Background: Real-world evidence on multimodality treatment and chemotherapy dose delivery in nonmetastatic soft tissue sarcoma (STS) remains limited.
Objectives: To evaluate patterns of multimodality treatment and relative dose intensity (RDI) of chemotherapy in adult patients with nonmetastatic STS treated with curative intent.
Methods: This retrospective study included patients aged ≥18 years with histologically confirmed intermediate- or high-grade STS (World Health Organization 2020 classification; Fédération Nationale des Centres de Lutte Contre le Cancer grade 2–3) in whom treatment was initiated with curative intent and who received at least one treatment modality (surgery ± chemotherapy ± radiotherapy) between January 2016 and December 2024. Data regarding treatment patterns and RDI and toxicity were extracted from hospital records. Survival outcomes were estimated using the Kaplan–Meier method and compared using the log-rank test.
Results: A total of 103 patients were included. The median age was 48 years (range, 18–85). The majority of patients had extremity tumours (75%), and 89.3% had grade 3 disease. Synovial sarcoma was the most common histology (28%). Surgery was performed in 98.1%, achieving clear margins in 84.5%. Radiotherapy was administered in 66% (94% postoperative). Chemotherapy was given to 57%, predominantly in the adjuvant setting (51.5%). Among 53 evaluable patients, RDI 100% for both ifosfamide and doxorubicin was achieved in 13% only, and RDI ≥ 85% in 70%. At a median follow-up of 59.4 months, median overall survival (OS) and disease-free survival (DFS) were not reached; 4 years OS and DFS were 74.6% and 58%, respectively. Trimodality treatment (surgery, radiotherapy and chemotherapy) was associated with the longest mean OS (98.7 months) compared with other treatment modalities (86.5, 79.9, 51.3 and 10.0 months for surgery + radiotherapy, surgery + chemotherapy, surgery alone and chemotherapy alone, respectively). Mean OS differed significantly across treatment groups (p < 0.001). Adjuvant chemotherapy was associated with superior OS (95.1 versus 76.5 months; p = 0.009). Grade ≥3 febrile neutropenia was seen in 18%. Mean OS was numerically longer among patients with an RDI ≥ 85% than among those with an RDI <85% (98.6 versus 76.4 months); however, this difference did not reach statistical significance (p = 0.313).
Conclusion: Adjuvant chemotherapy was associated with improved survival in appropriately selected patients with nonmetastatic STS. However, maintaining optimal RDI of chemotherapy in real-world practice is challenging and associated with higher observed toxicity rates than reported in clinical trials.
