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R F Ozols

Publications and source records attributed to R F Ozols.

At least 19 recordsLinked to original sources

Time-dependent pharmacodynamic models in cancer chemotherapy: population pharmacodynamic model for glutathione depletion following modulation by buthionine sulfoximine (BSO) in a Phase I trial of melphalan and BSO.

The development of time-dependent pharmacodynamic models in cancer chemotherapy has been extremely limited. A population approach was used to develop such a model to describe the effect of buthionine sulfoximine (BSO), via its active S-isomer (S-BSO), on glutathione (GSH) depletion in peripheral mononuclear cells. The Phase I trial utilized escalating doses of BSO, from 5 to 17 gm/m2, as a multiple infusion regimen. The population model consisted of a linear 2-compartment pharmacokinetic model coupled to an indirect response model. The indirect response model consisted of a GSH compartment with input and output rate processes that are modulated as a function of S-BSO and GSH concentrations. The model predicted the observed gradual depletion of GSH, a nadir at approximately 30 h after the last dose of BSO, and a return to baseline GSH levels. On the basis of an IC50 estimate of about 1.6 microM for inhibition of gamma-glutamylcysteine synthetase, the target enzyme of BSO, the population model predicted near identical GSH concentration time profiles over the dose range studied. Time-dependent pharmacodynamic models are seen as a powerful means to design dosing regimens and to provide a mathematical platform for mechanistic based models.

Adult

Evidence for altered regulation of gamma-glutamylcysteine synthetase gene expression among cisplatin-sensitive and cisplatin-resistant human ovarian cancer cell lines.

We have shown previously that tumor cell resistance to cisplatin is associated with elevated intracellular levels of glutathione, which is accomplished at least in part by increased expression of the heavy subunit of gamma-glutamylcysteine synthetase (gamma-GCS). To investigate the mechanism by which gamma-GCS expression is elevated, we have examined four related human ovarian cancer cell lines with increasing cisplatin resistance. Relative amounts of steady-state gamma-GCS mRNA in CP70, C30, and C200 were 4.8, 6.0, and 10.6, respectively, compared to the parental A2780 cell line, and a proportional increase in the transcriptional rate but not RNA stability was demonstrated. In contrast, no increase in mRNA for the gamma-GCS light subunit was found. To determine the mechanism of upregulation of this mRNA, we have cloned the promoter of the gene that encodes the heavy subunit of gamma-GCS. This region contains AP-1, NF-kappa B, XRE, AP-2, EpRE, CAAT, and TATA box elements upstream of the transcription initiation site and two MREs between this site and the start codon for the protein. Using gel mobility shift assays, we have found nuclear extract binding activity to the AP-1 response element to be closely associated with the level of gamma-GCS gene expression. A supershift assay showed that the AP-1 DNA-binding complexes are predominantly formed by dimers of JUN family members. Consistent with this finding, the expression of c-JUN was found to be elevated in the resistant cells. In contrast to AP-1 binding, AP-2 and NF-kappa B binding were inversely related to resistance. Furthermore, we have examined a partial revertant of the C200-resistant cells, which shows lower glutathione levels, and found decreased gamma-GCS expression associated with decreased AP-1 binding activity.

Antineoplastic Agents

Characterization of chromosome 9 in human ovarian neoplasia identifies frequent genetic imbalance on 9q and rare alterations involving 9p, including CDKN2.

