[Clinicopathological characteristics of NTRK-rearranged mesenchymal tumors in childhood].

Objective: To investigate the clinical and pathological features of pediatric NTRK-rearranged tumors. Methods: Four NTRK-rearranged soft tissue tumors and one renal tumor at Shanghai Children's Medical Center, Shanghai Jiaotong University and Singapore KK Women's and Children's Hospital from January 2017 to September 2019 were identified. Pan-TRK immunohistochemistry, and the ALK and ETV6 gene break-apart fluorescence in situ hybridizations (FISH) were performed. NTRK gene rearrangement was detected using sequencing-based methods. Results: There were 3 males and 2 females in this study. The patients were between 3 months and 13 years of age. Histologically, the tumors were infiltrative spindle cell tumors with variable accompanying inflammatory cells. Immunohistochemistry showed positive reactivity for pan-TRK in all tumors, with nuclear staining for NTRK3 fusion, and cytoplasmic staining for NTRK1 fusion. The molecular testing revealed NTRK gene fusions (one each of TPM3-NTRK1, ETV6-NTRK3 and DCTN1-NTRK1, and two cases of LMNA-NTRK1). Two patients were receiving larotrectinib. The others were are well without disease, with follow-up durations of 9 to 29 months. Conclusions: NTRK-rearranged mesenchymal tumors from soft tissue sites and kidney are identified. A novel DCTN1-NTRK1 fusion is described. Pan-TRK immunohistochemistry is useful for diagnosis. NTRK-targeted therapy may be an option for unresectable, recurrent or metastatic cases.

[Application of the pathological classification of "CCCG-WT-2016" (2019 revision) for treatment of Wilms tumors].

Objective: To describe our experiences in application of the 2019 revision of "CCCG-WT-2016" for the diagnosis of Wilms tumors. Methods: Ninety-one cases of Wilms tumor diagnosed at Shanghai Children's Medical Center from January 2015 to December 2018 were collected. All cases were reviewed by two senior pathologists, including one from China and the other from Singapore, according to the 2019 revision of "CCCG-WT-2016." Results: The specimens were obtained by core biopsy (n=21), primary nephrectomy (n=41), post-chemotherapy nephrectomy/resection (n=18), or biopsy/resection of metastatic/relapse/post-chemotherapy metastatic lesion(s) (n=11). The specimens of core biopsy and primary nephrectomy (n=62) all had favorable histology.Twelve post-chemotherapy nephrectomy cases were subdivided into three risk groups: low risk (n=0), intermediate risk (n=10) and high risk (n=2). Six post-chemotherapy resection cases were subdivided into 3 risk groups:low risk (n=0), intermediate risk (n=5) and high risk (n=1). The remaining 11 cases were comprised of metastatic, relapse, and post-chemotherapy metastatic lesions. The concordance rate of the two senior pathologists was 100%(91/91). Conclusions: The 2019 revision of "CCCG-WT-2016" is clearly written and easy to use. It can serve as the basis of accurate classification for clinical treatment.

[A randomized controlled study of erlotinib versus pemetrexed combined with cisplatin in neoadjuvant therapy of stage â ¢A EGFR-mutant lung adenocarcinoma].

Objective: To evaluate the feasibility, efficacy and safety of epidermal growth factor receptor-tyrosine kinase inhibitors(EGFR-TKIs) for neoadjuvant therapy. Methods: Eighty-six patients with stage ⅢA EGFR-mutant lung adenocarcinoma were assigned to 2 groups (n=43 in each group) according to the random number table method: neoadjuvant targeted therapy group (single oral dose of erlotinib 150 mg per day, for 9 weeks) and neoadjuvant chemotherapy group (2 cycles of pemetrexed combined with cisplatin chemotherapy followed by 3- week discontinuation). Surgical treatment was underwent after imaging efficacy evaluation. Results: In neoadjuvant targeted therapy group, 4 achieved complete response (CR), 25 achieved partial response (PR), giving an objective response rate (ORR) of 67.4%. In pathological response, 8 patients had grade Ⅰ, 20 patients had grade Ⅱ, giving a pathological response rate of 65.1%. The most frequent adverse events (AEs) were rash and diarrhea. In neoadjuvant chemotherapy group, 2 had CR and 17 had PR, giving an ORR of 44.2%. In pathological response, 3 patients had grade Ⅰ, 15 patients had grade Ⅱ, giving a pathological response rate of 41.9%. The main AEs were hematologic toxic effects. The ORR, histological efficacy and hematologic toxicity showed statistical significance between the two groups (P<0.05). The neoadjuvant targeted therapy group had 90.7% resection rate, (299.8±23.4) ml of hemorrhage volume during operation, (5.2±0.4) days of extubation time and 9.3% postoperative complication rate. Corresponding results were 83.7%, (308.9±22.7) ml, (5.4±0.6) days and 11.6% in neoadjuvant chemotherapy group, which showed no statistical significance (P>0.05). Conclusions: Neoadjuvant targeted treatment for stage ⅢA lung adenocarcinoma harboring EGFR mutations. The regimen could be considered as a choice of neoadjuvant treatment for patients with stage ⅢA EGFR-mutant lung adenocarcinoma.