Clinical and biological landscape of constitutional mismatch-repair deficiency syndrome: an International Replication Repair Deficiency Consortium cohort study.

BACKGROUND: Constitutional mismatch repair deficiency (CMMRD) syndrome is a rare and aggressive cancer predisposition syndrome. Because a scarcity of data on this condition contributes to management challenges and poor outcomes, we aimed to describe the clinical spectrum, cancer biology, and impact of genetics on patient survival in CMMRD. METHODS: In this cohort study, we collected cross-sectional and longitudinal data on all patients with CMMRD, with no age limits, registered with the International Replication Repair Deficiency Consortium (IRRDC) across more than 50 countries. Clinical data were extracted from the IRRDC database, medical records, and physician-completed case record forms. The primary objective was to describe the clinical features, cancer spectrum, and biology of the condition. Secondary objectives included estimations of cancer incidence and of the impact of the specific mismatch-repair gene and genotype on cancer onset and survival, including after cancer surveillance and immunotherapy interventions. FINDINGS: We analysed data from 201 patients (103 males, 98 females) enrolled between June 5, 2007 and Sept 9, 2022. Median age at diagnosis of CMMRD or a related cancer was 8·9 years (IQR 5·9-12·6), and median follow-up from diagnosis was 7·2 years (3·6-14·8). Endogamy among minorities and closed communities contributed to high homozygosity within countries with low consanguinity. Frequent dermatological manifestations (117 [93%] of 126 patients with complete data) led to a clinical overlap with neurofibromatosis type 1 (35 [28%] of 126). 339 cancers were reported in 194 (97%) of 201 patients. The cumulative cancer incidence by age 18 years was 90% (95% CI 80-99). Median time between cancer diagnoses for patients with more than one cancer was 1·9 years (IQR 0·8-3·9). Neoplasms developed in 15 organs and included early-onset adult cancers. CNS tumours were the most frequent (173 [51%] cancers), followed by gastrointestinal (75 [22%]), haematological (61 [18%]), and other cancer types (30 [9%]). Patients with CNS tumours had the poorest overall survival rates (39% [95% CI 30-52] at 10 years from diagnosis; log-rank p<0·0001 across four cancer types), followed by those with haematological cancers (67% [55-82]), gastrointestinal cancers (89% [81-97]), and other solid tumours (96% [88-100]). All cancers showed high mutation and microsatellite indel burdens, and pathognomonic mutational signatures. MLH1 or MSH2 variants caused earlier cancer onset than PMS2 or MSH6 variants, and inferior survival (overall survival at age 15 years 63% [95% CI 55-73] for PMS2, 49% [35-68] for MSH6, 19% [6-66] for MLH1, and 0% for MSH2; p<0·0001). Frameshift or truncating variants within the same gene caused earlier cancers and inferior outcomes compared with missense variants (p<0·0001). The greater deleterious effects of MLH1 and MSH2 variants as compared with PMS2 and MSH6 variants persisted despite overall improvements in survival after surveillance or immune checkpoint inhibitor interventions. INTERPRETATION: The very high cancer burden and unique genomic landscape of CMMRD highlight the benefit of comprehensive assays in timely diagnosis and precision approaches toward surveillance and immunotherapy. These data will guide the clinical management of children and patients who survive into adulthood with CMMRD. FUNDING: The Canadian Institutes for Health Research, Stand Up to Cancer, Children's Oncology Group National Cancer Institute Community Oncology Research Program, Canadian Cancer Society, Brain Canada, The V Foundation for Cancer Research, BioCanRx, Harry and Agnieszka Hall, Meagan's Walk, BRAINchild Canada, The LivWise Foundation, St Baldrick Foundation, Hold'em for Life, and Garron Family Cancer Center.

High-Risk Histopathological Features of Retinoblastoma following Primary Enucleation: A Global Study of 1426 Patients from 5 Continents.

