Phase II study of gemcitabine (2',2'-difluorodeoxycytidine) in previously treated ovarian cancer patients.

BACKGROUND: Platinum-containing combination chemotherapy has resulted in improved survival rates in patients with advanced ovarian carcinoma, but the majority of the patients still die of their disease. It is therefore important to develop new non-cross-resistant drugs. Gemcitabine (2',2'-difluorodeoxycytidine) has shown a broad spectrum of antineoplastic activity in tumor cell cultures in vitro and in animal tumor models. Clinical activity also has been reported in a variety of solid tumor types. PURPOSE: Our purpose was to assess the clinical activity of gemcitabine in previously treated ovarian cancer patients and to further characterize the toxicity of the compound. METHODS: Gemcitabine (800 mg/m2) was given intravenously once a week for 3 consecutive weeks, followed by 1 week of rest. A maximum of two different prior treatment regimens was allowed. Response was assessed by pelvic examination and/or ultrasound and computed tomography scans every other course. RESULTS: Fifty patients were eligible; 35 (70%) had bulky disease (tumor greater than 5 cm in diameter). All patients had received prior platinum-containing combination chemotherapy. Forty-two patients were assessable for response. Eight (19%) of the 42 patients (95% confidence interval = 9%-34%) achieved a partial response, with a median response duration of 8.1 months (range, 4.4-12.5 months). All responders started treatment with gemcitabine within 6 months of prior treatment, and seven of the eight responders were resistant to first-line platinum-containing combination chemotherapy. Overall median time to progression was 2.8 months (range, 0.2 12.5 months), and overall median survival was 6.2 months (range, 0.2-26.0 months). Forty-eight patients were assessable for toxicity. Leukocytopenia and thrombocytopenia were the main toxic effects that caused dose omissions (27% and 14%, respectively) and dose reductions (37% and 21%, respectively). A transient mild flu-like syndrome occurred in 28% of the patients, and treatment-related peripheral edema developed in 22%. Grade 1 hematuria (53% of patients), grade 1-2 proteinuria (79% of patients), and liver toxicity that was mostly grade 1-2 (59% of patients) were also observed. CONCLUSIONS: Gemcitabine is a well-tolerated new drug with activity in platinum-resistant ovarian cancer patients. IMPLICATIONS: Confirmatory trials are needed, and the activity of gemcitabine in previously untreated patients should be assessed.

Comparison of the predictive power of different prognostic indices for overall survival in patients with advanced ovarian carcinoma.

Validation of a 5-covariate prognostic index (PI5) (performance status, stage, residual tumor size, histological grade, and ascites) derived from a group of 268 Dutch patients with advanced ovarian carcinoma was performed in a similar study of 301 Danish patients. Analysis of survival suggested an alternative 4-covariate PI (performance status, residual tumor size, age, weight/body surface) for the latter group. As residual tumor size and performance status were common to both indices, the predictive power of this 2-covariate PI (PI2) was also assessed in the Danish study and, subsequently, validated in the Dutch patients. The PI5 defined 10 and 9% of the Dutch patients as low and high risk patients with 3-year survival rates of 80 and 8%, respectively. In the Danish study the PI5 classified 14% to be high risk patients with a 3-year survival rate of 18%. Only a few patients (3%) were classified as low risk, making comparisons irrelevant. The PI2 classified 33 and 26% of the Danish patients as having 3-year survival rates of 67 and 13%, respectively. The corresponding Dutch PI2 values were 41 and 15% of the patients with 3-year survival rates of 60 and 8%, respectively. Although the PI5 possessed a better validity in the Danish study than the PI2 in the Dutch study, the PI2 may be the best prognostic index available for general use.

Reduced glutathione protects against cisplatin-induced neurotoxicity in rats.

