High cumulative rate of secondary leukemia after continuous etoposide treatment for solid tumors in children and young adults

Nanoparticle-mediated metronomic chemotherapy in cancer: A paradigm of precision and persistence

Current methods of cancer therapy have demonstrated enormous potential in tumor inhibition. However, a high dosage regimen of chemotherapy results in various complications which affect the normal body cells. Tumor cells also develop resistance against the prescribed drugs in the whole treatment regimen increasing the risk of cancer relapse. Metronomic chemotherapy is a modern treatment method that involves administering drugs at low doses continuously, allowing the drug sufficient time to take its effect. This method ensures that the toxicity of the drugs is to a minimum in comparison to conventional chemotherapy. Nanoparticles have shown efficacy in delivering drugs to the tumor cells in various cancer therapies. Combining nanoparticles with metronomic chemotherapy can yield better treatment results. This combination stimulates the immune system, improving cancer cells recognition by immune cells. Evidence from clinical and pre-clinical trials supports the use of metronomic delivery for drug-loaded nanoparticles. This review focuses on the functionalization of nanoparticles for improved drug delivery and inhibition of tumor growth. It emphasizes the mechanisms of metronomic chemotherapy and its conjunction with nanotechnology. Additionally, it explores tumor progression and the current methods of chemotherapy. The challenges associated with nano-based metronomic chemotherapy are outlined, paving the way for prospects in this dynamic field.

Incidence of subsequent malignancies after total body irradiation-based allogeneic HSCT in children with ALL - long-term follow-up from the prospective ALL-SCT 2003 trial

Total body irradiation (TBI)-based conditioning is associated with superior leukemia-free survival in children with ALL undergoing HSCT. However, the risk for subsequent malignant neoplasms (SMN) remains a significant concern. We analyzed 705 pediatric patients enrolled in the prospective ALL-SCT-BFM-2003 trial and its subsequent registry. Patients >2 years received conditioning with TBI 12 Gy/etoposide (n = 558) and children ≤2 years of age or with contraindications for TBI received busulfan/cyclophosphamide/etoposide (n = 110). The 5- and 10-year cumulative incidence of SMN was 0.02 ± 0.01 and 0.13 ± 0.03, respectively. In total, 39 SMN (34 solid tumors, 5 MDS/AML) were diagnosed in 33 patients at a median of 5.8 years (1.7-13.4), exclusively in the TBI group. Of 33 affected patients, 21 (64%) are alive at a median follow-up of 5.1 years (0-9.9) after diagnosis of their first SMN. In univariate analysis, neither age at HSCT, donor type, acute GVHD, chronic GVHD, nor CMV constituted a significant risk factor for SMN. The only significant risk factor was TBI versus non-TBI based conditioning. This analysis confirms and quantifies the increased risk of SMN in children with ALL after conditioning with TBI. Future strategies to avoid TBI will need careful tailoring within prospective, controlled studies to prevent unfavorable outcomes.

Etoposide, an anticancer drug involved in therapy-related secondary leukemia: Enzymes at play

Etoposide is a semi-synthetic glycoside derivative of podophyllotoxin, also known as VP-16. It is a widely used anticancer medicine in clinics. Unfortunately, high doses or long-term etoposide treatment can induce therapy-related leukemia. The mechanism by which etoposide induces secondary hematopoietic malignancies is still unclear. In this article, we review the potential mechanisms of etoposide induced therapy-related leukemia. Etoposide related leukemogenesis is known to depend on reactive oxidative metabolites of etoposide, notably etoposide quinone, which interacts with cellular proteins such as topoisomerases II (TOP2), CREB-binding protein (CREBBP), and T-Cell Protein Tyrosine Phosphatase (TCPTP). CYP3A4 and CYP3A5 metabolize etoposide to etoposide catechol, which readily oxidizes to etoposide quinone. As a poison of TOP2 enzymes, etoposide and its metabolites induce DNA double-stranded breaks (DSB), and the accumulation of DSB triggers cell apoptosis. If the cell survives, the DSB gives rise to the likelihood of faulty DNA repair events. The gene translocation could occur in mixed-lineage leukemia (MLL) gene, which is well-known in leukemogenesis. Recently, studies have revealed that etoposide metabolites, especially etoposide quinone, can covalently bind to cysteines residues of CREBBP and TCPTP enzymes, . This leads to enzyme inhibition and further affects histone acetylation and phosphorylation of the JAK-STAT pathway, thus putatively altering the proliferation and differentiation of hematopoietic stem cells (HSC). In brief, current studies suggest that etoposide and its metabolites contribute to etoposide therapy-related leukemia through TOP2 mediated DSB and impairs specific enzyme activity, such as CREBBP and TCPTP.

