 months (12-58 months). Nine patients had a complete response (CR) at 3 months after the radiotherapy; Among the 9 patients, 3 patients had a local relapse; one patient with local and distant relapse.

CONCLUSION

Due to only one DLT experienced, it is possible to a dose of 50 mg/day for phase II studies, however this should be considered with caution.

Salvage Therapy with Oral Etoposide in Recurrent and/or Metastatic Squamous Cell Carcinoma of the Head and Neck

BACKGROUND

The purpose of this retrospective evaluation was to assess the palliative effect of oral etoposide in heavily pretreated patients with squamous cell carcinoma of the head and neck.

PATIENTS AND METHODS

Between October 1995 and February 2003, a total of 26 patients with metastatic and/or recurrent squamous cell carcinoma of the head and neck (SCCHN) were treated with oral etoposide. Therapy consisted of etoposide at a total dose of 100 mg daily for 7 days and was repeated every 4 weeks until progression of disease or for a maximum of 8 courses. Eighteen patients underwent primary surgery of the tumour followed by adjuvant irradiation or surgery after neoadjuvant radiochemotherapy. Eight patients had primary irradiation with or without concomitant chemotherapy. All patients previously received at least one palliative chemotherapy with cisplatin/5-floururacil (5-FU) or cisplatin/taxotere. Patients did not routinely receive anti-emetic medication.

RESULTS

All patients were eligible for toxicity and survival assessment, and 24 of 26 patients for response evaluation according to an intention-to-treat principle. Two patients had a partial response (8 percent); disease was stable in 9 patients (35 percent) and progressed in 13 patients (50 percent). The median time to progression for all patients was 3 months (range, 2-54), and median overall survival was 10 months (range, 2-52). Toxicity was in general mild and moderate (Grade 1 and 2), except three patients, who experienced Grade 3 anaemia, and one patient who had Grade 3 thrombocytopenia without bleeding complications. Severe nonhematologic adverse reactions were not seen, except for alopecia.

CONCLUSION

Our data suggest that oral etoposid is markedly effective, in regard to stabilization of disease and survival, and an excellent tolerated therapy for pretreated patients with recurrent and/or metastatic head and neck carcinomas. Its advantage over other commonly used and more intensive regimens such as 5-fluorouracil (5-FU) + cisplatin or taxane-containing combinations is its superior tolerance, in particular the incidence of nausea and vomiting, complete alopecia, and/or hematologic complications.

Etoposide attenuates zymosan-induced shock in mice

Zymosan-induced generalized inflammation is a convenient model to study the process of acute and chronic inflammatory processes resulting in multiple organ dysfunction syndrome. Macrophages as a source of many pro-inflammatory mediators are the major players in shock and further organ failure. Etoposide is a cytostatic drug known to reduce macrophages and monocytes in blood circulation. In the present study we have investigated whether the ability of etoposide to diminish macrophage number would have an impact on the course of zymosan-induced shock. The drug injected at a dose of 10 mg/kg 1 day before zymosan, significantly reduced the mortality and decreased the organ toxicity in Balb/c mice. Simultaneously, an inhibition of TNF-alpha production by alveolar and peritoneal macrophages was observed. Etoposide administered into mice with severe combined immunodeficiency (SCID) did not change the survival rate and had a little influence on organ toxicity. Our findings suggest that the beneficial action of etoposide might be attributed to the reduction of macrophages and alteration of their functions. Its effect depends on the presence of functional T and B lymphocytes. The results deserve further investigation of etoposide as a perspective therapeutic tool for inhibiting the excessive inflammatory response and to be helpful for revealing mechanisms of shock development.

Methyltrioxorhenium catalysed synthesis of highly oxidised aryltetralin lignans with anti-topoisomerase II and apoptogenic activities

A novel and efficient procedure to prepare highly oxidised aryltetralin lignans, such as isopodophyllotoxone and (-)-aristologone derivatives, by oxidation of podophyllotoxin and galbulin with methylrhenium trioxide (MTO) and novel MTO heterogeneous catalysts is reported. It is noteworthy that in the case of isopodophyllotoxone derivatives the functionalisation of the C-4 position of the C-ring and the ring-opening of the D-lactone moiety increased the activity against topoisomerase II while causing the undesired inhibition of tubulin polymerisation to disappear. The novel (-)-aristologone derivatives showed apoptogenic activity against resistant human lymphoma cell lines.

