Secondary acute myeloid leukemia after etoposide therapy for retinoblastoma

Hematological Second Primary Malignancy in Pediatric Retinoblastoma: A Case Report and Systematic Review

PURPOSE

The impact of heredity and treatment modalities on the development of hematologic second primary malignancies (SPMs) is unclear. This study primarily reviewed the literature on patients with hematologic SPMs after retinoblastoma.

METHODS

The PubMed and Web of Science databases were searched to identify all cases of hematologic SPMs after retinoblastoma through December 2023 (International prospective register of systematic reviews CRD42023488273).

RESULTS

Sixty-one patients from 35 independent publications and our case were included. Within the cohort, 15 patients (51.7%) were male, and 14 patients (48.3%) were female. Of the 43 cases with known heritability status, 27 (62.8%) were classified as heritable and 16 (37.2%) as nonheritable. The median age at diagnosis was 18 months (IQR: 7.00-36.00). The geographic distribution of patients was diverse, with North America accounting for 35.0% (21/60) of cases. The following treatment strategies were used: 11.9% (5/42) of patients received neither chemotherapy nor radiotherapy, 33.3% (14/42) received chemotherapy alone, 11.9% (5/42) received radiotherapy alone, and 42.9% (18/42) received a combination of chemotherapy and radiotherapy. The median delay between retinoblastoma diagnosis and SPM diagnosis was 40 months (IQR: 22.00-85.00). Among the 61 cases, acute myeloid leukemia accounted for 44.3% (27/61), followed by acute lymphoblastic leukemia in 21.3% (13/61), Hodgkin's lymphoma in 11.5% (7/61), non-Hodgkin's lymphoma in 9.8% (6/61), chronic myeloid leukemia in 3.3% (2/61), and acute natural killer cell leukemia in 1.6% (1/61).

CONCLUSIONS

Vigilant systemic surveillance for hematologic SPMs in retinoblastoma survivors, especially those treated with systemic chemotherapy and those with hereditary conditions, is warranted to improve management strategies and patient outcomes.

Therapy for Vitreous Seeding Caused by Retinoblastoma. A Review

Retinoblastoma is the most common primary malignant intraocular tumor in children. Seeding, specifically the dispersion of the tumor into the adjacent compartments, represents a major parameter determining the degree of retinoblastoma according to the International Classification of Retinoblastoma. In this article we focused on vitreous seeding, one of the main limiting factors in the successful "eye preservation treatment" of retinoblastoma. This article presents an overview of the history of vitreous seeding of retinoblastoma, established treatment procedures and new-research modalities. The introduction of systemic chemotherapy in the treatment of retinoblastoma at the end of the 1990s represented a significant breakthrough, which enabled the progressive abandonment of radiotherapy with its attendant side effects. However, the attained concentrations of chemotherapeutics in the vitreous space during systemic chemotherapy are not sufficient for the treatment of vitreous seeding, and the toxic effects of systemic chemotherapy are not negligible. A significant change came with the advent of chemotherapy in situ, with the targeted administration of chemotherapeutic drugs, namely intra-arterial and intravitreal injections, contributing to the definitive eradication of external radiotherapy and a reduction of systemic chemotherapy. Although vitreous seeding remains the most common reason for the failure of intra-arterial chemotherapy, this technique has significantly influenced the original treatment regimen of children with retinoblastoma. However, intravitreal chemotherapy has made the greatest contribution to increasing the probability of preservation of the eyeball and visual functions in patients with advanced findings. Novel local drug delivery modalities, gene therapy, oncolytic viruses and immunotherapy from several ongoing preclinical and clinical trials may represent promising approaches in the treatment of vitreous retinoblastoma seeding, though no clinical trials have yet been completed for routine use.

