Brachytherapy for Pediatric Patients at Gustave Roussy Cancer Campus: A Model of International Cooperation for Highly Specialized Treatments.

PURPOSE: Childhood cancer is rare, and treatment is frequently associated with long-term morbidity. Disparities in survival and long-term side effects encourage the establishment of networks to increase access to complex organ-conservative strategies, such as brachytherapy. We report our experience of an international cooperation model in childhood cancers. METHODS AND MATERIALS: We examined the outcome of all children referred to our center from national or international networks to be treated according to a multimodal organ-conservative approach, including brachytherapy. RESULTS: We identified 305 patients whose median age at diagnosis was 2.2 years (range, 1.4 months to 17.2 years). Among these patients, 99 (32.4%) were treated between 2015 and 2020; 172 (56.4%) were referred from national centers; and 133 (43.6%) were international patients from 31 countries (mainly Europe). Also, 263 patients were referred for primary treatment and 42 patients were referred for salvage treatment. Genitourinary tumors were the most frequent sites, with 56.4% bladder/prostate rhabdomyosarcoma and 28.5% gynecologic tumors. In addition to brachytherapy, local treatment consisted of partial tumor resection in 207 patients (67.9%), and 39 patients (13%) had additional external radiation therapy. Median follow-up was 58 months (range, 1 month to 48 years), 93 months for national patients, and 37 months for international patients (P < .0001). Five-year local control, disease-free survival, and overall survival rates were 90.8% (95% confidence interval [CI], 87.3%-94.4%), 84.4% (95% CI, 80.1%-89.0%), and 93.3% (95% CI, 90.1%-96.5%), respectively. Patients referred for salvage treatment had poorer disease-free survival (P < .01). Implementation of image guided pulse-dose-rate brachytherapy was associated with better local control among patients with rhabdomyosarcoma referred for primary treatment (hazard ratio, 9.72; 95% CI, 1.24-71.0). At last follow-up, 16.7% patients had long-term severe treatment-related complications, and 2 patients (0.7%) had developed second malignancy. CONCLUSIONS: This retrospective series shows the feasibility of a multinational referral network for brachytherapy allowing high patient numbers in rare pediatric cancers. High local control probability and acceptable late severe complication probability could be achieved despite very challenging situations. This cooperation model could serve as a basis for generating international reference networks for high-tech radiation such as brachytherapy to increase treatment care opportunities and cure probability.

First-Time Diagnosis After an Emergency Presentation in Children With Cancer.

AIM: To determine the prevalence rate of cancer diagnoses by an emergency route, the related risk factors and whether the emergency diagnosis was associated with poorer outcome. METHODS: Retrospective observational study with identification of patients diagnosed at the Pediatric Oncology Unit of "Sapienza" University between 2008 and 2018. The percentage of patients who received a first-time diagnosis after an emergency presentation was determined. Two-year survival and clinical factors, such as sex, age and histology, associated to emergency presentation were evaluated. RESULTS: Of 207 patients (109 girls and 98 boys; median age, 120 months), with a first-time diagnosis of solid tumor, 5.8% were diagnosed during an emergency admission after a median latency time of 2.5 days. Cases with an emergency diagnosis were younger compared with those who were diagnosed electively (median age, 30 months vs 120 months, P < 0.005). Higher prevalence rate of emergency presentation was detected in patients with lymphoma compared with those with no lymphoma disease (28.6% vs 4.1%; P < 0.0001). All patients were managed to overcome their emergency presentation, 33.3% of these died later. No statistically significant difference for 2-year overall survival was found between patients with an emergency diagnosis and those with elective diagnosis (66.7% vs 81.0%; odds ratio, 2.1; confidence interval, 0.6-7.5; P = 0.22). CONCLUSIONS: A minor but not negligible number of pediatric patients come to a first-time diagnosis of cancer as result of a life-threatening event; risk factors were younger age and lymphoma disease. The emergency event can be successfully treated, and it was not related to a poorer survival.