Antitumor activity of unsaturated fatty acid esters of 4'-demethyldeoxypodophyllotoxin

Unsaturated fatty acid esters of 4'-demethyldeoxypodophyllotoxin (DDPT) were prepared and tested for antitumor activity. The esters showed increased in vivo antitumor activity despite the lower in vitro activity than DDPT. Especially, the ester (DFE12) of all-cis-11,14-eicosadienoic acid was much better (IR, 83%) than VP-16 (IR, 60%) without loss of body weight. Unsaturated fatty acids could be evaluated to be good carrier vehicles of DDPT.

Effects of induction therapy on wound healing at bronchial anastomosis sites in rats

OBJECTIVES

Preoperative chemotherapy is frequently used for advanced lung cancer. As a valid alternative to pneumonectomy, bronchoplasty has the advantage of enabling lung parenchyma function to be preserved. The effects of antineoplastic agents on healing bronchial anastomosis remain unclear. We studied the effects of preoperative chemotherapy on wound healing in bronchial anastomoses and clarified causes of wound healing impairment in rats.

METHODS

In experiment I, at 3 days before surgery, rats were injected with cyclophosphamide, doxorubicin, and vincristine (CAV group) or cisplatin and etoposide (PVP treated rats). In experiment II, at 48 hrs before surgery, rats were treated with rabbit antirat macrophage serum and antirat monocyte chemoattractant protein-1 antibody to inhibit macrophage infiltration. On days 3, 5, and 7 after bronchus anastomosis, wound healing was assessed by examining bursting strength and hydroxyproline tissue content.

RESULTS

CAV-treated rats showed significant impaired wound healing, marked severe leucopenia, and reduced macrophage infiltration. The PVP group showed no significant changes. In experiment II, rats exhibited inhibited macrophage infiltration, which is associated with significantly impaired of wound healing.

CONCLUSIONS

Our study suggests that induction chemotherapy, associated with leukopenia in the early phase of wound healing, increases the risk of bronchial anastomosis leakage. Postoperative macrophage depletion is one of the most important causes of impaired wound healing.

Prodrug Mono Therapy: synthesis and biological evaluation of an etoposide glucuronide-prodrug

A glucuronide-based prodrug of etoposide has been synthesized for a Prodrug Mono Therapy strategy. The aim is to selectively liberate the active compound by beta-D-glucuronidase already present in necrotic tumours. Outside from these sites, this enzyme is known to be localised inside the lysosomes. The three components of this prodrug are the glucuronic acid (substrate of the enzyme), the spacer (for a faster cleavage), and the active etoposide. In vitro, the prodrug was shown to be less cytotoxic and more water-soluble than etoposide itself. Finally, in the presence of the beta-D-glucuronidase, cleavage of the prodrug with complete release of the drug has been observed.

Study of either ifosfamide or teniposide compared to a standard chemotherapy for extensive disease small cell lung cancer: an Eastern Cooperative Oncology Group randomized study (E1588)

This randomized study of previously untreated patients with extensive disease small cell lung cancer was designed (a) to compare the survival of patients treated with either effective standard chemotherapy or an investigational anti-cancer drug as initial therapy and (b) to evaluate response rates and toxic effects of such therapies. One hundred and thirty-five patients were randomly assigned to receive as initial therapy, either the standard CAV regimen--cyclophosphamide (1000 mg/m(2)), doxorubicin (50 mg/m(2)) and vincristine (1.4 mg/m(2)) every 3 weeks--or the phase II drugs ifosfamide (1.5 gm/m(2)/days 1-5) with mesna (300 mg/m(2)) dose at 0, 4 and 8 h after IV daily ifosfamide every 3 weeks or teniposide (60 mg/m(2)/days 1-5) every 3 weeks. Nonresponders received salvage chemotherapy-etoposide (120 mg/m(2) on days 1, 2 and 3) and cisplatin (60 mg/m(2) on day 1), repeated every 3 weeks. Among the 46 patients on CAV, there were two complete and 24 partial responses (56%). Among the 43 patients on ifosfamide, there were three complete and 18 partial responses (49%), while among the 46 patients on teniposide, there were two complete and 18 partial responses (43%). Eighty-three of the patients proceeded onto salvage regimen, of which 81 were analyzable for response and toxicity. Among the 81 patients who continued on salvage therapy and were evaluable for response, the overall best response rate was 61% for CAV+salvage, 54% for ifosfamide+salvage, and 53% for teniposide+salvage. These rates were not significantly different (P=0.962). Of the 135 analyzable patients, 130 (96%) have died. The estimated median survival time was 42 weeks for CAV patients, 43 weeks for ifosfamide, and 38 weeks for teniposide. Seven patients survived longer than 2 years (four on CAV, one on ifosfamide and two on teniposide). There were 29 life-threatening complications to the induction regimen (22 (48%) on CAV, four (9%) on ifosfamide and three (7%) on teniposide) and seven lethal complications (two on CAV, four on ifosfamide and one on teniposide). The treatments were significantly different with respect to the overall degree of toxicity (P < 0.0001) with CAV being more toxic. The data of this study, like the previous ECOG study suggests that the administration of a new agent followed by effective salvage chemotherapy in the treatment of extensive disease small cell lung cancer may have no adverse effect on survival.

