Abstract: Objective? To summarize the efficacy of WT- 2016 regimen in the treatment of Wilms tumor. Methods The clinical data of Wilms tumors treated with CCCG-WT- 2016 regimen from March 2017 to April 2019 were retrospectively analyzed. The children were followed up until April 1 , 2020 , and survival outcomes were described by Kaplan-Meier method. Results A total of 43 children ( 23 boys and 20 girls) were included, with a median age of 2 . 40 ( 0 . 83 ~ 2 . 00 ) years. The left, right and bilateral sides were affected in 23 , 19 and 1 patients respectively. There were 7 cases of stage Ⅰ, 7 cases of stage Ⅱ, 21 cases of stage Ⅲ, 6 cases of stage Ⅳ and 2 cases of stage Ⅴ. The pathological classification results were 38 cases of favorable histology (FH) type and 5 cases of unfavorable histology (uFH) type. The median follow-up of all patients was 24 . 13 ( 17 . 23~ 31 . 10 ) months. Except 1 relapsed child who needed further intensive treatment, the rest of the children had completed the treatment. There were 4 deaths ( 9 . 3 %), of which 2 were due to recurrence, 1 due to disease progression and 1 due to septic shock. There were 4 cases of recurrence ( 9 . 3 %), including 3 cases of metastasis to the lungs ( 1 case of in-situ tumor recurrence with pulmonary metastasis) and 1 case of metastasis to the mediastinum. Estimated 2 -year overall survival (OS) and progressionfree survival (PFS) was ( 93 . 02 ± 3 . 89 ) % and ( 90 . 58 ± 4 . 49 ) % respectively for all patients. The overall incidence of sepsis, respiratory infection, drug-induced liver injury and grade 4 myelosuppression were 14 . 0 %, 18 . 6 %, 7 . 0 %, and 39 . 5 % consecutively. The adverse reactions of grade 4 myelosuppression were the decreases in leukocytes by 32 . 6 %, neutrophils absolute value by 34 . 9 %,, platelets by 23 . 3 % and hemoglobin by 9 . 3 %. Conclusion WT- 2016 regimen has improved the prognosis of children with Wilms tumor.

Key words: Wilms tumor; nephroblastoma; chemotherapy; survival analysis; myelosuppression