Multiparametric analysis of etoposide exposed mesenchymal stem cells and Fanconi anemia cells: implications in development of secondary myeloid malignancy

Secondary acute myeloid leukemia (sAML) may develop following a prior therapy or may evolve from an antecedent hematological disorder such as Fanconi Anemia (FA). Pathophysiology of leukemic evolution is not clear. Etoposide (Eto) is a chemotherapeutic agent implicated in development of sAML. FA is an inherited bone marrow (BM) failure disease characterized by genomic instability and xenobiotic susceptibility. Here, we hypothesized that alterations in the BM niche may play a critical/driver role in development of sAML in both conditions. Expression of selected genes involved in xenobiotic metabolism, DNA double-strand break response, endoplasmic reticulum (ER) stress, heat shock response and cell cycle regulation were determined in BM mesenchymal stem cells (MSCs) of healthy controls and FA patients at steady state and upon exposure to Eto at different concentrations and in recurrent doses. Expression of CYPA1, p53, CCNB1, Dicer1, CXCL12, FLT3L and TGF-Beta genes were significantly downregulated in FA-MSCs compared with healthy controls. Eto exposure induced significant alterations in healthy BM-MSCs with increased expression of CYP1A1, GAD34, ATF4, NUPR1, CXCL12, KLF4, CCNB1 and nuclear localization of Dicer1. Interestingly, FA-MSCs did not show significant alterations in these genes upon Eto exposure. As opposed to healthy MSCs DICER1 gene expression and intracellular localization was not altered on FA BM-MSCs after Eto treatment. These results showed that Eto is a highly potent molecule and has pleiotropic effects on BM-MSCs, FA cells show altered expression profile compared to healthy controls and Eto exposure on FA cells shows differential profile than healthy controls.

Downregulation of MST4 Underlies a Novel Inhibitory Role of MicroRNA Let-7a in the Progression of Retinoblastoma

Purpose

Retinoblastoma (RB) is the most common intraocular malignancy in children. Deregulation of several microRNAs (miRNAs) has been identified in RB. However, the specific effect of let-7a on RB remains unclear. The present study aims to explore the effect of let-7a on malignant biological behaviors of RB cells and angiogenesis in RB.

Methods

The expressions of let-7a and mammalian sterile-20 like kinase 4 (MST4) in RB were determined with the use of real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. Next, in order to explore effects of let-7a and MST4 on RB cellular functions, RB cells were transfected with let-7a-mimic, let-7a inhibitor, si-MST4, or co-transfected with let-7a-mimic and oe-MST4 plasmids. Subsequently, the interaction among let-7a, MST4, and the MAPK signaling pathway was evaluated by RT-qPCR, dual-luciferase reporter gene assay, and Western blot analysis. Finally, the effects of let-7a and MST4 were further confirmed in vivo by injecting nude mice with RB cells stably expressing let-7a agomir or sh-MST4.

Results

Rb tissues and cells presented with downregulated Let-7a and upregulated MST4. Let-7a negatively targeted MST4 to block the activation of the MAPK signaling pathway. Upregulation of let-7a promoted apoptosis, and facilitated proliferation, angiogenesis, migration, and invasion of RB cells by decreasing MST4. Elevation of let-7a or silencing MST4 restricted angiogenesis and tumorigenesis in RB mice.

Conclusions

Taken together, let-7a inhibits angiogenesis in RB by silencing MST4 and inhibiting the MAPK signaling pathway.

Genes and environment: effects on the development of second malignancies in retinoblastoma survivors

Although it is a rare cancer, retinoblastoma has served as an important model in our understanding of genetic cancer syndromes. All patients with a germinal rb1 mutation possess a risk of the development of second malignancies. Approximately 40-50% of all retinoblastoma cases are considered germinal cases and recent work has indicated that nearly all retinoblastoma patients probably demonstrate a degree of mosaicism for the rb1 mutation, and thus are at risk of secondary malignancies. The risk of the development of these cancers continues throughout the patients' lives due to the loss of a functional RB1 protein and its critical tumor suppressive function in all cells. These cancers can develop in diverse anatomic locations, including the skull and long bones, soft tissues, nasal cavity, skin, orbit, brain, breast and lung. Treatments used for retinoblastoma such as external-beam radiation and chemotherapy can have a significant impact on the risk for and pattern of development of these secondary cancers. Second malignancies are the leading cause of death in germinal retinoblastoma survivors in the USA and thus continue to be an important subject of study in this patient population. Second malignancies following the germinal form of retinoblastoma are the subject of this review.

