The real-life outcome of pazopanib in patients with advanced soft tissue sarcoma: A retrospective cross-sectional study of a Turkish cohort

Real-world outcomes of pazopanib in metastatic soft tissue sarcoma: a retrospective Turkish oncology group (TOG) study

AIM

Description of patient characteristics, effectiveness and safety in Turkish patients treated with pazopanib for metastatic soft tissue sarcoma (STS).

PATIENTS AND METHODS

This multicenter study is based on retrospective review of hospital medical records of patients (≥ 18 years) treated with pazopanib for non-adipocytic metastatic STS at 37 Oncology clinics across Turkey. Objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS) and overall survival (OS) were evaluated with further analysis of data on the three most common histological subtypes (leiomyosarcoma [LMS], undifferentiated pleomorphic sarcoma [UPS], synovial sarcoma [SS]) in the cohort.

RESULTS

Data of 552 adults (57.6% women, median age: 52 years) were analyzed. DCR and ORR were 43.1% and 30.8%, respectively. Median PFS was 6.7 months and OS was 13.8 months. For LMS, UPS and SS, median PFSs were 6.1, 5.9 and 7.53 months and median OSs were 15.03, 12.87 and 12.27 months, respectively. ECOG ≥ 2 was associated with poor PFS and OS. Liver metastasis was only a factor for progression. Second-line use of pazopanib (vs. front-line) was associated with better PFS, its use beyond third line predicted worse OS. Adverse events (AE) occurred in 82.7% of patients. Most common AEs were fatigue (58.3%) and anorexia (52.3%) which were graded as ≥ 3 in 8.2% and 7.4% of patients, respectively.

CONCLUSION

Pazopanib is effective and well-tolerated in treatment of non-adipocytic metastatic STS. Its earlier use (at second-line), good performance status may result in better outcomes. Worldwide scientific collaborations are important to gain knowledge on rarer STS subtypes by conducting studies in larger patient populations.

Real-World Outcome and Prognostic Factors of Pazopanib in Advanced Soft Tissue Sarcoma

Purpose

Pazopanib has been approved for treating soft tissue sarcomas (STS) after chemotherapy. We aimed to evaluate the prognostic factors, clinical outcomes, and tolerability of pazopanib in patients with STS.

Patients and Methods

Forty-five patients treated between June 2015 and August 2019 were reviewed. Clinical outcome was measured by assessing the disease control rate (DCR) using Response Evaluation Criteria in Solid Tumors (version 1.1). Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method. Adverse effects were assessed using the Common Terminology Criteria for Adverse Events (version 5.0).

Results

The median age of patients at diagnosis was 28 (interquartile range (IQR), 23–45) years. Pazopanib was used as the second-line treatment in 46.7% and the subsequent line in 53.3% of patients. The overall DCR was 55.6%, and at 8 and 12 weeks, it was 52.3% and 35.5%, respectively; the median duration of response was 7 (IQR: 2–18) months. Pazopanib-induced hypothyroidism was associated with DCR, with an odds ratio of 7 (95% confidence interval [95% CI: 1.7–27.5], p<0.01). The median PFS and OS were 4.1 (95% CI: 0.85–7.42) and 12.4 months (95% CI: 6.5–18.36), respectively. Hypothyroidism and response to pazopanib, better ECOG PS, histological subtypes desmoid tumor/aggressive fibromatosis (DT/AF), and alveolar soft part sarcoma (ASPS) were favorable prognostic factors for PFS. Hypothyroidism and response to pazopanib were significant favorable factors for OS. There was no statistical difference in the OS between patients using pazopanib as the second-line therapy and those using it as the subsequent-line therapy.

Conclusion

Pazopanib is an effective treatment for STS. However, it showed variability in the clinical outcome in favor of ASPS and an outstanding response in the DT/AF subtype. Pazopanib-induced hypothyroidism is a good prognostic factor for disease control and is associated with prolonged PFS and OS.