Long-term risk of subsequent cancer incidence among hereditary and nonhereditary retinoblastoma survivors

Subsequent Renal Cancer Among Childhood Cancer Survivors: Analysis of Surveillance, Epidemiology, and End Results

Renal cancer, although still rare among individuals under 45 years of age, is on the rise in the general population. The risk and timing of subsequent renal cancer in survivors of childhood cancer is not well established. Using the SEER registry, we reported the incidence of subsequent malignant renal neoplasms after treatment for primary malignancy diagnosed under 20 years of age. We evaluated clinical characteristics, standardized incidence ratio (SIR), and Kaplan-Meier survival estimates. Fifty-three survivors developed subsequent renal cancer (54 total cases). Of these, 54.7% were female, 88.7% were white, and 13.2% were Hispanic. Mean ages at primary malignancy and subsequent renal cancer were 10.1 and 31.1 years, respectively. Forty-seven cases were second cancers, 6 were third, and 1 was fourth. For survivors of childhood cancer, the overall SIR for renal cancer was 4.52 (95% CI: 3.39-5.89). The 5-year overall survival rate after development of subsequent renal cancer was 73% (95% CI: 58%-83%). Renal cancer occurs 4.5 times more frequently in childhood cancer survivors than in the general population, necessitating long-term care considerations.

Incidence of second primary cancers in patients with retinoblastoma: a systematic review and meta-analysis

Introduction

This systematic review and meta-analysis aimed to examine the risk of second primary cancers (SPCs) among retinoblastoma (Rb) patients, both hereditary and nonhereditary. Previous studies have reported on the long-term risk of SPCs in these patient populations, but a comprehensive synthesis of the existing evidence is lacking.

Methods

A systematic search was conducted in PubMed, EMBASE, and Cochrane Library from inception to 12 March 2023, supplemented by manual screening. Eligible studies were identified, and data were extracted. The primary outcome measure was the standardized incidence ratios (SIRs) of SPCs in Rb patients. Summary estimates were calculated using random or fixed effects models. The quality of included studies was assessed using the Newcastle-Ottawa Scale.

Results

Ten studies, including nine high-quality studies, were included in this review. The summary estimate of SIR for SPCs among hereditary Rb patients was 17.55 (95% CI=13.10-23.51), while the pooled estimate of SIR for SPCs among nonhereditary Rb patients was 1.36 (95% CI=0.90-2.04). Significant differences in SIRs for different SPC types were observed (P=0.028), including nasal cavity tumor (SIR=591.06, 95% CI=162.79-2146.01), bone tumor (SIR=442.91, 95% CI=191.63-1023.68), soft tissue sarcoma (SIR=202.93, 95% CI=114.10-360.93), CNS (SIR=12.84, 95% CI=8.80-18.74), and female breast cancer (SIR=3.68, 95% CI=2.52-5.37). Chemotherapy and radiation therapy were associated with an increased risk of SPCs among hereditary Rb patients.

Discussion

The findings of this review indicate that hereditary Rb patients have a significantly elevated risk of developing SPCs, whereas nonhereditary Rb patients do not show the same risk. Furthermore, significant differences were observed in the SIRs of different SPC types. Treatment techniques, specifically chemotherapy and radiation therapy, were associated with an increased risk of SPCs among hereditary Rb patients. These findings highlight the importance of radiation protection for Rb patients and the need for further research and tailored management strategies for this high-risk population.

Ocular and orbital tumors in childhood

Pediatric tumors of the eye and orbit can be benign or malignant as well as congenital or acquired and are usually distinctively different than those seen in adults. Although most of these neoplasms are benign (eg, dermoid cyst, chalazion, molluscum), their location near and within a vital organ can result in serious dermatologic and ophthalmologic sequelae. Lesions discussed include vascular lesions, retinoblastomas (the most common primary pediatric intraocular malignancy), rhabdomyosarcoma (the most common primary pediatric orbital malignancy), Langerhans cell histiocytosis, and metastatic lesions to the orbit (neuroblastoma, Ewing sarcoma). Although cysts and ocular melanoma can occur within the pediatric population, these conditions are covered in other contributions in this issue of Clinics in Dermatology.

