Predictors of Chemotherapy Induced Adverse Events in Pediatric Osteosarcoma Patients

Objective: To investigate the prevalence of chemotherapy-induced adverse events and the associated risk factors in pediatric patients with osteosarcoma. Methods: This retrospective cross-sectional study enrolled 90 pediatric osteosarcoma patients (with 1,017 chemotherapy cycles) treated at Srinagarind Medical Center, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand, between January 1, 2008 and December 31, 2018. The prevalence of major adverse events and a correlation between baseline characteristics and adverse events were analyzed using a generalized estimating equation model. Result: The prevalence of adverse events in 90 pediatric osteosarcoma patients (with 1,017 chemotherapy cycles) was determined as chemotherapy-induced nausea and vomiting (29.2%; n=296), hepatotoxicity (21.2%; n=215), anemia (70.69%; n=719), neutropenia (26.65%; n=271), and thrombocytopenia (13.65%; n=139). Factors associated with chemotherapy-induced hepatotoxicity included methotrexate dose ≥ 12 g/m2 (odds ratio [OR] 1.30; 95% confidence interval [CI] 1.22–1.39; P<0.001), plasma concentration of methotrexate at 72 hours >0.1 μM (OR 1.22; 95% CI 1.19–1.25; P<0.001), and pre-hydration rate ≤ 125 mL/m2/h (OR 1.10; 95% CI 1.07–1.12; P<0.001). Conclusion: Major adverse events are becoming more common in pediatric osteosarcoma patients, and risk factors include larger chemotherapy doses, higher plasma methotrexate concentrations, and a slower pre-hydration rate. The outcomes of the study could aid in the better treatment of toxicity in children with osteosarcoma.     

Giant-cell-rich tumors of bone

Neoplasms of bone with numerous non-neoplastic osteoclast type giant cells are relatively common and exhibit diverse phenotypes of the neoplastic cells. These tumors have a broad spectrum of biological potential which necessitates accurate recognition and diagnosis. Their clinicopathological features are overlapping, therefore, immunohistochemistry and molecular studies may be required for evaluation. Correlation with imaging studies provides additional information that should be incorporated into the pathological interpretation.     

四肢骨肉瘤保肢治疗与预后影响因素分析

目的探究四肢骨肉瘤保肢治疗与预后的危险因素。方法 89例四肢骨肉瘤患者行保肢治疗后随访3年,依据3年预后结局分为生存组(71例)与死亡组(18例),比较两组患者临床特征,分析死亡的相关因素,将相关因素代入Cox比例风险模型分析危险因素。结果生存组及死亡组四肢骨肉瘤患者Enneking分期及是否术后肺转移、治疗后病理性骨折、术前乳酸脱氢酶升高、完成化疗情况比较,差异均有统计学意义(P﹤0.05)。术后出现肺转移、未完成化疗及Enneking分期为Ⅱ期或Ⅲ期为四肢骨肉瘤保肢治疗后3年内死亡的危险因素(P﹤0.05)。结论尽早确诊、尽早治疗、积极预防病理性骨折、完成规范化疗及预防肺转移的发生能够辅助提高四肢骨肉瘤患者保肢治疗后的生存率。     

HSP90β干扰和过表达慢病毒载体的构建及其在骨肉瘤细胞Saos-2中的表达

目的:获得热休克蛋白90β(HSP90β)基因干扰和过表达慢病毒表达系统，并检测其在人骨肉瘤细胞株Saos-2中的表达水平。方法:设计合成shRNA，以慢病毒表达质粒构建HSP90β干扰和过表达载体，酶切电泳、测序技术鉴定载体构建是否成功。重组病毒转染H1299细胞，以嘌呤霉素筛选稳定转染的Saos-2细胞，通过荧光显微镜观察计数获得转染效率。将感染好的细胞分为干扰NC组（NEG-shRNA）、干扰组（shRNA-HSP90β）、过表达NC对照组（NEG-pEZ）及过表达组（pEZ-HSP90β）。通过qRT-PCR 与Western blotting 分别从mRNA 和蛋白表达水平验证目的基因的干扰和过表达水平。结果:插入慢病毒表达载体的基因片段与目的基因的碱基序列完全一致。病毒包装成功后，嘌呤霉素最小致死浓度1 μg/ml，感染复数200，感染人Saos-2的感染效率达80%，其中shRNA-HSP90β组干扰效率为86.35%，pEZ-HSP90β组的mRNA相对表达量增加2.8倍。进一步研究发现，shRNA-HSP90β组较NEG-shRNA组中HSP90β蛋白表达明显降低，pEZ-HSP90β组较NEG-pEZ组HSP90β蛋白表达增加。结论:HSP90β基因干扰和过表达慢病毒载体构建成功，并能够在Saos-2中稳定表达。     