PURPOSE: To evaluate high-risk histopathological features (HRHF) following primary enucleation of eyes with retinoblastoma (RB) and assess the patient outcomes across continents. METHODS: Retrospective study of 1426 primarily enucleated RB eyes from five continents. RESULTS: Of all, 923 (65%) were from Asia (AS), 27 (2%) from Australia (AUS), 120 (8%) from Europe (EUR), 162 (11%) from North America (NA), and 194 (14%) from South America (SA). Based on the continent (AS vs. AUS vs. EUR vs. NA vs. SA), the histopathology features included massive choroidal invasion (31% vs. 7% vs. 13% vs. 19% vs. 27%, p=0.001), post-laminar optic nerve invasion (27% vs. 0% vs. 16% vs. 21% vs. 19%, p=0.0006), scleral infiltration (5% vs. 0% vs. 4% vs. 2% vs. 7%, p=0.13), and microscopic extrascleral infiltration (4% vs. 0% vs. <1% vs. <1% vs. 4%, p=0.68). Adjuvant chemotherapy with/without orbital radiotherapy was given in 761 (53%) patients. Based on Kaplan-Meier estimates in different continents (AS vs. AUS vs. EUR vs. NA vs. SA), the 6-year risk of orbital tumor recurrence was 5% vs. 2% vs. 0% vs. 0% vs. 12% (p<0.001), systemic metastasis was reported in 8% vs. 5% vs. 2% vs. 0% vs. 13% (p=0.001), and death in 10% vs. 3% vs. 2% vs. 0% vs. 11% (p<0.001) patients. CONCLUSION: There is a wide variation in the infiltrative histopathology features of RB across continents, resulting in variable outcomes. SA and AS had a higher risk of orbital tumor recurrence, systemic metastasis, and death compared to AUS, EUR, and NA.

Dynamic Brain Imaging Response to Spinal Cord Stimulation Differential Frequencies DiFY SCS-PET Clinical Trial.

OBJECTIVES: This study with sequential 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)-computed tomography (CT) scanning was designed to investigate any objective measurable effect of differential frequency stimulation (40 Hz, 4000 Hz, and 10,000 Hz) on specific pain matrix areas in patients who underwent spinal cord stimulation (SCS) for intractable lumbar neuropathic pain. MATERIALS AND METHODS: In this single-center, randomized, blinded study, four brain 18F-FDG PET scans were performed for each patient-at baseline before SCS implant and after 40-Hz, 4000-Hz, and 10,000-Hz stimulation. After 40-Hz stimulation for four weeks, patients were randomized 1:1 (4000 Hz/10,000 Hz), crossing over at another four weeks. 18F-FDG PET-CT brain scans acquired on the GE-Discovery 710 PET system (GE Healthcare, Chicago, IL) with 128-slice CT (250-MBq dose) were analyzed using the PMOD software (PMOD Technologies Ltd, Zurich, Switzerland). A total of 18 pain regions, the right and left prefrontal cortex (PFC), insula, anterior cingulate cortex (ACC), hippocampus, amygdala, primary somatosensory cortices, secondary somatosensory cortices (SSCII), thalami, parabrachial, and periaqueductal gray (PAG), were analyzed. RESULTS: A total of 14 patients received 40 Hz for four weeks before crossing over to 10,000 Hz/4000 Hz. A total of 57 PET-CT scans (15 for baseline and 14 each for 40 Hz, 4000 Hz, and 10,000 Hz) were analyzed for maximum standardized uptake value (SUVmax), with a statistically significant difference in SUVmax between 40 Hz and baseline (p = 0.002) and 4000 Hz and baseline (p = 0.001) when pooled across 18 pain matrices. There was no statistical difference in SUVmax between 10,000 Hz and baseline. The pooled analysis showed a proportionately higher thalamic region reduction (59.5%) in metabolic activity than other pain matrices, PFC (52%), insula (50%), ACC (52%), SSCII (49%), and PAG (52%). CONCLUSION: This large cohort of brain PET scans (n = 57) shows statistically significant differences in brain metabolic activity at 40 Hz and 4000 Hz from baseline, with effect on both nociceptive and affect-cognitive pathways (proportionately higher reduction in the thalamus), highlighting the possible mechanism of SCS. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT03716557.

A Novel Pulsed Stimulation Pattern in Spinal Cord Stimulation: Clinical Results and Postulated Mechanisms of Action in the Treatment of Chronic Low Back and Leg Pain.

