Treatment with topotecan plus cyclophosphamide in children with first relapse of neuroblastoma

Phase 1 study of high-dose DFMO, celecoxib, cyclophosphamide and topotecan for patients with relapsed neuroblastoma: a New Approaches to Neuroblastoma Therapy trial

BACKGROUND

MYC genes regulate ornithine decarboxylase (Odc) to increase intratumoral polyamines. We conducted a Phase I trial [NCT02030964] to determine the maximum tolerated dose (MTD) of DFMO, an Odc inhibitor, with celecoxib, cyclophosphamide and topotecan.

METHODS

Patients 2-30 years of age with relapsed/refractory high-risk neuroblastoma received oral DFMO at doses up to 9000 mg/m2/day, with celecoxib (500 mg/m2 daily), cyclophosphamide (250 mg/m2/day) and topotecan (0.75 mg/m2/day) IV for 5 days, for up to one year with G-CSF support.

RESULTS

Twenty-four patients (median age, 6.8 years) received 136 courses. Slow platelet recovery with 21-day courses (dose-levels 1 and 2) led to subsequent dose-levels using 28-day courses (dose-levels 2a-4a). There were three course-1 dose-limiting toxicities (DLTs; hematologic; anorexia; transaminases), and 23 serious adverse events (78% fever-related). Five patients (21%) completed 1-year of therapy. Nine stopped for PD, 2 for DLT, 8 by choice. Best overall response included two PR and four MR. Median time-to-progression was 19.8 months, and 3 patients remained progression-free at >4 years without receiving additional therapy. The MTD of DFMO with this regimen was 6750 mg/m2/day.

CONCLUSION

High-dose DFMO is tolerable when added to chemotherapy in heavily pre-treated patients. A randomized Phase 2 trial of DFMO added to chemoimmunotherapy is ongoing [NCT03794349].

Prognostic factors for intermediate- or high-risk neuroblastomas in children in China

BACKGROUND

Evidence regarding the characteristics and prognosis of neuroblastoma (NBL) in China is limited. We aimed to investigate the characteristics and prognosis of intermediate- or high-risk NBL in children in China.

METHODS

We included 147 patients with intermediate- or high-risk NBL evaluated from January 2006 to March 2015. The patients were aged 1 month to 15.5 years, 66% of them were boys, and 117 (79.6%) were diagnosed with high-risk NBL.

RESULTS

After a median follow-up of 32.5 months, 80 (45.6%) patients survived, with a median survival time of 48 months (95% confidence interval [CI]: 36.41-59.59). High-risk patients (hazard ratio [HR]: 12.467; 95% CI: 11.029-12.951), partial response (PR) (HR: 1.200; 95% CI: 1.475-2.509) or progression disease (PD) (HR: 1.924; 95% CI: 1.623-3.012) after induction chemotherapy, and intracranial metastasis (HR: 3.057; 95% CI: 0.941-4.892) were independent risk factors for survival (p < 0.05) and postrelapse survival (p < 0.05). NBL relapse, male sex, and PR or PD after induction chemotherapy were risk factors for event-free survival (p < 0.05).

CONCLUSIONS

In addition to previously established independent risk factors, such as age, risk group, and relapse, efficacy of induction chemotherapy and intracranial metastasis play significant roles in the prognosis of NBL.

Dinutuximab beta plus conventional chemotherapy for relapsed/refractory high-risk neuroblastoma: A single-center experience

Background

Relapsed/refractory high-risk neuroblastoma has a dismal prognosis. Anti-GD2-mediated chemo-immunotherapy has a notable anti-tumor activity in patients with relapsed/refractory high-risk neuroblastoma. The purpose of this study was to analyze the efficacy and safety of the combination of immunotherapy with dinutuximab beta (DB) and chemotherapy in patients with relapsed/refractory high-risk neuroblastoma.

Methods

All patients received the Turkish Pediatric Oncology Group NB 2009 national protocol for HR-NB treatment at the time of diagnosis. Salvage treatments were administered after progression or relapse. The patients who could not achieve remission in primary or metastatic sites were included in the study. The most common chemotherapy scheme was irinotecan and temozolomide. DB was administered intravenously for 10 days through continuous infusion with 10 mg/m² per day. The patients received 2 to 14 successive cycles with duration of 28 days each. Disease assessment was performed after cycles 2, 4, and 6 and every 2 to 3 cycles thereafter.

