Treatment Outcomes in Children and Adolescents with Relapsed or Progressed Solid Tumors: a 20-year, Single-Center Study.

Background: By estimating the survival rates and exploring prognostic factors in pediatric patients with relapsed or progressed solid tumors, our purpose was to generate background data for future studies.

Methods: We reviewed the medical records of 258 patients with solid tumors who experienced relapse/progression and received subsequent salvage treatment between 1996 and 2016.

Results: A total of 60 patients remained progression-free during first-line salvage treatment, while the remaining 198 patients experienced relapse/progression again; 149 underwent second-line salvage treatment. A total of 76 patients underwent high-dose chemotherapy and autologous stem cell transplantation (HDCT/auto-SCT), and 44 patients received allogeneic SCT. The 10-year progression-free survival (PFS) and overall survival (OS) from relapse/progression were 18.4% ± 2.7% and 24.5% ± 3.0%, respectively. Survival rates were relatively higher in patients with anaplastic ependymoma, initially non-high-risk neuroblastoma, osteosarcoma, Wilms tumor and retinoblastoma. A multivariate analysis showed that relapse/progression during initial treatment, metastatic relapse/progression, and impossible debulking surgery were independent poor prognostic factors for both PFS and OS. Patients who exhibited a complete response or partial response during conventional salvage treatment showed significantly higher survival after SCT than those with stable disease or progressive disease (10-year OS: 54.8% ± 7.0% vs. 7.0% ± 3.5%, P < 0.001).

Conclusion: The prognosis of relapsed/progressed pediatric solid tumors still remains unsatisfactory. New, effective treatment strategies are needed to overcome limitations of current approaches. Hopefully, the background data generated herein will be used in future clinical trials involving patients with relapsed/progressed solid tumors.