Intra-arterial cisplatin plus oral etoposide for the treatment of recurrent malignant glioma: a phase II study

Twenty-five adults with recurrent malignant glioma were enrolled into a phase II clinical study. All patients had undergone surgical resection and had failed radiotherapy and first-line treatment with nitrosourea-based chemotherapy; five had failed second-line chemotherapy. Our objective was to test the efficacy of combining intra-arterially (i.a.) infused cisplatin and oral etoposide. Using conventional angiographic technique to access anterior/posterior cerebral circulation, cisplatin 60 mg/m2 was administered by i.a. infusion on day 1 of treatment. Oral etoposide 50 mg/m2/day was given days 1-21, with a 7 day rest interval between courses. Response to treatment was evaluated in 20 patients. Two patients with anaplastic astrocytoma had partial responses (PR) and six patients experienced stable disease (SD) for an overall response rate (PR +/- SD) of 40%. The median time to disease progression (MTP) following treatment for the responder subgroup was 18 weeks. The median survival time from treatment (MST) for the responders (n = 8) and non-responders (n = 12) was 56.5 weeks and 11 weeks, respectively. Combined i.a. cisplatin and oral etoposide was well-tolerated, but produced an objective response in only a minority of patients. Those considered responders (PR + SD) experienced significant survival advantage when compared to the non-responders. Nonetheless, i.a. delivery of chemotherapy is an expensive and technologically burdensome treatment for most patients to access, requiring proximity to a major center with neuro-oncological and neuroradiological clinical services. This is of special concern for patients suffering recurrent disease with progressive neurological symptoms at a time in their course when quality of life must be safeguarded and palliation of symptoms should be the therapeutic goal. Despite the efforts of previous investigators to use this combination of agents to treat recurrent malignant glioma, we cannot recommend the use of i.a. chemotherapy for salvage treatment of this disease.

Superiority of high-dose platinum (cisplatin and carboplatin) compared to carboplatin alone in combination chemotherapy for small-cell lung carcinoma: a prospective randomised trial of 280 consecutive patients

PURPOSE

A prospective randomized trial in small-cell lung cancer (SCLC) was performed to determine if intensification of the platinum dose by giving cisplatin and carboplatin in combination to patients with SCLC yields higher response rates and survival, than carboplatin alone in a combination chemotherapy regimen.

PATIENTS AND METHODS

Between September 1992 and October 1997, 280 patients were included in a two armed prospective randomized trial, stratified by stage of disease, LDH and performance status. The treatment was in arm A: three courses induction chemotherapy with carboplatin (AUC = 4, day 1), cisplatin (35 mg/m2, days 2 and 3), teniposide (50 mg/m2, day 1-5), vincristine (1.3 mg/m2, day 1) every four weeks, followed by cyclophosphamide (3 g/m2, day 84), 4-epirubicin (4-epidoxorubicin) (150 mg/m2, day 112), and finally one course cisplatin, carboplatin, teniposide and vincristine, (days 140-144). Arm B also comprised a total of six courses, identical to those in arm A except for omission of cisplatin.

RESULTS

There were no significant differences in the overall treatment outcome for A vs. B, in terms of response rates (72% in both arms), complete response rates (40% and 34%, respectively), or median survival (314 days and 294 days, respectively). However, for patients with limited disease both the CR rate (54% vs. 37%, P < 0.05), overall survival (log-rank test, P < 0.05), and the two-year survival rate (11% vs. 6%, P < 0.05) were higher in the high-dose platinum arm compared to the carboplatin alone arm.

