The platelet-sparing effect of paclitaxel is not related to changes in the pharmacokinetics of carboplatin

The role of carboplatin in combination with paclitaxel in patients with castration-resistant prostate cancer

Background: The aim of the present study was to examine the efficacy of carboplatin in combination with paclitaxel in patients with metastatic castration-resistant prostate cancer pretreated with multiple regimens including docetaxel and androgen receptor-targeted agents. Methods: Clinical data from patients treated with carboplatin plus paclitaxel were collected retrospectively from a single institution. Results: 43 patients with metastatic castration-resistant prostate cancer were identified. Median number of cycles was ten (range: 1 to 23), prostate-specific antigen response was observed in 18 (42%) patients, median progression-free survival was 115 days and median overall survival was 8.1 months. Conclusion: Combination chemotherapy using taxane with carboplatin is an effective and well-tolerated therapy in heavily pretreated patients with metastatic castration-resistant prostate cancer.

Drawing a link between the thromboxane A2 pathway and the role of platelets and tumor cells in ovarian cancer

Ovarian cancer is the most lethal gynecologic malignancy among women. Due to the heterogeneity and complexity of the disease, as well as the insidious onset of symptoms, timely diagnosis remains extremely challenging. Despite recent advances in chemotherapy regimens for ovarian cancer patients, many still suffer from recurrence and ultimately succumb to the disease; thus, there is an urgent need for the identification of novel therapeutic targets. Within this rapidly evolving field, the role of platelets in the ovarian cancer tumor microenvironment has garnered increased attention. It is well-established that platelets and tumor cells exhibit bidirectional communication in which platelets enhance tumor cell invasion, extravasation, and protection from host system defenses, while tumor cells serve as platelet agonists, increasing platelet adhesion, aggregation, and degranulation. This mini-review focuses on the platelet-tumor cell relationship in ovarian cancer, specifically highlighting the essential role of bioactive lipid mediators at this interface.

The Efficacy of Low-Dose Paclitaxel Added to Combination Chemotherapy of Carboplatin and Gemcitabine or Pegylated Liposomal Doxorubicin

OBJECTIVE

Paclitaxel is known to produce the "platelet-sparing effect" that prevents the carboplatin-induced decrease in platelet count. We conducted a pilot study to assess whether the addition of low-dose paclitaxel to carboplatin-based combination chemotherapy prevents thrombocytopenia.

METHODS

Patients with platinum-sensitive recurrent ovarian cancer received intravenous (IV) paclitaxel at 60 mg/m(2) followed by IV carboplatin at an area under the curve of 6 and IV pegylated liposomal doxorubicin at 30 mg/m(2) on day 1 in a 28-day cycle (DC-LOP) or IV gemcitabine at 1000 mg/m(2) on days 1 and 8 in a 21-day cycle (GC-LOP).

RESULTS

During May 2011 to December 2011, 7 patients received 29 cycles of DC-LOP; during January 2012 to May 2013, 15 patients received 88 cycles of GC-LOP. Grade 3/4 thrombocytopenia occurred in 2 (33%) of 6 and 9 (56%) of 16 patients in the DC-LOP and GC-LOP groups, respectively. No grade 3/4 nonhematological toxicity was observed. Only one patient who received GC-LOP had grade 2 sensory and motor peripheral neuropathy. Paclitaxel-related toxicities, including muscle pain, arthralgia, and peripheral neuropathy, were consistently rare and mild. The response rates of DC-LOP and GC-LOP were 33% (0, complete response; 2, partial response; 3, stable disease; 1, progression disease) and 50% (2, complete response; 6, partial response; 7, stable disease; 1, progression disease), respectively.

CONCLUSIONS

Although low-dose paclitaxel addition did not alleviate thrombocytopenia in the setting of this pilot study, the results do not deny the existence of the "platelet-sparing effect" by low-dose paclitaxel. Further investigation of the carboplatin-based combination chemotherapy including a drug with mild hematological toxicity is warranted.