Risk factors associated with delayed methotrexate clearance and increased toxicity in pediatric patients with osteosarcoma

High‐dose methotrexate (HD‐MTX; 12 g/m²) is part of standard therapy for pediatric osteosarcoma (OS). Risk factors associated with MTX toxicity in children with OS are not well defined. We investigated the association between peak MTX levels (four‐hour) and delayed MTX clearance or treatment toxicity. Information was retrieved from electronic medical records of 33 OS patients treated with HD‐MTX at Texas Children's Hospital from 2008 to 2015. We found that the four‐hour MTX level did not contribute to toxicity or delayed MTX clearance. We demonstrated that certain demographic characteristics are associated with delayed clearance and increased toxicity.     

Epiphyseal osteosarcoma revisited: four illustrative cases with unusual histopathology and literature review

Osteosarcomas arising in the epiphysis are extremely rare and easily missed in the diagnostic consideration of epiphyseal tumors. It is the purpose of this study to delineate the clinical pathological characteristics of ‘epiphyseal osteosarcoma’ under the definition of ‘a solitary long bone osteosarcoma radiographically considered an epiphyseal tumor for which the main radiologic differential diagnosis would encompass giant cell tumor, chondroblastoma and clear cell chondrosarcoma’. Four such cases with unusual histopathology were retrieved among 110 cases of osteosarcoma. Their clinical, radiological and pathological features, together with all 10 reported cases, were analyzed. The radiographic diagnoses of our four cases include two giant cell tumors, one chondroblastoma and one clear cell chondrosarcoma but turn out to be fibroblastic, giant cell rich, telangiectatic and epithelioid variant of epiphyseal osteosarcoma. Including our patients, the 14 reported epiphyseal osteosarcomas comprise 8 males and 6 females, the age at presentation ranges from 11 to 39 years, two‐third in the second decade, 71.4% affect the femur. Due to their epiphyseal locations, many carry benign radiological diagnoses notably giant cell tumor and chondroblastoma. Epiphyseal osteosarcomas may not only masquerade as benign radiological bony lesions but also assume many histological patterns; orthopedic surgeons, radiologists and pathologists should be aware of such possibility. Their behavior and prognosis are dictated by the histologic types, grading and staging rather than location.     

Intermittent Internal Fixation With a Locking Plate to Preserve Epiphyseal Growth Function During Limb-Salvage Surgery in a Child With Osteosarcoma of the Distal Femur: A Case Report

Limb shortening is a problem associated with surgery for osteosarcoma of the lower extremity in adolescents, as the tumors frequently occur near the epiphysis. Herein we report the use of a less invasive stabilization system (LISS) and an intermittent fixation method to preserve the growth function of epiphysis in an 11-year-old patient with an osteosarcoma of the distal femur.The 11-year-old male presented with left knee enlargement and pain for 2 weeks, and magnetic resonance imaging (MRI) and biopsy were consistent with osteosarcoma of the left distal femur. After preoperative chemotherapy, en bloc tumor resection was performed with margins based on MRI findings preserving the epiphyseal growth plate, the tumor cavity was filled with inactivated bone and bone cement, and a LISS was used to stabilize the femur. Aggressive postoperative chemotherapy was given. Approximately 105 weeks after surgery radiography showed that the distal end of the plate had moved superior to the epiphysis along with bone growth. Locking screws were placed in the distal part of the LISS plate to stabilize the re-implanted bone, and external fixation was not needed.The patient was able to walk with the crutches 1 week postoperatively, and bear weight on the extremity 6 weeks postoperatively. At 6 years after surgery, the patient''s height had increased 52 cm, shortening of the affected limb was only 1 cm, and the circumference of the affected limb was 2 cm smaller than that of the contralateral limb. There was no significant discomfort in the affected limb, and there was no gait abnormality. The patient could jump and run, and could participate in sports including basketball and badminton to the same degree as his peers.In summary, the novel method of bone reconstruction and fixation provided good results in a child with an osteosarcoma of the distal femur. This fixation method preserves the osteogenic function of the epiphysis and restored bone integrity simultaneously, and provides good functional recovery.     