OBJECTIVES: The aim of this article is to discuss the possible mechanisms of action (MOAs) and results of a pilot study of a novel, anatomically placed, and paresthesia-independent, neurostimulation waveform for the management of chronic intractable pain. MATERIALS AND METHODS: A novel, multilayered pulsed stimulation pattern (PSP) that comprises three temporal layers, a Pulse Pattern layer, Train layer, and Dosage layer, was developed for the treatment of chronic intractable pain. During preliminary development, the utility was evaluated of anatomical PSP (aPSP) in human subjects with chronic intractable pain of the leg(s) and/or low back, compared with that of traditional spinal cord stimulation (T-SCS) and physiological PSP. The scientific theory and testing presented in this article provide the preliminary justification for the potential MOAs by which PSP may operate. RESULTS: During the pilot study, aPSP (n = 31) yielded a greater decrease in both back and leg pain than did T-SCS (back: -60% vs -46%; legs: -63% vs -43%). In addition, aPSP yielded higher responder rates for both back and leg pain than did T-SCS (61% vs 48% and 78% vs 50%, respectively). DISCUSSION: The novel, multilayered approach of PSP may provide multimechanistic therapeutic relief through preferential fiber activation in the dorsal column, optimization of the neural onset response, and use of both the medial and lateral pathway through the thalamic nuclei. The results of the pilot study presented here suggest a robust responder rate, with several subjects (five subjects with back pain and three subjects with leg pain) achieving complete relief from PSP during the acute follow-up period. These clinical findings suggest PSP may provide a multimechanistic, anatomical, and clinically effective management for intractable chronic pain. Because of the limited sample size of clinical data, further testing and long-term clinical assessments are warranted to confirm these preliminary findings.

Effectiveness of high dose spinal cord stimulation for non-surgical intractable lumbar radiculopathy - HIDENS Study.

OBJECTIVES: Spinal cord stimulation (SCS) is being increasingly used in non-surgical intractable low back pain. This study was designed to evaluate the efficacy of high-dose (HD) SCS utilizing sub-perception stimulation with higher frequency and pulse width in non-surgical predominant low-back pain population at 12 months. MATERIALS AND METHODS: A total of 20 patients were recruited (280 screened between March 2017 and July 2018) to undergo percutaneous fluoroscopic-guided SCS (Medtronic 8 contact standard leads and RestoreR IPG), with T8 and T9 midline anatomical parallel placement. Sixteen patients completed 12 months follow-up (500 Hz frequency, 500 µs pulse width, and 25% pulse density). Differences in patients' clinical outcome (NRS back, NRS leg, ODI, PGIC, and PSQ) and medication usage (MQS) at 1, 3, and 12 months from the baseline were assessed using non-parametric Wilcoxon paired test. RESULTS: The mean NRS scores for back pain (baseline 7.53) improved significantly at 1, 3, and 12 months; 2.78 (p < 0.001), 4.45 (p = 0.002), and 3.85 (p = 0.002), respectively. The mean NRS score for leg pain (baseline 6.09) improved significantly at 1 and 3 months; 1.86 (p < 0.001) and 3.13 (p = 0.010), respectively. Mean NRS for leg pain at 12 months was 3.85 (p = 0.057). ODI and sleep demonstrated significant improvement as there was consistent improvement in medication particularly opioid usage (MQS) at 12 months. CONCLUSIONS: This study demonstrates that anatomical placement of leads with sub-perception HD stimulation could provide effective pain relief in patients who are not candidates for spinal surgery.

Metabolic Imaging of Pain Matrix Using 18 F Fluoro-deoxyglucose Positron Emission Tomography/Computed Tomography for Patients Undergoing L2 Dorsal Root Ganglion Stimulation for Low Back Pain.

INTRODUCTION: Nociceptive signals from lumbar intervertebral discs ascend in the sympathetic chain via the L2 dorsal root ganglion (L2 DRG), a potential target for discogenic low back pain in neuromodulation. Positron Emission Tomography/Computed Tomography (PET-CT) measures functional changes in the brain metabolic activity, identified by the changes in the regional cerebral blood flow (rCBF) as determined by the changes of F-18 Fluoro-deoxyglucose (18 F FDG) tracer within brain tissues. METHODS AND MATERIALS: Nine patients were recruited to explore the changes in PET-CT imaging at baseline and four-weeks post implantation of bilateral L2 DRG neurostimulation leads and implantable pulse generator (IPG). PET-CT scans were performed 30 min following an IV injection of 250±10% MBq of 18 F FDG tracer. Fifteen frames were acquired in 15 min. PET list-mode raw data were reconstructed and normalized appropriately to a brain anatomical atlas. RESULTS: Nine patients were recruited to the study, where PET-CT imaging data for five patients were analyzed. The right and left insular cortex, primary and secondary somato-sensory cortices, prefrontal cortex, anterior cingulate cortex, thalamus, amygdala, hippocampus and the midline periaqueductal areas, were assessed for any changes in the metabolic activity. A total of 85 pain matrix regions were delineated SUV (standardized uptake value)MAX , SUV MEAN ± SD, and SUVPEAK were calculated for each of these regions of the brain and were compared pre- and post-L2 DRG stimulation. Sixty-one of the 85 matrices showed an increase in metabolic activity whereas 24 matrices showed a reduction in metabolic activity. CONCLUSION: This is the first ever study reporting the changes in cerebral metabolic activity and multi-frame static brain 18 F FDG PET imaging after L2 DRG stimulation for discogenic low back pain. Predominantly an increased metabolic activity in nociceptive brain matrices are seen with an increased in F18 F FDG uptake following L2 DRG stimulation.