Efficacy of vincristine and carboplatin as chemo-reduction for advanced bilateral retinoblastoma, the Saudi experience

PURPOSE

To evaluate the efficacy of a 2-drug chemotherapy regimen without external-beam radiotherapy (EBRT) and/or without enucleation in bilateral retinoblastoma.

METHODS

From 1996 to 2010, 79 patients were diagnosed with bilateral RB and were eligible for chemotherapy. Chemotherapy was administered prior to and/or following local therapy to the eye. All patients received 3 cycles of chemo-reduction with carboplatin and vincristine, additional cycles of the same or other chemotherapy, local therapy, EBRT and enucleation were determined according to re-evaluation by the ophthalmologist.

RESULTS

Advanced disease was seen in 115 (79%) eyes (group IV and V: 96, Group D and E: 19) out of 146 affected eyes. Tumor response after chemotherapy was observed in 78 patients (98.7%); complete response in 25 (32.1%), partial response in 49 (62.8%) Four (5.1%) had progressive disease. A total of 50 (63.3%) patients required EBRT; 38 for persistent disease, 4 for progressive disease, 2 for new lesions, 2 for re-activation and 4 for disease control. Enucleation was required in 15 (19%). Secondary malignancies occurred in two patients who underwent EBRT; one osteogenic sarcoma and one rhabdomyosarcoma then later osteogenic sarcoma. The 10 year overall survival was 96.3% with a median follow-up time of 3.124 ± 0.536 years (95%CI: 2.074-4.174).

CONCLUSIONS

The 2-drug chemotherapy regimen combined with local therapy appears to be adequate therapy for low stage disease but not in patients with advanced disease. The occurrence of secondary cancers in this group of patients is worrisome further highlighting the deleterious effects of EBRT.

Acute leukemia as a secondary malignancy in children and adolescents: current findings and issues

Secondary acute leukemia is a devastating complication in children and adolescents who have been treated for cancer. Secondary acute lymphoblastic leukemia (s-ALL) was rarely reported previously but can be distinguished today from recurrent primary ALL by comparison of immunoglobulin and T-cell receptor rearrangement. Secondary acute myeloid leukemia (s-AML) is much more common, and some cases actually may be second primary cancers. Treatment-related and host-related characteristics and their interactions have been identified as risk factors for s-AML. The most widely recognized treatment-related risk factors are alkylating agents and topoisomerase II inhibitors (epipodophyllotoxins and anthracyclines). The magnitude of the risk associated with these factors depends on several variables, including the administration schedule, concomitant medications, and host factors. A high cumulative dose of alkylating agents is well known to predispose to s-AML. The prevalence of alkylator-associated s-AML has diminished among pediatric oncology patients with the reduction of cumulative alkylator dose and limited use of the more leukemogenic alkylators. The best-documented topoisomerase II inhibitor-associated s-AML is s-AML associated with epipodophyllotoxins. The risk of s-AML in these cases is influenced by the schedule of drug administration and by interaction with other antineoplastic agents but is not consistently found to be related to cumulative dose. The unpredictable risk of s-AML after epipodophyllotoxin therapy may discourage the use of these agents, even in patients at a high risk of disease recurrence, although the benefit of recurrence prevention may outweigh the risk of s-AML. Studies in survivors of adult cancers suggest that, contrary to previous beliefs, the outcome of s-AML is not necessarily worse than that of de novo AML when adjusted for cytogenetic features. More studies are needed to confirm this finding in the pediatric patient population.