Molecular Dissection of Induced Platinum Resistance through Functional and Gene Expression Analysis in a Cell Culture Model of Bladder Cancer

We report herein the development, functional and molecular characterization of an isogenic, paired bladder cancer cell culture model system for studying platinum drug resistance. The 5637 human bladder cancer cell line was cultured over ten months with stepwise increases in oxaliplatin concentration to generate a drug resistant 5637R sub cell line. The MTT assay was used to measure the cytotoxicity of several bladder cancer drugs. Liquid scintillation counting allowed quantification of cellular drug uptake and efflux of radiolabeled oxaliplatin and carboplatin. The impact of intracellular drug inactivation was assessed by chemical modulation of glutathione levels. Oxaliplatin- and carboplatin-DNA adduct formation and repair was measured using accelerator mass spectrometry. Resistance factors including apoptosis, growth factor signaling and others were assessed with RNAseq of both cell lines and included confirmation of selected transcripts by RT-PCR. Oxaliplatin, carboplatin, cisplatin and gemcitabine were significantly less cytotoxic to 5637R cells compared to the 5637 cells. In contrast, doxorubicin, methotrexate and vinblastine had no cell line dependent difference in cytotoxicity. Upon exposure to therapeutically relevant doses of oxaliplatin, 5637R cells had lower drug-DNA adduct levels than 5637 cells. This difference was partially accounted for by pre-DNA damage mechanisms such as drug uptake and intracellular inactivation by glutathione, as well as faster oxaliplatin-DNA adduct repair. In contrast, both cell lines had no significant differences in carboplatin cell uptake, efflux and drug-DNA adduct formation and repair, suggesting distinct resistance mechanisms for these two closely related drugs. The functional studies were augmented by RNAseq analysis, which demonstrated a significant change in expression of 83 transcripts, including 50 known genes and 22 novel transcripts. Most of the transcripts were not previously associated with bladder cancer chemoresistance. This model system and the associated phenotypic and genotypic data has the potential to identify some novel details of resistance mechanisms of clinical importance to bladder cancer.

Paclitaxel Enhances Carboplatin-DNA Adduct Formation and Cytotoxicity

This rapid report focuses on the pharmacodynamic mechanism of the carboplatin/paclitaxel combination and correlates it with its cytotoxicity. Consistent with the synergistic to additive antitumor activity (the combination index ranging from 0.53 to 0.94), cells exposed to this combination had significantly increased carboplatin-DNA adduct formation when compared to that of carboplatin alone (450 ± 30 versus 320 ± 120 adducts per 10(8) nucleotides at 2 h, p = 0.004). Removal of paclitaxel increased the repair of carboplatin-DNA adducts: 39.4 versus 33.1 adducts per 10(8) nucleotides per hour in carboplatin alone (p = 0.021). This rapid report provides the first pharmacodynamics data to support the use of carboplatin/paclitaxel combination in the clinic.

Polymorphisms in SLCO1B3 and NR1I2 as genetic determinants of hematotoxicity of carboplatin and paclitaxel combination

Aim: The goal of our study was to assess the impact of patients’ genetic background on their sensitivity to carboplatin/paclitaxel hematotoxicity. Patients & methods: Parameters describing sensitivity to neutropenia and to thrombocytopenia of 201 patients were extracted from a previous pharmacokinetic/pharmacodynamics analysis, in order to assess their association with 52 candidates SNPs in 18 genes. Results: Carriers of a T allele of SLCO1B3-rs4149117 were 19% less sensitive to thrombocytopenia than the homozygotes for the G allele (p = 0.00279). Carriers of two copies of the ATG haplotypes of NR1I2-rs1523130, rs3814055 and rs1523127 were 19% less sensitive to thrombocytopenia than those harboring other haplotypes (p = 0.025). Conclusion: Our results revealed the importance of SLCO1B3 and NR1I2 in the sensitivity to carboplatin/paclitaxel thrombocytopenia.

Modelling chemotherapy effects on granulopoiesis

Background

Although the growth-factor G-CSF is widely used to prevent granulotoxic side effects of cytotoxic chemotherapies, its optimal use is still unknown since treatment outcome depends on many parameters such as dosing and timing of chemotherapies, pharmaceutical derivative of G-CSF used and individual risk factors. We showed in the past that a pharmacokinetic and –dynamic model of G-CSF and human granulopoiesis can be used to predict the performance of yet untested G-CSF schedules. However, only a single chemotherapy was considered so far.

In the present paper, we propose a comprehensive model of chemotherapy toxicity and combine it with our cell kinetic model of granulopoiesis. Major assumptions are: proportionality of cell numbers and cell loss, delayed action of chemotherapy, drug, drug-dose and cell stage specific toxicities, no interaction of drugs and higher toxicity of drugs at the first time of application. Correspondingly, chemotherapies can be characterized by a set of toxicity parameters which can be estimated by fitting the predictions of our model to clinical time series data of patients under therapy. Data were either extracted from the literature or were received from cooperating clinical study groups.