DNMT3A and DNMT3B Targeting as an Effective Radiosensitizing Strategy in Embryonal Rhabdomyosarcoma.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in childhood. Recently, we demonstrated the overexpression of both DNA methyltransferase 3A (DNMT3A) and 3B (DNMT3B) in RMS tumour biopsies and cell lines compared to normal skeletal muscle. Radiotherapy may often fail due to the abnormal expression of some molecules able to drive resistance mechanisms. The aim of this study was to analyse the involvement of DNMT3A and DNMT3B in radioresistance in RMS. RNA interference experiments against DNMT3A/3B were performed in embryonal RMS cells, upon ionizing radiation (IR) exposure and the effects of the combined treatment on RMS cells were analysed. DNMT3A and DNMT3B knocking down increased the sensitivity of RMS cells to IR, as indicated by the drastic decrease of colony formation ability. Interestingly, DNMT3A/3B act in two different ways: DNMT3A silencing triggers the cellular senescence program by up-regulating p16 and p21, whilst DNMT3B depletion induces significant DNA damage and impairs the DNA repair machinery (ATM, DNA-PKcs and Rad51 reduction). Our findings demonstrate for the first time that DNMT3A and DNMT3B overexpression may contribute to radiotherapy failure, and their inhibition might be a promising radiosensitizing strategy, mainly in the treatment of patients with metastatic or recurrent RMS tumours.

Abdominal Recurrence after Robotic Nephron-Sparing Surgery for Wilms Tumor in an Adult Patient.

A 31-year-old man was referred to an adult urologist for a renal polar mass that measured 7.2 cm in maximum diameter. Robotic assisted complete tumor excision for suspicious renal cell carcinoma was carried out, preserving the rest of the left kidney. Histopathology showed a Wilms tumor (WT) with positive margins. No postoperative therapy was made, and the patient shortly presented an abdominal recurrence. The patient was referred to our pediatric oncology unit; he received preoperative chemotherapy, followed by surgery (completion nephrectomy and removal of neoplastic deposits in the omentum and parietal peritoneum), postoperative chemotherapy, and abdomen radiotherapy. He is well at the 5-year follow-up. Peritoneal dissemination after laparoscopic nephron-sparing surgery (NSS) in a child with a 10-cm WT was previously reported. We suggest open NSS for large WT may be safer than laparoscopic or robotic NSS because carbon dioxide pneumoperitoneum and traumatic handling of tumor may predispose to tumor cell migration. An abdominal WT relapse in adults can be salvaged by multimodal therapy recommended by current pediatric WT guidelines.

Zero-ischemia testis-sparing surgery for probably benign pediatric testicular tumors.

Permanent ischemia-induced testicular damage may occur as early as 30 min in prepupertal rats. With the goal of potentially enhancing testicular function and fertility preservation, we performed testis-sparing surgery (TSS) without ischemia for testicular lesions in select children with negative markers and high likelihood of benignity on ultrasonography. Preliminary experience suggests that off-clamp TSS should be more liberally encouraged, especially in infants and prepubertal children, given their particularly vulnerable spermatic cord elements.

Resection of Inferior Vena Cava Without Reconstruction for Intravascular Intrusion of Wilms Tumor.

Persistent inferior vena cava (IVC) tumor thrombus in Wilms tumor patients represents a management challenge. We describe three pediatric cases with preoperative evaluation documenting complete IVC occlusion and well-developed collaterals. They underwent nephrectomy and tumor thrombus removal accomplished with circumferential resection of the retrohepatic IVC without vascular reconstruction. All patients are asymptomatic and disease-free at 9, 2.5, and 2 years after stopping therapy. Cavectomy without reconstruction is safe and well tolerated in Wilms tumor patients with completely occlusive IVC tumor thrombus. Additionally, when performed en bloc with nephrectomy and with clear margins, cavectomy obviates the need for radiotherapy per protocol.

Clinically relevant radioresistant rhabdomyosarcoma cell lines: functional, molecular and immune-related characterization.

BACKGROUND: The probability of local tumor control after radiotherapy (RT) remains still miserably poor in pediatric rhabdomyosarcoma (RMS). Thus, understanding the molecular mechanisms responsible of tumor relapse is essential to identify personalized RT-based strategies. Contrary to what has been done so far, a correct characterization of cellular radioresistance should be performed comparing radioresistant and radiosensitive cells with the same isogenic background. METHODS: Clinically relevant radioresistant (RR) embryonal (RD) and alveolar (RH30) RMS cell lines have been developed by irradiating them with clinical-like hypo-fractionated schedule. RMS-RR cells were compared to parental isogenic counterpart (RMS-PR) and studied following the radiobiological concept of the "6Rs", which stand for repair, redistribution, repopulation, reoxygenation, intrinsic radioresistance and radio-immuno-biology. RESULTS: RMS-RR cell lines, characterized by a more aggressive and in vitro pro-metastatic phenotype, showed a higher ability to i) detoxify from reactive oxygen species; ii) repair DNA damage by differently activating non-homologous end joining and homologous recombination pathways; iii) counteract RT-induced G2/M cell cycle arrest by re-starting growth and repopulating after irradiation; iv) express cancer stem-like profile. Bioinformatic analyses, performed to assess the role of 41 cytokines after RT exposure and their network interactions, suggested TGF-ß, MIF, CCL2, CXCL5, CXCL8 and CXCL12 as master regulators of cancer immune escape in RMS tumors. CONCLUSIONS: These results suggest that RMS could sustain intrinsic and acquire radioresistance by different mechanisms and indicate potential targets for future combined radiosensitizing strategies.