Mithramycin induces promoter reprogramming and differentiation of rhabdoid tumor

Rhabdoid tumor (RT) is a pediatric cancer characterized by the inactivation of SMARCB1, a subunit of the SWI/SNF chromatin remodeling complex. Although this deletion is the known oncogenic driver, there are limited effective therapeutic options for these patients. Here we use unbiased screening of cell line panels to identify a heightened sensitivity of rhabdoid tumor to mithramycin and the second-generation analogue EC8042. The sensitivity of MMA and EC8042 was superior to traditional DNA damaging agents and linked to the causative mutation of the tumor, SMARCB1 deletion. Mithramycin blocks SMARCB1-deficient SWI/SNF activity and displaces the complex from chromatin to cause an increase in H3K27me3. This triggers chromatin remodeling and enrichment of H3K27ac at chromHMM-defined promoters to restore cellular differentiation. These effects occurred at concentrations not associated with DNA damage and were not due to global chromatin remodeling or widespread gene expression changes. Importantly, a single 3-day infusion of EC8042 caused dramatic regressions of RT xenografts, recapitulated the increase in H3K27me3, and cellular differentiation described in vitro to completely cure three out of eight mice.

Drug Repurposing for Retinoblastoma: Recent Advances

Retinoblastoma is the intraocular malignancy that occurs during early childhood. The current standard of care includes chemotherapy followed by focal consolidative therapies, and enucleation. Unfortunately, these are associated with many side and late effects. New drugs and/or drug combinations need to be developed for safe and effective treatment. This compelling need stimulated efforts to explore drug repurposing for retinoblastoma. While conventional drug development is a lengthy and expensive process, drug repurposing is a faster, alternate approach, where an existing drug, not meant for treating cancer, can be repurposed to treat retinoblastoma. The present article reviews various attempts to test drugs approved for different purposes such as calcium channels blockers, non-steroidal antiinflammatory drugs, cardenolides, antidiabetic, antibiotics and antimalarial for treating retinoblastoma. It also discusses other promising candidates that could be explored for repurposing for retinoblastoma.

Old drugs still work! Oral etoposide in a relapsed medulloblastoma

Medulloblastoma is the most common malignant brain tumor in children. Approximately 30% of children with medulloblastoma will progress or relapse despite being treated. New therapies have been proposed in recent years, including high-dose chemotherapy, immunotherapy, and targeted therapy. However, the best treatment for these patients remains unclear, and in this situation prognosis is poor. Oral etoposide has been used as a single agent or in combination for treating relapsed brain tumors since the 1990s. We report an 8-year-old patient with recurrent metastatic medulloblastoma who had an excellent response after treatment with oral etoposide, maintaining a great quality of life. As clinicians, we must always try to include our patients in clinical trials; however, when this is not possible, we should not forget that "old drugs" such as oral etoposide may work in some patients, with a good response of the tumor, and what is most important, providing the patient with a good quality of life.

Characteristics and Predictors for Secondary Leukemia and Myelodysplastic Syndrome in Ewing and Osteosarcoma Survivors

PURPOSE

Long-term survivors of Ewing sarcoma (ES) and osteosarcoma may be at risk for therapy-related acute leukemia or myelodysplastic syndrome (t-AL/MDS).

METHODS AND MATERIALS

We retrospectively reviewed the clinicopathologic characteristics of 1071 patients with osteosarcoma (n = 757) and ES (n = 314) who were treated between 1985 and 2014. Multivariable competing risk analysis was used to analyze predictors of t-AL/MDS, including a radiation dose (≥55.8 Gy vs <55.8 Gy) × disease site (pelvis/spine vs other) interaction term. A supplemental nested case-control study was conducted to assess the association between cumulative chemotherapy dose and t-AL/MDS.

RESULTS

The median follow-up for surviving patients was 97 months (range, 0.03-380). Twenty patients developed t-AL/MDS, all of whom received chemotherapy and 15 of whom were treated with radiation therapy. Radiation therapy to ≥55.8 Gy was associated with development of t-AL/MDS (adjusted hazard ratio, 2.89; 95% confidence interval [CI], 1.23-6.80; P = .015), and there was a significant radiation dose × disease site interaction term (adjusted hazard ratio, 6.70; 95% CI, 2.71-16.53; P_interaction < .001). The 5-year cumulative incidence of t-AL/MDS in patients receiving ≥55.8 Gy radiation therapy to the pelvis or spine was 5.0% (95% CI, 0.9-14.9) for osteosarcoma and 10.7% for ES (95% CI, 3.3-23.2). In our nested case-control study, cumulative doses of ifosfamide and etoposide were associated with development of t-AL/MDS.