Evaluating implementation of a hospital-based cancer registry to improve childhood cancer care in low- and middle-income countries.

PURPOSE: Cancer is a leading cause of global childhood mortality, affecting 400,000 children annually. While treatable with modern therapies, children living in low- and middle-income countries (LMICs) have limited access to care and lower survival rates. Hospital-based cancer registries (HBCRs) collect detailed patient information to critically evaluate and evolve care. The St. Jude Global Childhood Cancer Analytics Resource and Epidemiological Surveillance System (SJCARES) is a cloud-based HBCR network facilitating quality data collection of pediatric cancer. Wide variation in the success of implementation has warranted further research into the implementation approach, to create a sustainable and adaptable HBCR in LMICs. METHODS: Seven of 89 sites using the SJCARES registry were selected, stratified by global region and stage of implementation. Semi-structured interviews were conducted with key groups (clinicians, administrators, data clerks) using an interview guide developed from the Consolidation Framework for Implementation Research (CFIR). Interviews were conducted via a video-telephone software program and transcribed by a transcription service. Transcripts were thematically coded using rapid qualitative analysis. RESULTS: A total of 18 participants (11 clinicians, 4 administrators, 3 data clerks) were interviewed. Several barrier themes were identified, including: difficulty integrating the registry into existing workflow; lack of resources; lack of government or administrative support; and damaged, misplaced, or illegible medical records. Facilitator themes were identified, including: internal support for the registry; clear and extensive training; and dedicated support staff. CONCLUSION: Interviewed participants identified key barriers and facilitators to the implementation of the SJCARES registry across multiple phases. We plan to use these results to develop targeted implementation strategies including a readiness assessment tool to help guide more successful implementation of the SJCARES registry and other HBCRs in LMICs.

Functions of patient- and family-centered pediatric cancer communication in Pakistan.

Background: Communication is an essential aspect of high-quality patient- and family-centered care. A model for pediatric cancer communication developed in the United States defined eight communication functions. The purpose of this study was to explore the relevance of these functions in Pakistan as part of an effort to understand the role of culture in communication. Materials and methods: Semi-structured interviews were conducted with 20 clinicians and 18 caregivers of children with cancer at two major cancer centers. Interviews were conducted in Urdu or English and transcribed and translated as necessary. Two independent coders used a priori codes related to the communication model as well as novel codes derived inductively. Thematic analysis focused on operationalization of the functional communication model. Results: Clinicians and caregivers in Pakistan discussed the importance of all eight communication functions previously identified including: information exchange, decision-making, managing uncertainty, enabling family self-management, responding to emotions, supporting hope, providing validation, and building relationships. The operationalization of these functions was influenced by Pakistani cultural context. For example, information-exchange included the importance of addressing preconceptions and community myths, while managing uncertainty included strong references to religion and faith-based coping. Essential to all eight functions was trust between the family and the medical team. Discussion: These findings support the use of this functional communication model in diverse pediatric oncology settings and emphasize the importance of trust. Culturally sensitive operationalization of these functions could inform the adaptation of tools to measure communication and interventions aimed at supporting the needs of parents of children with cancer.

Treatment Outcomes and Definition Inconsistencies in High-Risk Unilateral Retinoblastoma: Outcomes and Definition Variances in High-Risk Rb.