We have examined 41 forms of ovarian cancer for genetic alterations on chromosome 9 using a combination of five RFLP DNA probes and 15 simple tandem repeat polymorphisms. Genetic imbalance (i.e., loss of heterozygosity, microsatellite instability, amplification) for 1 or more informative markers on chromosome 9 was observed in 66% (27 of 41) of our tumor panel. Genetic imbalance was observed on 9q in 59% (24 of 41) of tumors informative for at least one locus. In contrast, only 13% (5 of 40) of informative tumors demonstrated a genetic alteration involving 9p. Furthermore, allelic loss on 9q was more common in late stage tumors (63%, 17 of 27) and poorly differentiated tumors (75%, 15 of 20) as compared to benign and early stage tumors (30%, 3 of 10). Evaluation of 15 tumors showing limited regions of genetic imbalance has identified 2 candidate tumor suppressor regions on 9q and 1 on 9p. Interestingly, the regions defined to 9p21-p24, 9q31, and 9q32-q34 all overlap with several known disease loci. In this aspect, the potential role of the CDKN2 gene at 9p21-p22 in ovarian carcinogenesis was assessed in an extended panel of ovarian tumors, 11 human ovarian carcinoma cell lines, and 1 cervical tumor cell line. With the use of comparative multiplex PCR, homozygous deletions were detected in 16 of 115 (14%) fresh tumors and 3 of 12 cancer cell lines. For those tumors demonstrating allelic loss for markers on 9p no somatic mutations were observed in the retained allele of CDKN2, as determined by single-strand conformation polymorphism analysis, but a mutation was observed in an additional cell line. Furthermore, CDKN2 mRNA levels were similar in the 9 cancer cell lines that retain CDKN2, as compared to normal human ovarian surface epithelial cell lines. Overall, our results suggest the potential involvement of a gene or genes on chromosome 9q and de-emphasize a significant role for the CDKN2 gene on 9p in the initiation and progression of ovarian cancer.

Adenocarcinoma, Mucinous

Phase I study of phosphonacetyl-L-aspartate, 5-fluorouracil, and leucovorin in patients with advanced cancer.

Low-dose phosphonacetyl-L-aspartate (PALA) may potentiate both 5-fluorouracil (5-FU) incorporation into RNA and thymidylate synthase inhibition by 5-fluorodeoxyuridylate (5-FdUMP). The gastrointestinal toxicity of 5-FU is not increased by PALA administration. Exogenous leucovorin, on the other hand, which enhances thymidylate synthase inhibition, appears to increase the clinical toxicity of 5-FU in a dose-dependent manner. As a result, the clinical use of high-dose leucovorin requires a marked dose reduction of 5-FU. Extracellular leucovorin levels of 1 microM suffice to maximize the enhancement of thymidylate synthase inhibition in several models. We conducted a trial to add leucovorin to the PALA/5-FU regimen. We chose a leucovorin dose that was predicted to yield end-infusion total reduced folate concentrations of 1 microM. The major endpoint was to determine the maximum tolerated dose of 5-FU in this combination. The regimen consisted of 250 mg/m2 PALA given on day 1 and, 24 h later, escalating 5-FU doses ranging from 1,850 to 2,600 mg/m2 admixed with 50 mg/m2 leucovorin and given by 24-h infusion. Courses were repeated weekly. A total of 24 patients with a median performance status of 1 were entered at three dose levels. Diarrhea was dose-limiting; 6/13 patients had grade II or worse diarrhea at 2,600 mg/m2. Dose modification resulted in a mean dose intensity of 2,300 mg/m2 at both the 2,600- and 2,300-mg/m2 dose levels. The 2,300-mg/m2 dose is suitable for phase II testing of this regimen. Three patients (two with breast cancer and 1 with sarcoma) had a partial remission. We measured steady-state concentrations (Css) of 5-FU in 23 patients. The mean Css increased with dose from 0.738 to 1.03 micrograms/ml. Total body clearance did not vary with dose in this range. Patients with grade II or worse diarrhea had a higher mean Css (1.10 +/- 0.19) than those with grade O or I toxicity (0.835 +/- 0.25, P < 0.02). Total bioactive folates (bound and free) were measured using a biological assay. Pretreatment values ranged from 2 to 52 nM and were not predictive of toxicity. End-infusion (23-h) values were somewhat lower than predicted and ranged from 400 to 950 nM. The risk of diarrhea was positively correlated with end-infusion total folate values. In a logistic regression analysis, total folate values obtained at 23 h were a more powerful predictor of diarrhea than were 5-FU Css values.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult

Paclitaxel and carboplatin in combination in the treatment of advanced non-small-cell lung cancer: a phase II toxicity, response, and survival analysis.