CONCLUSIONS

The intensification of platinum dose (cisplatin plus carboplatin) in combination chemotherapy significantly increased the complete response rate, overall survival and number of two-year survivors among SCLC patients with limited disease compared to combination therapy with carboplatin alone, suggesting that a more aggressive treatment to this category of patients is worthwhile, while no difference in treatment outcome was observed for patients with extensive disease.

Phase II trial of oral etoposide in recurrent or refractory endometrial adenocarcinoma: a southwest oncology group study

Oral etoposide has activity in a wide variety of tumors and is well tolerated. Therefore, the efficacy of oral etoposide was assessed as a treatment of metastatic endometrial cancer. To be eligible for this group-wide Southwest Oncology Group trial, patients had to have histologically proven metastatic or recurrent endometrial carcinoma; no previous cytotoxic therapy; and adequate renal, hepatic, and hematologic function, and they had to have given informed consent. Therapy consisted of oral etoposide, 50 mg daily on days 1-21 on a 28-day schedule. Therapy was continued in the absence of toxicity or disease progression. Forty-four eligible women, with a median age of 68 years (range 38-84 years) were treated. Radiotherapy had been delivered to 33 and hormomal therapy to 21. The median duration of therapy was 69 days (range 7-510 days). The treatment was well tolerated. Only one patient had grade 4 neutropenia, and a second had grade 4 anemia. Three patients had grade 3 nausea. One complete and five partial responses (14%) were observed. An additional four patients had unconfirmed responses. Tumor regressions were noted in nodes, bone, and visceral organs. While oral etoposide has only a modest level of activity when used in chemonaive patients, the minimal toxicity of this drug makes it a candidate for use in combination chemotherapy.

Cisplatin, etoposide, and paclitaxel in the treatment of patients with extensive small-cell lung carcinoma

PURPOSE

The combination of cisplatin, etoposide, and paclitaxel was studied in patients with extensive small-cell lung cancer in a phase I component followed by a phase II trial to determine the maximum-tolerated dose (MTD), characterize toxicity, and estimate response and median survival rates.

PATIENTS AND METHODS

Forty-one patients were treated between October 1993 and April 1997. Doses for the initial cohort were cisplatin 75 mg/m(2) on day 1, etoposide 80 mg/m(2)/d on days 1 to 3, and paclitaxel 130 mg/m(2) on day 1 over 3 hours. Cycles were repeated every 3 weeks for up to six cycles. The MTD was reached in the first six patients. In these six patients and in the next 35 patients, who were entered onto the phase II trial, response and survival were estimated.

RESULTS

At the initial dose level, one of six patients developed febrile neutropenia, and five of six achieved targeted neutropenia (nadir absolute granulocyte count, 100 to 1,000/microL) without any other dose-limiting toxicity, defining this level as the MTD. Grade 4 neutropenia was observed in 88 (47%) of 188 total courses administered at or less than the MTD. Neutropenia was associated with fever in only 17 (9%) of 188 courses, but two patients experienced neutropenic sepsis that was fatal. Nonhematologic toxicity greater than grade 2 was observed in 10 (5%) of 188 total courses, with fatigue, peripheral neuropathy, and nausea/vomiting most common. The overall objective response rate was 90% of 38 assessable patients: six complete responses (16%) and 28 partial responses(74%). Median progression-free and overall survival durations were 31 and 47 weeks, respectively.

CONCLUSION

The combination of cisplatin, etoposide, and paclitaxel produced response and survival rates similar to those of other combinations and was well tolerated.

Etoposide: four decades of development of a topoisomerase II inhibitor

Podophyllin-containing materials have been used as folk medicines for centuries. In the 1950s, scientists began a search to identify a more effective podophyllotoxin derivative. These efforts eventually resulted in the development of a new class of antineoplastic agents which target the DNA unwinding enzyme, topoisomerase II. The history of the development of one of the first identified topoisomerase II inhibitors, etoposide, is reviewed in this paper. Critical developments in etoposide's mechanism of action, pharmacology and administration schedule are summarised. The clinical benefits of the recently marketed etoposide prodrug, etoposide phosphate (Etopophos) are also detailed. The current status of other clinically approved anticancer agents which target topoisomerase II is briefly reviewed.

