Carboplatin and recurrent childhood brain tumors

Phase II study of ifosfamide in childhood brain tumors: a report by the French Society of Pediatric Oncology (SFOP)

Forty-two evaluable pediatric patients with a variety of recurrent primary brain tumors participated in a phase II ifosfamide trial. Their mean age was 10 years. All patients were treated with ifosfamide, 3 g/m2/day for 2 days every 2 weeks. Response was assessed on clinical and radiological criteria after at least 2 courses of therapy. The overall response rate was 12% (5/42). One complete and 2 partial responses were documented in 21 patients with medulloblastoma. A partial response was demonstrated in 1 patient with primitive neurectodermal tumor (PNET) and in 1 patient with ependymoma. No activity was observed in astrocytic tumors. Toxicity was primarily neurologic (16 out of 54 patients, 30%). Hematological toxicity, without severe morbidity, was encountered in 9% of courses (16/179). Ifosfamide, administered at this dose regimen has modest efficacy in the treatment of recurrent childhood medulloblastoma and ependymoma and appears inactive for gliomas. Further trials with other dose schedules are necessary to assess the activity of this drug. However, according to the neurotoxicity observed in our trial, we would not recommend building a protocol using ifosfamide for highly progressive brain tumors.

Carboplatin in advanced hormone refractory prostatic cancer patients

25 patients with measurable or evaluable metastatic prostate cancer, progressive after hormonal treatment, were treated weekly with carboplatin 150 mg/m2 intravenously. The weekly schedule allowed higher dose intensity carboplatin administration with respect to the common monthly cycles. Toxicity was manageable even in elderly patients with extensive bone metastases and consisted primarily of myelosuppression. 4 out of 24 evaluable patients (17%) had a partial response and 12 (50%) had disease stabilisation. The median response duration was 7 months. Prostate-specific antigen and prostatic acid phosphatase serial values showed a correlation with disease response in only 47 and 50% of patients, respectively. These results suggest that carboplatin possesses a moderate but definite activity in prostate cancer patients.

Postoperative chemotherapy without radiation in young children with malignant non-astrocytic brain tumours. A report from the Australia and New Zealand Childhood Cancer Study Group (ANZCCSG)

Young children with malignant brain tumours have particularly poor survival and manifest severe sequelae of radiation therapy. A multi-institutional pilot study of post-operative primary chemotherapy for children under 3 years with primitive neuroectodermal tumours (PNET) or ependymoma was initiated in 1987. The chemotherapy protocol comprised carboplatin, vincristine and the "eight drugs in 1 day" regimen. Radiation was recommended only if tumour progression or recurrence was documented. A total of 14 patients between 5 and 36 months of age were enrolled. Seven had supratentorial tumours (PNET, pinealoblastoma, intracranial retinoblastoma) with multiple predictors of adverse outcome. Four of these responded to initial chemotherapy but subsequently progressed and all had died by 16 months from diagnosis. The seven patients with infratentorial tumours (three medulloblastomas, four ependymomas) had more favourable predictors of outcome: no meningeal dissemination and gross macroscopic resection in six of the seven cases. One patient progressed rapidly and died within 5 months. The other six are alive at 37-57 months from diagnosis. Four are in continuous complete remission at 57, 51, 41 and 37 months, respectively from the time of their tumour resection. One is described as having stable disease with a persistent radiographic lesion at 41 months from diagnosis. One has relapsed on two occasions and is the only surviving patient to have been irradiated. Intelligence scores for the six long-term survivors have thus for remained within the normal range. It is suggested that some infants with standard-risk ependymoma and, possibly, medulloblastoma may be cured without radiation therapy.

Nephrotoxicity following carboplatin use in children: is routine monitoring of renal function necessary?