CONCLUSIONS

Patients with osteosarcoma and ES receiving ≥55.8 Gy of radiation therapy to the pelvis or spine appear to be at increased risk for t-AL/MDS. Treatment with high cumulative doses of chemotherapy may further augment this risk.

Metronomic Four-Drug Regimen Has Anti-tumor Activity in Pediatric Low-Grade Glioma; The Results of a Phase II Clinical Trial

Background: Metronomic chemotherapy (MC) is defined as the frequent administration of chemotherapy at doses below the maximal tolerated dose and with no prolonged drug-free break. MC has shown its efficacy in adult tumor types such as breast and ovarian cancer and has to some extent been studied in pediatrics.

Objective: To assess the anti-tumor activity and toxicity of a four-drug metronomic regimen in relapsing/refractory pediatric brain tumors (BT) with progression-free survival (PFS) after two cycles as primary endpoint.

Methods: Patients ≥4 to 25 years of age were included with progressing BT. Treatment consisted of an 8-week cycle of celecoxib, vinblastine, and cyclophosphamide alternating with methotrexate. Kepner and Chang two-steps model was used with 10 patients in the first stage. If stabilization was observed in ≥2 patients, 8 additional patients were recruited. Assessment was according WHO criteria with central radiology review.

Results: Twenty-nine patients (27 evaluable) were included in two groups: ependymoma (group 1, N = 8), and miscellaneous BT (group 2): 3 medulloblastoma (MB), 5 high grade glioma (HGG), 11 low grade glioma (LGG), 2 other BT. After first stage, recruitment for ependymoma was closed [one patient had stable disease (SD) for 4 months]. Cohort 2 was opened for second stage since 1 HGG and 3 LGG patients had SD after two cycles. Recruitment was limited to LGG for the second stage and 2 partial responses (PR), 6 SD and 2 progressive disease (PD) were observed after two cycles. Of these patients with LGG, median age was 10 years, nine patients received vinblastine previously. Median number of cycles was 6.8 (range: 1–12). Treatment was interrupted in five patients for grade 3/4 toxicity.

Conclusion: This regimen is active in patients with LGG, even if patients had previously received vinblastine. Toxicity is acceptable.

Trial Registration: This study was registered under clinicaltrials.gov – NCT01285817; EUDRACT nr: 2010-021792-81.

Secondary Acute Leukemia in Sarcoma Patients: A Population-Based Study

PURPOSE

To compare rates of secondary acute leukemia between sarcoma patients and the general population, using data from the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) registry, and to examine whether various patient, tumor, and treatment factors were associated with development of a secondary acute leukemia.

METHODS AND MATERIALS

Patients with a primary diagnosis of connective tissue malignancy between 1973 and 2008 in the SEER database were included. Multivariable competing risk analysis was used to determine risk factors associated with subsequent development of acute leukemia. Using observed-to-expected ratios, we compared incidence rates of secondary acute leukemia between sarcoma patients and the general population.

RESULTS

A total of 72,945 patients were identified, with median follow-up of 131 months. On multivariable competing risk analysis, factors associated with increased risk of secondary acute leukemia included receipt of radiation therapy (hazard ratio [HR] 1.67, P=.02), distant disease (HR 2.67, P=.004), male gender (HR 1.53, P=.03), year of diagnosis (HR 0.98, P=.049), and Ewing sarcoma histology (HR 9.95, P < .0001) and osteosarcoma histology (HR 5.06, P=.0001). The observed-to-expected ratio for development of a secondary acute leukemia was 3.67 (95% confidence interval [CI] 1.95-6.28), 3.41 (95% CI 2.73-4.20), and 1.6 (95% CI 1.38-8.19) for acute lymphocytic leukemia, acute myeloid leukemia, and acute monocytic leukemia, respectively. The 10-year cumulative incidence of secondary acute leukemia for patients who did and did receive radiation therapy was 0.3% versus 0.1% (P=.02).

CONCLUSIONS

Patients treated for sarcoma, in particular those with Ewing sarcoma and osteosarcoma histology, seem to have a higher incidence of secondary acute leukemia as compared with the general population. Treatment factors including radiation therapy and chemotherapy seem to play a role in this increased risk, although the absolute incidence nevertheless remains very small.

