Impact of trametinib on the neuropsychological profile of NF1 patients

PURPOSE

The use of trametinib in the treatment of pediatric low-grade gliomas (PLGG) and plexiform neurofibroma (PN) is being investigated in an ongoing multicenter phase II trial (NCT03363217). Preliminary data shows potential benefits with significant response in the majority of PLGG and PN and an overall good tolerance. Moreover, possible benefits of MEK inhibitor therapy on cognitive functioning in neurofibromatosis type 1 (NF1) were recently shown which supports the need for further evaluation.

METHODS

Thirty-six patients with NF1 (age range 3-19 years) enrolled in the phase II study of trametinib underwent a neurocognitive assessment at inclusion and at completion of the 72-week treatment. Age-appropriate Wechsler Intelligence Scales and the Trail Making Test (for children over 8 years old) were administered at each assessment. Paired t-tests and Reliable Change Index (RCI) analyses were performed to investigate change in neurocognitive outcomes. Regression analyses were used to investigate the contribution of age and baseline score in the prediction of change.

RESULTS

Stable performance on neurocognitive tests was revealed at a group-level using paired t-tests. Clinically significant improvements were however found on specific indexes of the Wechsler intelligence scales and Trail Making Test, using RCI analyses. No significant impact of age on cognitive change was evidenced. However, lower initial cognitive performance was associated with increased odds of presenting clinically significant improvements on neurocognitive outcomes.

CONCLUSION

These preliminary results show a potential positive effect of trametinib on cognition in patients with NF1. We observed significant improvements in processing speed, visuo-motor and verbal abilities. This study demonstrates the importance of including neuropsychological evaluations into clinical trial when using MEK inhibitors for patients with NF1.

Protocol for evaluation of the feasibility and preliminary efficacy of a targeted transition readiness workshop intervention for pediatric brain tumor survivors

BACKGROUND

Pediatric brain tumor survivors (PBTS) are at risk of physical, cognitive, and psychosocial challenges related to their diagnosis and treatment. Routine follow-up care as adults is therefore essential to their long-term health and quality of life. In order to successfully navigate to adult healthcare, it is recommended that youth develop transition readiness skills. Existing transition readiness interventions often focus on disease management. However, PBTS are also at risk of social competence and cognitive functioning challenges. In this paper, we describe the protocol of this pilot study and the methodology that will be used for the evaluation of the feasibility, acceptability, and preliminary efficacy testing of the first targeted transition intervention workshops specifically designed to meet the needs of PBTS and their caregivers.

METHODS

This study will use a mixed method to evaluate three 1 ½-h workshops targeted for dyads (N = 40) of PBTS (14 years or older) and their parents. Dyads will be recruited via a community pediatric cancer organization and the long-term follow-up clinic of a large pediatric hospital. Participants will complete an online survey which includes the Transition Readiness Assessment Questionnaire (TRAQ) before and after the workshops. Each workshop will cover a specific topic related to PBTS transition readiness: disease management, social competence, and cognitive functioning. Workshops will follow the same structure: topic presentation, discussion by a post-transfer survivor or parent, teaching two strategies, and workshop evaluation. Workshops will be co-led by healthcare specialists and patient partners. Feasibility and acceptability will be assessed via recruitment, attendance, retention, and Likert scales, and they will be analyzed by describing and comparing rates. Satisfaction will be measured using satisfaction surveys and audio-recorded focus groups. Qualitative data will be described through thematic content analysis. In order to test the preliminary efficacy of this study, we will compare transition readiness skills pre- and post-workshops using paired samples T test and ANCOVA to examine the impact of workshop on TRAQ skills.

DISCUSSION

Results of the study will inform refinement and future broader implementation of targeted transition readiness workshops for the specific needs of pediatric brain tumor survivors.