PURPOSE: To determine the activity and toxicity of combination paclitaxel (24 hours) and carboplatin in advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Eligibility required measurable disease (stage IV or stage IIIB with malignant pleural effusion), Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1, absolute neutrophil count > or = 2,000/microL, platelet count > or = 100,000/microL serum creatinine concentration < or = 1.5 mg/dL, and bilirubin level < or = 2 mg/dL. Paclitaxel was initially administered at a dose of 135 mg/m2/d, followed by carboplatin on day 2 at a targeted area under the concentration-time curve (AUC) of 7.5 using the Calvert formula. Granulocyte colony-stimulating factor (G-CSF) 5 micrograms/kg subcutaneously (SC) on days 3 to 17 was introduced during the second and subsequent cycles. In patients who sustained less than grade 4 myelosuppression, the paclitaxel dose was sequentially escalated 40 mg/m2 per cycle to a maximum of 215 mg/m2. Treatment was repeated at 3-week intervals for six cycles. RESULTS: From June 1993 through February 1994, 54 patients were enrolled; 53 are assessable for toxicity and response. The median age was 62 years (range, 34 to 84). Sixty-nine percent were male, 65% had adenocarcinoma, and 93% had stage IV disease. Two hundred sixty-eight cycles were administered; 32 patients (59%) completed all six cycles. Twenty-five unanticipated hospitalizations occurred during treatment (9.3% of cycles) in 20 patients (37%). Myelosuppression was the principal toxicity; grade 3 or 4 granulocytopenia occurred in 57% of patients after the first cycle, but decreased to 35% during the second cycle after introduction of G-CSF and consistently remained < or = 22% during subsequent cycles. Seven episodes of neutropenic fever occurred, all during the first cycle. Grade 3 or 4 thrombocytopenia and anemia occurred in 47% and 33% of patients, respectively. Eight patients (15%) required platelet transfusions and 16 (30%) required packed RBC support. Neuropathy, myalgias/arthralgias, and thrombocytopenia, although generally mild, were cumulative. The paclitaxel dose was boosted to 215 mg/m2 in > or = 70% of patients who received three or more cycles. At an AUC of 7.5, the median first-cycle carboplatin dose was 424 mg/m2 (range, 273 to 709 mg/m2). The objective response rate was 62%, with five (9%) complete responses and 28 (53%) partial responses. The median progression-free survival time was 28 weeks and the median survival time 53 weeks. The 1-year survival rate is 54%. CONCLUSION: The paclitaxel-carboplatin combination is active in advanced NSCLC and may enhance survival; it merits further investigation in phase III trials.

Adult

USA update on paclitaxel in ovarian cancer.

In the United States, the role of paclitaxel in the treatment of advanced ovarian cancer has expanded markedly in the last 2 years. The drug was initially approved by the Food and Drug Administration for refractory ovarian cancer. However, on the basis of a large prospective randomized trial by the Gynaecologic Oncology Group, paclitaxel together with a platinum compound has now become accepted as a standard form of chemotherapy for previously untreated patients with ovarian cancer. There still remain many unanswered questions as how to best utilize paclitaxel together with platinum compounds. Clinical trials are currently in progress evaluating the dose intensity of paclitaxel, the effect of schedule of administration, and the relative efficacy and toxicity of paclitaxel plus carboplatin vs. paclitaxel plus cisplatin.

Antineoplastic Combined Chemotherapy Protocols

Current status of chemotherapy for ovarian cancer.