BET inhibition therapy counteracts cancer cell survival, clonogenic potential and radioresistance mechanisms in rhabdomyosarcoma cells.

The antitumour effects of OTX015, a first-in-class BET inhibitor (BETi), were investigated as a single agent or in combination with ionizing radiation (IR) in preclinical in vitro models of rhabdomyosarcoma (RMS), the most common childhood soft tissue sarcoma. Herein, we demonstrated the upregulation of BET Bromodomain gene expression in RMS tumour biopsies and cell lines compared to normal skeletal muscle. In vitro experiments showed that OTX015 significantly reduced RMS cell proliferation by altering cell cycle modulators and apoptotic related proteins due to the accumulation of DNA breaks that cells are unable to repair. Interestingly, OTX015 also impaired migration capacity and tumour-sphere architecture by downregulating pro-stemness genes and was able to potentiate ionizing radiation effects by reducing the expression of different drivers of tumour dissemination and resistance mechanisms, including the GNL3 gene, that we correlated for the first time with the RMS phenotype. In conclusion, our research sheds further light on the molecular events of OTX015 action against RMS cells and indicates this novel BETi as an effective option to improve therapeutic strategies and overcome the development of resistant cancer cells in patients with RMS.

Evaluation of Nephron-Sparing Surgery as Potential Risk Factor for Relapse in Unilateral Wilms Tumor.

BACKGROUND: The aim of the study was to assess the prognostic significance of nephron-sparing surgery (NSS) without tumor size limits as a risk factor for relapse in children with unilateral Wilms Tumor (WT). METHODS: A 28-y retrospective single-center review was performed. Prognostic relevance of age, gender, stage, histology, nephrectomy (N), and NSS was analyzed. RESULTS: Sixty-nine cases (42 females and 27 males) with WT, off-therapy from 21 to 325 mo after chemotherapy mainly based on the International Society of Pediatric Oncology trials, were treated at our institution. Five cases were excluded (three children with synchronous bilateral WT and two adults with unilateral WT). Of 64 children with unilateral WT, 51 underwent N and 13 NSS without tumor size limits. Indeed, two-thirds of children who underwent NSS presented with a tumor diameter >4 cm. Overall, nine patients (14%) had a relapse (male-to-female ratio = 1:8). Initial surgery was N in eight cases and NSS in another one. Relapse rates in N and NSS groups were 15.7% and 7.7% (P = nonsignificant), respectively; the relapse rates in N and NSS groups were 8.6% and 7.7% (P = nonsignificant) for stages I-II unilateral WT cohort, respectively. On univariate analysis, factors correlated with probability of relapse were unfavorable histology (P < 0.002) and stage III disease (P < 0.01). CONCLUSIONS: In unilateral WT, NSS, whenever feasible, does not seem to increase the risk of recurrence. A multicenter prospective trial is required to carefully evaluate this risk.

Bevacizumab-containing regimen in relapsed/progressed brain tumors: a single-institution experience.