Carboplatin is an effective chemotherapeutic agent against many solid tumours. Although it is thought to be less nephrotoxic than its precursor cisplatin, current paediatric treatment protocols require regular monitoring of renal glomerular function during and after carboplatin use. Because accurate assessment of renal function in children requires measurement of isotope-clearance glomerular filtration rates (GFRs), routine monitoring is costly and time consuming. We studied 26 paediatric patients who were receiving chemotherapy that included 500-600 mg/m2 of carboplatin per course. 51Cr-EDTA GFRs were measured initially and after one to seven courses (median four). There was no measurable difference between renal function before and after carboplatin (P = 0.8). Our study shows that routine monitoring of renal glomerular function is unnecessary. Carboplatin use in patients who have had unilateral nephrectomy as part of their treatment is also discussed. Paediatric oncology literature concerning nephrotoxicity and carboplatin is reviewed.

Intracranial germ cell tumours: I. Experience with platinum based chemotherapy and implications for curative chemoradiotherapy

The results of treatment with platinum based combination chemotherapy in ten patients with intracranial germ cell tumours (GCT) are presented. Two patients, treated for relapse within the central nervous system (CNS), attained partial responses of short duration. One patient with systemic relapse was successfully salvaged with chemotherapy. Seven patients received primary chemotherapy, six of whom received a 'CNS friendly' regimen consisting of vincristine, etoposide, carboplatin (VEJ) prior to craniospinal axis (CSA) irradiation. Three complete and three partial responses, and one patient with stable disease, were seen prior to irradiation. All seven patients are alive and remain disease-free at a median time of 12 months after treatment. Current treatment policy for germinomas attaining complete response to two courses of VEJ is a lowered CSA dose prescription, while non-germinomatous germ cell tumours (NGGCT) receive standard total dose CSA irradiation.

Cerebrospinal fluid pharmacokinetics of carboplatin in children with brain tumors

The pharmacokinetics of carboplatin in cerebrospinal fluid (CSF) and plasma was studied in five children with brain tumors (four medulloblastomas and one ependimoblastoma) who underwent preirradiation treatment with carboplatin. Carboplatin pharmacokinetics was studied following the administration of 600 mg/m2 as a 1-h infusion. Four children were treated a few weeks after surgery, whereas one child with an unresectable tumor was treated prior to surgery. All patients had a ventricular-peritoneal CSF shunt connected to a subcutaneous reservoir. Total platinum and free carboplatin were measured. The mean AUC values for free carboplatin in CSF and plasma were 2.29 +/- 1.20 and 8.18 +/- 1.27 mg ml-1 min, respectively. The mean ratio of CSF AUC to plasma AUC was 0.28 (range, 0.17-0.46). Both plasma peak levels and AUC values showed limited interpatient variability. On the other hand, carboplatin levels in CSF showed substantial interpatient variability, with a greater than 5-fold difference in peak levels and a 3-fold difference in AUC values being recorded. The interpatient difference in CSF pharmacokinetics may have been related at least in part to the different anatomical alterations induced by the surgical procedures or by the presence of a large tumor mass. In the four evaluable patients exhibiting macroscopic residual tumor, we observed one complete remission (CR) and two partial remissions (PR) following two cycles that consisted of two doses of 600 mg/m2 carboplatin given on 2 consecutive days (total dose, 1200 mg/m2) and were separated by a 1-month interval. These results may give some indication as to the optimal dose and schedule for carboplatin administration in the treatment of primitive neuroectodermic tumors (PNET).

Experimental basis for increasing the therapeutic index of cis-diamminedicarboxylatocyclobutaneplatinum(II) in brain tumor therapy by a high-zinc diet

