Pilot study of a high-dose carboplatin-based salvage strategy for relapsing or refractory germ cell cancer

High dose chemotherapy and stem cell support in the treatment of germ cell cancer

PURPOSE

The current status of high dose chemotherapy with autologous stem cell support in patients with germ cell cancer is reviewed.

MATERIALS AND METHODS

Advanced germ cell cancer can be cured in most patients using chemotherapy with or without surgery. A small fraction of patients fail to achieve a marker remission, have residual viable carcinoma at post-chemotherapy surgery or have relapse after remission. Phase II trials suggest that autologous stem cell support is more active than standard dose chemotherapy in patients with relapse. A comprehensive literature review, focusing on trials published in the last decade, is followed by a discussion of current trials and recommendations for the use of autologous stem cell support in germ cell cancer.

RESULTS

In early trials about 15% of patients with multiple relapsed and refractory disease had durable remission with high dose carboplatin and etoposide. Most regimens now add high dose cyclophosphamide or ifosfamide to carboplatin and etoposide. Together with the use of autologous stem cell support in less heavily-pretreated patients, these regimens have produced durable remissions in 40% to 50% of patients. Multivariate analyses led to the identification of prognostic factors at diagnosis and predictive factors during therapy which were associated with a low rate of durable remission. Ongoing randomized trials of autologous stem cell support early in relapse or as part of initial therapy are designed to study and validate further these prognostic factors.

CONCLUSIONS

For patients with poor risk presenting features, the role of autologous stem cell support has not been proven and awaits the results of an ongoing United States intergroup trial. Patients with residual cancer at post-chemotherapy surgery may have a substantial risk of relapse despite additional cycles of the same drugs used to achieve marker remission. For select patients in this category alternatives to additional cycles of the original chemotherapy may include established second line regimens or autologous stem cell support. The role of autologous stem cell support for germ cell tumor in relapse may be challenged by the future discovery of new agents for these diseases.

High-dose chemotherapy in adult patients with germ cell tumors

BACKGROUND

Approximately 80% of patients with advanced germ cell tumors (GCTs) can be cured with cisplatin-based chemotherapy. Patients with poor-prognosis disease have a cure rate of only 50%, whereas patients with first relapse have only a 25% chance of prolonged survival and potential cure following standard therapy. High-dose chemotherapy (HDC) is being investigated in patients with GCTs to improve the results of salvage treatment and in first-line setting for poor prognosis disease.

METHODS

The authors review the results of the clinical trials that have evaluated the role of HDC in GCT patients. Data were obtained using a computer-assisted MEDLINE search, and meeting abstracts with clinical relevance in this field were hand-searched. Open randomized phase III studies are described and examined.

RESULTS

Several phase II studies have shown a possible benefit for patients with recurrent disease, but the preliminary results of a phase III randomized trial did not demonstrate a survival advantage for HDC after three courses of standard-dose chemotherapy in the salvage therapy of patients in whom first-line treatment has failed. Three prospective, randomized trials are evaluating the role of HDC in a first-line setting.

CONCLUSIONS

New HDC strategies are emerging, involving new drugs (eg, paclitaxel), intensive induction regimens, and upfront and/or multiple courses of HDC. The evaluation of mature data of randomized trials will better define the role of HDC in this disease.

Double dose-intensive chemotherapy with autologous stem cell support for relapsed and refractory testicular cancer: the University of Michigan experience and literature review

Testicular cancer patients refractory or in relapse after primary chemotherapy have < or =25% 5-year progression-free survival with salvage. To improve prognosis, patients entered a phase I/II tandem dose-escalation trial of carboplatin (1500-2100 mg/m(2)) and etoposide (1200-2250 mg/m(2)) with ABMT. Patients were eligible for a second cycle if disease progression was absent and performance status allowed. From August 1990 to June 1998, 29 males (25 NSGCT) were treated. At the time of ABMT, 10 were chemosensitive, four were chemoresistant, and 10 were absolutely refractory to platinum. Disease status (no. patients) at transplant: primary refractory disease (six), first relapse (10), second relapse (eight), third relapse (five). Fifteen (52%) received both transplants. Treatment-related mortality was 10%. Best response after ABMT included: two CR, one CR surgically NED, five PR, three PR surgically NED, seven SD, and eight PD. Eight (28%) patients are continuously progression-free a median 60 months (range, 31-93) from first ABMT. Three seminoma patients remain progression-free. Of five long-term NSGCT survivors, four were treated in first relapse with platinum-sensitive disease. Eighteen relapses occurred a median of 4 months after ABMT I (two late relapses at 28 and 44 months). The median PFS and OS for the whole group are 4 and 14 months, respectively. Patients with relapsed/ refractory testicular cancer benefit most from ABMT if they have platinum-sensitive disease in first relapse. Patients who do poorly despite ABMT have a mediastinal primary site, true cisplatin-refractory disease, disease progression prior to ABMT, and/or markedly elevated betaHCG at ABMT. New treatment modalities are needed for the latter group.