Performance of the eHealth decision support tool, MIPOGG, for recognising children with Li-Fraumeni, DICER1, Constitutional mismatch repair deficiency and Gorlin syndromes

BACKGROUND

Cancer predisposition syndromes (CPSs) are responsible for at least 10% of cancer diagnoses in children and adolescents, most of which are not clinically recognised prior to cancer diagnosis. A variety of clinical screening guidelines are used in healthcare settings to help clinicians detect patients who have a higher likelihood of having a CPS. The McGill Interactive Pediatric OncoGenetic Guidelines (MIPOGG) is an electronic health decision support tool that uses algorithms to help clinicians determine if a child/adolescent diagnosed with cancer should be referred to genetics for a CPS evaluation.

METHODS

This study assessed MIPOGG's performance in identifying Li-Fraumeni, DICER1, Constitutional mismatch repair deficiency and Gorlin (nevoid basal cell carcinoma) syndromes in a retrospective series of 84 children diagnosed with cancer and one of these four CPSs in Canadian hospitals over an 18-year period.

RESULTS

MIPOGG detected 82 of 83 (98.8%) evaluable patients with any one of these four genetic conditions and demonstrated an appropriate rationale for suggesting CPS evaluation. When compared with syndrome-specific clinical screening criteria, MIPOGG's ability to correctly identify children with any of the four CPSs was equivalent to, or outperformed, existing clinical criteria respective to each CPS.

CONCLUSION

This study adds evidence that MIPOGG is an appropriate tool for CPS screening in clinical practice. MIPOGG's strength is that it starts with a specific cancer diagnosis and incorporates criteria relevant for associated CPSs, making MIPOGG a more universally accessible diagnostic adjunct that does not require in-depth knowledge of each CPS.

The Burden of Surviving Childhood Medulloblastoma: A Population-Based, Matched Cohort Study in Ontario, Canada

PURPOSE

Survivors of childhood medulloblastoma suffer from substantial late effects. We characterized these sequelae using real-world health services data in a population-based cohort of medulloblastoma survivors.

METHODS

All 5-year medulloblastoma survivors diagnosed age < 18 years between 1987 and 2015 in Ontario, Canada, were identified and matched 1:5 with population controls. Index date was 5 years from latest pediatric cancer event. Linkage to provincial administrative health data allowed for comparison of cumulative incidences of several adverse outcomes.

RESULTS

Two hundred thirty survivors, 81.3% of whom had received craniospinal irradiation, were matched with 1,150 controls. The 10-year postindex cumulative incidence of all-cause mortality was 7.9% (95% CI, 3.9 to 11.8) in survivors versus 0.6% (95% CI, 0.1 to 1.1) in controls (hazard ratio [HR], 21.5; 95% CI, 9.8 to 54.0). The cumulative incidence of stroke was higher in survivors (4.8%; 95% CI, 2.2 to 9.0) compared with controls (0.1; 95% CI, 0.01 to 0.7; HR, 45.6; 95% CI, 12.8 to 289.8). Hearing loss requiring an amplification device was present in 24.9% (95% CI, 18.8 to 31.4) of survivors versus 0.3% (95% CI, 0.1 to 1.0) of controls (HR, 96.3; 95% CI, 39.7 to 317.3). Disability support prescription claims were submitted by 44.5% (95% CI, 37.1 to 51.6) of survivors versus 5.5% (95% CI, 4.2 to 7.1) of controls (HR, 10.0; 95% CI, 7.3 to 13.6). Female survivors were significantly less likely to deliver a liveborn child compared with controls (HR, 0.2; 95% CI, 0.1 to 0.7).

CONCLUSION

Survivors of medulloblastoma have significant long-term medical sequelae, increased all-cause mortality, and are frequently dependent on disability supports. Efforts to reduce the toxicity of current therapy, specifically incorporating molecularly informed risk stratification to spare low- and intermediate-risk survivors the toxicity of treatment, are urgently needed. These findings should prompt a re-evaluation of our current treatment approaches where research focused on late-effect interventions should be prioritized.