Results

Model assumptions proved to be feasible in explaining granulotoxicity of 10 different chemotherapeutic drugs or drug-combinations applied in 33 different schedules with and without G-CSF. Risk groups of granulotoxicity were traced back to differences in toxicity parameters.

Conclusion

We established a comprehensive model of combined G-CSF and chemotherapy action in humans which allows us to predict and compare the outcome of alternative G-CSF schedules. We aim to apply the model in different clinical contexts to optimize and individualize G-CSF treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12918-014-0138-7) contains supplementary material, which is available to authorized users.

A microdosing approach for characterizing formation and repair of carboplatin-DNA monoadducts and chemoresistance

Formation and repair of platinum (Pt)-induced DNA adducts is a critical step in Pt drug-mediated cytotoxicity. Measurement of Pt-DNA adduct kinetics in tumors may be useful for better understanding chemoresistance and therapeutic response. However, this concept has yet to be rigorously tested because of technical challenges in measuring the adducts at low concentrations and consistent access to sufficient tumor biopsy material. Ultrasensitive accelerator mass spectrometry was used to detect [(14)C]carboplatin-DNA monoadducts at the attomole level, which are the precursors to Pt-DNA crosslink formation, in six cancer cell lines as a proof-of-concept. The most resistant cells had the lowest monoadduct levels at all time points over 24 hr. [(14)C]Carboplatin "microdoses" (1/100th the pharmacologically effective concentration) had nearly identical adduct formation and repair kinetics compared to therapeutically relevant doses, suggesting that the microdosing approach can potentially be used to determine the pharmacological effects of therapeutic treatment. Some of the possible chemoresistance mechanisms were also studied, such as drug uptake/efflux, intracellular inactivation and DNA repair in selected cell lines. Intracellular inactivation and efficient DNA repair each contributed significantly to the suppression of DNA monoadduct formation in the most resistant cell line compared to the most sensitive cell line studied (p < 0.001). Nucleotide excision repair (NER)-deficient and -proficient cells showed substantial differences in carboplatin monoadduct concentrations over 24 hr that likely contributed to chemoresistance. The data support the utility of carboplatin microdosing as a translatable approach for defining carboplatin-DNA monoadduct formation and repair, possibly by NER, which may be useful for characterizing chemoresistance in vivo.

Population pharmacokinetics and pharmacodynamics of paclitaxel and carboplatin in ovarian cancer patients: a study by the European organization for research and treatment of cancer-pharmacology and molecular mechanisms group and new drug development group

PURPOSE

Paclitaxel and carboplatin are frequently used in advanced ovarian cancer following cytoreductive surgery. Threshold models have been used to predict paclitaxel pharmacokinetic-pharmacodynamics, whereas the time above paclitaxel plasma concentration of 0.05 to 0.2 micromol/L (t(C > 0.05-0.2)) predicts neutropenia. The objective of this study was to build a population pharmacokinetic-pharmacodynamic model of paclitaxel/carboplatin in ovarian cancer patients.

EXPERIMENTAL DESIGN

One hundred thirty-nine ovarian cancer patients received paclitaxel (175 mg/m(2)) over 3 h followed by carboplatin area under the concentration-time curve 5 mg/mL*min over 30 min. Plasma concentration-time data were measured, and data were processed using nonlinear mixed-effect modeling. Semiphysiologic models with linear or sigmoidal maximum response and threshold models were adapted to the data.

RESULTS

One hundred five patients had complete pharmacokinetic and toxicity data. In 34 patients with measurable disease, objective response rate was 76%. Neutrophil and thrombocyte counts were adequately described by an inhibitory linear response model. Paclitaxel t(C > 0.05) was significantly higher in patients with a complete (91.8 h) or partial (76.3 h) response compared with patients with progressive disease (31.5 h; P = 0.02 and 0.05, respectively). Patients with paclitaxel t(C > 0.05) > 61.4 h (mean value) had a longer time to disease progression compared with patients with paclitaxel t(C > 0.05) < 61.4 h (89.0 versus 61.9 weeks; P = 0.05). Paclitaxel t(C > 0.05) was a good predictor for severe neutropenia (P = 0.01), whereas carboplatin exposure (C(max) and area under the concentration-time curve) was the best predictor for thrombocytopenia (P < 10(-4)).