Differential expression of DNA topoisomerase II alpha and II beta genes between small cell and non-small cell lung cancer

DNA topoisomerase II (Topo II) inhibitors are widely used in lung cancer chemotherapy, but small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) show different sensitivity to them. In this study, we examined the gene expression levels of both isoforms of Topo II (II alpha and II beta) in lung cancer specimens to investigate the differential expression between SCLC and NSCLC. The expression levels of the Topo II alpha and Topo II beta genes were assessed in 80 autopsy samples (40 primary tumors and 40 corresponding normal lung tissues) by using the reverse transcription polymerase chain reaction. We found that the expression levels of the Topo II alpha gene in tumors were significantly higher than those in normal lung tissues, and that those in SCLC were significantly higher than those in NSCLC. There were no significant differences in Topo II beta gene expression between tumors and normal lung tissues and between SCLC and NSCLC. Further-more, correlation analysis revealed that Topo II alpha expression was correlated with Topo II beta expression in both tumor and normal lung tissues. These results indicate that a difference exists in the regulation of the Topo II gene between lung tumors and normal lung tissues. Our finding of differential expression of Topo II alpha between SCLC and NSCLC also suggests that the Topo II alpha expression level is associated with sensitivity to Topo II inhibitors.

Palladated and platinated complexes derived from phenylacetaldehyde thiosemicarbazone with cytotoxic activity in cis-DDP resistant tumor cells. Formation of DNA interstrand cross-links by these complexes

In the present paper we report the synthesis and characterization by 1H 13C NMR and heteronuclear 2D NMR spectroscopies of two new metallic complexes derived from phenylacetaldehyde thiosemincarbazone: Pt(C9H11N3S)Cl2, compound 2, and Pd(C9H11N3S)Cl2, compound 3. The testing of the cytotoxic activity of these compounds against several human and murine cell lines sensitive and resistant to cis-DDP suggests that compounds 2 and 3 may be considered potential anticancer agents since they exhibit 1C50 values in a microM range similar to cisplatin (cis-DDP). The cytotoxic activity of these compounds is higher in cis-DDP-resistant tumor cells than that of other antitumor drugs such as etoposide and adriamycin. On the other hand, the analysis of the interaction of compounds 2 and 3 with linear plasmid DNA indicate that both compounds, particularly compound 3, have an enhanced capacity to form DNA interstrand cross-links in comparison with cis-DDP.

Cisplatin, ifosfamide, and prolonged oral etoposide in the treatment of patients with extensive small cell lung carcinoma

BACKGROUND

The combination of cisplatin, ifosfamide, and prolonged oral etoposide (PIE) was studied in patients with extensive small cell lung carcinoma (SCLC) in a Phase I trial followed by a Phase II trial to determine the maximum tolerated dose (MTD), characterize toxicity, and estimate response and median survival rates.

METHODS

Thirty-three patients were treated between October 1991 and December 1994. Doses for the initial cohort were cisplatin 20 mg/m2/day, ifosfamide 1500 mg/m2/day with mesna (all given intravenously on Days 1-3), and oral etoposide 50 mg/m2 on Days 4-17. This cycle was repeated every 4 weeks for up to 6 cycles. The MTD was reached for the first 9 patients. For these 9 patients and the next 24 patients, who were entered in the Phase II trial, response and survival were estimated.

RESULTS

Dose-limiting toxicity was manifested as Grade 4 neutropenia in 3 of 3 patients (associated with fever in 2 of 3), and Grade 4 thrombocytopenia was encountered in 2 of 3 patients at the second dose level. Of 6 patients treated at the first dose level, 4 achieved targeted myelosuppression (absolute granulocyte count nadir <1000), but only 1 experienced Grade 4 neutropenia, defining this level as the MTD. Grade 4 neutropenia and/or thrombocytopenia was observed in 36 (24%) of a total of 152 courses administered at or below the MTD. Nonhematologic toxicity above Grade 2 was uncommon, excluding nausea and vomiting. Overall objective response rate was 93% of 30 evaluable patients: 5 (17%) complete responses and 23 partial responses (76%). Median failure free and overall survival durations were 36 and 54 weeks, respectively.

CONCLUSIONS

The combination of cisplatin, ifosfamide, and oral etoposide produced encouraging failure free and overall median survival rates in patients with extensive SCLC. These results warrant further evaluation of this regimen in the initial therapy of patients with limited stage disease.