A multi-institutional retrospective pooled outcome analysis of molecularly annotated pediatric supratentorial ZFTA-fused ependymoma

Background

ZFTA-RELA (formerly known as c11orf-RELA) fused supratentorial ependymoma (ZFTAfus ST-EPN) has been recognized as a novel entity in the 2016 WHO classification of CNS tumors and further defined in the recent 2021 edition. ZFTAfus ST-EPN was reported to portend poorer prognosis when compared to its counterpart, YAP1 ST-EPN in some previously published series. The aim of this study was to determine the treatment outcome of molecularly confirmed and conventionally treated ZFTAfus ST-EPN patients treated in multiple institutions.

Methods

We conducted a retrospective analysis of all pediatric patients with molecularly confirmed ZFTAfus ST-EPN patients treated in multiple institutions in 5 different countries (Australia, Canada, Germany, Switzerland, and Czechia). Survival outcomes were analyzed and correlated with clinical characteristics and treatment approaches.

Results

A total of 108 patients were collated from multiple institutions in 5 different countries across three continents. We found across the entire cohort that the 5- and 10-year PFS were 65% and 63%, respectively. The 5- and 10-year OS of this cohort of patients were 87% and 73%. The rates of gross total resection (GTR) were high with 84 out of 108 (77.8%) patients achieving GTR. The vast majority of patients also received post-operative radiotherapy, 98 out of 108 (90.7%). Chemotherapy did not appear to provide any survival benefit in our patient cohort.

Conclusion

This is the largest study to date of contemporaneously treated molecularly confirmed ZFTAfus ST-EPN patients which identified markedly improved survival outcomes compared to previously published series. This study also re-emphasizes the importance of maximal surgical resection in achieving optimal outcomes in pediatric patients with supratentorial ependymoma.

Upfront BRAF/MEK inhibitors for treatment of high-grade glioma: A case report and review of the literature

Background

High-grade gliomas (HGG) with BRAFV600E mutation represent a unique subset of central nervous system tumors. Targeted therapies including BRAF and MEK inhibitors are now being explored as possible new treatment options.

Methods

We report an 18-year-old female with a grade 3 pleomorphic xanthoastrocytoma treated upfront with dabrafenib and trametinib. We also conducted a systematic literature review of patients with HGG and BRAFV600E mutations treated with BRAF inhibitors.

Results

Despite local recurrences resected surgically, the patient has been on dabrafenib and trametinib for more than 54 months. Thirty-two patients with HGG and BRAFV600E mutations treated with BRAF inhibitors were retrieved through our systematic review of the literature. Only 1 young patient with an anaplastic ganglioglioma was treated upfront with a BRAF inhibitor with a curative intent. Best response reported with radiation therapy and systemic therapy was a stable disease (SD) for 18 patients (56.3%) and progressive disease (PD) for 9 patients (28.1%). Responses to treatment regimens that included BRAF inhibitors were reported in 31 patients and included 4 complete responses (12.9%), 23 partial responses (74.2%), 2 SDs (6.5%), and 2 PDs (6.5%).

Conclusions

Our patient had durable disease control with dabrafenib and trametinib. Given favorable responses reported in patients with HGG treated with BRAF inhibitors, we believe that upfront targeted therapy is a possible treatment approach that should be studied in the context of a clinical trial.

CTNI-04. TRAM-01: A PHASE 2 STUDY OF TRAMETINIB FOR PEDIATRIC PATIENTS WITH NEUROFIBROMATOSIS TYPE 1 AND PLEXIFORM NEUROFIBROMAS

BACKGROUND

Plexiform neurofibromas (PN) are observed in up to 50% of patients with neurofibromatosis type 1 (NF1). Trametinib has been used widely to treat PN but limited data has been reported on its efficacy within a clinical trial.

METHODS

This ongoing multicenter phase II trial includes patients with pediatric low-grade glioma and PN. Patients received daily oral trametinib (MEK inhibitor) for eighteen 28-day cycles. The volumes of PN were centrally quantified using a new semi-automatic 3D segmentation method.