PURPOSE: To compare the clinical outcomes of children with unilateral retinoblastoma (Rb) and high-risk histopathology features (HRHF) following upfront enucleation with/without adjuvant chemotherapy, and investigate cases locally considered non-HRHF but converted to a standardized HRHF definition. DESIGN: Retrospective multinational clinical cohort study. METHODS: Children with Rb who presented to 21 centers from 12 countries between 2011-2020, and underwent primary enucleation were recruited. Centers retrieved clinical data and were asked to report detailed histopathology findings, as well as indicate cases defined locally as high-risk. For analysis, only unilateral cases with standardized HRHF, defined as retrolaminar optic nerve invasion, massive choroidal invasion, scleral invasion, anterior-segment involvement, and/or combined non-massive choroidal and prelaminar/laminar optic nerve invasion, were included. Main Outcome Measures included orbital tumor recurrence, systemic metastasis, survival and number and outcome of cases converted to standardized HRHF. RESULTS: A total of 600 children presenting to 14 centers in 9 countries were included. Of these, 505 (84.2%) were considered locally as HRHF and received adjuvant chemotherapy. After a median follow-up period of 39.2±1.6 months (range: 0.8-60.0 months), 36 (6.0%) had orbital tumor recurrence, 49 (8.2%) metastasis, and 72 (12.0%) children died. Children not receiving adjuvant chemotherapy were at significantly increased risk of orbital tumor recurrence, metastasis, and death (p ≤0.002). Of the study children, 63/600 (10.5%) were considered locally non-HRHF, but converted to standardized HRHF and included in the analysis. Of these, 6/63 (9.5%) had orbital tumor recurrence, 5/63 (7.9%) metastasis, and 6/63 (9.5%) children died. Isolated minor choroidal invasion with prelaminar/laminar optic nerve invasion was reported in 114 (19.0%) children, but considered locally as HRHF only in 68/114 (59.6%). Of these, 6/114 (5.3%) children developed metastasis and subsequently died, yielding a number needed to treat of 15. CONCLUSION: Based on this multinational cohort of children with Rb, we recommend the use of adjuvant chemotherapy following upfront enucleation and diagnosis of HRHF. Variation exists worldwide among centers when defining HRHF, resulting in adverse patient outcomes, warranting standardization.

Differences in Childhood Growth Parameters Between Patients With Somatic and Heritable Retinoblastoma.

Purpose: Little is known regarding differences in childhood growth between somatic and heritable retinoblastoma (Rb) populations. We aimed to compare childhood growth parameters between somatic and heritable Rb cohorts at birth and at time of diagnosis with Rb. Methods: A multinational, longitudinal cohort study was conducted with patients from 11 centers in 10 countries who presented with treatment naïve Rb from January to December 2019. Variables of interest included age, sex, and size characteristics at birth and at time of presentation, as well as germline mutation status. After Bonferroni correction, results were statistically significant if the P value was less than 0.005. Results: We enrolled 696 patients, with 253 analyzed after exclusion criteria applied. Between somatic (n = 39) and heritable (n = 214) Rb cohorts, with males and females analyzed separately, there was no significant difference in birth weight percentile, weight percentile at time of diagnosis, length percentile at time of diagnosis, weight-for-length percentile at time of diagnosis, or change of weight percentile from birth to time of diagnosis. Patients with heritable Rb had a smaller mean weight percentile at birth and smaller mean weight and length percentiles at time of diagnosis with Rb, although this difference was not statistically significant. All cohorts experienced a slight negative change of weight percentile from birth to time of diagnosis. No cohort mean percentiles met criteria for failure to thrive, defined as less than the 5th percentile. Conclusions: Children with Rb seem to have normal birth and childhood growth patterns. There is no definitive evidence that somatic or heritable Rb has a biological or environmental impact on childhood growth parameters.

Capacity building for pediatric neuro-oncology in Pakistan- a project by my child matters program of Foundation S.

Introduction: Initiated in June 2019, this collaborative effort involved 15 public and private sector hospitals in Pakistan. The primary objective was to enhance the capacity for pediatric neuro-oncology (PNO) care, supported by a My Child Matters/Foundation S grant. Methods: We aimed to establish and operate Multidisciplinary Tumor Boards (MTBs) on a national scale, covering 76% of the population (185.7 million people). In response to the COVID-19 pandemic, MTBs transitioned to videoconferencing. Fifteen hospitals with essential infrastructure participated, holding monthly sessions addressing diagnostic and treatment challenges. Patient cases were anonymized for confidentiality. Educational initiatives, originally planned as in-person events, shifted to a virtual format, enabling continued implementation and collaboration despite pandemic constraints. Results: A total of 124 meetings were conducted, addressing 545 cases. To augment knowledge, awareness, and expertise, over 40 longitudinal lectures were organized for healthcare professionals engaged in PNO care. Additionally, two symposia with international collaborators and keynote speakers were also held to raise national awareness. The project achieved significant milestones, including the development of standardized national treatment protocols for low-grade glioma, medulloblastoma, and high-grade glioma. Further protocols are currently under development. Notably, Pakistan's first pediatric neuro-oncology fellowship program was launched, producing two graduates and increasing the number of trained pediatric neuro-oncologists in the country to three. Discussion: The initiative exemplifies the potential for capacity building in PNO within low-middle income countries. Success is attributed to intra-national twinning programs, emphasizing collaborative efforts. Efforts are underway to establish a national case registry for PNO, ensuring a comprehensive and organized approach to monitoring and managing cases. This collaborative initiative, supported by the My Child Matters/Foundation S grant, showcases the success of capacity building in pediatric neuro-oncology in low-middle income countries. The establishment of treatment protocols, fellowship programs, and regional tumor boards highlights the potential for sustainable improvements in PNO care.