Reduced glutathione (GSH) is reported to diminish cisplatin-induced neurotoxicity, and it was for this reason that we studied GSH in an animal model of cisplatin neuropathy. The neuropathy was evaluated by measuring the sensory nerve conduction velocity (SNCV) in young adult Wistar rats. GSH injections (i.v.) were given twice weekly, within five minutes before cisplatin was injected (i.p.). In a first experiment GSH (500 mg/kg) in combination with a low-dose cisplatin treatment (1 mg/kg, 10 weeks) was investigated. Animals treated with cisplatin and placebo developed a neuropathy (SNCV at week 10: age controls, 61.9 m/s; cisplatin alone, 44.2 m/s), whereas rats treated with cisplatin and GSH did not (SNCV, 61.9 m/s). The same dose of GSH was used in combination with a high-dose cisplatin schedule (2 mg/kg, 5 weeks' treatment plus 5 weeks' recovery). Again, GSH protected animals against the development of neuropathy (SNCV at week 10: age controls, 61.9 m/s; cisplatin alone, 50.6 m/s; cisplatin plus GSH, 61.1 m/s). In another experiment four lower doses of GSH (25, 50, 100, and 200 mg/kg) were tested in combination with the low-dose cisplatin protocol (1 mg/kg, 11 weeks). The cisplatin group developed a neuropathy (SNCV at week 11: cisplatin alone, 50.2 m/s; age controls, 60.6 m/s). Only the dose of 200 mg GSH/kg was found to protect against the development of a neuropathy (SNCV, 61.0 m/s). In an antitumor study GSH administered at 300 mg/kg in combination with cisplatin at 1.5 mg/kg did not diminish the curative effect of cisplatin. We conclude that GSH prevents cisplatin-induced neuropathy and that it should be investigated further in the clinic.

Increased hydrogen peroxide concentration in human tumor cells due to a nitroxide free radical.

Evidence is presented that the nitroxide free radical, TEMPO, at concentrations commonly used to prevent oxidative damage, increases the intracellular hydrogen peroxide concentration. To investigate the origin of this increased hydrogen peroxide concentration, we have incubated various human tumor cell lines with compounds interfering with the generation of active oxygen metabolites. Sodium azide, inhibitor of the respiratory chain, the iron-chelating agent desferrioxamine, superoxide dismutase and catalase had no effect on the hydrogen peroxide concentration. Metyrapone, inhibitor of the cytochrome P450 system, was demonstrated to decrease, but not completely prevent, the hydrogen peroxide production. N-ethylmaleimide, a sulphydryl-bond alkylating agent, was able to completely prevent the increased hydrogen peroxide production. We conclude that, by increasing the cellular hydrogen peroxide concentration, TEMPO exerts a pro-oxidant effect. This increase in hydrogen peroxide production seems to be mediated by the induction of oxidase activity in the cytochrome P450 system, but other cellular systems involved in electron transport may also play a role.

Predictability of the survival of patients with advanced ovarian cancer.

Based on material from two clinical trials performed by The Netherlands Joint Study Group for Ovarian Cancer, we constructed a prognostic index (PI) with considerable predictive power for long-term survival of patients treated with cytotoxic combination chemotherapy including cisplatin. The pretreatment characteristics needed for the calculation of the PI are the Karnofsky index, the site of metastases expressed as the International Federation of Gynecology and Obstetrics (FIGO) stage, the size of residual tumor, the Broders' grade, and the presence of ascites. In the subgroup comprising the 10% of the patients with the best prognosis, 4-year survival was 75%, whereas all of the patients in the subgroup comprising the 10% with the poorest prognosis died within 4 years, which illustrates the large variability of the prognosis among patients. The PI was found to retain its value after response was achieved. The information provided by the PI can be expected to be useful in treatment planning and for proper stratification of patients in clinical trials.

Randomized trial comparing two combination chemotherapy regimens (CHAP-5 v CP) in advanced ovarian carcinoma.