The Potential of Aqueous Humor Sampling in Diagnosis, Prognosis, and Treatment of Retinoblastoma

Retinoblastoma (RB) is a rare malignant tumor that arises in the developing retina in one or both eyes of children. Pathogenic variants of the RB1 tumor suppressor gene drive the majority of germline and sporadic RB tumors. Considering the risk of tumor spread, the biopsy of RB tumor tissue is contraindicated. Advancement of chemotherapy has led to preservation of more eye globes. However, this has reduced access to tumor material from enucleation specimens. Recently, liquid biopsy of aqueous humor (AH) has advanced the RB tumor- or eye-specific genetic analysis. In particular, nucleic acid analysis of AH demonstrates the genomic copy number profiles and RB1 pathogenic variants akin to that of enucleated RB eye tissue. This advance reduces the previous limitation that genetic assessment of the primary tumor could be done only after enucleation of the eye. Additionally, nucleic acid evaluation of AH allows the exploration of the genomic landscape of RB tumors at diagnosis and during and after treatment. This review explores how AH sampling and AH nucleic acid analysis in RB patients assist in diagnosis, prognosis, and comprehending the pathophysiology of RB, which will ultimately benefit individualized treatment decisions to carefully manage this ocular cancer in children.

Risk of Second Tumors in Retinoblastoma Survivors after Ionizing Radiation: A Review

Retinoblastoma (RB) is the most common ocular neoplasm in children, whose development depends on two mutational events that occur in both alleles of the retinoblastoma susceptibility gene (RB1). Regarding the nature of these mutational events, RB can be classified as hereditary if the first event is a germline mutation and the second one is a somatic mutation in retina cells or nonhereditary if both mutational events occur in somatic cells. Although the rate of survival of RB is significantly elevated, the incidence of second malignant neoplasms (SMNs) is a concern, since SMNs are the main cause of death in these patients. Effectively, RB patients present a higher risk of SMN incidence compared to other oncology patients. Furthermore, evidence confirms that hereditary RB survivors are at a higher risk for SMNs than nonhereditary RB survivors. Over the decades, some studies have been performed to better understand this subject, evaluating the risk of the development of SMNs in RB patients. Furthermore, this risk seems to increase with the use of ionizing radiation in some therapeutic approaches commonly used in the treatment of RB. This review aims to clarify the effect of ionizing radiation in RB patients and to understand the association between the risk of SMN incidence in patients that underwent radiation therapy, especially in hereditary RB individuals.

Global trends in the epidemiology of bladder cancer: challenges for public health and clinical practice

Bladder cancer is among the ten most common cancers globally, causes considerable morbidity and mortality and is, therefore, a substantial burden for health-care systems. The incidence of bladder cancer is affected by demographic trends, most notably population growth and ageing, as well as exposure to risk factors, especially tobacco smoking. Consequently, the incidence has not been stable throughout the world over time, nor will it be in the near future. Further primary prevention efforts are of the utmost importance to reduce the medical and financial burden of bladder cancer on populations and health-care systems. Simultaneously, less-invasive and lower-cost approaches for the diagnosis of both primary and recurrent bladder cancers are required to address challenges posed by the increasing shortage of health-care professionals and limited financial resources worldwide. In this regard, urinary biomarkers have demonstrated promising diagnostic accuracy and efficiency. Awareness of the risk factors and symptoms of bladder cancer should also be increased in society, particularly among health-care professionals and high-risk groups. Studies investigating the associations between lifestyle factors and bladder cancer outcomes are scarce and should be a research priority. In this Review, we outline global trends in bladder cancer incidence and mortality, and discuss the main risk factors influencing bladder cancer occurrence and outcomes. We then discuss the implications, challenges and opportunities of these epidemiological trends for public health and clinical practice.