Second malignant neoplasm following childhood cancer: A nested case-control study of a recent cohort (1987-2004) from the Childhood Cancer Registry of the Rhône-Alpes region in France

From a population-based cohort of cases of first cancers diagnosed between 1987 and 2004, before the patient's age of 15 years, the authors conducted a nested case-control study, matching 64 patients who experienced a second malignant neoplasm (SMN) with 190 controls. SMNs comprised 10 leukemia or myelodysplastic syndromes, 5 lymphomas induced by Epstein-Barr virus after allograft, and 49 solid tumors, including mainly 25 carcinomas (17 of the thyroid), 9 bone sarcomas, and 7 central nervous system (CNS) tumors. The median latency occurrence was 6.5 years, and that of thyroid carcinomas induced by 12 Gy fractioned total body irradiation (TBI) was 7.6 years. The relative risk (RR) of an SMN was increased by genetic and family factors and increased 17 to 69 times according to the dose of radiotherapy administered in the region for the first cancer. Age younger than 4 years at the time of radiotherapy increased the risk of SMN. Chemotherapy adjusted according to the dose of radiotherapy administered in the field yielded a greater RR of an SMN only for cumulative doses exceeding 2 g/m² of epipodophyllotoxin but not for alkylating agents or platinum compounds. The RR of secondary leukemia increased 10-fold following high doses of epipodophyllotoxin >2 g/m² but was not affected by alkylating agents or anthracyclines. The crude RR of a solid SMN developing after radiotherapy was very high at 18 and reached 90.7 for thyroid carcinoma after TBI, whereas the authors observed no increased risk associated with chemotherapy. These results confirm the risk of secondary leukemia after epipodophyllotoxin and of solid tumor after radiotherapy.

Exploiting molecular biology for diagnosis and targeted management of pediatric low-grade gliomas

The majority of brain tumors arising in children are low-grade gliomas. Although historically categorized together as pediatric low-grade gliomas (PLGGs), there is significant histologic and genetic diversity within this group. In general, prognosis for PLGGs is excellent, and limitation of sequelae from tumor and treatment is paramount. Advances in high-throughput genetic sequencing and gene expression profiling are fundamentally changing the way PLGGs are classified and managed. Here, we review the histologic subtypes and highlight how recent advances in elucidating the molecular pathogenesis of these tumors have refined diagnosis and prognostication. Additionally, we discuss how characterizing specific genetic alterations has paved the way for the rational use of targeted therapies that are currently in various phase clinical trials.

Metronomic chemotherapy

Toxic effects and chemoresistance are major hurdles in chemotherapy and to avoid these problems caused by traditional chemotherapeutic regimens, a new modality of drug administration called “metronomic chemotherapy” has emerged. Such regimen involves the frequent administration of conventional chemotherapeutic agents at very low doses to target activated endothelial cells in tumors, the advantages of which include minimal adverse effects and a rare chance of developing acquired drug resistance. Previously it was thought that they act by targeting angiogenesis, but recently additional mechanisms have been discovered which has established metronomic chemotherapy as a type of multi-targeted therapy. The knowledge gained from the preclinical studies of metronomic chemotherapy, along with clinical experience, will help to design better therapeutic protocols against cancer. Detailed pharmacogenomic and pharmacoproteomic studies on tumor endothelial cells and large multi-centered clinical trials, integrating bio-marker analyzes, are needed to investigate and validate the best treatment combinations for each tumor type and patient population.

Conservative treatment modalities in retinoblastoma

Retinoblastoma is the most common primary intraocular malignancy of childhood. A potentially curable cancer, its treatment has improved significantly over the last few decades. The purpose of this article is to review the literature on various conservative treatment modalities available for the treatment of retinoblastoma and their effectiveness, when used alone or in combination. Pubmed, Medline, Embase, and the Cochrane library were searched through 2012 for published peer reviewed data on conservative treatment modalities for retinoblastoma. Various studies show that while enucleation remains the standard of care for advanced intraocular tumors, conservative modalities that can result in globe salvage and preservation of useful vision are being increasingly employed. Such modalities include systemic chemotherapy, focal consolidation with transpupillary thermotherapy, laser photocoagulation and cryotherapy, plaque brachytherapy, and delivery of local chemotherapy using subconjunctival, sub-tenon, or intra-arterial routes. When used alone or in combination, these treatment modalities can help in avoidance of external beam radiotherapy or enucleation, thus reducing the potential for long-term side effects, while salvaging useful vision. Radioactive plaque brachytherapy has an established role in selected patients with intraocular retinoblastoma. Local injections of chemotherapeutic agents via the sub-tenon or sub-conjunctival route have been used with varying degrees of success, usually as an adjunct to systemic chemotherapy. Intra-arterial ophthalmic artery delivery of melphalan has shown promising results. It is important to recognize that today, several treatment options are available that can obviate the need for enucleation, and cure the cancer with preservation of functional vision. A thorough knowledge and understanding of these conservative treatment modalities is essential for appropriate management.