Results

Between January 2020 and March 2022, nineteen patients received a total of 125 cycles of DB and chemotherapy. Objective responses were achieved in 12/19 (63%) patients, including complete remission in 6/19 and partial response in 6/19. Stable disease was observed in two patients. The remaining five patients developed bone/bone marrow and soft tissue progression after 2-4 cycles of treatment. The most common Grade ≥3 toxicities were leukopenia, thrombocytopenia, hypertransaminasemia, fever, rash/itching and capillary leak syndrome, respectively.

Conclusion

Our study results suggest that DB-based chemo-immunotherapy seems to be suitable with encouraging response rates in patients with relapsed/refractory high-risk neuroblastoma.

Treatment outcomes among high-risk neuroblastoma patients receiving non-immunotherapy regimen: Multicenter study on behalf of the Thai Pediatric Oncology Group

BACKGROUND

Neuroblastoma is the most common extracranial malignant solid tumor during childhood. Despite intensified treatment, patients with high-risk neuroblastoma (HR-NBL) still carry a dismal prognosis. The Thai Pediatric Oncology Group (ThaiPOG) proposed the use of a multimodality treatment to improve outcomes of HR-NBL in non-immunotherapy settings.

METHODS

Patients with HR-NBL undergoing ThaiPOG protocols (ThaiPOG-NB-13HR or -18HR) between 2013 and 2019 were retrospectively reviewed. Patient demographic data, treatment modalities, outcomes, and prognostic factors were evaluated and analyzed.

RESULTS

A total of 183 patients with HR-NBL undergoing a topotecan containing induction regimen were enrolled in this study. During the consolidation phase (n = 169), 116 patients (68.6%) received conventional chemotherapy, while 53 patients (31.4%) underwent hematopoietic stem cell transplantation (HSCT). The 5-year overall survival (OS) and event-free survival (EFS) were 41.2% and 22.8%, respectively. Patients who underwent HSCT had more superior 5-year EFS (36%) than those who received chemotherapy (17.1%) (p = .041), although they both performed similarly in 5-year OS (48.7% vs. 39.8%, p = .17). The variation of survival outcomes was observed depending on the number of treatment modalities. HSCT combined with metaiodobenzylguanidine (MIBG) treatment and maintenance with 13-cis-retinoic acid (cis-RA) demonstrated a desirable 5-year OS and EFS of 65.6% and 58.3%, respectively. Poorly or undifferentiated tumor histology and cis-RA administration were independent factors associated with relapse and survival outcomes, respectively (p < .05).

CONCLUSION

A combination of HSCT and cis-RA successfully improved the outcomes of patients with HR-NBL in immunotherapy inaccessible settings.

High-Risk Neuroblastoma: Poor Outcomes Despite Aggressive Multimodal Therapy

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Neuroblastoma (NBL) is a highly malignant embryonal tumor that originates from the primordial neural crest cells. NBL is the most common tumor in infants and the most common extracranial solid tumor in children. The tumor is more commonly diagnosed in children of 1-4 years of age. NBL is characterized by enigmatic clinical behavior that ranges from spontaneous regression to an aggressive clinical course leading to frequent relapses and death. Based on the likelihood of progression and relapse, the International Neuroblastoma Risk Group classification system categorized NBL into very low risk, low risk, intermediate risk, and high risk (HR) groups. HR NBL is defined based on the patient's age (> 18 months), disease metastasis, tumor histology, and MYCN gene amplification. HR NBL is diagnosed in nearly 40% of patients, mainly those > 18 months of age, and is associated with aggressive clinical behavior. Treatment strategies involve the use of intensive chemotherapy (CTR), surgical resection, high dose CTR with hematopoietic stem cell support, radiotherapy, biotherapy, and immunotherapy with Anti-ganglioside 2 monoclonal antibodies. Although HR NBL is now better characterized and aggressive multimodal therapy is applied, the outcomes of treatment are still poor, with overall survival and event-free survival of approximately 40% and 30% at 3-years, respectively. The short and long-term side effects of therapy are tremendous. HR NBL carries a high mortality rate accounting for nearly 15% of pediatric cancer deaths. However, most mortalities are attributed to the high frequency of disease relapse (50%) and disease reactiveness to therapy (20%). Newer treatment strategies are therefore urgently needed. Recent discoveries in the field of biology and molecular genetics of NBL have led to the identification of several targets that can improve the treatment results. In this review, we discuss the different aspects of the epidemiology, biology, clinical presentations, diagnosis, and treatment of HR NBL, in addition to the recent developments in the management of the disease.