One hundred ninety-one patients with advanced epithelial ovarian carcinoma were treated with either a combination of doxorubicin and a five-day course of cisplatin alternating with cyclophosphamide and hexamethylmelamine orally for 14 days (CHAP-5) or cyclophosphamide and cisplatin both administered intravenously (IV) on a single day at 3-week intervals (CP). At a median follow-up time of 45 months, treatment with each of these combinations resulted in the same remission rates (80% and 74%, respectively) and exactly the same progression-free survival and overall survival (median, 26 months). Despite adequate hydration, more renal toxicity was encountered in the CP-treated patients than in those who received CHAP-5. Disabling neurotoxicity and severe myelosuppression were encountered more frequently in the patients treated with CHAP-5. Because the toxicity was lower and CP treatment required shorter hospitalization, the single-day regimen was considered preferable for future use. The Karnofsky index was the only independent predictor for response, whereas both this index and the size of residual tumor before chemotherapy were predictive of survival. After correcting for other prognostic factors, it was determined that tumor size associated with improved survival was less than 1 cm. The site of metastases in International Federation of Gynecology and Obstetrics (FIGO) stage IV patients did not influence survival within this category. The results of this study confirm our previous findings that patients with microscopic remnants at second-look have a survival similar to that of patients who are histopathologically free of disease. This makes the significance of so-called pathologically confirmed complete remission questionable. The survival benefit of debulking surgery performed during chemotherapy seems only minimal for patients in whom debulking has already been attempted before treatment. Like others, we have found the CP regimen to have a good therapeutic index.

Palliative pamidronate treatment in patients with bone metastases from breast cancer.

PURPOSE: An open, randomized study was performed to assess the effects of supportive pamidronate treatment on morbidity from bone metastases in breast cancer patients. PATIENTS AND METHODS: Eighty-one pamidronate patients and 80 control patients were monitored for a median of 18 and 21 months, respectively, for events of skeletal morbidity and the radiologic course of metastatic bone disease. The oral pamidronate dose was 600 mg/d (high dose [HD]) during the earliest study years, then changed to 300 mg/d (low dose [LD]) because of gastrointestinal toxicity. Twenty-nine of 81 pamidronate (HD/LD) patients first received 600 mg/d and were then changed to 300 mg/d; 52 of 81 pamidronate LD patients received 300 mg/d throughout the study. Tumor treatment was unrestricted. RESULTS: An overall intent-to-treat analysis was performed. In the pamidronate group, the occurrence of hypercalcemia, severe bone pain, and symptomatic impending fractures decreased by 65%, 30%, and 50%, respectively; event-rates of systemic treatment and radiotherapy decreased by 35% (P < or = .02). The event-free period (EFP), radiologic course of disease, and survival did not improve. Subgroup analyses suggested a dose-dependent treatment effect. Compared with their controls, in pamidronate HD/LD patients, events occurred 60% to 90% less frequently (P < or = .03) and the EFP was prolonged (P = .002). In pamidronate LD patients, event-rates decreased by 15% to 45% (P < or = .04). Gastrointestinal toxicity of pamidronate caused a 23% drop-out rate, but other cancer-associated factors seemed to contribute to this toxicity. CONCLUSION: Pamidronate treatment of breast cancer patients efficaciously reduced skeletal morbidity. The effect appeared to be dose-dependent. Further research on dose and mode of treatment is mandatory.

Exploratory phase III study of paclitaxel and cisplatin versus paclitaxel and carboplatin in advanced ovarian cancer.