Metallothionein (MT), a ubiquitous intracellular protein, confers resistance to the toxic effects of platinum compounds. Since a high-zinc diet has been shown to induce MT synthesis in extracerebral tissues but not in brain, we investigated whether it could provide an experimental basis for decreasing the hematotoxicity of carboplatin without impairing its activity against brain tumors. After 2 weeks on either a high-zinc diet or a control diet (zinc content, 180 vs 10 ppm), mice and rats received various doses of carboplatin or Hanks' balanced salt solution by i.p. injection. The hematotoxicity of carboplatin was evaluated with an assay of colony-forming units of granulocytes and mononuclear cells in mice. The high-zinc diet enabled a 50% increase in the carboplatin dose without increasing hematotoxicity. The antitumor activity was evaluated with an assay of the colony-forming efficiency of gliosarcoma cells from 9L brain tumors in rats. The high-zinc diet did not alter the efficacy of carboplatin against this brain tumor. Northern blot analysis confirmed that the high-zinc diet induced MT mRNA in the kidney but not in the brain of mice and rats; it also showed MT mRNA induction in bone marrow cells of mice but not in rat 9L brain tumors. These results suggest that increasing the dietary intake of zinc might increase the therapeutic index of carboplatin in the treatment of brain tumors.

Platinum-based chemotherapy for recurrent CNS tumours in young patients

Twenty nine patients (median age 12 years) with a CNS tumour, received platinum-based chemotherapy for assessable disease. In 23 patients there was an objective response with improvement lasting for a median duration of 11 months. There was little difference in the response to cisplatinum or carboplatin therapy. The response rates in specific disease groups were: medulloblastoma 8/10, two with a complete response (CR) and six with a partial response (PR); ependymoma 1/5 PR; pineal retinoblastoma 5/5 with three CR and two PR; primitive neurectodermal tumours (PNET) 2/2 PR and pineal germ cell tumours 6/6 with four CR and two PR. It is concluded that platinum-based chemotherapy has a beneficial effect on CNS tumours of the CNS, especially medulloblastoma, ectopic intracranial retino-blastoma and pineal germ cell tumours.

Comparison of the cytotoxic activities of cisplatin and carboplatin against glioma cell lines at pharmacologically relevant drug exposures

Carboplatin has lower nephro- and neurotoxicities and better penetration into brain tissue than cisplatin. If carboplatin has comparable cytotoxicity against glioma cells, it might have a therapeutic advantage in the treatment of malignant gliomas. Using an assay of colony-forming efficiency, we compared the cytotoxicity of these two drugs in human glioma cell lines SF-126, SF-188, U87-MG, and U251-MG. The experiments were designed so that the product of in vitro drug concentration (C) and time (T) would encompass the same range of values as the C x T of the ultrafilterable platinum plasma fraction as determined by pharmacokinetic studies in man. The in vitro stability of the drugs was evaluated by measuring the cytotoxicity of aged drugs with a microculture tetrazolium assay. Cisplatin and carboplatin were both stable during the 2-h treatment. The cytotoxic activities of these drugs at clinically achievable levels of drug exposure were of the same order of magnitude. These results, in conjunction with the lower nephro- and neurotoxicities of carboplatin, the higher platinum levels in brain tissue after treatment with carboplatin, and the encouraging results of carboplatin in the clinical treatment of brain tumors that have been demonstrated in other studies, suggest that carboplatin might be preferable to cisplatin in the treatment of patients with malignant glioma.

Treatment of recurrent malignant supratentorial gliomas with carboplatin (CBDCA)

Twenty patients with malignant supratentorial gliomas progressing after radiation therapy and chemotherapy with nitrosoureas received intravenous carboplatin, 450 mg/m2. Courses of therapy were repeated every four weeks. Therapeutic evaluation was performed monthly using neurologic examination and CT scan of the brain. Of 19 patients evaluable for response, 2 (10%) responded to therapy and 6 (30%) had stable disease. The estimated median time to tumor progression for responding and stable patients was 6 months. Median duration of survival was 6 months for all patients. Of 20 patients evaluable for toxicity, none had renal or auditory toxicity. Side effects consisted of hematologic toxicity in 4 patients (20%): one patient had grade 4 toxicity requiring discontinuation of carboplatin and 3 patients had grade 2-3 toxicity.