Significant response to oral Etoposide in the treatment of an unresectable cardiac sarcoma

Primary cardiac sarcomas are rare and carry a poor prognosis. The standard of care is complete resection. Outcomes for patients without complete resection are dismal, and the benefit of adjuvant therapy is uncertain. A 9-year-old girl presented with a large right-sided cardiac mass. After biopsy, the tumor was classified as an undifferentiated sarcoma. Resection was not feasible due to apparent invasion of the right ventricle and atrioventricular groove. Treatment with oral etoposide resulted in a 97% reduction in tumor volume and allowed for complete resection of residual tumor. She is alive with no evidence of disease 25 months from diagnosis.

Treatment for recurrent medulloblastoma with intrathecal liposomal cytarabine and systemic metronomic combination therapy

The prognosis of recurrent medulloblastoma is dismal, with a median survival of less than 1 year. Our patient was initially diagnosed with high-risk medulloblastoma when he was 14 years old. He had a recurrence 18 months after the end of therapy. Recurrence treatment consisted of 13 intrathecal applications of liposomal cytarabine over an 18-month period, and oral metronomic antiangiogenic therapy with thalidomide, celecoxib, and etoposide. Side effects from the intrathecal treatment were most likely related to arachnoiditis despite prolonged prophylaxis with steroids. He also developed partial hearing loss. Neutropenia was the main side effect of the metronomic therapy. He remains alive, with a good quality of life and without evidence of disease 34 months from the start of recurrence therapy. This combination of local antineoplastic and systemic antiangiogenic therapy seems to be promising for recurrent medulloblastoma. However, more patients and standardized protocols are needed to verify the benefit of this combination therapy and to define the correct duration of treatment.

Pilot study of a pediatric metronomic 4-drug regimen

Background

Metronomic chemotherapy (MC) is defined as the frequent administration of chemotherapy at doses below the maximal tolerated dose and with no prolonged drug-free break. MC is gaining interest as an alternative strategy to fight resistant cancer.

Objective

to assess the safety of 4 drug MC regimen in pediatric patients with refractory or relapsing various tumors types.

Setting

From November 2008 to December 2010, in three academic pediatric oncology centers, 16 children (median age 12 years old; range 5.5-20) were included in this pilot study. This treatment was proposed to children with refractory disease for whom no further effective treatments were available. Most frequent diagnosis were medulloblastoma/cerebral PNET (5) osteosarcoma (5), and one case each of nephroblastoma, high grade glioma, Hodgkin lymphoma, rhabdomyosarcoma, neuroblastoma and kidney rhabdoid tumour. The MC regimen consisted in cycles of 56 days (8 weeks) with weekly vinblastine 3 mg/m² (week 1-7), daily cyclophosphamide 30 mg/m² (days 1-21), and twice weekly methotrexate 10 mg/m²; (days 21-42), and daily celecoxib 100 mg to 400 mg twice daily (days1-56) followed by a 2-weeks chemotherapy break. Adverse events were determined through laboratory analysis and investigator observations.

Results

One objective response was observed in a patient with Hodgkin lymphoma, and 4 patients experienced disease stabilization and continued their treatment for 3 cycles (24 weeks) or more. At last follow-up, 7 patients (43%) are alive including 1 still undergoing treatment. During the overall 36 cycles of treatments received by patients, 4 grade IV toxicities and 24 grade III toxicities were observed in 11 cycles in only 10 different patients.

Conclusion

The metronomic regimen we report here was well tolerated and associated with disease stabilization. This regimen is currently being evaluated in a national multicenter phase II study.

Long-term cognitive and cardiac outcomes after prenatal exposure to chemotherapy in children aged 18 months or older: an observational study

BACKGROUND

Chemotherapy for the treatment of maternal cancers during pregnancy has become more acceptable in the past decade; however, the effect of prenatal exposure to chemotherapy on cardiac and neurodevelopmental outcomes of the offspring is still uncertain. We aimed to record the general health, cardiac function, and neurodevelopmental outcomes of children who were prenatally exposed to chemotherapy.

METHODS

We did an interim analysis of a multicentre observational cohort study assessing children who were prenatally exposed to maternal cancer staging and treatment, including chemotherapy. We assessed children at birth, at age 18 months, and at age 5-6, 8-9, 11-12, 14-15, or 18 years. We did clinical neurological examinations, tests of the general level of cognitive functioning (Bayley or intelligence quotient [IQ] test), electrocardiography and echocardiography, and administered a questionnaire on general health and development. From age 5 years, we also did audiometry, the Auditory Verbal Learning Test, and subtasks of the Children's Memory Scale, and the Test of Everyday Attention for Children, and we also completed the Child Behavior Checklist. This study is registered with ClinicalTrials.gov, number NCT00330447.