Comparison of DNA topoisomerase II alpha expression in small cell and nonsmall cell carcinoma of the lung. In search of a mechanism of chemotherapeutic response

BACKGROUND

Small cell carcinoma of the lung (SCLC) is distinguished from nonsmall cell carcinoma (NSCLC) by its exquisite initial sensitivity to chemotherapy. Antineoplastic drugs effective against SCLC include doxorubicin, etoposide, and others. Recently, the molecular target of these drugs has been identified as the alpha form of DNA topoisomerase II, which is important in DNA replication and in the separation of chromosomes during normal cellular division. In this study we compared DNA topoisomerase II alpha expression in SCLC and NSCLC by immunohistochemistry. We hypothesized that the sensitivity of SCLC and relative insensitivity of NSCLC to these chemotherapeutic agents stem from different frequencies of DNA topoisomerase II alpha expression.

METHODS

DNA topoisomerase II alpha expression was analyzed in 17 cases of SCLC and 24 cases of NSCLC by immunohistochemistry utilizing a monoclonal antibody recognizing the alpha isoform of DNA topoisomerase II. A topo II index was determined by dividing the number of tumor nuclei expressing DNA topoisomerase II by the total number of tumor nuclei counted.

RESULTS

A significantly higher frequency of DNA topoisomerase II alpha expression was identified in SCLC (P < 0.001). The average topo II index for SCLC was 0.60 (range: 0.45-0.76) compared with NSCLC, 0.31 (range: 0.05-0.75).

CONCLUSIONS

We conclude that DNA topoisomerase II alpha is expressed at a higher frequency in SCLC than in NSCLC, and that this expression is possibly involved in the response of SCLC to chemotherapeutic agents.

Mechanisms of resistance of human small cell lung cancer lines selected in VP-16 and cisplatin

BACKGROUND

The combination of VP-16 and cisplatin is one of the most active regimens available for the treatment of small cell lung cancer (SCLC), however, most tumors eventually become resistant to these drugs.

METHODS

To investigate the problem of resistance to VP-16 and cisplatin in patients with SCLC, we established two resistant sublines from the drug sensitive human SCLC line, NCI-H209, by in vitro selection in VP-16 and cisplatin.

RESULTS

The VP-16-selected cell line, H209/VP, was more than 100-fold resistant to VP-16, and displayed cross-resistance to VM-26 and other topoisomerase II interactive drugs, but not to vinca alkaloids. There was no difference in accumulation of VP-16 in H209/VP compared with its parent cell line. The level of topoisomerase II-alpha was reduced to 8% of that in the parent cell line, and there was an altered form of this enzyme with a molecular weight of 160 kilodaltons (kDa), in addition to the normal 170 kDa protein. The cisplatin-selected cell line, H209/CP, was 11.5-fold resistant to cisplatin, with only a low level of cross-resistance to other platinum compounds including carboplatin, tetraplatin, iproplatin, and lobaplatin. This line was highly cross-resistant to vinca alkaloids, but not to anthracyclines or epipodophyllotoxins. The H209/CP cell line was not resistant to cadium chloride, suggesting that alterations in metallothionein are unlikely to be a cause of resistance. Although glutathione (GSH) levels were increased nearly 2-fold in H209/CP, there was no difference in levels of the GSH-related enzymes glutathione-S-transferase, glutathione peroxidase, and glutathione reductase, compared with the parent line. The H209/CP line had a 1.4-fold elevation of topoisomerase II-alpha. The accumulation of cisplatin was reduced in this cell line, and there were fewer DNA-interstrand cross links formed in the presence of cisplatin in H209/CP, compared with the parent line. Neither H209/VP nor H209/CP expressed MDR1, the gene for P-glycoprotein. The MRP gene was expressed at a slightly higher level in the H209/VP cell line, but there was no significant increase in expression of this gene in the H209/CP cell line.

CONCLUSIONS

The resistance of the H209/VP cell line is associated with an alteration of topoisomerase II-alpha, whereas the resistance in the H209/CP line is associated with reduced drug accumulation.

Phase I study and clinical pharmacological evaluation of daily oral etoposide combined with carboplatin in patients with lung cancer