CONCLUSIONS

In this group of patients, paclitaxel t(C > 0.05) is a good predictive marker for severe neutropenia and clinical outcome, whereas carboplatin exposure is a good predictive marker for thrombocytopenia.

Randomized phase II study comparing paclitaxel and carboplatin versus mitoxantrone in patients with hormone-refractory prostate cancer

OBJECTIVES

Mitoxantrone/prednisone was the 2002 palliative reference treatment for hormone-refractory prostate cancer (HRPC). Paclitaxel and carboplatin has demonstrated antitumor activity in HRPC. The therapeutic benefit of such treatment was compared with that of mitoxantrone.

METHODS

A randomized Phase II study was conducted that included 40 patients with HRPC who had not undergone chemotherapy. Patients in arm A received paclitaxel (175 mg/m2 every 3-week cycle) and carboplatin (area under the curve of 5 every 3-week cycle). Patients in arm B received mitoxantrone (12 mg/m2 every 3-week cycle). All the patients treated were receiving low-dose prednisone. The primary endpoint was the prostate-specific antigen response.

RESULTS

The prostate-specific antigen response to paclitaxel and carboplatin was significantly greater (40% [95% confidence interval 18.5% to 61.5%] versus 10% [95% confidence interval 1% to 32%], P = 0.031) and more durable (8.6 versus 2 months, P = 0.015) than the response to mitoxantrone. A tendency was noted for patients with measurable disease who were receiving paclitaxel and carboplatin to have a somewhat greater objective response rate than those who received mitoxantrone (23% [95% confidence interval 5.3% to 55%] versus no objective response, P = 0.060). The median overall survival was 14.5 months for the paclitaxel and carboplatin arm compared with 11.1 months for the mitoxantrone arm. The group given paclitaxel and carboplatin had significantly greater rates of sensitive neuropathy (50% versus 0%, P = 0.00026).

CONCLUSIONS

The 3-week regimen of paclitaxel and carboplatin induced a greater and more durable prostate-specific antigen response than did mitoxantrone for HRPC treatment. The major additive toxicity induced was peripheral neuropathy due to paclitaxel. Investigations with paclitaxel and carboplatin regimens merit large Phase III studies.

Evaluation of Calvert's Formula for Dosage Adjustment of Carboplatin in Japanese Patients with Hormone Refractory Prostate Cancer

For hormone refractory prostate carcinoma, a combination therapy of paclitaxel and carboplatin is used to expect life extension. We investigated the pharmacokinetics of carboplatin in Japanese prostate cancer patients (n=10, 55-72 years), and evaluated the usefulness of Calvert's formula in the individualized dosing adjustment. They were intravenously administered carboplatin (area under the free plasma concentration versus time curve (AUC)=5 mg.min/ml), following the intravenous administration of paclitaxel (175 mg/m(2)). The dosage of carboplatin for each patient was determined with Calvert's formula using individual creatinine clearance values. Plasma concentration of total platinum was measured sequentially and the pharmacokinetic parameters of carboplatin were determined in each patient. Plasma concentration of total carboplatin after intravenous infusion well fitted the two-compartment model. Carboplatin clearance was 62.0+/-12.7 ml/min (mean+/-S.D.), and linearly related to the individual creatinine clearance (r(2)=0.64, p<0.01). The actual AUC for total carboplatin was 8.20+/-1.11 mg.min/ml, and its inter-individual variability was decreased to 65% of that in carboplatin clearance, indicating the effectiveness of Calvert's formula for dosage adjustment of carboplatin. Leucopenia of grade 4 according to the National Cancer Institute's Common Toxicity Criteria was found in one patient, but no patient demonstrated thrombocytopenia. In conclusion, determining carboplatin dosage based on Calvert's formula decreased the inter-individual variability in the actual AUC compared with that in the carboplatin clearance, and a target AUC of 5 mg.min/ml of carboplatin was comparatively safe for Japanese patients with prostate cancer.

A phase II trial of weekly paclitaxel and every 3 weeks of carboplatin in potentially platinum-sensitive ovarian and peritoneal carcinoma

OBJECTIVE

Paclitaxel administered weekly in equal cumulative doses is associated with less hematologic and non-hematologic toxicity than an every 3-week administration. We studied weekly paclitaxel and 3-week carboplatin in potentially platinum-sensitive recurrent ovarian and peritoneal carcinoma.

