1745P - How to optimize the response with trabectedin in soft tissue sarcomas? Data from a high-volume center

Background

Approximately 30-40% will develop distant metastasis and will eventually succumb to the disease. Beyond first-line, disease control is modest, with median progression-free survival (PFS) ranging 2.6–4.6 months The value of trabectedin (T) has been emphasized beyond the first line in the treatment of metastatic soft tissue sarcomas. There are data of T + Radiotherapy (RT) in combination,30Gy in 10 sessions.

Methods

Retrospective review of patients' medical records who have received trabectedin in the last 5 years. Descriptive analysis has been conducted. In a subsequent step, progression-free survival (PFS) and overall survival (OS) were analyzed. A specific analysis was conducted on the subgroup that received a combination with RT.

Results

We analyzed 207 patients, with a predominance of women 116 (56%) and 91 men. 73 pts get treatment at second line (2L), and 75 pts get trabectedin in third line (3L). PFS in all patients is around 6 months influence due to time patients get treatment. PFS in pts treated at 2L 14 month, 6 month as 3L, and lower in subsequences lines. P=0,001. OS (43m vs 41) p=no significance. Leiomyosarcoma (Lei) and liposarcoma (Lipo) exhibit the best PFS compared to the others, with statistical significance. A lesser response to trabectedin was observed in those presenting with metastatic disease at onset (PFS 6m (M1) vs 9 (M0)) There was no objective worsening in PFS for patients who experienced dose reduction or delayed administration. 80 pts were treated with RT, most patients were Lei (24), Lipo (20), synovial sarcoma (8), UPS (7), pleomorphic rhabdomyosarcoma (5) and stromal sarcoma (3). PFS in those receiving concurrent RT(9m) versus those who did not (5m) p=0,086. Disease control rate in irradiated lesion was 89%, with a better response in Lei and synovial sarcomas.

Conclusions

All patients treated showed benefit with PFS 6 month, higher than literature review. There are significant differences with a higher PFS in patient with lower number of previous lines. There are various factors that influence the response, such as metastatic presentation, metastasis location, histological subtype, and RT. RT provides adequate disease control, with improvement in the survival of these patients.

Clinical trial identification

Editorial acknowledgement

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.