In nine patients (pts) with soft tissue sarcoma refractory to conventional therapy (incomplete response or relapse) intensified chemotherapy was administered combining 0.75 mg/m (2) topotecan, 100 mg/m (2) etoposide, 100 mg/m (2) carboplatin and 200 mg/m (2) cyclophosphamide on day 1-5 (TECC). To avoid prolonged intervals between the serial TECC courses autologous hematopoietic stem cell supports (median 1.0 x 10(6) CD34+ cells per kg body weight (bw), range 0.5-2.8 x 10(6) CD34+ cells/kg bw, SD 0.6 x 10(6) CD34+ cells/kg bw) were given on day 7. All pts received granulocyte colony stimulating factor (GCSF) from day 8 in addition. All together 39 TECC courses (minimum 2 courses, maximum 6 courses per pt) were administered, with a median interval of 32 (range 21-52) days until recovery. Leukopenia (<1000/microl) occurred 9 days (range 3-13 days; SD 2.4 days) after end of chemotherapy and persisted for 9 (range 3-15 days; SD 3 days) days. In 31/39 TECC courses readmission to hospital was required for supportive therapy mainly due to neutropenic fever. In this period pts received 0.83 (range 0-1) red blood cell units and 2.35 (range 1-4) platelet units. C-reactive protein in neutropenic pts as an indicator for infection after TECC chemotherapy was detectable after 36 of 39 chemotherapy courses leading to further supportive therapy (median 10.4 mg/dl, range 1.1-28.3 mg/dl; SD 6.67 mg/dl). Duration of total inpatient treatment per TECC course including supportive therapy was in median 13.5 days (range 7-53 days; SD 4.3 days). Only two children had a prolonged infection (77 and 100 days). Clinical and objective tumor responses, defined as complete remission, very good partial response and partial response were observed in 9/9 pts at eight weeks after the last TECC course and were maintained at six months in 7/9 pts. Median time to progression and median overall survival time after TECC chemotherapy were 20.3 months and 25.2 months, respectively. These data provide evidence that in very high risk pts refractory to standard high risk therapy, a combination of TECC chemotherapy and stem cell support is feasible in pts with incomplete remission respectively relapsed STS pts and demonstrates promising antineoplastic activity. Therefore, this regimen warrants further investigation in prospective trials.