Clear cell sarcoma of the kidney in Austrian children: Long‐term survival after relapse

Abstract

Introduction Clear cell sarcoma of the kidney (CCSK) is a rare malignant childhood renal tumour. Recently, the central nervous system (CNS) was found to be the most frequent site of relapse associated with a poor outcome. Optimal treatment strategies are scarce. Patients and Methods Retrospective data analysis of all Austrian children with CCSK. They were enrolled in the Austrian‐Hungarian Wilms Tumour Study (AHWTS) 1989, the SIOP93‐01 or the SIOP2001 study between 1990 and 2019. Demographic, diagnostic, treatment‐related variables and survival data were analysed. Results We identified 12 children with CCSK (M = 7, F = 5; median age 1.6 years). All had localised disease (stage I: 2; stage II: 2; stage III: 8) at diagnosis, and a first complete remission (CR1) was achieved in 12/12. Six patients are in an ongoing CR1 (median follow‐up 10 years). Six other patients had a relapse (local 1; brain 5) a median time of 2.4 years from diagnosis. Two patients died of the disease 4 months and 2.8 years after first relapse. Four of five patients with CNS relapse are in CR2 with a median follow‐up time of 9.3 years after relapse diagnosis. Relapse treatment included a combination of chemotherapy, radiation and surgery. Two children received high‐dose chemotherapy followed by autologous stem cell rescue, and one child received intrathecal mafosphamide. Long‐term side effects after treatment were impaired tubular renal function (n = 4), cardiomyopathy (n = 1) and growth disorders (n = 1). Conclusions In this series, the brain was the most common site of relapse. Long‐term survival after recurrence was achievable with intensive multimodal therapy.

Meta-Analysis on Long-Term Outcomes of Pediatric Renal Cancer Survivors Following COG and SIOP Protocols

“…We finally included 16 studies in the research (8 studies for each treatment approach group), for a total of 715 patients, 367 in the SIOP group and 348 in the COG group. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] All studies are reported in ►Table 1.…”

“…11,19 High risk for selective reporting was associated with three studies. 8,10,15 Furthermore, 30% of the studies were associated with low risk, 50% with high risk for other types of bias, 7,8,[11][12][13][14][15]17 and the remaining 20% with unclear risk for other bias 18,20 (►Fig. 2).…”

“…For the SIOP group, EFS was mentioned in six studies, 7,13,14,17,18,20 with average EFS of 85.85%. In Friesenbichler et al, 14 which included only patients with kidney clear cell sarcoma of the kidney, had EFS of 45%, even though OS was similar to rates in the other studies (90%). Altogether EFS was 90.89%.…”

Overall survival nomogram and relapse-related factors of clear cell sarcoma of the kidney: A study based on published patients

“…Rarity represents the greatest barrier to advances in the diagnosis and treatment of CCSK. There have been several follow-up clinical studies on CCSK relapse (5,(16)(17)(18)32). Most of them were single-center observations with small samples.…”

“…A combined SIOP and Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) study showed that relapse occurs in about 16% of patients (5). Several follow-up clinical studies on relapse of CCSK showed that relapse patients who receive only primary treatment with resection + chemotherapy + radiotherapy exhibit a poor prognosis due to the absence of effective treatment standards for relapsed CCSK (16)(17)(18). These were mostly single-center studies with a small sample size and no analysis of relapse-related factors.…”