Intensive and timely chemotherapy, the key of success in testicular cancer

More than 90% of patients with advanced germ cell tumors (GCT) are curable since the introduction of cisplatin-based chemotherapy, but only half of them with poor-risk characteristics and less than a quarter after the first relapse are cured by conventional chemotherapy. In this review, we have studied the results of dose-intensity in conventional chemotherapy and high-dose chemotherapy (HDCT) in the treatment of GCT patients. In first line, only one randomized trial of HDCT was performed and no benefit was demonstrated. One US randomized trial is ongoing. In first salvage treatment, no randomized trial was performed, and a European trial (IT94) is ongoing. In the refractory situation, there is no indication of high-dose chemotherapy. In conclusion, high-dose chemotherapy is not a standard treatment for different situations. New strategies are needed to improve the survival rate of poor prognosis germ cell tumor patients.

High dose chemotherapy with autologous stem cell rescue in adults with malignant primary brain tumors

High dose chemotherapy (HDCT) with autologous (bone marrow or peripheral blood) stem cell rescue (ASCR) has had success in the treatment of some malignant pediatric brain tumors. We report a series of adults enrolled in one of three HDCT and ASCR protocols for malignant primary brain tumors. Overall toxic mortality was 18%; chemotherapy regimen, tumor type, and prior treatment did not predict transplant-related mortality. Patients over the age of 30 had a higher rate of toxic mortality. Patients with recurrent medulloblastoma had a significant improvement in long-term survival (median: 34 months) as compared with historical reports; two patients with glioblastoma survive beyond four years without progression, but overall, a significant improvement in long-term survival could not be demonstrated for malignant gliomas.

Chemotherapy of metastatic testicular germ cell tumors: relationship of histologic response to size reduction and changes in tumor markers

BACKGROUND

Although testicular germ cell tumor is one of the most curable cancers, approximately 20% of advanced cases remain incurable. In this study we investigate factors that may predict a poor response to standard chemotherapeutic regimens and thus allow earlier initiation of more aggressive measures.

METHODS

We analyzed the records of 19 patients with metastatic testicular germ cell tumors (8 seminomas and 11 nonseminomas). Sixteen patients underwent surgical exploration for residual tumors following chemotherapy, and the histological findings on the resulting specimens were correlated with reductions in tumor size observed on computed tomography and with changes in tumor marker levels.

RESULTS

Complete necrosis was obtained in 10 of 12 lesions that shrank by at least 80%, while continued existence of teratoma or cancer was confirmed in 9 of 11 lesions with smaller size reductions. An initial human chorionic gonadotropin-beta subunit (HCG-beta) level more than 100 times the upper limit of normal appeared to predict poor histological response (teratoma/cancer) to chemotherapy. Slow fall (prolonged half-life) of tumor markers during chemotherapy also correlated with poor histological response.

CONCLUSION

Factors which predict poor histological response of tumors to chemotherapy include size reduction less than 80%, initial HCG-beta levels more than 100 times the upper limit of normal, and prolonged half-life of tumor markers (placental alkaline phosphatase, alpha-fetoprotein and HCG-beta).

The toxicity of radiotherapy following high-dose chemotherapy with peripheral blood stem cell support in high-risk breast cancer: a preliminary analysis

High-dose chemotherapy with autologous bone marrow and/or peripheral blood stem cell (PBSC) support is increasingly employed in the adjuvant treatment of high-risk breast cancer. Subsequent radiotherapy has been reported to be associated with morbidity and mortality resulting from pulmonary toxicity. In addition, the course of radiation therapy may be hampered by excess myelosuppression. The aim of this study was to investigate the contribution to radiation-induced toxicity of a high-dose chemotherapy regimen (CTC) that incorporates cyclophosphamide, thiotepa and carboplatin, in patients with high-risk breast cancer. In two randomised single institution studies, 70 consecutive patients received anthracycline-containing adjuvant chemotherapy (FEC: 5-fluorouracil, epirubicin and cyclophosphamide) followed by radiotherapy to achieve maximal local control. Of these patients, 34 received high-dose CTC with autologous PBSC support. All patients tolerated the full radiation dose in the planned time schedule. Radiation pneumonitis was observed in 5 patients (7%), 4 of whom had undergone high-dose chemotherapy (P = 0.38). All 5 responded favourably to prednisone. Fatal toxicities were not observed. Myelosuppression did not require interruption or untimely discontinuation of the radiotherapy, although significant reductions in median nadir platelet counts and haemoglobin levels were observed in patients who had received high-dose chemotherapy (P = 0.0001). The median nadir of WBC counts was mildly but significantly decreased during radiotherapy (P = 0.01). Red blood cell or platelet transfusions were rarely indicated. Adequate radiotherapy for breast cancer can be safely administered after high-dose CTC with autologous PBSC support. Radiation-induced myelotoxicity is clearly enhanced following CTC, but this is of little clinical significance. Radiation pneumonitis after high-dose therapy may occur more often in patients with a history of lung disease or after a relatively high radiation dose to the chest wall. Other high-dose regimens, particularly those incorporating drugs with known pulmonary toxicity (such as BCNU), may predispose patients to radiation pneumonitis.