Fatal thrombocytopenia and liver failure associated with carboplatin therapy

A patient with fatal severe thrombocytopenia and acute hepatic necrosis complicating carboplatin (JM8, CBDCA, NSC 241240) therapy is described. The patient, an 18-year-old man with acute lymphocytic leukemia, was given high-dose carboplatin as a part of a phase I trial of this agent for the treatment of leukemia. Carboplatin (270 mg/m2/day) was administered as an intravenous infusion on five consecutive days, and the patient died 10 days after his last dose of carboplatin from complications of thrombocytopenia and acute liver necrosis. Autopsy revealed hemorrhage into the substance of the myocardium and hemorrhagic centrilobular liver necrosis. The temporal relationship between the initial rise in this patient's liver function tests and treatment with carboplatin suggests that this patient's liver failure was in part due to carboplatin. The autopsy findings of hemorrhage into the substance of the myocardium and centrolobular liver necrosis suggest that, in addition to its direct effects, carboplatin may have also contributed indirectly to this patient's liver failure through the complications of thrombocytopenia.

Activity and toxicity of carboplatin and iproplatin in relapsed high-grade glioma

A total of 15 patients with relapsed high-grade glioma were treated with carboplatin (400 mg/m2) or iproplatin (300 mg/m2). All had received previous radiotherapy, and 12 had previously undergone chemotherapy. One of the ten patients treated with carboplatin and one of the five treated with iproplatin achieved a partial remission as determined by repeat computerised tomographic (CT) scan. Myelosuppression was considerable, as three patients developed grade IV neurotoxicity, which was fatal in one case. Although carboplatin and iproplatin showed activity against malignant glioma, the study was closed because of unacceptable toxicity.

Prolonged response to carboplatin in an infant with brain stem glioma

Adults and children with brain stem gliomas have a mean survival time of 15 months after radiation therapy (XRT). Infants with this tumor present additional complexities for treatment because of possible neurotoxicity of the radiation to the developing brain. We report a 15-month-old child with biopsy-proven brain stem glioma with clinical and radiographic evidence of disease progression. She was treated with 24 monthly courses of carboplatin without radiation therapy and has had a 39+ month response. The clinical response started after 3 months and the radiographic evidence was documented at 10 months by magnetic resonance imaging. The toxicity was minimal. Longitudinal neuropsychological assessment demonstrated continued improvement at 36 months post diagnosis but with some motor functioning below expected age levels. Cervico-medullary astrocytoma in a young patient may be the appropriate clinical setting for future trials of chemotherapy without XRT.

Carboplatin in childhood brain tumors. A Children's Cancer Study Group Phase II trial

Between October 1985 and March 1988, Children's Cancer Study Group institutions entered 95 patients with recurrent brain tumors into a Phase II trial of carboplatin 560 mg/m2 every 4 weeks. Complete or partial responses were observed for one of 19 evaluable children with brainstem glioma, two of 14 with ependymoma, six of 19 with medulloblastoma or central nervous system primitive neuroectodermal tumor (PNET), and none of 15 with high-grade astrocytoma. Of 33 children with medulloblastoma, ependymoma, or central nervous system PNET, five of 12 with no prior cisplatin exposure had responses, and two of 21 with prior cisplatin exposure had responses (P = 0.03). Thirty-four percent of patients had absolute neutrophil count nadirs less than 500/microliters, and 37% had platelet count nadirs less than 25,000/microliters. Sixteen percent had moderate to severe otoxicity, 10% had nausea and vomiting, and none had nephrotoxicity.

Chemotherapy for medulloblastoma/primitive neuroectodermal tumors of the posterior fossa

Chemotherapy has only marginal efficacy in adult malignant brain tumors. In contrast, drug therapy is considerably more effective in medulloblastoma/primitive neuroectodermal tumors (MB/PNET) of the posterior fossa, the most common childhood primary central nervous system tumor. At the time of disease recurrence, a variety of different single agents and drug combinations result in tumor shrinkage and increased survival. The addition of chemotherapy to standard radiotherapy improves the rate and length of disease-free survival for those children with MB/PNET who have the most extensive tumors at diagnosis. It remains to be determined which drug or drug combinations are the most effective in MB/PNET, and which patients are most likely to benefit from chemotherapy. Chemotherapy may be useful to reduce or, in selected cases, obviate the need for radiotherapy and reduce treatment-related sequelae.