AIM: The aim of the study is to assess tumor response, treatment-related toxicities, progression-free survival (PFS), and overall survival (OS) in patients with relapsed/refractory brain tumors treated with bevacizumab-containing regimen. METHODS: Patients that had received I and II line treatments with or without megatherapy were included. Doses and schedule were as follows: bevacizumab (BVZ) 10 mg/kg i.v. with irinotecan (IRI) 150 mg/m2 i.v. every 2 weeks ± temozolamide (TMZ) 200 mg/m2 p.o. daily for 5 days every 4 weeks. TMZ was omitted in heavily pretreated cases. RESULTS: Between 2013 and 2018, 12 patients (3F/9M), median age 161 months (range 66-348), affected with medulloblastoma (n 7), or low-grade glioma (n 2), or high-grade glioma (n 3), received BVZ/IRI association (median courses 20, range 4-67); 3 of them continued single-agent BVZ (median courses 23, range 8-39). TMZ (median courses 8, range 2-26) was administered in eight patients and then stopped in three of them because of myelotoxicity or lack of compliance. Treatment was well tolerated. After 3 months, two complete responses, two partial responses, seven stable diseases, and one progressive disease were observed. Nine cases experienced an improvement in neurological symptoms. Median time to progression was 11 months (95% confidence interval, 4-18 months). Six-month and 2-year PFS were 75% and 42%, respectively. The OS is 33%; interestingly, two cases (one medulloblastoma and one high-grade glioma) are progression-free off-therapy since 30 and 48 months, respectively. CONCLUSIONS: BVZ/IRI association ± TMZ showed encouraging therapeutic activity and low toxicity in this series of relapsed/refractory brain tumors.

PARP inhibitors affect growth, survival and radiation susceptibility of human alveolar and embryonal rhabdomyosarcoma cell lines.

PURPOSE: PARP inhibitors (PARPi) are used in a wide range of human solid tumours but a limited evidence is reported in rhabdomyosarcoma (RMS), the most frequent childhood soft-tissue sarcoma. The cellular and molecular effects of Olaparib, a specific PARP1/2 inhibitor, and AZD2461, a newly synthesized PARP1/2/3 inhibitor, were assessed in alveolar and embryonal RMS cells both as single-agent and in combination with ionizing radiation (IR). METHODS: Cell viability was monitored by trypan blue exclusion dye assays. Cell cycle progression and apoptosis were measured by flow cytometry, and alterations of specific molecular markers were investigated by, Real Time PCR, Western blotting and immunofluorescence experiments. Irradiations were carried out at a dose rate of 2 Gy (190 UM/min) or 4 Gy (380 UM/min). Radiosensitivity was assessed by using clonogenic assays. RESULTS: Olaparib and AZD2461 dose-dependently reduced growth of both RH30 and RD cells by arresting growth at G2/M phase and by modulating the expression, activation and subcellular localization of specific cell cycle regulators. Downregulation of phospho-AKT levels and accumulation of γH2AX, a specific marker of DNA damage, were significantly and persistently induced by Olaparib and AZD2461 exposure, this leading to apoptosis-related cell death. Both PARPi significantly enhanced the effects of IR by accumulating DNA damage, increasing G2 arrest and drastically reducing the clonogenic capacity of RMS-cotreated cells. CONCLUSIONS: This study suggests that the combined exposure to PARPi and IR might display a role in the treatment of RMS tumours compared with single-agent exposure, since stronger cytotoxic effects are induced, and compensatory survival mechanisms are prevented.

Topotecan/carboplatin regimen for refractory/recurrent rhabdomyosarcoma in children: Report from the AIEOP Soft Tissue Sarcoma Committee.

INTRODUCTION: From 2002 to 2011, the Italian Soft Tissue Sarcoma Committee explored a combination of topotecan and carboplatin as a second-line strategy for children with resistant or relapsing rhabdomyosarcoma. METHODS: Patients received two blocks of topotecan 2 mg/m2 on days 1, 2, and 3, and carboplatin 250 mg/m2 on days 4 and 5, followed by alternating blocks of topotecan-cyclophosphamide and carboplatin-etoposide for a total of six courses with 3-week intervals. Tumor response was assessed after two cycles, and local control was implemented when feasible. RESULTS: A total of 38 patients were included in this study: 18/38 had alveolar rhabdomyosarcoma (RMS), 10/38 had metastatic disease at diagnosis, 8/38 had tumor progression during first-line chemotherapy, 21/38 had locoregional relapses, and 9/38 had distant relapses. Thirty-two patients could be assessed for tumor response to topotecan-carboplatin, and 9 (28%) showed a complete or partial response. Twenty-four patients experienced grade IV hematologic toxicity, while transient grade 1 tubulopathy, grade 3 mucositis, transient grade 2 nephrotoxicity, and a grade 2 decline in cardiac function occurred in one patient each. The 5-year overall and progression-free survival rates were 17% and 14%, respectively. CONCLUSION: the prognosis for children with resistant or relapsing RMS remains unsatisfactory. The topotecan-carboplatin regimen was well-tolerated. Though in case of late relapse the response rate was similar to those reported for other regimes, the result achieved remains unsatisfactory. New approaches, possibly including target agents, seem more attractive for future studies.

