Diagnosis, treatment and prognosis of 10 children with advanced clear cell sarcoma of kidney

Objective To investigate the clinical features, diagnosis, treatment and prognosis of advanced clear cell sarcoma of kidney(CCSK) in children. Methods The clinical data of 10 children with advanced CCSK hospitalized in Department of Pediatrics of Beijing Tongren Hospital, Capital Medical University from January 2014 to December 2017 were collected, and their clinical features, diagnosis, treatment and prognosis were analyzed retrospectively. Results (1) Clinical features of CCSK: ten cases of CCSK included 6 boys and 4 girls, with the median onset age of 32 months; 7 cases were left CCSK and 3 cases were right CCSK.There were 9 cases of stage Ⅲ and 1 case of stage Ⅳ at the time of initial diagnosis, when 4 cases were misdiagnosed as other renal tumors at the time of initial diagnosis(40%, 4/10 cases). Five patients with stage Ⅲ CCSK had recurrence and metastasis during treatment and follow-up, and the main distant metastasis sites were lung, bone, liver and brain.(2) Treatment and prognosis of CCSK: seven cases received surgery combined with radiotherapy and chemotherapy, and 3 cases whose parents gave up treatment adopted non-standardized treatment.The median follow-up time was 33.5 months.Seven patients survived and 3 cases died.The 3-year overall survival rate of all 10 patients was 65.6%.The 3-year overall survival rate of stage Ⅲ was 74.1%, and that of stage Ⅳ was 0.The prognosis of stage Ⅲ was significantly better than that of stage Ⅳ(χ2=9, P=0.003). Among the 5 recurrent cases, only 1 case achieved completely remission, 2 cases achieved partially remission, 1 case suffered from disease progression and 1 case died.The 3 cases without recurrence were given standardized treatment of surgery, che-motherapy and radiotherapy, and all were completely remitted. Conclusions CCSK is easy to be misdiagnosed, and the risk of recurrence and distant metastasis is high in stage Ⅲ patients during treatment and follow-up.Stage Ⅲ patients who actively receive standard treatment including surgery, chemotherapy and radiotherapy have good prognosis, while the mortality of patients with relapse and distant metastasis is high. Key words: Clear cell sarcoma of kidney; Child; Diagnosis; Prognosis