How Macrophages Become Transcriptionally Dysregulated: A Hidden Impact of Antitumor Therapy

Tumor-associated macrophages (TAMs) are the essential components of the tumor microenvironment. TAMs originate from blood monocytes and undergo pro- or anti-inflammatory polarization during their life span within the tumor. The balance between macrophage functional populations and the efficacy of their antitumor activities rely on the transcription factors such as STAT1, NF-κB, IRF, and others. These molecular tools are of primary importance, as they contribute to the tumor adaptations and resistance to radio- and chemotherapy and can become important biomarkers for theranostics. Herein, we describe the major transcriptional mechanisms specific for TAM, as well as how radio- and chemotherapy can impact gene transcription and functionality of macrophages, and what are the consequences of the TAM-tumor cooperation.

Neuroblastoma patient-derived cultures are enriched for a mesenchymal gene signature and reflect individual drug response

Ex vivo evaluation of personalized models can facilitate individualized treatment selection for patients, and advance the discovery of novel therapeutic options. However, for embryonal malignancies, representative primary cultures have been difficult to establish. We developed patient‐derived cell cultures (PDCs) from chemo‐naïve and post–treatment neuroblastoma tumors in a consistent and efficient manner, and characterized their in vitro growth dynamics, histomorphology, gene expression, and functional chemo‐response. From 34 neuroblastoma tumors, 22 engrafted in vitro to generate 31 individual PDC lines, with higher engraftment seen with metastatic tumors. PDCs displayed characteristic immunohistochemical staining patterns of PHOX2B, TH, and GD2 synthase. Concordance of MYCN amplification, 1p and 11q deletion between PDCs and patient tumors was 83.3%, 72.7%, and 80.0% respectively. PDCs displayed a predominantly mesenchymal‐type gene expression signature and showed upregulation of pro‐angiogenic factors that were similarly enriched in culture medium and paired patient serum samples. When tested with standard‐of‐care cytotoxics at human C_max‐equivalent concentrations, MYCN‐amplified and non‐MYCN‐amplified PDCs showed a differential response to cyclophosphamide and topotecan, which mirrored the corresponding patients’ responses, and correlated with gene signatures of chemosensitivity. In this translational proof‐of‐concept study, early‐phase neuroblastoma PDCs enriched for the mesenchymal cell subpopulation recapitulated the individual molecular and phenotypic profile of patient tumors, and highlighted their potential as a platform for individualized ex vivo drug‐response testing.

Apatinib plus retinoic acid as maintenance for children with relapsed stage 4 high-risk neuroblastoma: Two case reports

INTRODUCTION

Metastatic neuroblastoma (NB) is an aggressive malignancy with a poor prognosis. Many patients present with relapsed high-risk NB after undergoing first-line treatment, and there is no standard therapy available in this setting.

PATIENT CONCERNS

The present study aimed to present the cases of 2 patients with recurrent high-risk NB.

DIAGNOSIS

Two children with International Neuroblastoma Stage System stage 4 high-risk NB chemotherapy. The disease recurrent after finishing the treatment.

INTERVENTIONS

Both patients (34 months old and 41 months old) experienced recurrence, received second-line treatment, and then received maintenance treatment using apatinib plus retinoic acid. The apatinib (10 mg/kg per day) and retinoic acid (160 mg/m per day) were administered on alternating 2-week cycles, which was continued for 1 year.

OUTCOMES

The 2 patients had achieved complete response by the 1-year follow-up after starting apatinib plus retinoic acid, and did not experience any adverse drug reactions.

CONCLUSION

The outcomes from these cases suggest that apatinib plus isotretinoin might be an option for maintenance therapy in patients with recurrent high-risk NB.

Clinical outcomes and prognostic factors to predict treatment response in high risk neuroblastoma patients receiving topotecan and cyclophosphamide containing induction regimen: a prospective multicenter study

BACKGROUND

Neuroblastoma is the most common extra-cranial solid tumor among children. Despite intensive treatment, patients with advanced disease mostly experience dismal outcomes. Here, we proposed the use of topotecan and cyclophosphamide containing induction regimen as an upfront therapy to high risk neuroblastoma patients.