长链非编码RNA TUG1调控miR-138-5p对骨肉瘤细胞增殖、凋亡、侵袭和迁移的影响

目的:探讨长链非编码RNA(LncRNA)牛磺酸调节基因1(TUG1)调控miR-138-5p对骨肉瘤细胞增殖、凋亡、侵袭和迁移的影响。方法:在骨肉瘤细胞U-2OS中转染TUG1 siRNA和siRNA control，qRT-PCR测定干扰效果，MTT测定增殖，流式细胞术测定凋亡，Transwell小室测定细胞侵袭和迁移。starBase预测TUG1与miR-138-5p有结合位点，双荧光素酶报告载体鉴定靶向调控关系。将miR-138-5p抑制物和TUG1 siRNA共转染至骨肉瘤细胞中，测定干扰miR-138-5p对下调TUG1的骨肉瘤细胞增殖、凋亡、侵袭和迁移的影响。结果:转染TUG1 siRNA后的骨肉瘤细胞中TUG1表达水平明显低于转染siRNA control后的细胞（P<0.05）。下调TUG1后的骨肉瘤细胞增殖、侵袭和迁移能力降低，细胞凋亡率升高（P<0.05）。野生型TUG1荧光素酶报告载体与miR-138-5p共转染后细胞荧光素酶活性降低（P<0.05）。与转染TUG1 siRNA的细胞比较，miR-138-5p抑制物和TUG1 siRNA共转染后的细胞增殖、侵袭和迁移能力升高，细胞凋亡率降低（P<0.05）。结论:下调LncRNA TUG1表达通过调控miR-138-5p表达抑制骨肉瘤细胞增殖、侵袭、迁移能力并诱导细胞凋亡。     

miR-513a-5p慢病毒载体的构建及其对人骨肉瘤细胞放疗敏感性的影响

目的:构建miR-513a-5p慢病毒过表达载体，转染人骨肉瘤细胞株，观察miR-513a-5p对人骨肉瘤细胞放疗敏感性的影响。方法:PCR法扩增人miR-513a-5p基因，克隆入pLentis-CMV-GFP-MCS-PGK-PURO载体获得重组质粒pLentis-miR513a，双酶切鉴定并测序后将正确的重组质粒和对照质粒转染293FT细胞制备慢病毒，分别转染骨肉瘤HOS和U2OS细胞，qRT-PCR法及荧光显微镜鉴定转染结果。克隆形成实验、MTT法检测miR-513a-5p高表达HOS和U2OS细胞在X射线照射下细胞存活情况。结果:双酶切及测序结果确定成功构建miR-513a-5p慢病毒载体pLentis-miR513a。qRT-PCR结果提示，转染骨肉瘤细胞株后miR-513a-5p表达显著升高。克隆形成实验结果显示miR-513a-5p高表达后骨肉瘤细胞在X射线照射下细胞增殖减慢。MTT结果提示miR-513a-5p高表达骨肉瘤细胞经X射线照射后细胞存活减少。结论:成功构建了miR-513a-5p慢病毒载体，建立了高效稳定表达miR-513a-5p的骨肉瘤细胞株，高表达miR-513a-5p能显著增加X射线照射后骨肉瘤细胞的放疗敏感性。     

Aneurysmal bone cyst inadvertently treated with chemotherapy—A series of three cases

Aneurysmal bone cyst (ABC) is a benign locally aggressive tumor that occurs in childhood and early adulthood. Most relevant differential diagnoses are the telangiectatic osteosarcoma and the giant cell tumor. In the present case series chemotherapy following the EURAMOS or the Euro‐Ewing 99 protocol was externally applied in three patients with the misdiagnosis of ABC as malignant bone tumor. In all three cases, a significant reduction of the volume of the ABC was achieved. This is the first report about the use of neoadjuvant chemotherapy in ABC. Chemotherapy reduces the size of an ABC and leads to progressive sclerosis.