FINDINGS

236 cycles of chemotherapy were administered in 68 pregnancies. We assessed 70 children, born at a median gestational age of 35·7 weeks (range 28·3-41·0; IQR 3·3; 47 women at <37 weeks), with a median follow-up period of 22·3 months (range 16·8-211·6; IQR 54·9). Although neurocognitive outcomes were within normal ranges, cognitive development scores were lower for children who were born preterm than for those born at full term. When controlling for age, sex, and country, the score for IQ increased by an average 11·6 points (95% CI 6·0-17·1) for each additional month of gestation (p<0·0001). Our measurements of the children's behaviour, general health, hearing, and growth corresponded with those of the general population. Cardiac dimensions and functions were within normal ranges. We identified a severe neurodevelopmental delay in both members of one twin pregnancy.

INTERPRETATION

Fetal exposure to chemotherapy was not associated with increased CNS, cardiac or auditory morbidity, or with impairments to general health and growth compared with the general population. However, subtle changes in cardiac and neurocognitive measurements emphasise the need for longer follow-up. Prematurity was common and was associated with impaired cognitive development. Therefore, iatrogenic preterm delivery should be avoided when possible.

FUNDING

Research Foundation-Flanders; Research Fund-K U Leuven; Agency for Innovation by Science and Technology; Stichting tegen Kanker; Clinical Research Fund-University Hospitals Leuven; and Belgian Cancer Plan, Ministery of Health.

Second malignant neoplasms following childhood cancer: a study of a recent cohort (1987-2004) from the childhood cancer registry of the Rhône-Alpes region (ARCERRA) in France

Studies of second malignant neoplasms (SMNs) in childhood are generally conducted in old cohorts. The aim of this study was to determine the actual incidence of all SMNs in a recent cohort. The authors studied a cohort of 2907 children included in the population-based Childhood Cancer Registry of the Rhône-Alpes Region for a first cancer diagnosed between 1987 and 2004. Total follow-up was 22,722 person-years, with a median follow-up of 9.8 years (range, 00.0-22.8 years). Fifty-four SMNs were reported in 52 patients. Overall median latency was 5.9 years. Cumulative incidence rates were 2.2% at 10 years and 3.9% at 15, with an overall standardized incidence ratio (SIR) of 13.9 (95% confidence interval [CI], 10.4-18.3) and absolute excess risk of 2.2. The SMNs were 12 thyroid carcinomas (SIR 57.1); 9 bone tumors (SIR 32.0); 8 leukemias (SIR 11.9); 5 lymphomas, all related to Epstein-Barr virus following allograft, (SIR 6.7); 5 CNS tumors (SIR 10.5); 4 soft tissue sarcomas (SIR 17.4); 4 carcinomas (no breast cancer); and 7 other cancers. Twelve SMNs appeared after total body irradiation, 16 after focal radiotherapy, and 8 leukemias after chemotherapy. The risk of secondary cancer was highest after retinoblastomas (SIR 41.8), Hodgkin lymphomas (SIR 20.8), leukemias (SIR 18.4), soft tissue sarcomas, CNS tumors, and bone tumors. These recent cohort findings show, on one hand, a high incidence of SMNs but do not capture breast cancers because of the relatively short follow-up and, on the other hand, a different distribution of first and second cancers.

Moving forward with metronomic chemotherapy: meeting report of the 2nd International Workshop on Metronomic and Anti-Angiogenic Chemotherapy in Paediatric Oncology

Metronomic chemotherapy, which is defined by the frequent, repetitive administration of chemotherapeutic drugs at relatively low doses, and without prolonged drug-free break, is an emerging strategy to fight cancer. Initially thought to act by targeting tumor angiogenesis, additional mechanisms have been recently unveiled, and metronomic chemotherapy is now considered to represent a form of multitargeted therapy. Despite representing a genuine alternative for advanced and/or high-risk cancer therapy, the development of metronomic approaches in pediatric oncology is still in the early stage. The few numbers of large-scale state-of-the-art clinical trials, issues regarding terminology and the limited understanding of the complex and intertwined mechanisms of action of metronomic treatments have limited progress in this important field of research. On March 18 and 19, 2010, the 2nd International Workshop on Metronomic and Anti-Angiogenic Chemotherapy in Paediatric Oncology was held in Marseille, France, and brought together clinicians, basic scientists, physician-scientists, trainees, and students from all around the world. The main aim of this international meeting was to provide a unique forum to 1) reflect on the major advances that have been made in this field of research since its creation, 2) communicate results from the most recent clinical trials and preclinical studies, 3) discuss the current and future challenges of the field, and 4) set forth a solid framework for future collaborative biologic and clinical studies. The present report documents the main preclinical and clinical data that were presented in the keynote and best abstract sessions and delivers the key messages from the meeting.