Long-term renal function and hypertension in adult survivors of childhood sarcoma: Single center experience.

AIM: Little data is available on long-term renal impairment in survivors from childhood sarcoma. We investigated the prevalence of renal impairment and hypertension after very long-term follow-up in survivors who reached adulthood after treatment for childhood sarcoma. METHODS: A cross-sectional single center study was performed. Outcomes included estimating glomerular filtration rate (eGFR), albuminuria, glycosuria, serum phosphate and magnesium, tubular reabsorption phosphate (TRP), chronic kidney disease (CKD) according to the "Kidney Disease: Improving Global Outcomes" (KDIGO) guidelines and blood pressure (BP). RESULTS: Out of 87 > 5-year sarcoma survivors, 30 adults (10F/20M, median age at diagnosis 9 years, median age at investigation 26 years, median follow-up 16 years, mean 19 years) were identified. Renal impairment was detected in four cases (13.3%); three of these fulfilled the criteria for CKD. Among the adult survivors, a subgroup of 15 cases (50%) had received ifosfamide without confounding factors such as a diagnosis of genito-urinary rhabdomyosarcoma or administration of other potentially nephrotoxic chemotherapy (platinum-based drugs or methotrexate); no renal dysfunction was detected in this subgroup. In the whole cohort of sarcoma survivors, hypertension was diagnosed in four cases (13.3%); BP was significantly correlated with body mass index [p .014]. CONCLUSION: In our series of adult survivors treated for a diagnosis of sarcoma in their childhood, the prevalence of CKD was 10%. We found survivors treated with ifosfamide as the only nephrotoxic agent did not present glomerular or tubular toxicity at long term follow-up, but further studies including a larger number of cases are required to confirm it.

Vincristine, Irinotecan, and Bevacizumab in Relapsed Wilms Tumor With Diffuse Anaplasia.

The prognosis of relapsed Wilms tumor (WT) with diffuse anaplasia is dismal, therefore, novel therapeutic strategies need to be explored. We reported on 2 consecutive cases with relapsed anaplastic WT who presented a partial response after 2 courses of vincristine, irinotecan, and bevacizumab association. This regimen may have a role in the treatment of patients with anaplastic advanced WT.

Biliary tract rhabdomyosarcoma: a report from the Soft Tissue Sarcoma Committee of the Associazione Italiana Ematologia Oncologia Pediatrica.

INTRODUCTION: Rhabdomyosarcoma is a soft tissue malignant musculoskeletal tumor frequent in children. Biliary duct localization is extremely rare, but it is the most common cause of malignant obstructive jaundice in pediatric patients. METHODS: This report describes a series of 10 patients under 18 years of age with biliary tract rhabdomyosarcoma who were enrolled, from 1979 to 2004, in 3 consecutive Italian pediatric cooperative protocols that had been drawn up by the Soft Tissue Sarcoma Committee of the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP). RESULTS: Considering initial and delayed surgery, tumor resection was achieved in 7 cases, 3 complete with free margins (2 liver transplants) and 4 with microscopic residual disease. Chemotherapy was given to all patients and radiotherapy to 3. At present, 5 patients survive in complete remission 90-200 months after diagnosis while 4 died of disease progression or relapse and 1 of liver transplant-related complications. CONCLUSIONS: Better outcomes in this series were associated with the feasibility of conservative surgery due to the favorable location of the tumor, in particular in the common bile duct. Chemotherapy and radiotherapy might obviate the need for demolitive surgery or liver transplant, which were linked to worse outcomes in our series.

Sudden benzodiazepine-induced resolution of post-operative pediatric cerebellar mutism syndrome: a clinical-SPECT study.

Post-operative pediatric cerebellar mutism syndrome (PPCMS) is a clinical syndrome arising from cerebellar injury and characterized by absence of speech and other possible symptoms and signs. Rare reports described some benefit after administration of dopamine agonist therapy, but no treatment has proven efficacy. In this paper, we report on the dramatic, sudden resolution of PPCMS induced by midazolam administration in a boy who underwent posterior fossa surgery for choroid plexus papilloma of the fourth ventricle. In addition to clinical improvement, post-midazolam single-photon emission computed tomography also demonstrated amelioration of brain perfusion.