PURPOSE: To determine the side effects and feasibility of cisplatin and carboplatin each in combination with paclitaxel as front-line therapy in advanced epithelial ovarian cancer. PATIENTS AND METHODS: Patients were randomly allocated to receive paclitaxel 175 mg/m(2) intravenously as a 3-hour infusion followed by either cisplatin 75 mg/m(2) or carboplatin (area under the plasma concentration-time curve of 5), both on day 1. The schedule was repeated every 3 weeks for at least six cycles. Women allocated to paclitaxel-cisplatin were admitted to the hospital, whereas the carboplatin regimen was administered to outpatients. RESULTS: A total of 208 eligible patients were randomized. Both regimens could be delivered in an optimal dose and without significant delay. Paclitaxel-carboplatin produced significantly less nausea and vomiting (P: <.01) and less peripheral neurotoxicity (P: =.04) but more granulocytopenia and thrombocytopenia (P: <.01). The overall response rate in 132 patients with measurable disease was 64% (84 of 132 patients), and in patients with elevated CA 125 levels at start, it was 74% (132 of 178 patients). With a median follow-up time of 37 months, the median progression-free survival time of all patients was 16 months and the median overall survival time was 31 months. The small number of patients entered onto the study caused wide confidence intervals (CIs) around the hazards ratio for progression-free survival of paclitaxel-carboplatin compared with paclitaxel-cisplatin (hazards ratio, 1.07; 95% CI, 0.78 to 1.48) and did not allow conclusions about efficacy. CONCLUSION: Paclitaxel-carboplatin is a feasible regimen for outpatients with ovarian cancer and has a better toxicity profile than paclitaxel-cisplatin.

Carboplatin in combination therapy for ovarian cancer.

Cisplatin today is a cornerstone of combination chemotherapy for ovarian cancer. Carboplatin seems equal to cisplatin in antitumour activity, but has a different toxicity profile. After a feasibility study, a randomized phase III study in ovarian cancer stage II, III, and IV was undertaken, comparing carboplatin with cisplatin in combination with cyclophosphamide, doxorubicin and hexamethylmelamine. Preliminary analysis of this study reveals no statistically significant difference in response rate. Notwithstanding equal haematological toxicity, the other side effects evoked by carboplatin in combination treatment are much milder than those evoked by cisplatin. Further analysis will be necessary to draw definite conclusions about the results obtained.

The in vitro response of human tumour cells to desferrioxamine is growth medium dependent.

Iron chelating agents have been demonstrated to inhibit tumour cell growth. However, in vitro and in vivo results using desferrioxamine a hexadentate iron chelating agent, for anti-cancer treatment are not always in agreement. Therefore, we have studied the response of three human tumour cell lines (HL-60 promyelocytic leukaemia, MCF-7 breast cancer and HepG2 hepatoma), grown in culture medium supplemented with either human pooled (HPS) or fetal bovine serum (FBS), to desferrioxamine. Desferrioxamine, at micromolar concentrations, induced severe cytotoxicity in all tumour cell lines grown in FBS medium. When grown in HPS medium, comparable desferrioxamine cytotoxicity was observed in the millimolar range. The addition of 50% saturated human transferrin to FBS medium resulted in protection against desferrioxamine cytotoxicity. HL-60 cells were further studied for iron metabolism characteristics. HL-60 cells, grown in medium with FBS, were found to have an 8.4 fold increase in surface transferrin receptor (TfR) expression (P < 0.001) as compared with HL-60 cells grown in medium with HPS. However, iron uptake of HPS cultured HL-60 cells, after incubation with saturated human transferrin, was higher, resulting in a higher concentration of iron in HPS cultured HL-60 cells as compared with FBS cultured cells (1.72 +/- 0.02 mumol/g protein v. 1.32 +/- 0.14 mumol/g protein; P < 0.001). Using desferrioxamine it was shown that TfR expression is dependent on the biological availability of iron in the cell. Consistent with the lower iron content in FBS cultured cells, we conclude that the cytotoxicity of desferrioxamine is dependent on the ability of cells to replenish cellular iron stores from the culture medium. Cells grown in FBS medium lack this ability and are therefore more susceptible to desferrioxamine.

Systemic treatment in disseminated endometrial cancer.

Both hormonal agents and chemotherapy are of value in the treatment of selected patients with endometrial cancer. In unselected patients with advanced disease about 25% respond to progestational agents and 40% to combination chemotherapy. The choice between the two treatments is made on the basis of a number of prognostic factors, such as receptor status, tumour grade, performance status and tumour burden. Further improvement of treatment outcome is to be expected from new agents such as gonadotrophin releasing hormone analogues, taxol and modulation of 5-fluorouracil.