RESULTS

As of May 15, 2022, 46 patients with PN were enrolled in the study and the recruitment was completed for this study arm. Thirty-four completed treatment and were available for analysis. For these patients, the median age was 10.5 years (range 0.7-19.8). The median volume of PN at baseline was 51cm3 (range 2.6 to 487.6). Among the 34 patients, 28 (82.4%) completed 18 cycles as planned. Two patients discontinued due to adverse reaction, three patients refused to continue treatment and one patient discontinued treatment based on physician decision. Median duration of treatment was 16.8 months (range 2.8 to 16.8). Median duration of follow-up was 30.4 months (range 8.2 to 42). A total of 38 PN were available for volumetric analysis. Using RECIST evaluation, the overall response rate was 13.1%. Volumetric assessment demonstrated an overall response rate of 64.7% (22/34 patients), and 65.8% (25/38 PN) of PN showed a decrease of more than 20% in volume. Median volume change was -30% (range -93.5 to 14.3). Thirty-one patients (91.1%) had durable response without progression (lasting ≥ 1 year). After discontinuation of treatment, one patient underwent surgery and three patients resumed MEK inhibitor.

CONCLUSION

We report outcome and volumetric quantification of PN treated with trametinib within a large clinical trial. Based on the current results, trametinib is effective and offers durable response.

Selumetinib for symptomatic, inoperable plexiform neurofibromas in children with neurofibromatosis type 1: A national real-world case series

Neurofibromatosis type 1-associated plexiform neurofibromas can cause debilitating symptoms and be life threatening. Treatment options are limited, given their tendency to regrow following surgery and their propensity to transform into malignant tumours following radiation. Selumetinib is an oral selective inhibitor of RAS-mitogen-activated protein kinase (MAPK) 1 and 2, which has shown efficacy for tumour shrinkage/stabilisation and symptom improvement. We report a national case series of 19 children treated with selumetinib. All patients experienced symptom improvement or stabilisation with an acceptable toxicity profile, including those patients previously treated with trametinib. This real-world experience confirms previous trials showing significant clinical benefit for this patient population.

HGG-11. Clinical characteristics and clinical evolution of a large cohort of pediatric patients with primary central nervous system (CNS) tumors and tropomyosin receptor kinase (TRK) fusion

BACKGROUND: TRK fusions are detected in less than 3% of CNS tumors. Given their rarity, there are limited data on the clinical course of these patients. METHODS: We contacted 166 oncology centers worldwide to retrieve data on patients with TRK fusion-driven CNS tumors. Data extracted included demographics, histopathology, NTRK gene fusion, treatment modalities and outcomes. Patients less than 18 years of age at diagnosis were included in this analysis. RESULTS: Seventy-three pediatric patients with TRK fusion-driven primary CNS tumors were identified. Median age at diagnosis was 2.4 years (range 0.0–17.8) and 60.2 % were male. NTRK2 gene fusions were found in 37 patients (50.7%), NTRK1 and NTRK3 aberrations were detected in 19 (26.0%) and 17 (23.3%), respectively. Tumor types included 38 high-grade gliomas (HGG; 52.1%), 20 low-grade gliomas (LGG; 27.4%), 4 embryonal tumors (5.5%) and 11 others (15.1%). Median follow-up was 46.5 months (range 3-226). During the course of their disease, a total of 62 (84.9%) patients underwent surgery with a treatment intent, 50 (68.5%) patients received chemotherapy, 35 (47.9%) patients received radiation therapy, while 34 (46.6%) patients received NTRK inhibitors (3 as first line treatment). Twenty-four (32.9%) had no progression including 9 LGG (45%) and 9 HGG (23.6%). At last follow-up, only one (5.6%-18 evaluable) patient with LGG died compared to 11 with HGG (35.5%-31 evaluable). For LGG the median progression-free survival (PFS) after the first line of treatment was 17 months (95% CI: 0.0-35.5) and median overall survival (OS) was not reached. For patients with HGG the median PFS was 30 months (95% CI: 11.9-48.1) and median OS was 182 months (95% CI 20.2-343.8). CONCLUSIONS: We report the largest cohort of pediatric patients with TRK fusion-driven primary CNS tumors. These results will help us to better understand clinical evolution and compare outcomes with ongoing clinical trials.