METHODS

Patients with high risk neuroblastoma undergoing ThaiPOG high risk neuroblastoma protocol from 2016 to 2017 were studied. All patients received 6 cycles of induction regimen consisting of 2 cycles topotecan (1.2 mg/m²/day) and cyclophosphamide (400 mg/m²/day) for 5 days followed by cisplatin (50 mg/m²/day) for 4 days combined with etoposide (200 mg/m²/day) for 3 days on the third and fifth cycles and cyclophosphamide (2100 mg/m²/day) for 2 days combined with doxorubicin (25 mg/m²/day) and vincristine (0.67 mg/m²/day) for 3 days on the fourth and sixth cycles. Treatment response after the 5th cycle before surgery and treatment-related toxicities after each topotecan containing induction cycle were evaluated. Relevant prognostic factors were analyzed to measure the treatment response among those patients.

RESULTS

In all, 107 high risk neuroblastoma patients were enrolled in the study. After the 5th cycle of induction regimen, the patients achieved complete response (N = 2), very good partial response (N = 40), partial response (N = 46) and mixed response (N = 19). None of the patients experienced stable disease or disease progression. The most significant prognostic factor was type of healthcare system. The most common adverse effect was febrile neutropenia followed by mucositis, diarrhea and elevated renal function.

CONCLUSION

The topotecan and cyclophosphamide containing induction regimen effectively provides favorable treatment response. The regimen is well tolerated with minimal toxicity among patients with high risk neuroblastoma in Thailand.

Prevalence and Clinical Correlations of Somatostatin Receptor-2 (SSTR2) Expression in Neuroblastoma

Alternative radiolabeled, targeted agents are being investigated for children with relapsed neuroblastoma (NB) who do not respond to I-metaiodobenzylguanidine (MIBG) therapy. (DOTA-Tyr)-octreotate targets somatostatin receptors (SSTRs), particularly SSTR2, which are expressed on NB cells. We investigated SSTR2 expression in NB tumors (36 high-risk [HR]; 33 non-HR patients) and correlated SSTR2 levels with clinical features, norepinephrine transporter (NET) expression, and MIBG avidity. SSTR2 and NET immunohistochemistry scores (0 to 3) were calculated on biopsies using digital image analysis based on staining intensity and distribution. Clinical data were correlated with SSTR2 expression. Median SSTR2 score for 69 patients was 1.31 (0.26 to 2.55). Non-HR NB was associated with a higher SSTR2 score (P=0.032). The SSTR2 expression did not correlate with age, International Neuroblastoma Staging System (INSS) stage, MYCN amplification and histology. Higher SSTR2 scores were observed in MIBG-avid versus MIBG-nonavid NB. SSTR2 score was not significantly associated with NET score (r=-0.062, P=0.62). Twenty-six patients who relapsed or progressed had a median SSTR2 score of 1.33 (0.26 to 2.55). Patients with NB including relapsed or progressive disease showed SSTR2 expression at diagnosis, suggesting they could be candidates for radiolabeled-DOTA-conjugated peptide imaging or therapy.

A systematic review of re-induction chemotherapy for children with relapsed high-risk neuroblastoma

BACKGROUND

Despite aggressive multimodal therapy, >50% of children with high-risk neuroblastoma (HRNB) relapse. Survival after relapse is rare, and no consensus currently exists on the most effective therapy.

OBJECTIVE

To conduct a systematic review of the literature on effectiveness of re-induction chemotherapy in children with relapsed HRNB.

METHODS

Database searches were performed to identify studies looking at response to 1st line chemotherapy for children >12 months at diagnosis with first relapse of HRNB. Studies not reporting separate outcomes for HRNB patients or of refractory patients only were excluded. Two independent reviewers extracted the data and assessed study quality using a modified Newcastle-Ottawa tool.

RESULTS

Nine studies were identified fitting the inclusion criteria. All except one were single arm cohorts, and two were retrospective database reviews from single centres. One was a multicentre randomised controlled trial. All used a version of the validated International Neuroblastoma Response Criteria with 8 recording best ever response and 1 at a specified time, and 5 had central review. The proportion of relapsed patients varied from 24 to 100% with 30-93% receiving upfront myeloablative therapy. The response rate varied from 6 to 64%; however, because of heterogeneity, studies were not directly comparable, and no single treatment emerged as the most effective re-induction therapy.

CONCLUSIONS

To date, there is no clear superior re-induction therapy for 1st relapse of HRNB. Randomised controlled trials with separate arms for relapsed versus refractory disease are needed to determine optimal re-induction chemotherapy to act as a backbone for testing newer targeted agents.

