Posters— Medical Oncology

INFLUENCE OF LOCALLY ADVANCED AND RECURRENT DISEASE ON SURVIVAL OF PATIENTS WITH ADVANCED SOFT TISSUE SARCOMAS. A RETROSPECTIVE ANALYSIS OF THE EORTC SOFT TISSUE AND BONE SARCOMA GROUP (STBSG)

Reichardt P, Van Glabbeke MM, Mouridsen HT, Verweij J, Radford J, Rodenhuis S, Azzarelli A, Le Cesne A, Buesa J, Keizer HJ, van Oosterom A, Kirkpatrick AL, Nielsen OS (EORTC Soft Tissue and Bone Sarcoma Group and EORTC Data Center, Brussels, Belgium)

To establish the influence of locally advanced, recurrent and metastatic disease on survival of patients with advanced soft tissue sarcomas, a retrospective analysis using the database of the EORTC STBSG was conducted. 1622 patients treated in 5 different studies with anthracycline based chemotherapy as first-line treatment of advanced soft tissue sarcomas were included in the analysis. Patients were grouped into 5 categories: locally advanced, recurrent disease, metastatic disease, locally advanced plus metastases, and recurrent disease plus metastases. Information on age, sex, performance status, histology by pannel diagnosis, grade, and time of recurrence or metastases since first diagnosis are available on all patients. Overall response rates in the 5 categories were 26, 32, 28, 24, and 19 %, respectively, which was significant with a p-value of 0.016 (overall chi-square test).

The median overall survival in the 5 categories was 416, 345, 388, 275, and 303 days, respectively, which was significant with an overall p-value of 0.0001 (logrank test). Univariate comparison of patients with locally advanced disease and patients with recurrent disease showed a significant difference with a p-value of 0.0127. Comparing patients with local recurrence alone with patients with metastases + local or recurrent disease did not reveal a statistically significant difference (p=0.8397). Patients with locally advanced disease versus all other patients had a significantly superior survival with a p-value of 0.0001. In the multivariate analysis, using the published model for risk factors (Van Glabbeke et al., J Clin Oncol 17:150-157, 1999) the independent prognostic value of 3 additional variables was tested: presence of locally advanced disease, presence of recurrent disease and presence of metastases. As expected, age, grade, liver involvement and performance status remained highly significant. Looking at the new variables, only presence of recurrent disease was an independently statistically significant negative factor for survival with a p-value of 0.0325.

Conclusions: Response rates are the lowest in patients with locally advanced disease plus metastases and especially recurrent disease plus metastases, probabely due to higher tumor burden. Presence of recurrent disease represents an independent risk factor associated with inferior survival and should therefore be considered as a stratification factor in trials where the principal end-point is survival.