Aspects of surgery in ovarian and endometrial carcinoma.

In ovarian cancer and endometrial cancer the surgeon plays an important role in both the staging procedure and in the removal of as much of the tumour as possible. Although uniform treatment policies have not been developed, a better understanding of the pattern of spread in both tumours allows for accurate staging and can be of help in selecting patients for more extended treatment and saving others from unnecessary overtreatment.

Reaction kinetics of cisplatin and its monoaquated species with the modulating agents (di)mesna and thiosulphate.

The reactive and rapidly excreted thiol mesna (2-mercaptoethane-sulphonate sodium) has the potential to reduce the dose-limiting nephrotoxicity of cisplatin by chemical neutralisation of the latter in the kidney. The reaction kinetics of cisplatin with mesna and its disulphide, dimesna, was studied at 37 degrees C in unbuffered 0.15 mol/l NaCl (pH 5.3) and in 0.15 mol/l NaCl buffered with 0.02 mol/l Hepes (pH 7.4). The reaction mixtures were analysed for intact cisplatin. In the presence of mesna or dimesna 0.5 mol/l as anticipated in urine for conditions of renal protection, the half-life (t1/2) of 0.2 mmol/l cisplatin was less than 6 min. t1/2 of 151 and 629 min were found in the presence of mesna and dimesna concentrations of 5 mmol/l and 3 mmol/l, respectively, anticipated in plasma under conditions of renal protection. Cis-diamminemonoaquamonochloroplatinum(II) 0.2 mmol/l reacted rapidly with 50 mmol thiosulphate and 0.5 mol/l (di)mesna (t1/2 less than or equal to 1 min). This platinum species also reacted rapidly with 2.6 mmol/l thiosulphate (t1/2 less than 1 min), a concentration reached in plasma for conditions under renal protection. Reaction of the monoaquated form of cisplatin proceeded slowly in the presence of dimesna or mesna concentrations (less than 5 mmol/l), as anticipated in plasma under renal protecting conditions. It is hypothesised that renal protection by the strong nucleophiles, thiosulphate, mesna and dimesna occurs rather by neutralisation of the aquated species in the lumen of the renal tubulus than by neutralisation of intact cisplatin, and that neutralisation of these species in plasma contributes significantly to the protecting effect.

Phase II clinical trial of doxifluridine in patients with advanced ovarian cancer.

35 evaluable patients were treated with 5'-deoxy-5-fluorouridine (doxifluridine), a fluoropyrimidine derivative. All patients had been heavily pretreated and had refractory disease. Treatment with doxifluridine at a dosage of 3000 mg/m2 given intravenously for 5 successive days at 3-week intervals led to 6 partial remissions (17%). The main side-effects were central neurotoxicity, stomatitis and myelotoxicity, resulting in 2 toxic deaths. In patients with renal function disturbances, toxicity proved to be more severe. We concluded that the drug should not be used in patients with renal impairment. Because responses have been encountered, further evaluation of the drug may be warranted in the less toxic oral form.

Long-term survival in ovarian cancer. Mature data from The Netherlands Joint Study Group for Ovarian Cancer.