Non-High-Risk Neuroblastoma: Classification and Achievements in Therapy

Neuroblastoma, a tumor of the sympathetic nervous system, is the most common extra-cranial neoplasm of childhood. Variables with prognostic significance in patients with neuroblastoma, including age at diagnosis, disease stage, tumor histology, MYCN gene amplification, tumor cell ploidy, and the presence of segmental chromosomal aberrations are utilized to classify patients based on risk of disease recurrence. Patients with non-high-risk neuroblastoma, low- and intermediate-risk categories, represent nearly half of all newly diagnosed cases. This group has an excellent event-free and overall survival with current therapy. Over time, the objective in treatment of non-high-risk neuroblastoma has been reduction of therapy intensity to minimize short- and long-term adverse events all the while maintaining excellent outcomes.

Novel Therapies for Relapsed and Refractory Neuroblastoma

While recent increases in our understanding of the biology of neuroblastoma have allowed for more precise risk stratification and improved outcomes for many patients, children with high-risk neuroblastoma continue to suffer from frequent disease relapse, and despite recent advances in our understanding of neuroblastoma pathogenesis, the outcomes for children with relapsed neuroblastoma remain poor. These children with relapsed neuroblastoma, therefore, continue to need novel treatment strategies based on a better understanding of neuroblastoma biology to improve outcomes. The discovery of new tumor targets and the development of novel antibody- and cell-mediated immunotherapy agents have led to a large number of clinical trials for children with relapsed neuroblastoma, and additional clinical trials using molecular and genetic tumor profiling to target tumor-specific aberrations are ongoing. Combinations of these new therapeutic modalities with current treatment regimens will likely be needed to improve the outcomes of children with relapsed and refractory neuroblastoma.

Phase I study of perifosine monotherapy in patients with recurrent or refractory neuroblastoma

PURPOSE

Perifosine is an alkylphospholipid analog that inhibits or modulates signaling through signal transduction pathways such as Akt, which is enhanced in neuroblastoma (NB) by activation of tyrosine kinase receptors. We conducted a phase I study of perifosine in Japanese patients with recurrent or refractory NB.

EXPERIMENTAL DESIGN

All patients enrolled were over 2 years of age; all had refractory or relapsed NB and a performance status of greater than 50%. Perifosine was orally administered at a loading dose (100-300 mg) on day 1 and at a maintenance dose (50-150 mg) from day 2 onward. Dose-limiting toxicity (DLT) and pharmacokinetics were assessed in Step 1 and safety and efficacy in Step 2.

RESULTS

Nineteen patients were recruited. No DLT was observed. Adverse reactions occurring in more than 30% of the patients were vomiting (63%), nausea (53%), and diarrhea (37%). The mean plasma concentration of perifosine was 27.5 ± 9.8 μM on day 15 and 27.3 ± 11.5 μM on day 29. The response rate (RR) in 18 patients evaluable according to modified International Neuroblastoma Response Criteria was 0%; the disease control rate (DCR) was 56%. Median progression-free survival (PFS) was 122 days. In 11 patients evaluable according to the Response Evaluation Criteria in Solid Tumors, the RR and DCR were 9% and 55%, respectively. The median PFS was not reached.

CONCLUSIONS

Perifosine monotherapy was well tolerated in Japanese patients with recurrent/refractory NB. Further investigations in combination with other anticancer or molecular targeted agents are warranted.

Optimization of liposomal topotecan for use in treating neuroblastoma

The purpose of this work was to develop an optimized liposomal formulation of topotecan for use in the treatment of patients with neuroblastoma. Drug exposure time studies were used to determine that topotecan (Hycamtin) exhibited great cytotoxic activity against SK-N-SH, IMR-32 and LAN-1 neuroblastoma human cell lines. Sphingomyelin (SM)/cholesterol (Chol) and 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)/Chol liposomes were prepared using extrusion methods and then loaded with topotecan by pH gradient and copper-drug complexation. In vitro studies showed that SM/Chol liposomes retained topotecan significantly better than DSPC/Chol liposomes. Decreasing the drug-to-lipid ratio engendered significant increases in drug retention. Dose-range finding studies on NRG mice indicated that an optimized SM/Chol liposomal formulation of topotecan prepared with a final drug-to-lipid ratio of 0.025 (mol: mol) was better tolerated than the previously described DSPC/Chol topotecan formulation. Pharmacokinetic studies showed that the optimized SM/Chol liposomal topotecan exhibited a 10-fold increase in plasma half-life and a 1000-fold increase in AUC0-24 h when compared with Hycamtin administered at equivalent doses (5 mg/kg). In contrast to the great extension in exposure time, SM/Chol liposomal topotecan increased the life span of mice with established LAN-1 neuroblastoma tumors only modestly in a subcutaneous and systemic model. The extension in exposure time may still not be sufficient and the formulation may require further optimization. In the future, liposomal topotecan will be assessed in combination with high-dose radiotherapy such as 131 I-metaiodobenzylguanidine, and immunotherapy treatment modalities currently used in neuroblastoma therapy.