MEDB-07. Long-term medical and functional outcomes of medulloblastoma survivors: a population-based, matched cohort study

BACKGROUND: Most medulloblastoma survivors suffer from late treatment-related sequelae. There are no population-based studies examining such late effects in a dedicated cohort of medulloblastoma survivors. METHODS: Using a provincial pediatric cancer registry, all 5+ year medulloblastoma survivors diagnosed between 1987-2015 in Ontario, Canada were identified and matched to cancer-free population controls based on age, sex, and geographical location. Cases were followed from the index date (five years from latest of diagnosis, or relapse or subsequent malignancy prior to age 18 years) until December 31, 2020 or censorship (death, or relapse or new cancer after age 18 years). Clinical data were linked to administrative health databases to estimate cumulative incidences and cause-specific hazard ratios (HR) of mortality, hospitalizations, strokes, hearing loss requiring a hearing aid, and receipt of homecare services between cohorts, accounting for matching and competing risks. RESULTS: We identified 230 cases [65.7% female; median diagnostic age: 7y, interquartile range (IQR) 4-10; median attained age: 24y, IQR 18-31] and 1150 controls. One hundred eighty-seven (81.3%) received craniospinal irradiation. Ten-year survival probability after index was 92.4% in cases and 99.4% in controls (HR 21.5, 95% CI 9.8-54.0). Cases were at higher risk for hospitalizations (HR 3.4, 95% CI 2.7-4.3), stroke (HR 45.6, 95% CI 12.8-289.8), hearing loss (HR 96.3, 95% CI 39.7-317.3), and requiring homecare services (HR 7.9, 95% CI 5.8-10.9). By 10 years after index, 4.8% (95% CI 2.2-9.0) of survivors had experienced a stroke compared to 0.1% (95% CI 0.01-0.7) of controls. CONCLUSIONS: Survivors of childhood medulloblastoma experienced an increased risk of mortality and serious morbidity compared to population controls. Consideration for mitigation strategies or early interventions in preventing neurovascular sequelae and hearing loss is warranted, as are dedicated supports for survivors.

NFB-08. TRAM-01: A Phase 2 study of trametinib for pediatric patients with neurofibromatosis type 1 and plexiform neurofibromas

BACKGROUND: Plexiform neurofibromas (PN) are found in up to 50% of patients with neurofibromatosis type 1 (NF1). Trametinib has been used widely to treat PN but limited data has been reported on its efficacy within a clinical trial. METHODS: This ongoing multicenter phase II trial includes patients with pediatric low-grade glioma and PN. The primary objective for PN was to evaluate the overall response rate based on RECIST 1.1 criteria after daily oral trametinib administration for eighteen 28-day cycles. The volumes of PN were centrally quantified using a new semi-automatic 3D segmentation method. RESULTS: As of January 1, 2022, 45 patients with PN were enrolled in the study. Twenty-eight completed treatment and were available for analysis. For these patients, the median age was 11.4 years (range 0.7-19.8) including 16 males (57.1%). The majority did not receive prior systemic therapies (71.4%). The median volume of PN at baseline was 49.5 cm3 (range 2.6 to 469). Among the 28 patients, 25 (89.3%) completed 18 cycles as planned. One patient discontinued due to adverse reaction, one patient refused to continue treatment and one patient discontinued treatment based on physician decision. Median duration of treatment was 15.9 months (range 4.6 to 16.8). Median duration of follow-up was 29.7 months (range 17.7 to 38.1). A total of 32 PN were available for volumetric analysis. Using RECIST evaluation, the overall response rate was 24.1%. Volumetric assessment demonstrated an overall response rate of 60.7% and 62.5% of PN showed a decrease of more than 20% in volume. Median decrease in volume was -30% (range -93.5 to 14.3). Twenty-seven patients (93.1%) had durable response without progression (lasting ≥1 year). CONCLUSION: We report outcome and volumetric quantification of PN treated with trametinib within a large clinical trial. Based on the current results, trametinib appears effective and offers durable response.

