Treatment of advanced, high-grade soft-tissue sarcoma with ifosfamide and continuous-infusion etoposide

Managing sarcoma: where have we come from and where are we going?

Sarcomas are a heterogeneous group of neoplasms of mesenchymal origin. Approximately 80% arise from soft tissue and 20% originate from bone. To date more than 100 sarcoma subtypes have been identified and they vary in molecular characteristics, pathology, clinical presentation and response to treatment. While sarcomas represent <1% of adult cancers, they account for approximately 21% of paediatric malignancies and thus pose some of the greatest risks of mortality and morbidity in children and young adults. Metastases occur in one-third of all patients and approximately 10-20% of sarcomas recur locally. Surgery in combination with preoperative and postoperative therapies is the primary treatment for localized sarcoma tumours and is the most promising curative possibility. Metastasized sarcomas, on the other hand, are treated primarily with single-agent or combination chemotherapy, but this rarely leads to a complete and robust response and often becomes a palliative form of treatment. The heterogeneity of sarcomas results in variable responses to current generalized treatment strategies. In light of this and the lack of curative strategies for metastatic and unresectable sarcomas, there is a need for novel subtype-specific treatment strategies. With the more recent understanding of the molecular mechanisms underlying the pathogenesis of some of these tumours, the treatment of sarcoma subtypes with targeted therapies is a rapidly evolving field. This review discusses the current management of sarcomas as well as promising new therapies that are currently underway in clinical trials.

Efficacy and safety of pharmacological interventions in second- or later-line treatment of patients with advanced soft tissue sarcoma: a systematic review

BACKGROUND

Current guidelines recommend anthracycline-based chemotherapy primarily with doxorubicin either as monotherapy or in combination with ifosfamide as the first-line treatment for most advanced STS subtypes. Therapeutic options after failure of doxorubicin and/or ifosfamide are limited. This study aimed to comprehensively review available data on the activity and safety of interventions in second- or later-line treatment of advanced STS.

METHODS

Electronic literature databases (Embase®, MEDLINE®, MEDLINE® In-Process, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews) were searched from 1980 to 01 March 2012 to identify randomised controlled trials (RCTs) and non-randomised studies (both prospective and retrospective) evaluating pharmacological interventions in patients with advanced STS pre-treated with anthracycline- and/or ifosfamide-based therapy.

RESULTS

The review identified six RCTs (one phase III and five phase II trials) and 94 non-randomised studies. Based on the primary trial endpoints, RCTs demonstrated favourable efficacy for pazopanib over placebo (PFS: 4.6 months vs. 1.6 months), gemcitabine plus dacarbazine over dacarbazine monotherapy (3-month PFS rate: 54.2% vs. 35.2%), and trabectedin 3-weekly schedule over weekly schedule (TTP: 3.7 months vs. 2.3 months. The non-randomised studies demonstrated heterogeneity in efficacy and safety results.

CONCLUSIONS

Across the RCTs, pazopanib over placebo, gemcitabine-dacarbazine over dacarbazine, and trabectedin 3-weekly over weekly regimen clearly demonstrated a PFS advantage in the second- and later-line treatment of advanced STS. With only one phase III trial in this setting, there is a clear need for additional comparative trials to better understand the risk: benefit ratios of available agents and combinations.

A Phase I/II Study of a 72-h Continuous Infusion of Etoposide in Advanced Soft Tissue Sarcoma

Purpose. The study was performed to assess the antitumour activity and toxicity of a 72-h continuous infusion of single-agent etoposide as second-line treatment for patients with locally advanced or metastatic soft tissue sarcoma (STS), following reports of substantial activity using this schedule of etoposide administration as first-line treatment in combination with ifosfamide.Patients/method. This was an open phase I/II trial performed at a single institution in patients with metastatic or locally advanced STS who had failed first-line treatment with doxorubicin + ifosfamide combination chemotherapy or, less commonly, single-agent treatment with doxorubicin or ifosfamide. Etoposide was given as a continuous intravenous infusion over 72 h. The starting dose level was 200 mg m(-2) day(-1) x 3 escalating in 10% steps in cohorts of three patients until dose-limiting toxicity was encountered.Results. Seventeen patients were treated, median age 47 years (range 26-71 years). No responses were seen in 16 assessable patients despite etoposide levels in the cotoxic range. The steady-state plasma concentration exceeded 8 mug ml-(1) in all patients and in patients treated at >/= 600 mg m -(2) the mean steady-state level was 14.4 mug ml -(1). The median event-free survival was 6 weeks (95% confidence interval (CI) 3.31-8.69) and the overall survival 16 weeks (95% CI 9.28-22.72). The maximum tolerated dose in this pretreated patient group was 200 mg mm(-2) day(-1) x 3. The dose-limiting toxicity was myelosuppression.Discussion. Etoposide given by 72-h infusion is inactive as second-line chemotherapy in STS. It is associated with significant toxicity when given in these doses, in this patient group.