Modification of the 8 drugs in 1 day regimen: feasibility of substitution of other agents

Six children (ages 2 to 14 years) with recurrent or poor risk primary brain tumors were treated with the '8 drugs in 1 day' chemotherapy regimen. As renal function deteriorated (median after five cycles), carboplatin was substituted in place of cisplatin at a median dose of 300 mg/m2 as a one hour infusion at hour three. Four patients also had their lomustine deleted and replaced by etoposide 100 mg/m2 at hour four. Compared to earlier cycles of chemotherapy, there was a moderate increase in transfusion requirement (especially platelets) but the incidences of fever and neutropenia were unchanged. Glomerular function as measured by nuclear glomerular filtration rate (GFR) remained unchanged or improved at the end of therapy. The severity of nausea and vomiting after substitution was markedly improved. Four of the six patients are still in complete remission 19 to 41 months after diagnosis or recurrence. It is feasible to substitute carboplatin and etoposide into the '8 drugs in 1 day' regimen when extramedullary toxicity is found.

Results of treatment of children with recurrent medulloblastoma/primitive neuroectodermal tumors with lomustine, cisplatin, and vincristine

Primitive neuroectodermal tumors/medulloblastoma (PNET/MB) are the most common posterior fossa tumors in childhood. Despite surgery and radiation therapy, 40% to 50% of children with PNET/MB will have recurrent disease. Various chemotherapeutic agents are transiently effective in recurrent PNET/MB, but long-lasting responses are rarely attainable. To increase the rate and duration of response in children with recurrent PNET/MB, the authors treated seven patients (ages 2-18 years; median, 10 years) with lomustine (CCNU) (100 mg/m2), cisplatin (CPDD) (90 mg/m2) and vincristine (VCR) (1.5 mg/m2; maximum, 2 mg) in a 6-week cycle for a maximum of eight cycles. Six of six evaluable patients responded to chemotherapy. Four patients had a complete response; three with complete disappearance of tumor by imaging studies; and one with eradication of extraneural disease for a median of 24 months from relapse (13-29 months). Overall disease-free survival was 18.5 months. All six patients have subsequently died of recurrent tumor. Major toxicities consisted of reversible bone marrow suppression (six of six), high frequency hearing loss (six of six) and decreased renal function (three of six). All patients required dosage modification for toxicity. A regimen of CCNU, VCR, and CPDD is effective therapy in children with relapsed PNET/MB and can produce relatively long-term disease control with good quality of life. Further investigation into the efficacy of this combination as adjuvant chemotherapy in newly diagnosed high-risk PNET/MB is now being performed.

A pilot study of high-dose carboplatin and pulsed etoposide in the treatment of childhood solid tumors

Carboplatin was administered at 1,000 mg/m2/course in combination with etoposide at 300 mg/m2/course to 23 patients aged 5 months to 16 years. Five patients were affected by neuroblastoma, four by CNS tumors, three by Ewing's sarcoma, two by rhabdomyosarcoma, two by malignant teratoma, two by Wilms' tumor, two by head and neck carcinoma, one by hepatoblastoma, one by synovial sarcoma, and one by Langerhans-cell histiocytosis. Eleven patients were pretreated, seven of them with high-dose cisplatin. The overall response rate was 7/11 (64%) for pretreated and 10/12 (83%) for previously untreated patients. Myelosuppression was the main side effect, with anemia and thrombocytopenia more pronounced than leukopenia. Gastrointestinal toxicity and ototoxicity were very mild; nephrotoxicity and neurotoxicity other than hearing loss were not observed. In children with malignant tumors, the therapeutic activity of carboplatin at high doses, even in combination chemotherapy, deserves further studies.