Cancer in Faisalabad and Nankana Sahib, Pakistan: 2017-2019; An Observational Study.

Introduction: The Punjab Cancer Registry's catchment area includes the districts of Faisalabad and Nankana Sahib. It is an observational and descriptive study that covers the 3 years from 2017 to 2019, evaluating the distribution of cancer in these two districts. Material and Methods: Data on incident cancer cases diagnosed between 2017 and 2019 among residents of Faisalabad and Nankana Sahib in Pakistan, reported by the participating centres of the Registry, were reviewed retrospectively. Figures and proportions for adults, children and adolescents were computed. Results: During 2017 and 2019, 5678 cases were reported from Faisalabad and 390 from Nankana Sahib, with over 50% seen in females. In both districts combined, among adult females, cancers of the breast, reproductive system, and hepatobiliary system were commonly diagnosed, while cancer of the lip/oral cavity/pharynx, hepatobiliary system and non-Hodgkin lymphoma were the leading diagnoses among adult males. In children and young adults (0-19 years), acute lymphoblastic leukaemia, Hodgkin lymphoma and non-Hodgkin lymphoma were the most common diagnoses. Conclusion: The cancer distribution reported from Faisalabad and Nankana Sahib is of utmost importance. However, the underreporting of cancer cases cannot be ruled out. More input from the collaborators is needed to ensure the completeness of cancer surveillance in the region.

Barriers and Facilitators of Quality Family-Centered Communication in Pakistan.

PURPOSE: Communication is a fundamental aspect of patient- and family-centered care. Unfortunately, there is a dearth of evidence regarding pediatric cancer communication in low- and middle-income countries, where over 90% of all children with childhood cancer live. The purpose of this study was to explore barriers and facilitators of quality communication within two pediatric cancer centers in Pakistan. METHODS: Semistructured interviews were conducted with 20 multidisciplinary pediatric cancer clinicians and 18 caregivers of children with cancer at Children's Hospital of Lahore and Indus Hospital in Karachi, Pakistan. Interviews were conducted in English or Urdu, audio-recorded, transcribed, and translated to English. Two researchers coded each transcript using an inductively derived codebook. Thematic content analysis focused on barriers and facilitators of high-quality communication. RESULTS: Pakistani clinicians and caregivers identified factors that affected the quality of patient-centered cancer communication. These included structural factors including setting, available interpreters, documentation, patient volume, teamwork, and financial support. Clinician-level communication barriers and facilitators included communication training, clinician distress/boundaries, and the ability to have recurrent conversations. Patient or family characteristics affecting communication included education, income status, primary language, and geography; the child's specific disease type; and relational elements such as social support, empowerment, and split decision makers. Participants identified existing or potential interventions related to each factor. CONCLUSION: Multilevel factors serve as either barriers or facilitators for pediatric cancer communication in Pakistan. Identification of these elements of communication is an essential step toward interventions aimed at improving patient- and family-centered care in resource limited settings.

Risk factors associated with abandonment of care in retinoblastoma: analysis of 692 patients from 10 countries.

BACKGROUND: Rates of care abandonment for retinoblastoma (RB) demonstrate significant geographical variation; however, other variables that place a patient at risk of abandoning care remain unclear. This study aims to identify the risk factors for care abandonment across a multinational set of patients. METHODS: A prospective, observational study of 692 patients from 11 RB centres in 10 countries was conducted from 1 January 2019 to 31 December 2019. Multivariate logistic regression was used to identify risk factors associated with higher rates of care abandonment. RESULTS: Logistic regression showed a higher risk of abandoning care based on country (high-risk countries include Bangladesh (OR=18.1), Pakistan (OR=45.5) and Peru (OR=9.23), p<0.001), female sex (OR=2.39, p=0.013) and advanced clinical stage (OR=4.22, p<0.001). Enucleation as primary treatment was not associated with a higher risk of care abandonment (OR=0.59, p=0.206). CONCLUSION: Country, advanced disease and female sex were all associated with higher rates of abandonment. In this analysis, enucleation as the primary treatment was not associated with abandonment. Further research investigating cultural barriers can enable the building of targeted retention strategies unique to each country.