Standard treatment for patients with advanced ovarian cancer has been cytoreductive surgery followed by combination chemotherapy. Until recently, platinum-based chemotherapy was considered optimal and patients were treated with regimens built around either cisplatin or carboplatin. Recently, paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) has been shown to be a highly active agent in refractory ovarian cancer patients. Subsequently, the Gynecologic Oncology Group performed a prospective randomized trial of paclitaxel plus cisplatin compared with cisplatin plus cyclophosphamide in suboptimal stage III and IV ovarian cancer patients. Based on higher response rates, longer time to progression, and marked improvement in median survival (37.5 months compared with 24.4 months), the Gynecologic Oncology Group currently considers paclitaxel plus cisplatin to be the new standard regimen for patients with advanced disease. More recently, paclitaxel plus carboplatin also has been evaluated in previously untreated patients. Using area under the curve dosing for carboplatin, it was demonstrated that this agent could be combined with paclitaxel (175 mg/m2 in a 3-hour infusion) with acceptable toxicity. All current Gynecologic Oncology Group protocols for untreated patients with ovarian cancer use a paclitaxel-based regimen. These clinical trials are evaluating the relative efficacy of carboplatin plus paclitaxel versus cisplatin plus paclitaxel as well as differences in dose and schedule and number of cycles of treatment. Investigational studies are continuing with high-dose chemotherapy that requires hematologic support as well as with intraperitoneal therapy (cisplatin or paclitaxel).

Antineoplastic Combined Chemotherapy Protocols

Carboplatin and paclitaxel in ovarian cancer.

A phase I trial of carboplatin plus paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) therapy for untreated patients with advanced ovarian cancer has been completed, demonstrating that these drugs can be combined in full doses with acceptable toxicity. This combination has now gone forward to be evaluated in prospective randomized trials. The Gynecologic Oncology Group will be doing a randomized trial comparing therapy with cisplatin plus paclitaxel versus carboplatin plus paclitaxel in patients with optimal stage III ovarian cancer. Patients with limited-stage disease but with poor prognostic features will be randomly assigned to receive either three or six cycles of carboplatin plus paclitaxel. Carboplatin will be dosed using the Calvert formula at an area under the plasma concentration versus time curve of 7.5 and paclitaxel will be administered at a dose of 175 mg/m2 by 3-hour continuous infusion. Cycles are planned to be administered every 21 days without granulocyte-colony stimulating factor.

Antineoplastic Combined Chemotherapy Protocols

Paclitaxel by 24- or 1-hour infusion n combination with carboplatin in advanced non-small cell lung cancer: the Fox Chase Cancer Center experience.

A phase II trial of combination paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) and carboplatin included 54 chemotherapy-naive patients with advanced non-small cell lung cancer. Eligibility mandated Eastern Cooperative Oncology Group performance status of 0 or 1 and adequate hematologic, renal, and hepatic function. Paclitaxel 135 mg/m2 over 24 hours preceded carboplatin dosed to an area under the concentration-time curve of 7.5. Six planned courses were given every 3 weeks. Granulocyte colony-stimulating factor was introduced during the second and subsequent cycles, and paclitaxel increased 40 mg/m2/cycle (maximum, 215 mg/m2) in patients with absolute neutrophil and platelet nadirs exceeding 500/microL and 50,000/microL, respectively. Grade 3 or 4 neutropenia, observed in 54% of patients during cycle 1, declined to 35% during cycle 2 and to 22% or less during cycles 3 through 6. Neuropathy, myalgias/arthralgias, and thrombocytopenia were mild but cumulative. In 53 evaluable patients, the objective response rate was 62%, with 9% complete remissions and a median response duration of 6 months (range, 1 to 19+ months). At median potential follow-up of 16 months, 9% of patients remain progression free (52+ to 80+ weeks). Median survival is 12.5 months; 1-year survival is 54%. Paclitaxel/carboplatin is highly active in advanced non-small cell lung cancer; granulocyte colony-stimulating factor abrogates neutropenia as the dose-limiting toxicity, but has no effect on the cumulative incidence of thrombocytopenia or treatment delays. One-hour paclitaxel infusion is minimally myelosuppressive, logistically easier, and less costly. A follow-up study combined paclitaxel (175 mg/m2) over 1 hour followed by carboplatin (area under the concentration-time curve, 7.5). In the absence of grade 4 myelosuppression, paclitaxel was increased 35 mg/m2/cycle (maximum, 280 mg/m2). Granulocyte colony-stimulating factor was implemented only after neutropenic fever or grade 4 neutropenia. Of 17 patients entered, 13 are evaluable for toxicity and seven for response. Four patients have sustained a partial response, two a minor response, and one stable disease. The incidence of grade 3 or 4 neutropenia, thrombocytopenia, and anemia in cycle 1 was 38%, 16%, and 0%, respectively, and 72%, 28%, and 28%, respectively, during cycle 2. Major nonhematologic toxicities include myalgias and arthralgias (54%) and fatigue and neuropathy (78%), the latter cumulative and progressive over successive cycles. Preliminary data suggest comparable activity for the 1- and 24 hour paclitaxel infusions in combination with carboplatin. The more severe neuropathy of the 1-hour paclitaxel/carboplatin combination may be related to the paclitaxel dosing schema (175 mg/m2 to as high as 280 mg/m2).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult

Modulation of glutathione and related enzymes in reversal of resistance to anticancer drugs.

Eukaryotic cells have evolved several mechanisms to protect cellular constituents, especially DNA, from highly reactive molecules entering from without. The greater affinity of electrophiles for thiol groups than for hydroxyl or amine groups provides a teleologic rationale that the availability of high concentrations of thiol could be protective of these other important entities. The major intracellular nonprotein thiol is the tripeptide glutathione.

Animals

Recurrent ovarian cancer. Effective radiotherapeutic palliation after chemotherapy failure.

BACKGROUND: Recurrent ovarian cancer after frontline chemotherapy is incurable; however, palliation of focal lesions often is needed to alleviate symptoms. Because published response rates to palliative irradiation (RT) among patients failing cisplatin-based chemotherapy are scarce, the authors attempted to define the palliative role of radiotherapy for symptomatic, localized ovarian cancer recurrences. Factors predicting a response to RT also were sought. METHODS: Between 1987 and 1993, 33 patients with ovarian cancer were irradiated at 47 sites with palliative intent after failing cisplatin-based chemotherapy regimens. Sites irradiated included the pelvis (n = 33), abdomen (n = 5), chest (n = 4), brain (n = 3), and other (n = 2). Median RT dose was 35 Gy (range: 7.5-45 Gy). The median fraction size was 2.5 Gy (range, 1-5 Gy). To determine dose effectiveness, the biologic effective dose (BED) was calculated according to the following formula: BED = total dose (1 + fractional dose/alpha/beta) using an alpha/beta value of 10. The median BED10 was 44 (range, 9-72). RESULTS: For the entire group, complete palliative response was 51% and overall palliative response was 79%. The median duration of palliation was 4 months, which reflected palliation until death in 90% of cases. The overall response rates by symptoms were: pulmonary symptom relief in 75%, vaginal bleeding control in 90%, rectal bleeding control in 85%, pain relief in 83%, and neurologic symptoms controlled in 50%. The likelihood of obtaining complete symptomatic response was significantly increased among those with high Karnofsky performance status (KPS > or = 70 vs. KPS < 70; 69% vs. 36%, P < 0.03) and among those who received a higher biologically effective dose of irradiation (BED10 > or = 44 vs. BED10 < 44; 68% vs 35%, P < 0.03). Complete palliative response rates were not influenced by histologic differentiation, the number of previously administered cisplatin regimens, or patient age. Treatment-related acute morbidities included diarrhea in 5 of 38 (13%) patients treated through abdominal or pelvic fields, and esophagitis in 2 of 5 treated through thoracic portals. Only one severe late morbidity (small bowel obstruction) was observed. CONCLUSIONS: Durable palliation of patients with ovarian cancer that recurs after cisplatin-based chemotherapy can be achieved with local radiotherapy, especially among patients with high performance status. Biologically effective doses of at least 44 Gy10 (e.g., 3500 cGy/14 fractions = BED10 of 44) should be sought to maximize the probability of complete response. Such dose-fractionation schedules can be delivered expeditiously with acceptable tolerance. These results are comparable to the published experience of second-line chemotherapy in the treatment of focally symptomatic ovarian cancer recurrences.