Phase I study of temozolomide combined with oral etoposide in children with recurrent or progressive medulloblastoma

BACKGROUND

The prognosis of recurrent or progressive medulloblastoma (MB) is still poor. This study was designed to investigate the potential therapeutic benefit of combination therapy with temozolomide (TMZ) and oral etoposide (VP-16) in children with progressive or relapsed MB. Given the oral administration of both drugs the regimen was administered outpatient.

METHODS

A phase I trial was conducted to establish the maximum tolerated dose (MTD) of TMZ and oral VP-16. This orally administered combination was investigated by classical 3+3 design. Cohorts of patients were enrolled at four different levels: (1) TMZ 120 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-8; (2) TMZ 150 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-8; (3) TMZ 150 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-10; (4) TMZ 150 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-12. Therapy was administered in 28-d courses. A total of 66 courses were administered to 14 patients with a median age of 5.7 years.

RESULTS

None of the 3 patients at dose levels 1 and 2 had dose-limiting toxicity (DLT). Of the 6 patients at dose level 3, 1 patient had DLT. At dose level 4, grade 4 thrombocytopaenia and neutropaenia were observed in the first 2 patients enrolled. Therefore, the MTD was established at dose level 3.

CONCLUSION

The recommended phase II dose in children is TMZ 150 mg/m(2) on days 1-5 and VP-16 50 mg/m(2) on days 1-10 every 28 d. The combination was well tolerated and demonstrated antitumour activity.

Metronomic chemotherapy: new rationale for new directions

Tumor angiogenesis is recognized as a major therapeutic target in the fight against cancer. The key involvement of angiogenesis in tumor growth and metastasis has started to redefine chemotherapy and new protocols have emerged. Metronomic chemotherapy, which is intended to prevent tumor angiogenesis, is based on more frequent and low-dose drug administrations compared with conventional chemotherapy. The potential of metronomic chemotherapy was revealed in animal models a decade ago and the efficacy of this approach has been confirmed in the clinic. In the past 5 years, multiple clinical trials have investigated the safety and efficacy of metronomic chemotherapy in a variety of human cancers. While the results have been variable, clinical studies have shown that these new treatment protocols represent an interesting alternative for either primary systemic therapy or maintenance therapy. We review the latest clinical trials of metronomic chemotherapy in adult and pediatric cancer patients. Accumulating evidence suggests that the efficacy of such treatment may not only rely on anti-angiogenic activity. Potential new mechanisms of action, such as restoration of anticancer immune response and induction of tumor dormancy are discussed. Finally, we highlight the research efforts that need to be made to facilitate the optimal development of metronomic chemotherapy.

Secondary malignancies across the age spectrum

Development of a second malignancy is one of the most serious late effects in survivors of both childhood and adult-onset cancers. Patterns of second malignancy risk across the age spectrum can differ in terms of the types of second malignancies observed, magnitude of the risks, the latency period, associated risk factors, and modifying influences. Potential explanations for the varying risk patterns by age include differences in susceptibility of individual tissue/organ to carcinogenesis based on stage of development and level of tissue maturity, microenvironment, attained age, and lifestyle factors. A thorough understanding of these differences is essential when considering treatment modifications in newly diagnosed cancer patients who are aimed at reducing the risk of second malignancy and other late effects without compromising cure. Moreover, an understanding of the variations in second cancer risk according to age at treatment is important in customizing patient follow-up.

Pediatric low-grade gliomas

Pediatric low-grade gliomas encompass a heterogeneous set of tumors of different histologies. Cerebellar pilocytic astrocytomas occur most frequently followed by supratentorial diffuse fibrillary astrocytomas. Recent research has implicated activation of the RAS/RAF/MEK pathway in tumorigenesis of these tumors. Surgery is the mainstay of therapy. Overall survival rates for patients whose tumors are completely resected are 90% or greater, 10 years from diagnosis. Conversely, most optic pathway/hypothalamic, deep midline, and brain stem gliomas have minimal potential for resection; these tumors can be difficult to treat and deserve special attention. Combination chemotherapy is currently recommended as front-line adjuvant treatment for progressive or recurrent tumors. Second-line radiotherapy can also improve overall survival but is associated with more frequent and significant neurocognitive, endocrine, and other long-term toxicities.

