[A long-term follow-up report of pediatric relapsed Wilms tumor after retreatment]

Objective: To investigate the long-term efficacy and prognostic factors of pediatric relapsed Wilms tumor (WT) after retreatment. Method: Sixteen children in Shanghai Children's Medical Center with relapsed Wilms tumor were enrolled consecutively in this study between April 2006 and June 2016. All patients were diagnosed according to pathology, imaging and medical and surgical oncologist's assistance. Relapse treatment included surgical excision, chemotherapy and selective radiation therapy. The clinical features, long-term outcomes and prognostic factors of patients were analyzed retrospectively.Survival data were analyzed by Kaplan-Meier.Log-Rank analysis was used for univariate analysis. Result: One case was excluded because of giving up the therapy even though no disease progress was identified. A total of 15 cases (5 males and 10 females) were included in this study. The median age at diagnosis was 3.8 years (range 0.5-9.1 years). The tumor staging at diagnosis included one case of stageⅠ, 7 cases of stageⅡand 7 cases of stage Ⅲ. Among cases of stage Ⅲ, 6 cases had radiation therapy history. The pathology of all patients' recurrent tumor was favorable histology (FH). The median follow-up time was 34.6 months (range 12.5-132.7 months) until March 21, 2017. The time from initial diagnosis to relapse was 7.9 months (range 3.1-17.9 months). Four cases experienced local recurrence, 9 cases relapsed with metastases (6 cases in lungs, 2 in livers, 1 in mediastinum) and 2 cases relapsed in both local site and with metastases. Except to 2 cases received irregular retreatment, 13 cases received regimen I (doxorubicin, vincristine, epoposide and cyclophosphamide for 25 weeks) as relapsed chemotherapy. Five cases received autologous bone marrow transplantation (ABMT). Until the last follow-up, 8 cases achieved continuous complete remission (range 6.7-104.3 months), 3 cases had relapse again or progressing and 4 cases died. The estimated 5-year overall survival (OS) rate and event free survival (EFS) rate were (70±15)% and (52±15)%. According to whether received ABMT or not, the 5-year EFS rate were 51% and 53%. According to whether relapsed within 6 months after diagnosis or not, the 5-year EFS rate were 38% and 56% respectively. Conclusion: The 5-year EFS rate of pediatric relapsed FH WT have reached above 50% by multi-disciplinary treatment in our experience and we encourage patients and doctors to receive retreatment.