Twenty-Year Retrospective Study of Post-Enucleation Chemotherapy in High-Risk Patients with Unilateral Retinoblastoma

Primary enucleation is a life-saving treatment for advanced intraocular retinoblastoma, particularly in patients with poor visual potential and functional contralateral eyes. This single-center study presents the treatment outcomes of patients with unilateral retinoblastoma who received primary enucleation and adjuvant chemotherapy with cyclophosphamide, vincristine, doxorubicin, and intrathecal methotrexate (CVDM) between 2000 and 2020. Twenty patients were enrolled in the study. The median age at diagnosis was 26 months (range, 1-45). Eighteen patients (90%) were in group E and two (10%) were in group D, according to the intraocular classification of retinoblastoma guidelines. Excluding one patient with an inadequate specimen, 19 patients (95%) had optic nerve involvement (ONI) at least up to the lamina cribrosa. Eight patients (40%) had choroidal invasion in addition to ONI. Two patients (10%) were surgical resection margin positive. The overall and event-free survival rates were 100% and 95%, respectively, for a median follow-up duration of 102.24 months (range 24.2-202.9). There were no relapses or deaths due to any cause, but one patient developed secondary rhabdomyosarcoma 99.6 months after chemotherapy. Treatment was well tolerated, with minimal hematotoxicity and hepatotoxicity. CVDM as a post-enucleation chemotherapy for advanced intraocular retinoblastoma has excellent outcomes with tolerable toxicity. However, in line with updated treatment trends, further risk stratification and lowering the treatment intensity should be considered. Continued long-term follow-up is required to further determine late effects.

Germline RB1 Mutation in Retinoblastoma Patients: Detection Methods and Implication in Tumor Focality

Purpose

The study aimed to generate a stepwise method to reduce the workload of full-scale RB1 sequencing for germline mutation screening in retinoblastoma (RB) patients. The implication of germline mutation in tumor focality was also determined in this study.

Methods

A stepwise method was created on the basis of "hotspot" exons analyzed using data on germline RB1 mutation in the RB1-Leiden Open Variation Database and then tested for mutation screening in the blood DNA of 42 patients with RB. The method was compared with the clinical next-generation sequencing (NGS) panel in terms of sequencing outcomes. The germline RB1 mutation was examined in association with multifocality in RB.

Results

Germline RB1 mutation was identified in 61% of all bilateral cases in the first step of the 3 stepwise method and in 78% and 89% for the two and three steps combined, respectively. NGS detected a mosaic variant of RB1 that was not detected by the first two steps and increased the sensitivity from 78% to 83%. Analysis of the relationship between mutation status and tumor focality indicated that multifocality in RB was dependent on germline RB1 mutation, confirming a higher tendency to have a germline RB1 mutation in patients with multifocal RB.

Conclusions

A 3 stepwise method reduces the workload needed for sequencing of the RB1 for bilateral cases. NGS outweighs conventional sequencing in terms of the identification of germline mosaic variants. Multifocal tumors in RB may be used to presume germline mutation.

Translational Relevance

The presence of "hotspot" exons of germline RB1 mutation in bilateral cases facilitates a mutation screening. However, when genetic testing is not available, multifocality in RB regardless of tumor laterality is predictive of germline RB1 mutation.

Trends in treatment of childhood cancer and subsequent primary neoplasm risk

BACKGROUND

The aim of the study was to investigate long-term risk and spectrum of subsequent neoplasm (SN) in childhood cancer survivors and to identify how trends in therapy influenced cumulative incidence of SN.

PATIENTS AND METHODS

The population-based cohort comprises 3271 childhood cancer patients diagnosed in Slovenia aged ≤ 18 years between 1st January 1961 and 31st December 2013 with a follow-up through 31st December 2018. Main outcome measures are standardised incidence ratios (SIRs), absolute excess risks (AERs), and cumulative incidence of SN.