In two studies initiated in 1979 and 1981, 377 patients were treated for advanced epithelial ovarian cancer. In the first study patients were randomly assigned to receive Hexa-CAF (hexamethylmelamine, cyclophosphamide, methotrexate, 5-fluorouracil) or CHAP-5 (cyclophosphamide, hexamethylmelamine, doxorubicin, cisplatin for 5 days) and in the second study to receive CHAP-5 or CP (cyclophosphamide, cisplatin on 1 day). Patients who did not respond to Hexa-CAF were offered subsequent treatment that included cisplatin. Median follow-up of patients in the first study was 9.5 years and in the second study 7.7 years. At 10 years 9% of the patients initially treated with Hexa-CAF and 21% of patients assigned to CHAP-5 were alive. Among the 10-year survivors treated with Hexa-CAF, 50% had experienced progressive disease but were alive as a result of retreatment with a cisplatin regimen. The survival curves of both studies revealed that approximately 60% of the patients who reached a complete remission were alive at 5 years and 40% at 10 years. Patients with microscopic disease at second-look had a less favourable outlook: 35% survived 5 years. Not recognised at first publication of both studies was the influence of tumour grade on survival. Before 5 years of follow-up, the good prognosis of grade 1 tumours (well differentiated) could not be detected. About 50% of patients with grade 1 tumours were alive at 5 and 30% at 10 years while these survival rates were halved for the other grades. Combination chemotherapy with cisplatin can enhance survival by more than 10% at 5 and 10 years compared with the best treatment of the precisplatin era: Hexa-CAF.

Phase II study of mitomycin-C and cisplatin in disseminated, squamous cell carcinoma of the uterine cervix. A European Organization for Research and Treatment of Cancer (EORTC) Gynecological Cancer Group study.

The aim of this study was to investigate the tumour response rate and toxicity of a combination chemotherapy consisting of mitomycin-C and cisplatin in patients with disseminated squamous-cell carcinoma of the uterine cervix. Chemotherapy consisted of mitomycin, 6 mg/m(2) intravenously (i.v.), and cisplatin, 50 mg/m(2) given i.v., both administered on day 1 of each cycle. The regimen was repeated at 4-weekly intervals. Mitomycin-C/cisplatin were used to treat 33 evaluable patients aged 29-67 years (median: 50 years). All patients except 1 had previously been treated with either surgery, radiation or both. At the initiation of chemotherapy, 8 patients had loco-regional and disseminated disease and 25 women had only distant metastases. The overall response rate was 42% (95% confidence interval (CI): 26-61%). Five complete and nine partial responses were observed with a median duration of response of 7.9 months (95% CI: 3.7-23.5 months). 9 patients had stable disease and 10 developed progressive disease during mitomycin-C/cisplatin-treatment. World Health Organization (WHO) grade III/IV side-effects were documented in 15 women, of whom 10 had gastro-intestinal toxicity, 3 had haematological toxicity, 1 had alopecia and 1 developed an allergic reaction to cisplatin. There were neither drug-related deaths nor severe or irreversible renal or hepatic dysfunction or peripheral neuropathy. The median progression-free survival was 5.0 months (95% CI: 3.6-6.2 months) for all patients and 10.5 months (95% CI: 6.2-15.2 months) for the responders. The median overall survival was 11.2 months (95% CI: 6.5-18.4 months).The mitomycin-C/cisplatin combination showed antitumour activity in the treatment of advanced or recurrent squamous-cell carcinoma of the uterine cervix. The regimen was well tolerated and could be administered on an outpatient basis.

Gemcitabine in cisplatin-resistant ovarian cancer.

Many new drugs have been tested in phase II studies in recent years. With a number of drugs the results vary because of differences in the patients recruited to these studies. A number of factors impact the response to second-line therapy, including the treatment-free interval between the end of previous therapy and the entry into phase II study, the bulk and stage of disease, the histology of the tumor, and hemoglobin level. The activity of the new drug tested is also important. It may be difficult to compare the results of different studies, as not all reports contain the same information. A report of a phase II study should contain information on all previous treatment, time since diagnosis, time since last treatment, tumor size at entry, hemoglobin values, performance status, histology, frequency of tests performed to evaluate toxicity, and clear definitions of response. Of the new drugs recently tested, the taxane paclitaxel has shown promising activity even in platinum-resistant patients. Gemcitabine, the novel nucleoside analog, also has shown activity in platinum-resistant patients in a phase II study. The response rate in this study was 19% (95% confidence limits, 9% to 34%). More importantly the responses were observed in a poor prognostic group of patients, characterized by primary platinum resistance, International Federation of Gynecology and Obstetrics stage IV, a treatment-free interval < or = 6 months, large bulky disease, and poorly differentiated/undifferentiated tumors. Both hematologic and nonhematologic toxicities were modest. The data suggest that gemcitabine, like paclitaxel, is non-cross-resistant to platinum.

