Increasing dose of Continuous Infusion Ifosfamide and Fixed dose of Bolus Epirubicin in Soft Tissue Sarcomas. A Study of the Italian Group on Rare Tumors

[Diagnosis and treatment of soft-tissue tumors]

The diagnostic and therapeutic management of patients with soft-tissue tumors would be similar to the approach used for bone tumors if it were not for one crucial factor: the absolute necessity to recognize a sarcoma. The predominant features are the size of the tumor and its superficial or deep localization. If the tumor is small and superficial, biopsy can be associated with immediate resection without risk of dissemination to the deep tissues: this is the biopsy-resection approach. If the tumor is deep or superficial but large sized, search for locoregional spread with MRI is necessary before undertaking any surgical procedure. MRI can help guide the biopsy and plan resection if the tumor is a sarcoma. A first biopsy is necessary to establish the histological diagnosis and elaborate the therapeutic strategy. Samples should be sent immediately to the pathology lab which should examine sterile fresh tissue. Experience has demonstrated that proper rules for diagnosis and treatment are not necessarily applied initially in approximately one-fourth of all subjects with a malignant soft-tissue tumor. Besides the medical problems caused by this situation, the patient loses a chance for cure. When the tumor is a sarcoma, surgery is the basis of treatment. Complementary radiation therapy may be necessary, particularly for high-grade tumors or if the surgical margin was insufficient. Systemic or locoregional chemotherapy can also be used for high-grade or non-resectable tumors.

A Phase I Study of Prolonged Ambulatory Infusion of Ifosfamide with Oral Mesna

BACKGROUND

Oral mesna allows investigation of ifosfamide as a prolonged ambulatory infusion for dose-intense out-patient use.

METHODS

Cohorts of 3 patients received escalating doses of ifosfamide from 200 to 1,000 mg/m2/day as continuous ambulatory infusion with oral mesna at 30% of the ifosfamide dose every 6 h commencing 2 h prior to ifosfamide infusion as uroprotection on a 14-day schedule with cycles repeated every 28 days.

RESULTS

Fifteen patients received a median of three cycles. Dose-limiting toxicities with cycle 1 were lethargy and hepatotoxicity at 1,000 mg/m2/14 days. Transient transaminase elevation was seen at all dose levels. The other grade 3 toxicities were single episodes of anaemia, granulocytopenia, nausea and hypotension. The best response was stable disease in a patient with thyroid cancer.

CONCLUSION

Ambulatory infusion of 600 mg/m2 ifosfamide with 180 mg/m2 oral mesna was considered suitable for phase II trials and delivers dose-intense out-patient therapy without urotoxicity.

Phase I study of twelve-day prolonged infusion of high-dose ifosfamide and doxorubicin as first-line chemotherapy in adult patients with advanced soft tissue sarcomas

PURPOSE

To determine whether a prolonged 12-day continuous infusion allows the administration of high-dose ifosfamide (IFO) with an acceptable toxicity profile when combined with full-dose doxorubicin (Adriamycin; ADM) as first-line chemotherapy in patients with advanced soft tissue sarcomas.

PATIENTS AND METHODS

Escalating doses of continuous infusion IFO (8-15 g/m2) given on days 1 to 12 in combination with ADM 75 mg/m2 given on day 8 and prophylactic granulocyte colony-stimulating factor support were administered every 4 weeks to 35 chemonaïve patients with advanced soft tissue sarcomas.

RESULTS

The maximum tolerated dose was IFO 15 g/m2. Hematological toxicity was the main dose-limiting toxicity and was dose dependent. Furthermore, thrombocytopenia was cumulative. Grade 4 (WHO) neutropenia and thrombocytopenia were recorded in 48% and 14% of courses, respectively. Eight patients experienced febrile neutropenia. A partial response was observed in 16 out of 30 assessable patients [53%, 95% confidence interval (CI) 25-63]; median time to progression was 25 weeks (range 4-91).

CONCLUSIONS

This study proved that a prolonged 12-day continuous infusion allows an increase in the total IFO dose that can be safely combined with ADM. A multicentric phase II study by the Italian Sarcoma Group to assess its antitumor activity is currently ongoing in patients with advanced soft tissue sarcomas.