METHODS

Paclitaxel at a dose of 80 mg/m(2) over 1 h in combination with carboplatin at an AUC of 5 was administered on day 1. Subsequent paclitaxel doses, modified based on the day of treatment ANC, were administered on days 8 and 15. Paclitaxel dose reductions to 75% of prior dose were performed for chemotherapy delays or toxicity.

RESULTS

Twenty-eight patients were studied. The median age was 59 (range 42-80). The median platinum-free interval was 12 months (range 7-129 months). A median of six courses (range 1-13) was administered. Paclitaxel dose reductions to 60 mg/m(2) were required in 85% of the patients. Grades 3 and 4 thrombocytopenia were seen in 5 and 0 patients, respectively. Grades 3 and 4 neutropenia were seen in 14 and 1 patients, respectively. One patient was hospitalized for neutropenic fever. Twenty of 26 (77%) evaluable patients have responded with 15 patients (58%) achieving a complete response.

CONCLUSIONS

Weekly paclitaxel at a dose of 60 mg/m(2) in combination with carboplatin at an AUC of 5 is well tolerated and active in potentially platinum-sensitive recurrent ovarian and peritoneal carcinoma.

A randomized cross-over trial to determine the effect of Cremophor EL on the pharmacodynamics and pharmacokinetics of carboplatin chemotherapy

PURPOSE

Paclitaxel, when combined with carboplatin, exhibits a platelet-sparing effect. Paclitaxel is formulated in Cremophor EL (CrEL), which has been shown in preclinical models to reduce haematological toxicity from radiotherapy and chemotherapy. We sought to determine the effect of a 3-h infusion of 20 ml/m2 (equivalent to 175 mg/m2 paclitaxel) CrEL on myelosuppression following carboplatin chemotherapy, and the effect of CrEL on carboplatin pharmacokinetics.

METHODS

A total of 16 patients with locally advanced or metastatic cancer were randomized to receive either CrEL or saline over 3 h prior to carboplatin (area under the curve, AUC, 5-7). Each patient was subsequently crossed over to the other treatment. Blood samples were collected at selected time-points for estimation of platinum AUC and 24-h platinum levels. Full blood counts were obtained three times per week.

RESULTS

Of the 16 patients randomized, 15 were evaluable. Myelosuppression was measured by percentage fall at nadir and nadir levels. No significant differences were obtained when comparing CrEL and saline with respect to the above end-points after adjusting for multiple testing. There was no evidence to indicate that CrEL altered the pharmacokinetics of carboplatin.

CONCLUSION

CrEL at this dose and schedule does not appear to be a major contributory factor to the platelet-sparing effect of paclitaxel when combined with carboplatin, nor does it alter the pharmacokinetics of carboplatin.

A Phase I and Pharmacokinetic Study of Weekly Paclitaxel and Carboplatin in Patients with Metastatic Esophageal Cancer

PURPOSE

To determine the maximum-tolerated dose, toxicity profile, and pharmacokinetics of a fixed dose of paclitaxel followed by increasing doses of carboplatin, given weekly to patients with advanced esophageal or gastric junction cancer.

EXPERIMENTAL DESIGN

Paclitaxel was administered on day 1 as a 1-h infusion at a fixed dose of 100 mg/m(2) followed by a 1-h infusion of carboplatin targeting an area under the curve (AUC) of 2-5 mg x min/ml, with cycles repeated on days 8, 15, 29, 36, and 43.

RESULTS

Forty patients [36 males; median (range) age, 57 (40-74) years] were enrolled. Dose-limiting toxicity was observed at a carboplatin AUC of 5 mg x min/ml and consisted of treatment delay attributable to myelosuppression. No grade 3/4 treatment-related nonhematological toxicity was observed. The highest dose intensity (>95% of the planned dose over time) was achieved with a carboplatin AUC of 4 mg x min/ml. The mean (+/-SD) AUCs of unbound (Cu) and total paclitaxel were 0.662 +/- 0.186 and 7.37 +/- 1.33 micro M x h, respectively. Clearance of Cu was 188 +/- 44.6 liter/h/m(2), which is not significantly different from historical data (P = 0.52). Cremophor EL clearance was 123 +/- 23 ml/h/m(2), similar to previous findings. Of 37 patients evaluable for response, 1 had complete response, 19 had partial response, and 10 had stable disease, accounting for an overall response rate of 54%.