A phase 2 study of trametinib for patients with pediatric glioma or plexiform neurofibroma with refractory tumor and activation of the MAPK/ERK pathway

2042

Background: Pediatric low-grade gliomas (PLGG) are the most frequent brain tumors in children and the majority of PLGG have activation of the MAPK/ERK pathway. Plexiform neurofibromas (PN) are found in up to 50% of patients with neurofibromatosis type 1 (NF1). Trametinib has been used widely to treat PLGG and PN, but no clinical trial has reported its efficacy. Methods: This multicenter phase II trial includes patients aged ≥ 1 month to ≤ 25 years with progressing/refractory PLGG groups or PN. The primary objective was to evaluate the overall response rate after daily oral trametinib administration for eighteen 28-day cycles. Results: As of January 31st, 2022, 60 patients with PLGG and 45 patients with PN have been enrolled. Median age is 9.5 years (range 1.8-25.4) for PLGG and 11 years (range 0.7-19.8) for PN. Median follow-up is 18 months (range 0.1-38.1). Fifty-three patients with PLGG were evaluable. The overall response includes: 1 complete response (CR) (1.9%), 7 partial response PR (13.2%), 17 minor response MR (32.1%), 23 stable disease (SD) (43.4%) and 5 progressive disease (PD) (9.4%). Twenty-eight patients with a total of 32 PN were available for volumetric analysis. Volumetric assessment demonstrated an overall response rate of 60.7% compared to 24.1% when using RECIST 1.1 and 62.5% of PN showed a decrease of more than 20% in volume. Median volume change was a decrease of 30% (range -93.5 to 14.3). A total of 59 (69.4%) patients discontinued treatment as planned after 18 cycles and 9 (10.6%) patients had to stop trametinib due to adverse events. Conclusions: Response rates observed in our study suggest that trametinib is a potentially effective targeted therapy for patients with recurrent/refractory PLGG and PN. Treatment was overall well tolerated. This trial will continue to gather data on duration of response and long-term outcome for PLGG and PN treated with trametinib. Clinical trial information: NCT03363217.

Long-term medical and functional outcomes of ependymoma survivors: A population-based, matched cohort study

10054

Background: Ependymoma is the third most common pediatric central nervous system tumour. Treatment approaches are intensive and may include surgery, radiation, and chemotherapy. There are no longitudinal population-based cohort studies evaluating the long-term medical and functional outcomes of survivors of childhood ependymoma. Methods: Using a provincial pediatric cancer registry, all 5+ year ependymoma survivors diagnosed between 1987-2015 in Ontario, Canada were identified and matched to cancer-free population controls based on age, sex, and geographical location. Cases were followed from the index date (5 years from latest of diagnosis, or relapse/subsequent malignancy prior to age 18 years) until December 31, 2020 or censorship (death, or relapse/ new cancer after age 18 years). Clinical data were linked to administrative health databases to estimate the cumulative incidences and cause-specific hazard ratios (HR) of mortality, hospitalizations, strokes, hearing loss requiring a hearing aid, receipt of homecare services, and subsequent malignant neoplasms (SMNs) between cohorts, accounting for matching and competing risks. Results: Of 166 ependymoma diagnoses in the study period, 70 (42.2%) were excluded, most commonly due to early death prior to the index date. Ninety-six cases were matched to 480 controls (Table). The 10-year survival probability after the index date was 92.8% in cases and 99.6% in controls (HR 9.3, 95% CI 2.3-45.2, p=0.002). Compared to controls, cases were at higher risk of hospitalization (HR 3.2, 95% CI 2.2-4.6, p<0.0001), stroke (HR 33.3, 95% CI 5.7-629.1, p<0.0001), and receiving homecare services (HR 4.1, 95% CI 2.5-6.5, p<0.0001). Cases were at high risk of hospitalizations, strokes, hearing loss, and SMNs, with cumulative incidences of 64.7% (95% CI 46.6-78.0), 9.7% (95% CI 3.4-19.9), 13.5% (95% CI 5.3-25.5), and 12.8% (95% CI 4.7-24.9) at 20-years post index date, respectively. Conclusions: As survival of pediatric ependymoma improves, establishing the burden of late morbidity is critical. Dedicated screening programs for late sensory and neurovascular sequelae are warranted, as are interventions during and following treatment to mitigate the risk of developing such complications. [Table: see text]