Epidermal growth factor receptor is overexpressed in neuroblastoma tissues and cells

Neuroblastoma is the most common abdominal malignant tumor in childhood. Immunotoxin (IT) that targets the tumor cell surface receptor is a new supplementary therapeutic treatment approach. The purpose of this study is to detect the expression of epidermal growth factor receptor (EGFR) in neuroblastoma cell lines and tissues, and to explore if IT therapy can be used to treat refractory neuroblastoma. The EGFR expression in human neuroblastoma tissue samples was detected by immunohistochemistry staining. The positive rate of EGFR expression was 81.0% in neuroblastoma tissue and 50.0% in gangliocytoma, respectively, but without statistical significance between them (P > 0.05). The positive rate of EGFR expression in favorable type and unfavorable type was 62.5% and 92.3%, respectively, but they were not statistically different (P > 0.05). Results from pre-chemotherapy and post-chemotherapy samples showed that there was no significant statistical difference (P > 0.05) between them in the EGFR expression. Furthermore, the EGFR expression levels in five neuroblastoma cell lines were measured using cell-based ELISA assay and western blot analysis. The results showed that the expression of EGFR was higher in KP-N-NS and BE(2)-C than those in other cell lines. Our results revealed that there are consistent and widespread expressions of EGFR in neuroblastoma tissues as well as in neuroblastoma cell lines, suggesting that it is possible to develop future treatment strategies of neuroblastoma by targeting at the EGFR.

A single center clinical analysis of children with neuroblastoma

In the present study, the cases of 59 children diagnosed with neuroblastoma (NB) were retrospectively analyzed to assess the association between the short-term efficacy of treatment and prognostic factors. In total, 59 patients with NB that were diagnosed between July 1, 2008 and June 30, 2013 at Shanghai Children's Hospital were enrolled in the present study. The follow-up was performed until December 31, 2013, and the data revealed that 43 patients (72.9%) achieved complete remission (CR) or partial remission (PR). The 3-year overall survival (OS) rate of patients with stage I, II, III, IV and IVs disease was 100, 100, 65.6, 34.8 and 85.7%, respectively (P=0.02). The 3-year OS and event-free survival rates were evidently increased in patients with favorable histology compared with the rates in the patients with unfavorable histology (P=0.046 and 0.030, respectively). Univariate statistical analysis revealed that the factors significantly associated with prognosis were patient age, tumor stage and risk group (P=0.004, 0.02 and 0.001, respectively). The present study identified that tumor stage, risk group and patient age are important prognostic factors for NB. An age of 18 months was also hypothesized to be the cut-off for the prognosis of patients.

Treatment of relapsed Wilms tumour (WT) patients: experience with topotecan. A report from the SIOP Renal Tumour Study Group (RTSG)

BACKGROUND

Topotecan has been variably incorporated in the treatment of patients with relapsed Wilms tumour (WT) who failed initial treatment with three or more effective drugs. Our objective was to describe outcome and to retrospectively investigate the potential role of topotecan in relapsed WT patients.

METHODS

Children who were treated with topotecan as part of their chemotherapeutic regimens for relapsed WT were identified and included in our retrospective study. Patient charts were reviewed for general patient characteristics, histology and stage at initial diagnosis, number and type of relapse, salvage treatment schedules, toxicity, response to treatment and outcome.

RESULTS

From 2000 to 2012, 30 children (median age at relapse 5.5 years, range 1.6-14.5 years) were identified to have received topotecan as part of their salvage regimens (primary progressive disease n = 3, first, second and third relapse n = 13, 9 and 2 respectively, partial response n = 3). Topotecan was administered as a single agent (12 patients) or in combination with other drugs (18 patients). Sixteen patients had high-risk histology according to the SIOP classification, 15 died within 12 months because of progressive disease. Fourteen patients had SIOP intermediate-risk histology of which four patients displayed objective responses to topotecan. Overall, 6 out of 14 intermediate-risk patients survived (median follow up of 6 years), however, three of whom (stage V) had bilateral nephrectomy after topotecan treatment.

CONCLUSIONS

Topotecan does not seem to show effectiveness in the treatment of relapsed WT patients with initial high-risk histology. In patients with intermediate-risk histology, the role of topotecan might deserve further attention, to prove its efficacy.