EORTC Group Phase II Study of Oral Etoposide for Pretreated Soft Tissue Sarcoma

Purpose. This study investigates the efficacy and toxicity of daily oral etoposide in chemotherapy for non-heavily pretreated advanced and metastatic soft tissue sarcoma (STS).

Subjects. Twenty-seven patients with progressive and measurable disease were treated. Median age was 53 years (range 20–71 years) and performance status WHO 0 or 1. Histologies included mainly leiomyosarcoma (8), malignant fibrous histiocytoma (4), rhabdomyosarcoma (4), liposarcoma (2) and synovial sarcoma (2). Fifteen patients had received prior radiotherapy, of whom three included sites with haematopoiesis. All patients had received prior chemotherapy, including adjuvant therapy (7) and mostly consisted of one two-drug schedule (ifosfamide and doxorubicin) or two single-drug regimens.

Methods. Chemotherapy consisted of etoposide (VP16-213), 50 mg m^-2 day^-1 × 21 q 4 weeks. Blood cell counts were done weekly. Dose reductions and a maximum delay of 2 weeks was allowed depending on cell counts during treatment and at the start of a new 4-week treatment cycle.

Results. No objective response was observed. Progressive disease was observed after two treatment cycles in 17/27 patients (68%) and after three cycles in 22/27 patients (81%). The other patients received three to five cycles. Twenty-four patients went off study due to progressive disease. Grade 3 and 4 neutropenia was observed in eight and one patients, respectively. Thrombocytopenia grade 3 was seen in two patients. Non-haematological toxicity grade 3 (nausea, diarrhoea or alopecia) was observed in three patients, and grade 4 (dyspnea, hypotension or haemorrhage) in three patients.

Discussion. No objective response was obtained. Oral etoposide at a dose of 50 mg m^-2 day^-1 × 21 q 4 weeks is inactive in chemotherapy of pretreated STS. Disease progression occurred within three cycles in the majority (81%) of patients. Toxicity of this regimen in non-heavily pretreated patients is low.

High-dose chemotherapy in the treatment of relapsed osteosarcoma: an Italian sarcoma group study

PURPOSE

To study the feasibility and activity of two courses of high-dose chemotherapy (HDCT) in patients with osteosarcoma in metastatic relapse.

PATIENTS AND METHODS

Patients with high-grade osteosarcoma in metastatic relapse (multiple metastases or solitary metastasis at intervals of less than 30 months) were eligible for study. High-dose chemotherapy consisted of carboplatin and etoposide followed by stem-cell rescue. A second course was planned 4 to 6 weeks after the first. Surgery was performed before or after HDCT.

RESULTS

Thirty-two patients were enrolled onto the study. At the end of the treatment, 25 patients were in complete remission (CR), six were alive with disease progression, and one died of toxicity. At present, 14 patients are alive with a median survival time of 23 months from study entry: four are in first CR, three are in second CR, and one is in fourth CR. Six patients are alive with disease. Eighteen patients (56%) died: 17 of disease and one of toxicity. Transplantation-related mortality was 3.1%. The relapse or progression disease rate was 84.4%. The 3-year overall survival rate is 20% and the 3-year disease-free survival rate is 12%.

CONCLUSION

HDCT combined with surgery is feasible and can induce CR in a large portion of patients. Two points, however, need to be considered: only patients who are chemosensitive to induction treatment can obtain CR after HDCT, and the length of remission is short, because most patients relapse. Thus novel strategies are needed to maintain the remission status or to treat patients who do not respond to induction treatment.

Soft tissue leiomyosarcomas and malignant gastrointestinal stromal tumors: differences in clinical outcome and expression of multidrug resistance proteins

PURPOSE

Several studies have reported clinical behavior and chemotherapy resistance in leiomyosarcomas, but these studies did not differentiate between soft tissue leiomyosarcomas (LMS) and malignant gastrointestinal stromal tumors (GIST). Multidrug resistance (MDR) has been associated with the expression of P-glycoprotein (P-gp), multidrug resistance protein (MRP(1)), and lung resistance protein (LRP). The aim of the present study was to compare LMS and GIST with respect to clinical outcome and MDR parameters.

PATIENTS AND METHODS

Clinical outcome was evaluated in 29 patients with a primary deep-seated LMS and 26 patients with a primary malignant GIST. Paraffin-embedded material, available for 26 patients with LMS and 25 with GIST, was used for immunohistochemical detection of P-gp, MRP(1), LRP, and c-kit.