Clinical trial and pharmacokinetics of carboplatin 560 mg/m2 in children

We report a clinical trial with carboplatin (CBDCA) in 15 children with malignant solid tumors recurrent after or resistant to conventional treatment. Based on previous phase I clinical trials, these children were given a dose of CBDCA 560 mg/m2 by intravenous infusion every 4 weeks. The study includes a pharmacokinetic analysis of CBDCA in three patients. This clinical trial shows the feasibility of this CB-DCA schedule, even after high cumulative doses of previous chemotherapy. As expected the main toxicity was hematologic but the risk of renal and ototoxicity is not excluded and these functions have still to be monitored when this relatively high dose of CBDCA chemotherapy is used.

Carboplatin: a clinical review

Carboplatin is a platinum analog that is less nephrotoxic, less neurotoxic, and less emetic than cisplatin, but has a similar spectrum of antitumor activity. Myelotoxicity is dose limiting. Carboplatin offers several advantages over cisplatin, in addition to a better quality of life. It may be useful in ABMT in refractory germ cell cancers in combination with etoposide. It may also prove useful in patients who have impaired renal function but require a drug with the efficacy of cisplatin.

Paediatric brachytherapy. II. Brain implantation

The case histories of four children with brain tumours, for whom stereotactic brachytherapy was indicated, are presented from the St Bartholomew's Hospital intracranial brachytherapy programme. The recent evolution of the computed-tomography-directed stereotactic technique is described and the uses of different radionuclides (198Au, 192Ir) are discussed. The future of brachytherapy for paediatric brain tumours is debated.

Carboplatin. A preliminary review of its pharmacodynamic and pharmacokinetic properties and therapeutic efficacy in the treatment of cancer

Carboplatin is a 'second-generation' platinum compound advocated for use in the treatment of patients with ovarian cancer and it has also shown promise in small cell lung cancer, squamous cell carcinomas of the head and neck, and seminomas. Overall, it would appear to have a similar qualitative spectrum of activity to cisplatin. There have been few comparative trials with carboplatin, either alone or in combination with other chemotherapeutic agents, but the limited data suggest comparable efficacy with cisplatin in ovarian cancer. Importantly, the toxicity profile of carboplatin is markedly different from that of cisplatin, with nephrotoxicity, neurotoxicity and ototoxicity occurring only infrequently with carboplatin. As with cisplatin, nausea and vomiting occur in many patients after carboplatin administration, but symptoms are usually delayed for several hours and are mild to moderate in severity - dose-limiting nausea and vomiting are infrequent with carboplatin. The dose-limiting toxicity of carboplatin is myelosuppression, with severe thrombocytopenia and less often leucopenia, which may be more severe in older patients or in those with renal impairment or those who have had previous chemotherapy. Thus, preliminary data suggest that carboplatin is a therapeutically equivalent alternative to cisplatin, but with a differing toxicity profile that should offer advantages over cisplatin in many patients.

Oxalato-platinum or 1-OHP, a third-generation platinum complex: an experimental and clinical appraisal and preliminary comparison with cis-platinum and carboplatinum

A new platinum complex, oxalatoplatin or l-OHP, which, at the same metal dose in experimental tests is as efficient as cisplatin, and is more so at a lower metal dose than carboplatin; which is as efficient in human tumors of the testis and ovary as these other analogs, and more so in melanoma and breast cancer; which is not nephrotoxic, cardiotoxic or mutagenic, and hardly hematotoxic and neurotoxic, is described and compared with the above-mentioned platinum complexes. Combined with 5Fu, it induces a high number of remissions in colorectal cancer, and has brought about cures in inoperable gastric cancers. Combined with carboplatin, it has resulted in a high proportion of cures in L1210-carrying mice, which no other two-by-two combination of these complexes has achieved.