Paclitaxel with carboplatin for the treatment of ovarian cancer.

Paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) (135 mg/m2 over 24 hours) plus cisplatin (75 mg/m2 at a rate of I mg/min) every 3 weeks is widely accepted as the new standard of treatment for women with advanced epithelial ovarian cancer. A higher dose of paclitaxel over a shorter infusion period is under investigation as an alternative because it looks at least as effective and is more convenient to administer. However, in combination with cisplatin this dose-time schedule causes neurotoxicity in an important number of patients that can preclude the delivery of an adequate total dose. One way to decrease the incidence of this side effect is to substitute cisplatin with the analogue carboplatin. From the present data the conclusion is warranted that it is feasible to combine both drugs in an adequate dose and with acceptable toxicity. The combination would allow administration to outpatients and may be more tolerable, allowing prolonged treatment. The combination also looks attractive for re-treatment of women who relapse after completing their first-line paclitaxel/cisplatin-based therapy and who have chemotherapy-sensitive disease and prognostic features indicating that there is a high likelihood of achieving a second durable remission.

Paclitaxel/carboplatin for the initial treatment of advanced ovarian cancer.

In 1996, the combination of cisplatin 75 mg/m2 plus 24-hour infusion of 135 mg/m2 paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) was proved to prolong survival in comparison with cyclophosphamide/cisplatin in women with advanced ovarian cancer. As a result, the paclitaxel/cisplatin combination was recommended to serve as the new standard of care. One year later, a European-Canadian group confirmed the efficacy of paclitaxel/cisplatin in a study in which the infusion period of paclitaxel was reduced from 24 to 3 hours and the dose of paclitaxel escalated to 175 mg/m2. These changes resulted in a lower incidence of myelosuppression but a higher rate of neurotoxicity. Replacing cisplatin with carboplatin, a platinum analogue without the neurotoxic effects, proved feasible, and several trials were initiated to compare the safety and efficacy of paclitaxel/carboplatin with paclitaxel/cisplatin. The results of two of these studies that have completed accrual and reported preliminary data have shown that paclitaxel/carboplatin can be administered safely to outpatients, is better tolerated than paclitaxel/cisplatin, and results in a better quality of life. So far, the larger study (accrual, 800 patients) has yielded equal durations of progression-free survival for both the carboplatin and cisplatin combinations. If future updates of these studies confirm the current results and show similar long-term survival, the combination of carboplatin area under the concentration-time curve 5 or 6 plus paclitaxel 175 mg/m2 given over 3 hours is an attractive regimen for the treatment of newly diagnosed epithelial ovarian cancer.

Paclitaxel (175 mg/m2 over 3 hours) with cisplatin or carboplatin in previously untreated ovarian cancer: an interim analysis.

The side effects of cisplatin (75 mg/m2) in combination with paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) (175 mg/m2 over 3 hours) are expected to be more severe and frequent than those of carboplatin (area under the concentration-time curve of 5) in combination with the same dose of paclitaxel, but the combinations are expected to be equally effective. A disadvantage of the cisplatin-based regimen is that patients need to be admitted to the hospital. The carboplatin regimen can be administered to outpatients. We tested both combinations administered every 3 weeks in a randomized phase III study in patients with previously untreated epithelial ovarian cancer. An interim analysis for toxicity was performed in 145 patients shortly after study closure. We observed a difference in the incidence of nausea, vomiting, and neurotoxicity favoring the women treated with the carboplatin regimen, but this regimen caused more myelotoxicity. Maturation of the study is awaited before survival data can be analyzed and final conclusions can be drawn.