CONCLUSIONS

This regimen is very tolerable and effective, and the recommended doses for additional studies are paclitaxel (100 mg/m(2)), with carboplatin targeting an AUC of 4 mg x min/ml.

Docetaxel and carboplatin as first-line chemotherapy in patients with advanced gynecological tumors. A phase I/II trial of the Arbeitsgemeinschaft Gynäkologische Onkologie (AGO-OVAR) Ovarian Cancer Study Group

OBJECTIVES

We performed a phase I-II study in patients with ovarian and other gynecological cancers to determine the dose-limiting toxicities, maximum tolerated dose (MTD) and efficacy of docetaxel/carboplatin.

METHODS

Thirty patients were treated in three cohorts with carboplatin (AUC 5) and escalating docetaxel (60, 75 and 90 mg/m2), administered intravenously on day 1, repeated every 3 weeks. Premedication consisted of 16 mg dexamethasone per os on day -1, and +1 and 4 mg intravenously before docetaxel.

RESULTS

A total of 6, 11 and 12 patients were eligible and treated on dose levels 1, 2 and 3, respectively. At docetaxel 90 mg/m2, febrile and prolonged neutropenia were dose-limiting, and 75 mg/m2 with carboplatin AUC 5 was considered the MTD. Prolonged neutropenia occurred in two, four and nine patients of dose levels 1-3, respectively, and febrile neutropenia in 2, 1, and 2 patients of dose level 1-3. Thrombocytopenia grade 4 was observed in one patient of dose level 1. Non-hematological toxicity including neuropathy was usually mild across all dose levels. Overall response rate was 73%. Median time to progression was 18.0 months, and median overall survival will exceed 24.4 months.

CONCLUSIONS

Docetaxel/carboplatin can be safely administered to patients with gynecological cancer despite substantial myelotoxicity and appears to be active in the treatment of ovarian cancer. Low neurotoxicity offers an option for comparison with paclitaxel-containing regimens.

First-line intraperitoneal carboplatin-based chemotherapy for 165 patients with epithelial ovarian carcinoma: results of long-term follow-up

OBJECTIVE

Currently, no long-term follow-up data are available on intraperitoneal (IP) carboplatin-based chemotherapy for ovarian carcinoma. In this study we evaluated retrospectively the survival and recurrence of a retrospective cohort of patients with epithelial ovarian cancer treated with first-line IP carboplatin-based therapy.

METHODS

Records were reviewed of 174 patients with epithelial ovarian cancer who received IP carboplatin-based therapy between 1990 and 2000. All patients underwent surgical staging, and implantable port systems were placed regardless of residual tumor size. The pathological slides were submitted and reviewed, and then nine patients were excluded because of borderline malignancies (n = 8), and wrong histology (n = 1). Therefore, the records of 165 patients were analyzed for survival. Tumor grade was determined by the Universal grading system. Statistical analysis included tests for association between potential prognostic factors, and between prognostic factors and survival. Survival probabilities were estimated by Kaplan-Meier methods, and prognostic factors for survival were evaluated by a Cox regression model.

RESULTS

The mean age of the patients was 53.7 years (range 21-83). The median follow-up was 41 months. The distribution by stage and histology was as follows: high risk (grade 2/3, clear cell, capsule rupture) stage I, 54; II, 21; III, 72; IV, 18; and serous, 75; clear cell, 30; mucinous, 27; endometrioid, 20; others, 13. The chemotherapy regimen was either carboplatin alone (n = 22) or in combination with cyclophosphamide (n = 116) or paclitaxel (n = 27). Catheter-related complications occurred in 16 (9.7%) cases. The chemotherapeutic response in 54 patients with measurable disease was 66.4%. The 5-year survival was 94.4% for stage I, and 87.9% for stage II. The median survival for optimal and suboptimal stage III/IV patients was 51 months and 34 months, respectively. The median survival of patients with stage III/IV disease was 51 months with carboplatin doses of 400 mg/m(2) or more, but it was only 25 months with carboplatin doses smaller than 400 mg/m(2). Poor prognostic factors, determined by Cox regression multivariate analysis, were clear cell histology (P < 0.001) and a carboplatin dose smaller than 400 mg/m(2) (P = 0.002).

CONCLUSIONS

Survival of patients who underwent carboplatin-based IP chemotherapy was excellent when the dose of carboplatin was higher than 400 mg/m(2). A prospective evaluation of IP carboplatin therapy with modern combination is warranted.