RESULTS

After median follow-up time of 21.5 years for 5-year survivors, 230 patients experienced 273 SN, including 183 subsequent malignant neoplasm (SMN), 34 meningiomas and 56 nonmelanoma skin cancers. 10.5% patients received radiotherapy only, 31% chemotherapy only, 26.9% a combination of chemotherapy and radiotherapy and 16.1% surgery only. The overall SIR was almost 3 times more than expected (SIR 2.9), with survivors still at 2-fold increased risk after attained age 50 years. The observed cumulative incidence of SMN at 30-year after diagnosis was significantly lower for those diagnosed in 1960s, compared with the 1970s and the 1980s (P heterogeneity < 0.001). Despite reduced use of radiotherapy over time, the difference in cumulative incidence for the first 15 years after diagnosis was not significant for patients treated before or after 1995 (p = 0.11).

CONCLUSIONS

Risks of developing a SMN in this study are similar to other European population-based cohorts. The intensity of treatment peaked later and use of radiotherapy declined slower compared to high income countries, making continuous surveillance even more important in the future.

The risk of cancer following high, and very high, doses of ionising radiation

It is established that moderate-to-high doses of ionising radiation increase the risk of subsequent cancer in the exposed individual, but the question arises as to the risk of cancer from higher doses, such as those delivered during radiotherapy, accidents, or deliberate acts of malice. In general, the cumulative dose received during a course of radiation treatment is sufficiently high that it would kill a person if delivered as a single dose to the whole body, but therapeutic doses are carefully fractionated and high/very high doses are generally limited to a small tissue volume under controlled conditions. The very high cumulative doses delivered as fractions during radiation treatment are designed to inactivate diseased cells, but inevitably some healthy cells will also receive high/very high doses. How the doses (ranging from <1 Gy to tens of Gy) received by healthy tissues during radiotherapy affect the risk of second primary cancer is an increasingly important issue to address as more cancer patients survive the disease. Studies show that, except for a turndown for thyroid cancer, a linear dose-response for second primary solid cancers seems to exist over a cumulative gamma radiation dose range of tens of gray, but with a gradient of excess relative risk per Gy that varies with the type of second cancer, and which is notably shallower than that found in the Japanese atomic bomb survivors receiving a single moderate-to-high acute dose. The risk of second primary cancer consequent to high/very high doses of radiation is likely to be due to repopulation of heavily irradiated tissues by surviving stem cells, some of which will have been malignantly transformed by radiation exposure, although the exact mechanism is not known, and various models have been proposed. It is important to understand the mechanisms that lead to the raised risk of second primary cancers consequent to the receipt of high/very high doses, in particular so that the risks associated with novel radiation treatment regimens-for example, intensity modulated radiotherapy and volumetric modulated arc therapy that deliver high doses to the target volume while exposing relatively large volumes of healthy tissue to low/moderate doses, and treatments using protons or heavy ions rather than photons-may be properly assessed.

Orbital nodular fasciitis in child with biallelic germline RBL2 variant

RBL2/p130 is one of three highly conserved members of the retinoblastoma (RB) protein family. It is strongly upregulated during neuronal differentiation and brain development, and is critical for survival of post-mitotic neurons. Similar to RB1, it has been implicated as a tumor suppressor gene and has been shown to be dysregulated in various types of cancer. Recent publications describe biallelic, germline loss of function variants in RBL2 in individuals with profound developmental delay. We report a child with profound developmental delay, microcephaly, and hypotonia, who developed fulminant exophthalmos at age 6 years. Brain MRI followed by a biopsy of an intra-orbital mass revealed a mesenchymal tumor. Post-surgical histopathologic examination of the resected tumor was compatible with diagnosis of nodular fasciitis. Exome sequencing from peripheral blood identified a biallelic frameshift variant (c.901dupT) in RBL2. Notably, no malignancies were reported in previous cases with RBL2 variants. This case provides a possible association between RBL2 and orbital tumors.