Age Factors

Relationship between platinum-DNA adduct formation and removal and cisplatin cytotoxicity in cisplatin-sensitive and -resistant human ovarian cancer cells.

We examined several aspects of platinum-DNA adduct formation and repair in cisplatin-sensitive and -resistant human ovarian cancer cell lines. The formation of cisplatin-interstrand crosslinks (ICLs) was measured in five DNA sequences by renaturing agarose gel electrophoresis. There were considerable differences (up to 4-fold) in ICL levels in these DNA sequences following a 4-h incubation with cisplatin; however, the pattern of ICL formation did not depend on whether the region was transcriptionally active or gene encoding. Incubation of purified DNA with cisplatin yielded an ICL pattern with considerably less variability between the regions examined. Cisplatin ICL and total DNA platination levels were significantly higher (up to 20- and 40-fold, respectively) in cisplatin-resistant cell lines as compared to the parental, cisplatin-sensitive cell line at equivalent levels of cisplatin cytotoxicity. Under cisplatin exposure conditions which yielded similar initial levels of sequence-specific ICLs, the cisplatin-resistant cells removed up to 2.5 times more ICLs by 12-h posttreatment than the parental cell line. Increased removal of the individual platinum-deoxyribonucleosides of platinum-DNA adducts was also observed in the highly resistant C200 cell line as determined by high performance liquid chromatography separation and quantitation by atomic absorption spectrometry. These results indicate that DNA repair contributes significantly to cisplatin resistance and that increased DNA-damage tolerance may also be a component of the resistance phenotype in this model system.

Cisplatin

Phase I/pharmacokinetic study of topotecan by 24-hour continuous infusion weekly.

Topotecan (SK&F 104864, hycamptamine, NSC 609699) is believed to exert its cytotoxic effects through inhibition of topoisomerase I, the activity of which recovers rapidly on removal of the drug in vitro. In vivo studies show that the activity of topotecan is schedule dependent, favoring repeated doses. Early human studies showed that topotecan (the active lactone) had a short half-life in plasma. To prolong drug exposure, we administered topotecan as a 24-h i.v. infusion and repeated it weekly. We treated 32 patients with doses of 1.0-2.0 mg/m2. Median performance status was 1, and all but four patients had received prior chemotherapy. Dose-limiting neutropenia occurred at doses > or = 1.75 mg/m2; nadirs were observed after 1-3 doses. The recommended phase II dose is 1.5 mg/m2/week. One patient with metastatic colon cancer had a partial response. Both plasma topotecan (lactone) and total topotecan (measured by converting the hydroxyacid form to the lactone by acidification of the sample) were measured by high-performance liquid chromatography in 21 patients. During infusion, mean topotecan plasma steady-state concentrations ranged from 4.7-11.4 nM. Plasma elimination was best fit to a one-compartment model with a mean t1/2 of 3.5 h. The mean total body clearance was 388 ml/min/m2. Concentrations of the inactive form approximated those of the lactone throughout. No evidence for dose-dependent pharmacokinetics was observed in this dose range. Pharmacodynamic analysis, using the sigmoid Emax model, revealed that the pharmacokinetic parameters of both lactone and total drug were positively correlated with bone marrow toxicity. Total drug steady-state plasma concentration provided a good estimate of neutropenia, suggesting a simple, easily monitored, pharmacokinetic parameter for adaptive dosing using this schedule. Phase II evaluation of this weekly schedule is indicated in solid tumors.

Adult

Role of platinum-DNA adduct formation and removal in cisplatin resistance in human ovarian cancer cell lines.