Twenty-eight patients with inoperable or relapsed lung cancer were given a combination of oral etoposide, administered once a day at doses ranging from 40 to 60 mg/m2/day (d) for 21 consecutive days, and carboplatin, administered intravenously over 1 h at doses ranging from 300 to 400 mg/m2 on day 1 to determine the appropriate doses of this combination. In addition, pharmacokinetic and pharmacodynamic analyses were performed. All the patients had a performance status of 0 to 1. Serum etoposide and free platinum (Pt) concentrations were measured using high-performance liquid chromatography and atomic absorption, respectively. Myelosuppression, nausea and vomiting were the dose-limiting toxicities of this schedule. The maximum tolerated dose (MTD) was 50 mg/m2/d oral etoposide for 21 days and 400 mg/m2 i.v. carboplatin on day 1. For heavily pretreated patients, the MTD was 40 mg/m2/d oral etoposide for 21 days and 350 mg/m2 i.v. carboplatin on day 1. No cumulative increase in the area under the concentration-time curve (AUC) for oral etoposide over time was observed. There were significant correlations between the free Pt serum level (6, 8, 12, 24 h post-dose) and etoposide AUC level (days 1, 10 and 21) for graded hematological toxicity, and the percentage decreases and nadir counts of hemoglobin, leukocytes, neutrophils and platelets. Several pharmacodynamic models were developed to predict the hematological toxicity. In order to facilitate pharmacodynamic evaluations in future studies, a limited sampling model for oral etoposide was also developed and validated.

The role of radiation oncology in small cell lung cancer

Small cell lung cancer comprises a histologic subgroup of bronchogenic carcinomas distinguished particularly by a responsiveness to cytotoxic agents, and equally by a strong tendency to disseminate, both to mediastinal and distant sites. At one time considered suitable only for short-term palliation by radiation therapy, this disease is now managed by both systemic and regional approaches, typically with close integration of radiotherapy and chemotherapy. Thoracic irradiation produces modest improvements in both survival and local control in small cell lung cancer, when the clinical extent is limited to the chest. The optimal parameters of dose, treatment volume, fractionation, and temporal integration with chemotherapy are not yet defined. When the disease is more extensive radiotherapy plays a useful palliative role. New biological insights are being brought to the clinic, and have stimulated new therapeutic initiatives in the treatment of this disease. Modified radiotherapy fractionation schemes and sophisticated integration of chemotherapy and radiation therapy have resulted in further advances. In addition to improved response rates and median survivals, combined modality approaches suggest, in addition, the possibility of cured subset in cases of disease confined to the chest. The adverse effects of thoracic irradiation are manageable and the more serious can be prevented with careful attention to volume and technique. Radiotherapy offers relief of many symptoms and cost-effective palliation of metastatic lesions in most body sites. Considered as a significant problem in oncology, and apart from efforts at primary prevention, major progress in this disease is most likely to result from research focussed on the limited disease subset, which, unfortunately, consists of no more than half the incident cases. These patients have a median survival of 12-18 months, and are sufficiently numerous that it is possible to detect meaningful treatment progress in clinical trials of a reasonable size. Nevertheless, the marked advances of two decades ago, when chemotherapy first came into widespread use, are not seen today. Progress is now more likely to be seen in modest improvements in survival or tumor control rates when control and experimental regimens are compared statistically in large trials or in meta-analyses. While the evidence supports the use of thoracic radiotherapy the ideal drug combination is unknown, and there is a real need for new agents of substantially greater activity than those available today. While more rational combinations of agents may be possible, it seems likely that the limits of tolerance are being reached.(ABSTRACT TRUNCATED AT 400 WORDS)

Etoposide: current status and future perspectives in the management of malignant neoplasms

Etoposide has demonstrated highly significant clinical activity against a wide variety of neoplasms, including germ-cell malignancies, small-cell lung cancer, non-Hodgkin's lymphomas, leukemias, Kaposi's sarcoma, neuroblastoma, and soft-tissue sarcomas. It is also one of the important agents in the preparatory regimens given prior to bone marrow and peripheral stem-cell rescue. Despite its high degree of efficacy in a number of malignancies, the optimal dose, schedule, and dosing form remain to be defined. It is possible that continuous or prolonged inhibition of the substrate, i. e., topoisomerase II, may be the key factor for the cytotoxic effects of etoposide. Clinical studies have shown the activity of etoposide to be schedule-dependent, with prolonged dosing, best accomplished by the oral dosing form, offering a therapeutic advantage. This benefit awaits validation by prospective randomized studies, some of which are in progress. Recent clinical investigations have focused on the use of etoposide in combination with (a) cytokines to ameliorate myelosuppression, the dose-limiting toxicity of etoposide; (b) agents such as cyclosporin A and verapamil to alter the p-glycoprotein (mdr1) function; and (c) topoisomerase I inhibitors to modulate the substrate upon which it acts. There is continued interest in the development of etoposide to its maximal clinical dimensions and in the examination of alternative biochemical and mechanistic approaches to further our understanding of this highly active agent.

