Survival of soft tissue sarcoma patients after completing six cycles of first-line anthracycline containing treatment: an EORTC-STBSG database study

Background Doxorubicin based chemotherapy is standard first line treatment for patients with soft tissue sarcoma. Currently several options to improve survival after doxorubicin based chemotherapy are being studied. This study reports on survival after completing 6 cycles of doxorubicin containing first line treatment, which is important when designing studies trying to improve outcomes of first line treatment. Methods A retrospective database analysis was performed on 2045 patients from 12 EORTC sarcoma trials (inclusion period 1980–2012) receiving first line doxorubicin based chemotherapy for advanced soft tissue sarcoma in order to establish progression free survival and overall survival after completing 6 cycles of first line doxorubicin based chemotherapy. Endpoints were overall survival and progression free survival. Factors studied were histologic subtype and type of doxorubicin chemotherapy. Results 748 of 2045 (36.6%) received at least 6 cycles and did not progress during or at the end of chemotherapy. 475 of 2045 (23.2%) of patients received exactly 6 cycles and did not progress during or at the end of chemotherapy. Median progression free survival after 6 cycles of doxorubicin based chemotherapy was 4.2 months (95% confidence interval 3.7–4.8) and median overall survival 15.7 months (14.0–17.8). Median progression free survival and overall survival from randomisation/registration were 8.7 months (95% confidence interval 8.2–9.1) and 20.1 months (95% confidence interval 18.3–22.3) respectively. Significant differences in progression free survival were found between chemotherapy regimens, but not for overall survival. These data are also reported for patients receiving 7 or more cycles of chemotherapy and for patients with 3 or more cycles of chemotherapy. Conclusion This large retrospective study is the first to report progression free survival and overall survival after completion of 6 cycles of first line doxorubicin containing chemotherapy. These results are important when designing new studies exploring for example maintenance therapy after doxorubicin based chemotherapy.