Pharmacokinetics and pharmacodynamics of carboplatin administered in a high-dose combination regimen with thiotepa, cyclophosphamide and peripheral stem cell support

The aim of this pharmacokinetic/pharmacodynamic study was to define the relationships of the carboplatin exposure with the toxicity in patients treated with high dose carboplatin (400 mg m-2 day-1), cyclophosphamide (1500 mg m-2 day-1) and thiotepa (120 mg m-2 day-1) for four consecutive days, followed by peripheral stem cell transplantation. Exposure to carboplatin was studied in 200 treatment days by measuring the area under the carboplatin plasma ultrafiltrate (pUF) concentration vs time curve (AUC). The AUC was obtained by using a previously validated limited sampling model. A total of 31 patients was studied who received one, two or three courses of this high-dose chemotherapy regimen. The unbound, plasma ultrafiltrate carboplatin was almost completely cleared from the body before each next treatment day in a course; the day-to-day AUC variation was 3.3%. The mean cumulative AUC over 4 days was 19.6 (range 14.1-27.2) mg ml-1 min-1. In 97 treatment days the carboplatin dose was calculated using the Calvert formula with the creatinine clearance as the measure for the glomerular filtration rate (GFR). For these courses, the inter-patient variability in pharmacokinetics was significantly reduced from 21% to 15% (P = 0.007) in comparison with the schemes where it was given as a fixed dose of 400 mg m-2. There were no relationships found between toxicity and the AUC of carboplatin, which may be due to the influence of overlapping toxicities of cyclophosphamide and thiotepa. However, the ototoxicity was strongly related to the cumulative carboplatin AUC. This toxicity was dose limiting for carboplatin in this schedule. It appeared that the carboplatin pharmacokinetics in these regimens were similar to those reported at conventional dosages. To reduce the inter-patient variation, the carboplatin dose can be calculated using the Calvert-formula with the creatinine clearance as the measure for the GFR.

Hemolytic uremic syndrome after high dose chemotherapy with autologous stem cell support

BACKGROUND

Chemotherapy intensification may lead to new forms of toxicity such as hemolytic uremic syndrome.

METHODS

Three patients are described who developed this complication 4 to 6 months after high dose chemotherapy followed by autologous stem cell support. The literature on this subject is reviewed.

RESULTS

One patient was conditioned with BEAC (carmustine, etoposide, cytosine arabinoside, and cyclophosphamide) and received autologous bone marrow. The other two underwent triple peripheral stem cell transplantation after conditioning with CTC (carboplatin, cyclophosphamide, and thiotepa). Symptoms were hypertension, microangiopathic hemolytic anemia, thrombocytopenia, and renal insufficiency. One patient had a retinal vein thrombosis. One patient died of a cardiac arrest shortly after the diagnosis was made. The remaining two achieved a partial remission: one with fresh frozen plasma without plasmapheresis and fresh frozen plasma, but improved on high dose intravenous immunoglobulin and vincristine.

CONCLUSIONS

Hemolytic uremic syndrome is a serious complication of the more intensive chemotherapy made possible by stem cell support. Because of the rapidly growing indications for this approach, an increase in this type of vascular complication is expected.

High-dose chemotherapy regimens for solid tumors

High-dose chemotherapy with blood progenitor cell transplantation is increasingly recognized as a potentially valuable treatment for breast cancer, germ cell cancer, ovarian cancer and other solid tumors. A variety of cytotoxic drugs, particularly alkylating agents, have been investigated either alone or in combinations. Current, predominantly small, phase I and phase II clinical trials to not adequately compare the efficacy of these regiments and patterns of dose-limiting extramedullary toxicity are emerging. Busulfan, carmustine (BCNU) and mitomycin C cause veno-occlusive disease (VOD) of the liver in some patients and the latter two agents also cause interstitial pneumonitis. Cisplatin and ifosfamide only allow minor dose escalation before renal failure becomes prohibitive. Cyclophosphamide, thiotepa, melphalan and etoposide allow substantial dose escalation above standard and are mainly associated with mucositis. Moderate dose escalations of mitoxantrone and carboplatin are possible, limited by cardiotoxicity and neurotoxicity, respectively. Advances in supportive care have abolished bone marrow suppression as the dose-limiting toxicity in chemotherapy. Severe and potentially fatal extramedullary toxicity following high-dose chemotherapy can only be avoided by administering agents with predictable toxicity patterns and by carefully considering their clinical pharmacology.