The role of maternal age & birth order on the development of unilateral and bilateral retinoblastoma: a multicentre study.

BACKGROUND/OBJECTIVES: Retinoblastoma is a common childhood intraocular malignancy, the bilateral form of which most commonly results from a de novo germline pathogenic variant in the RB1 gene. Both advanced maternal age and decreasing birth order are known to increase the risk of de novo germline pathogenic variants, while the influence of national wealth is understudied. This cohort study aimed to retrospectively observe whether these factors influence the ratio of bilateral retinoblastoma cases compared to unilateral retinoblastoma, thereby inferring an influence on the development of de novo germline pathogenic variants in RB1. SUBJECTS/METHODS: Data from 688 patients from 11 centres in 10 countries were analysed using a series of statistical methods. RESULTS: No associations were found between advanced maternal age, birth order or GDP per capita and the ratio of bilateral to unilateral retinoblastoma cases (p values = 0.534, 0.201, 0.067, respectively), indicating that these factors do not contribute to the development of a de novo pathogenic variant. CONCLUSIONS: Despite a lack of a definitive control group and genetic testing, this study demonstrates that advanced maternal age, birth order or GDP per capita do not influence the risk of developing a bilateral retinoblastoma.

Acute leukaemia in children with Down syndrome in a low middle-income country.

Down syndrome (DS) is the commonest chromosomal disorder and is considered to be the most common syndrome associated with acute leukaemia. The objective of this study was to determine the characteristics of acute leukaemia in children with DS in Pakistan. It was a retrospective, cohort study conducted over a 2-year period, and the data was analysed in SPSS 20.0 in terms of descriptive statistics. Nineteen DS patients with acute leukaemia were enrolled. The proportion of DS-acute leukaemia was found to be 1.84% among all cases of paediatric acute leukaemia. The mean age of presentation was 5.5 years ± 4.3 SD with a male to female ratio of 1.1:1. The precursor B-cell ALL was found in 13 (68.4%) and acute myeloid leukaemia was found in 6 (31.6%) patients of DS. Thirteen patients (68.4%) completed treatment, while 6 (31.6%) expired due to treatment-related toxicity. Mean overall survival was 38 months ± 5.34 SD. The status of diagnosis of DS before presentation with acute leukaemia was the only statistically significant factor associated with the outcome. Few distinct characteristics of DS-acute leukaemia have been found in our population. Treatment toxicity was the sole cause of treatment failure.

Radiofrequency denervation of the lumbar facet joints: guidelines for the RADICAL randomised controlled trial.

BACKGROUND AND AIM: The RADICAL trial has been funded by the National Institute for Health Research (NIHR) to evaluate the clinical and cost-effectiveness of radiofrequency denervation (RFD) for low back pain. Recommendations have been published which aim to standardise selection of patients and RFD technique. However, it is important to ensure these recommendations are acceptable to clinicians within the context of the trial. The aim of this work was to develop standardised criteria for the trial entry and RFD technique for implementation within the RADICAL trial. METHODS: Fourteen pain clinicians completed a survey, which involved reviewing the current recommendations and indicating whether they disagreed with any of the recommendations and if so why. Responses were collated and presented at a half-day workshop with 14 attendees. During the workshop, the National Low Back and Radicular Pain Pathway (NLBRPP) guidelines for patient selection and an article by Eldabe and colleagues presenting recommendations on the RFD technique were reviewed. Attendees discussed whether each component of the recommendations should be mandatory, mandatory with alteration or clarification or optional within the RADICAL trial. RESULTS: Attendees agreed during the workshop that 5 of the 10 criteria for patient selection described in the NLBRPP should be mandatory within the RADICAL trial. Three were agreed as mandatory criteria but required further clarification, one of which involved defining a positive response to a diagnostic medial branch block as ⩾60% pain relief. Two criteria had optional components. After reviewing the recommendations on the RFD technique from Eldabe and colleagues, seven components were agreed as mandatory, three were mandatory with alterations and three were optional. CONCLUSION: When evaluating complex interventions, such as RFD, it is important to ensure agreement and clarity on the clinical protocol, so that the intervention can be reproduced, if found to be effective.