Retinoblastoma Protein Paralogs and Tumor Suppression

The retinoblastoma susceptibility gene (RB1) is the first tumor suppressor gene discovered and a prototype for understanding regulatory networks that function in opposition to oncogenic stimuli. More than 3 decades of research has firmly established a widespread and prominent role for RB1 in human cancer. Yet, this gene encodes but one of three structurally and functionally related proteins that comprise the pocket protein family. A central question in the field is whether the additional genes in this family, RBL1 and RBL2, are important tumor suppressor genes. If so, how does their tumor suppressor activity overlap or differ from RB1. Here we revisit these questions by reviewing relevant data from human cancer genome sequencing studies that have been rapidly accumulating in recent years as well as pertinent functional studies in genetically engineered mice. We conclude that RBL1 and RBL2 do have important tumor suppressor activity in some contexts, but RB1 remains the dominant tumor suppressor in the family. Given their similarities, we speculate on why RB1 tumor suppressor activity is unique.

Increased risk of skin cancer in 1851 long-term retinoblastoma survivors

Hereditary retinoblastoma patients are at risk for developing cutaneous melanoma, but little is known about the role of sun exposure or other factors, and incidence of non-melanoma skin cancer (NMSC) is poorly understood. We investigated the incidence of melanoma and NMSC in a cohort of 1851 white, long-term retinoblastoma survivors (1020 hereditary and 831 nonhereditary) diagnosed from 1914-2006. During follow-up through 2016, 33 hereditary and 7 nonhereditary survivors developed melanoma, and 26 hereditary and 9 nonhereditary survivors developed NMSC. Most NMSC were on the head/neck whereas melanomas were more broadly distributed with patterns similar to melanoma-prone families. For both outcomes, median age at diagnosis was ∼20 years younger among hereditary than nonhereditary survivors. Fifty years following retinoblastoma diagnosis, the cumulative incidence in hereditary survivors was 4.5% for melanoma and 3.7% for NMSC; for nonhereditary survivors, it was 0.7% and 1.5%, respectively. Sun sensitivity and phenotypic characteristics generally did not vary by skin cancer status. Hereditary retinoblastoma survivors have an increased risk for melanoma and NMSC that occurred earlier compared with nonhereditary survivors, likely reflecting genetic factors. These findings among white retinoblastoma survivors support consensus-based recommendations for skin cancer screening and sun protection starting at young ages and continuing long-term.

Whole-Genome Sequencing of Retinoblastoma Reveals the Diversity of Rearrangements Disrupting RB1 and Uncovers a Treatment-Related Mutational Signature

The development of retinoblastoma is thought to require pathological genetic changes in both alleles of the RB1 gene. However, cases exist where RB1 mutations are undetectable, suggesting alternative pathways to malignancy. We used whole-genome sequencing (WGS) and transcriptomics to investigate the landscape of sporadic retinoblastomas derived from twenty patients, sought RB1 and other driver mutations and investigated mutational signatures. At least one RB1 mutation was identified in all retinoblastomas, including new mutations in addition to those previously identified by clinical screening. Ten tumours carried structural rearrangements involving RB1 ranging from relatively simple to extremely complex rearrangement patterns, including a chromothripsis-like pattern in one tumour. Bilateral tumours obtained from one patient harboured conserved germline but divergent somatic RB1 mutations, indicating independent evolution. Mutational signature analysis showed predominance of signatures associated with cell division, an absence of ultraviolet-related DNA damage and a profound platinum-related mutational signature in a chemotherapy-exposed tumour. Most RB1 mutations are identifiable by clinical screening. However, the increased resolution and ability to detect otherwise elusive rearrangements by WGS have important repercussions on clinical management and advice on recurrence risks.