A series of cisplatin-resistant cell lines were used to examine the formation and removal of platinum-DNA adducts from the overall genome and the formation and removal of cisplatin-interstrand cross-links from specific genomic regions. Cisplatin accumulation and DNA platination levels, which correlated linearly, were similar in three of the resistant cell lines despite differences in their primary cisplatin resistance. Increased platinum removal from total genomic DNA was found to be associated with increased resistance. Interstrand cross-link levels were found to be 2- to 4-fold lower in the 28S ribosomal RNA gene and a non-coding genomic region of the resistant cell lines as compared with the parental A2780 cell line. In addition, 1.2- to 2.7-fold more cross-links were formed in the non-coding region than in the ribosomal RNA gene in all of the cell lines. Interstrand cross-links were removed more rapidly from both regions of the highly cisplatin-resistant C80 and C200 cells and from the ribosomal RNA gene only in the cell lines of lower resistance. The results support a role for DNA repair and alterations in interstrand cross-link formation in cisplatin resistance and provide evidence for heterogeneous interstrand cross-link formation in the genome.

Cisplatin

Research directions in epithelial ovarian cancer.

Major improvements in survival from ovarian cancer will likely result from a combined effort in prevention, diagnosis, screening, and treatment. Oral contraceptives can decrease the risk of ovarian cancer in women with a family history of the disease. Screening currently is not routinely recommended and awaits further refinements in tumor markers and image techniques. Surgery and chemotherapy have been the cornerstones of treatment for most patients with ovarian cancer. Paclitaxel plus a platinum compound has now become a new standard chemotherapy regimen. However, numerous clinical questions need to be explored in prospectively randomized trials to determine how best to use this agent. Basic research in ovarian cancer will likely lead to the novel therapeutic targets and completely new approaches.

Antineoplastic Combined Chemotherapy Protocols

Carboplatin and Taxol (paclitaxel) in advanced ovarian carcinoma.

Addressing the need for more effective, less toxic therapies for patients with advanced ovarian cancer, a pilot study was conducted to evaluate the therapeutic potential of combination carboplatin/paclitaxel in previously untreated patients. Several factors provided the rationale for this study: paclitaxel plus cisplatin has been shown to be superior to standard treatment with cyclophosphamide plus cisplatin; carboplatin is equally effective and less toxic than cisplatin in ovarian cancer; paclitaxel plus carboplatin could potentially produce less nonhematologic toxicity than cisplatin plus paclitaxel; dosing of carboplatin based on the area under the carboplatin plasma concentration vs. time curve (AUC) would produce an acceptable degree of thrombocytopenia; and the potential additive neutropenia of carboplatin plus paclitaxel could be managed with the addition of growth factors. This study was designed in two parts: In part I, a fixed dose of paclitaxel (135 mg/m2 by 24-hour infusion every 21 days) was administered to study patients given escalating doses of carboplatin, beginning at an AUC of 5 and increasing to 7.5 and then to 10. Dose escalation was based on toxicity observed in the first treatment cycle, with granulocyte colony-stimulating factor added when dose-limiting toxicity developed. The second part was designed to evaluate carboplatin at the maximum tolerated dose with escalating doses of paclitaxel. Preliminary results of phase I of this study indicate that paclitaxel plus carboplatin can be combined at doses that encompass the therapeutic range of carboplatin given with paclitaxel 135 mg/m2. Subsequent phases of this trial are currently under way.

Antineoplastic Combined Chemotherapy Protocols

Treatment of ovarian cancer: current status.

Cytoreductive surgery followed by platinum-based combination chemotherapy has been standard therapy for patients with advanced epithelial ovarian cancer. Despite advances in surgery and in the development of a less toxic platinum compound (carboplatin), most patients with advanced ovarian cancer are not cured. Current clinical trials focus on dose-intense chemotherapy, routes and schedules of administration, and the role of paclitaxel (Taxol; Bristol-Myers Squibb Co, Princeton, NJ). This novel agent has been shown to be highly active in patients with platinum-resistant ovarian cancer. Paclitaxel together with platinum (ie, cisplatin or carboplatin) combinations are now being tested in prospective randomized trials and in pilot studies in previously untreated patients with advanced disease.

Clinical Trials as Topic