RESULTS

Mean overall survival (OS) was 72 months for LMS patients and 31 months for GIST patients (P: <.05). Metastases occurred in 16 (59%) of 27 assessable LMS patients and in 10 (56%) of 18 assessable GIST patients. LMS predominantly metastasized to the lungs (14 of 16 patients), whereas GIST tended to spread to the liver (five of 10 patients) and the abdominal cavity (three of 10 patients; P: <.001). P-gp and MRP(1) expression was more pronounced in GIST than in LMS (P: <.05): the mean percentage of P-gp expressing cells was 13.4% in patients with LMS and 38.4% in patients with GIST, and the mean percentage MRP(1) expressing cells was 13.3% in patients with LMS and 35.4% in patients with GIST. LRP expression did not differ between LMS and GIST. c-kit was expressed in 5% of the LMS patients and in 68% of the GIST patients.

CONCLUSION

LMS patients have a better survival than GIST patients, and the metastatic pattern is different. Expression of MDR proteins in LMS is less pronounced than in GIST.

Chemotherapy in soft tissue sarcoma. The Scandinavian Sarcoma Group experience

The first chemotherapy study of soft tissue sarcoma (STS) by the Scandinavian Sarcoma Group was started in 1981 (SSG I). It evaluated the single agent adjuvant doxorubicin in a randomized setting in patients with high-grade STS. No improvement was noted in the overall survival or disease-free survival rate. More intense chemotherapy was thereafter (1991-1994) evaluated in a phase 2 study, introducing ifosfamide and a continuous infusion of etoposide with growth factor (SSG X). The response rate of previously untreated patients was high (42%), but complete remissions were few. Analysis of patients undergoing surgery after preoperative chemotherapy suggested an increased survival. A recent meta-analysis of adjuvant chemotherapy for localized resectable STS in adults, including the SSG I trial, indicated a better disease-free survival and possibly improved overall survival (Thierny et al. 1997). At present, we are studying whether such a benefit can be shown in patients with high-risk prognostic criteria by giving adjuvant ifosfamide and doxorubicin treatment after primary surgery (SSG XIII). In the latter SSG study, started on July 1, 1998, the adjuvant therapy is evaluated in a phase 2 study in selected patients with high-grade STS and other unfavorable prognostic factors.

Ifosfamide and continuous infusion etoposide in advanced adult soft tissue sarcoma. A Scandinavian Sarcoma Group Phase II Study

The purpose of this study was to evaluate tumour response and toxicity to ifosfamide and continuous infusion etoposide in metastatic or locally advanced soft tissue sarcoma, with dose escalations under G-CSF (granulocyte colony-stimulating factor) support. Of 92 eligible patients (median age 51 years), 85% had tumours of high-grade malignancy and 82% had metastatic disease. Chemotherapy, the baseline dose, consisted of etoposide 600 mg/m2 as a 72 h infusion and ifosfamide 1500 mg/ m2/day for 3 days, followed by G-CSF support (VIG regimen). Stepwise 10% dose escalations were performed depending on haematological toxicity. For patients considered operable after induction chemotherapy, surgical resection of all identifiable residual tumour was attempted. Complete and partial response rates were 11% and 31%, for an overall response rate of 42% (95% CI 31-52%). Forty-eight per cent of courses were dose escalated by a median of 20%. Complete responders had significantly higher, and patients with progressive disease had significantly lower, dose levels than other patients. None of 20 patients with liver metastases responded despite high dose levels. Compared to a preceding pilot study, the addition of G-CSF led to significantly higher dose levels, improved schedule adherence and less haematological toxicity, but no apparent increase in response rate. In view of the modest dose of ifosfamide applied in this study, it is possible that the prolonged infusion of etoposide made a significant contribution to the regimen's antitumour activity, although this can only be determined definitively in a randomised study.

The outcome of advanced soft tissue sarcoma patients with complete tumour regression after either chemotherapy alone or chemotherapy plus surgery. The Scandinavian Sarcoma Group experience

The intensified induction regimens used and the potential use of high-dose consolidation chemotherapy (CT) in advanced soft tissue sarcomas (STS) has focused interest on the outcome of those patients who can achieve complete remission (CR) by current therapy. The files from four institutions with a special interest in STS were studied. 38 adult patients with advanced STS who were converted disease-free by either CT alone (n = 14) or CT followed by surgery (n = 24) were found. The median follow-up time was 29 months. The median disease-free survival (DFS) was 18 months and the estimated 2-year DFS 34%. The median disease-specific survival (DSS) was 40 months and the estimated 2-year DSS 78%. For patients who achieved CR by CT alone, and for patients who were converted to CR by surgery, the corresponding DFS figures were 23 months (estimated 2 year DFS 48%) and 10 months (26%) (P = 0.07), respectively. The histological response to CT significantly predicted outcome in patients subjected to surgery (DFS P value 0.004, DSS P value 0.02). Patients who achieved CR by surgery shortly after having achieved a clinical partial response (PR with early surgery) did better than those who where converted to CR by surgery after protracted CT following a clinical PR (PR with late surgery) (DFS P value 0.02, DSS P value 0.1). Our results confirm that CT alone can induce prolonged DFS in rare patients with advanced STS. In patients subjected to surgery, a good histological response indicates improved outcome.