Activity of topoisomerase inhibitors against Pneumocystis carinii in vitro and in an inoculated mouse model

Five topoisomerase II inhibitors (amsacrine [m-AMSA], two epipodophyllotoxins, and two quinolones) and the alkaloid camptothecin (a topoisomerase I inhibitor) were evaluated to assess their activities against Pneumocystis carinii. In vitro, both etoposide (VP-16) and teniposide (VM-26) at 1 microgram/ml suppressed P. carinii growth. Amsacrine was toxic to P. carinii and to the feeder cells in vitro. Camptothecin suppressed the growth of P. carinii in vitro only at 100 micrograms/ml. Studies in immunosuppressed mice demonstrated the efficacy of teniposide against P. carinii pneumonia, but successful administration of teniposide was schedule dependent with significant toxicity at therapeutic dosages.

Investigation of new agents in small-cell lung cancer

The identification of new agents active against small-cell lung cancer (SCLC) remains a high priority for clinical investigators. Recently, 2 very different approaches have been used to evaluate new agents in this disease. Some groups have opted to test new agents in previously untreated patients with extensive-stage SCLC, and the second approach is to continue to test new agents only in previously treated patients. Regardless of which method is used, it appears that new-agent activity can be assessed in either previously treated or untreated SCLC patients without compromising the therapeutic gains of the past 2 decades, provided proper patient selection guidelines are employed.

A phase II trial of cisplatin and prolonged administration of oral etoposide in extensive-stage small cell lung cancer

Etoposide is a schedule-dependent agent with greater activity against small cell lung cancer (SCLC) when a given dose is administered over several days compared with a 1-day administration of the same dose. In an attempt to capitalize on the schedule dependency of etoposide, 22 previously untreated extensive-stage SCLC patients were given cisplatin (100 mg/m2 on day 1) plus 21 days of low-dose, oral etoposide (50 mg/m2/d). Chemotherapy was repeated every 28 days for four cycles. Complete blood counts were monitored weekly, and etoposide was discontinued if either the leukocyte or platelet count dropped below 2000/microliters or 75,000/microliters, respectively. All 22 patients were evaluable for response; 18 had either a complete (9%) or partial response (73%), an overall response rate of 82% (95% confidence interval, 62% to 93%). The median response duration was 7 months, and the median survival was 9.9 months (range, 1 to 17+ months). Sixteen (73%) patients received all planned cycles of etoposide. In Cycle 1 of chemotherapy, the median leukocyte nadir was 2700/microliters (range, 100 to 6300/microliters), and median platelet nadir was 180,000/microliters (range, 51,000 to 397,000/microliters). Life-threatening leukopenia (less than 1000/microliters) was rare (3 of 74 cycles). There were three treatment-related deaths, only one of which was associated with neutropenia. One patient had mild renal insufficiency that resolved after discontinuation of therapy. Alopecia was observed in all patients, but other nonhematologic toxicities were uncommon. A randomized study is necessary to determine if this schedule of cisplatin and etoposide administration is superior to more standard methods. However, these data do not indicate a major survival benefit will be derived from increasing the duration of etoposide administration when used in combination with cisplatin given every 28 days.

Etoposide in the management of non-small cell lung cancer

Etoposide is a phase-specific, schedule-dependent derivative of podophyllotoxin that appears to act by inhibiting DNA-topoisomerase II. Early preclinical work demonstrated sharp activity in mouse leukemias and possible synergy with cisplatin. As a single agent (either orally or intravenously), it demonstrated limited benefit in non-small cell lung cancer (NSCLC), with response rates around 10%. In combination with cisplatin, it has become a mainstay of chemotherapeutic efforts, either as primary therapy or in conjunction with radiation. Response rates in advanced disease average around 30%, climbing to more than 50% in patients with Stage IIIA or IIIB disease. More recent work suggests that the issue of the true synergy of etoposide with cisplatin in NSCLC needs reassessment. The relative roles of etoposide and cisplatin in the combination are unclear, as several studies conflict. Pharmacokinetic data suggest that multiple daily fractions of etoposide are superior to prolonged infusions, warranting several future trials. The current major role for etoposide plus cisplatin would appear to be in multimodality therapy where the combination can be readily combined with radiation and/or surgery. Several other agents have been studied with etoposide or etoposide plus cisplatin (mitomycin, vindesine, doxorubicin, cyclophosphamide, ifosfamide, and carboplatin), but it is unclear whether the addition of any of them offers any response or survival advantage.