Reduced risk of secondary leukemia with fewer cycles of dose-intensive induction chemotherapy in patients with neuroblastoma

BACKGROUND

We report a prospective study of secondary leukemia (SL)/myelodysplastic syndrome (MDS) in neuroblastoma (NB) patients treated with > or =5 cycles of dose-intensive chemotherapy.

PROCEDURE

NB patients received induction with high-dose cyclophosphamide (4,200 mg/m(2))-doxorubicin (75 mg/m(2))-vincristine (cycles 1, 2, 4, 6, 8), and high-dose cisplatin (200 mg/m(2))-etoposide (600 mg/m(2)) (cycles 3, 5, 7). Bone marrow was examined every 1-3 months for > or =36 months, with inclusion of extensive chromosomal studies 1-3 months post-induction and 1-2x/year thereafter.

RESULTS

One hundred eight four patients received 5 (n = 76), 6 (n = 45), 7 (n = 59), or 8 (n = 4) cycles. Eight patients developed SL/MDS (only one each in the 5- and 6-cycle groups), at 12-50 months, including two cases detected in surveillance studies. Among 108 patients who received > or =6 cycles, the 5-year cumulative incidence was 7.1% (95% CI: 2%, 12.2%), versus 0% among 54 patients who received 5 cycles without maintenance oral etoposide. Five-year cumulative incidences were 1.46%, 2.28%, and 8.47% among patients in the 5-, 6-, and 7-cycle groups, with fewer cycles having a significantly lower risk (P = 0.048). There was no significant association of risk with potentially leukemogenic consolidative treatments (targeted radiotherapy, myeloablative therapy, and oral etoposide).

CONCLUSIONS

Reducing the number of dose-intensive cycles significantly decreases the risk of SL/MDS, yielding 5-year rates matching the low range (0.4-2.2%) reported for moderate-dose combination chemotherapy regimens used against other pediatric solid tumors.

Combined biodifferentiating and antiangiogenic oral metronomic therapy is feasible and effective in relapsed solid tumors in children: single-center pilot study

BACKGROUND

To outline an outpatient-based treatment for children with relapsed solid tumors, who already have been extensively pretreated, we defined a 4-drug protocol named COMBAT (combined oral maintenance biodifferentiating and antiangiogenic therapy). Using this protocol, we performed a pilot study to determine its feasibility in children with relapsed and/or high-risk pediatric solid tumors.

PATIENTS AND METHODS

22 children received the COMBAT protocol. Treatment consisted of daily celecoxib administration along with daily 13-cisretinoic acid (2 weeks on / 2 weeks off) and cycles of metronomic temozolomide (90 mg/m2 for 42 days) and low-dose etoposide (21 days). The treatment was scheduled for a period of 1 year.

RESULTS

9 of the 14 patients assessable for response demonstrated evidence of treatment benefit manifested as prolonged disease stabilization or response. The protocol medication was well tolerated with very good compliance. Only minimal side effects where observed which responded to dose modification or local therapy.

CONCLUSIONS

The COMBAT regimen is well tolerated by patients with intensive prior therapy including myeloablative regimens. Favorable responses observed in this cohort of patients support the further exploration of this and/or similar strategies in the treatment of pediatric solid tumors.

An analysis of SEER data of increasing risk of secondary malignant neoplasms among long-term survivors of childhood brain tumors

BACKGROUND

Advances made in treatment of a childhood brain cancer have extended the lives of many children and adolescents. Treatment success, however, brings the opportunity to assess late effects; most worrying among these are secondary malignant neoplasms (SMN). Even though the cumulative incidence is quite small, long-term follow-up is required because treatment-induced cancers can occur years after initial treatment.

PROCEDURE

The purpose of this project was to determine what treatments and what host characteristics of children treated for a primary brain cancer are associated with an increase in the risk of a SMN in long-term survivors. Data were analyzed from 2,056 5-year survivors, of primary brain cancer in the surveillance, epidemiology, and end results (SEER) database between 1973 and 1998. Thirty-nine patients developed a SMN. Cox regression models were used to evaluate the independent contribution of a number of risk factors.

RESULTS

The most important risk factor for developing a SMN in 5-year survivors was the era in which the primary cancer was treated. Compared to treatment prior to 1979, patients treated between 1979 and 1984 had a 4.7-fold increase in risk (P = 0.001), while those treated after 1985 had a 6.7-fold increase in risk. (P = 0.002). Patients treated most recently carry the greatest risk of SMN development even after controlling for radiotherapy. This could be due to the increase in intensive treatment compared to earlier years.

CONCLUSION

Although the absolute excess risk of SMN remains quite low, continued surveillance is needed to evaluate long-term effects of new therapies for primary brain tumors.