Lag Time between Onset of First Symptom and Treatment of Retinoblastoma: An International Collaborative Study of 692 Patients from 10 Countries.

BACKGROUND: The relationship between lag time and outcomes in retinoblastoma (RB) is unclear. In this study, we aimed to study the effect of lag time between onset of symptoms and diagnosis of retinoblastoma (RB) in countries based on their national-income and analyse its effect on the outcomes. METHODS: We performed a prospective study of 692 patients from 11 RB centres in 10 countries from 1 January 2019 to 31 December 2019. RESULTS: The following factors were significantly different among different countries based on national-income level: age at diagnosis of RB (p = 0.001), distance from home to nearest primary healthcare centre (p = 0.03) and mean lag time between detection of first symptom to visit to RB treatment centre (p = 0.0007). After adjusting for country income, increased lag time between onset of symptoms and diagnosis of RB was associated with higher chances of an advanced tumour at presentation (p < 0.001), higher chances of high-risk histopathology features (p = 0.003), regional lymph node metastasis (p < 0.001), systemic metastasis (p < 0.001) and death (p < 0.001). CONCLUSIONS: There is a significant difference in the lag time between onset of signs and symptoms and referral to an RB treatment centre among countries based on national income resulting in significant differences in the presenting features and clinical outcomes.

The Effects of Breastfeeding on Retinoblastoma Development: Results from an International Multicenter Retinoblastoma Survey.

The protective effects of breastfeeding on various childhood malignancies have been established but an association has not yet been determined for retinoblastoma (RB). We aimed to further investigate the role of breastfeeding in the severity of nonhereditary RB development, assessing relationship to (1) age at diagnosis, (2) ocular prognosis, measured by International Intraocular RB Classification (IIRC) or Intraocular Classification of RB (ICRB) group and success of eye salvage, and (3) extraocular involvement. Analyses were performed on a global dataset subgroup of 344 RB patients whose legal guardian(s) consented to answer a neonatal questionnaire. Patients with undetermined or mixed feeding history, family history of RB, or sporadic bilateral RB were excluded. There was no statistically significant difference between breastfed and formula-fed groups in (1) age at diagnosis (p = 0.20), (2) ocular prognosis measures of IIRC/ICRB group (p = 0.62) and success of eye salvage (p = 0.16), or (3) extraocular involvement shown by International Retinoblastoma Staging System (IRSS) at presentation (p = 0.74), lymph node involvement (p = 0.20), and distant metastases (p = 0.37). This study suggests that breastfeeding neither impacts the sporadic development nor is associated with a decrease in the severity of nonhereditary RB as measured by age at diagnosis, stage of disease, ocular prognosis, and extraocular spread. A further exploration into the impact of diet on children who develop RB is warranted.

Cancer Epidemiology in Lahore, Pakistan - 2010-2015.

OBJECTIVE: To study the cancer incidence rates in Lahore, which has an estimated annual population count of 10.3 million. STUDY DESIGN: Cross-sectional study. PLACE AND DURATION OF STUDY: Data on new cancer cases diagnosed between 2010 and 2015, among the residents of Lahore district, Pakistan, was reviewed retrospectively in 2015-2017. METHODOLOGY: Nineteen collaborating centres of the population-based Punjab Cancer Registry (PCR), representing both the government and private sectors, reported their cases to the coordinating office located within the Shaukat Khanum Memorial Cancer Hospital and Research Centre (SKMCH&RC). The age-standardised incidence rates (ASIR) per 100,000 population, over a six-year period, were computed. Sixteen 5-year age groups were created beginning from 0-4 to 70-74 years, followed by 75+ years. Graphs on the five-year age-specific incidence rates by gender, were also generated. RESULTS: Between 2010 and 2015, 33,028 new malignancies were recorded in Lahore, with the crude average annual incidence rate being 53.1. In adults, the highest ASIRs were noted for cancers of the breast (77.3) among females and of prostate (11.4) in men. Age-specific incidence rates for female breast cancer showed an upward trend at the age of 20 years, reaching a figure of 160 at the age of 55 years. Among males, the rates for prostate cancer started to increase at the age of 55 years and reached a peak of 93 at 75 years. CONCLUSION: These results warrant expanding cancer registration in the region and sharing statistics with policy-makers to establish hospitals accordingly to manage cancer, along with exploring various risk factors within the population.