Long-term medical and functional outcomes of medulloblastoma survivors: A population-based, matched cohort study

10053

Background: Most medulloblastoma survivors suffer from late treatment-related sequelae. There are no population-based studies examining such late effects in a dedicated cohort of medulloblastoma survivors. Methods: Using a provincial pediatric cancer registry, all 5+ year medulloblastoma survivors diagnosed between 1987-2015 at <18 years of age in Ontario, Canada were identified and matched to cancer-free population controls based on age, sex, and geographical location. Cases were followed from the index date (five years from latest of diagnosis, or relapse/subsequent malignancy prior to age 18 years) until December 31, 2020 or censorship (death, or relapse/new cancer after age 18 years). Clinical data were linked to administrative health databases to estimate the cumulative incidences and cause-specific hazard ratios (HR) of mortality, hospitalizations, strokes, hearing loss requiring a hearing aid, and receipt of homecare services between cohorts, accounting for matching and competing risks. We evaluated demographic, disease, and treatment predictors of mortality using Cox proportional hazards models. Results: Of 389 medulloblastoma diagnoses in the study period, 159 (40.9%) were excluded, most commonly due to early death prior to the index date. Two hundred thirty cases were matched to 1150 controls (Table). Ten-year survival probability after index was 92.4% in cases and 99.4% in controls (HR 21.5, 95% CI 9.8-54.0). Cases were at higher risk for hospitalizations (HR 3.4, 95% CI 2.7-4.3), stroke (HR 45.6, 95% CI 12.8-289.8), hearing loss (HR 96.3, 95% CI 39.7-317.3), and requiring homecare services (HR 7.9, 95% CI 5.8-10.9). By 10 years after index, 4.8% (95% CI 2.2-9.0) of survivors had experienced a stroke compared to 0.1% (95% CI 0.01-0.7) of controls. None of the candidate predictors were significantly associated with mortality on univariate analyses. Conclusions: Survivors of childhood medulloblastoma experienced an increased risk of mortality and serious morbidity compared to population controls. Consideration for mitigation strategies or early interventions for preventing neurovascular sequelae and hearing loss is warranted, as is dedicated supports for survivors. [Table: see text]

Subgroup and subtype-specific outcomes in adult medulloblastoma

Medulloblastoma, a common pediatric malignant central nervous system tumour, represent a small proportion of brain tumours in adults. Previously it has been shown that in adults, Sonic Hedgehog (SHH)-activated tumours predominate, with Wingless-type (WNT) and Group 4 being less common, but molecular risk stratification remains a challenge. We performed an integrated analysis consisting of genome-wide methylation profiling, copy number profiling, somatic nucleotide variants and correlation of clinical variables across a cohort of 191 adult medulloblastoma cases identified through the Medulloblastoma Advanced Genomics International Consortium. We identified 30 WNT, 112 SHH, 6 Group 3, and 41 Group 4 tumours. Patients with SHH tumours were significantly older at diagnosis compared to other subgroups (p < 0.0001). Five-year progression-free survival (PFS) for WNT, SHH, Group 3, and Group 4 tumours was 64.4 (48.0-86.5), 61.9% (51.6-74.2), 80.0% (95% CI 51.6-100.0), and 44.9% (95% CI 28.6-70.7), respectively (p = 0.06). None of the clinical variables (age, sex, metastatic status, extent of resection, chemotherapy, radiotherapy) were associated with subgroup-specific PFS. Survival among patients with SHH tumours was significantly worse for cases with chromosome 3p loss (HR 2.9, 95% CI 1.1-7.6; p = 0.02), chromosome 10q loss (HR 4.6, 95% CI 2.3-9.4; p < 0.0001), chromosome 17p loss (HR 2.3, 95% CI 1.1-4.8; p = 0.02), and PTCH1 mutations (HR 2.6, 95% CI 1.1-6.2; p = 0.04). The prognostic significance of 3p loss and 10q loss persisted in multivariable regression models. For Group 4 tumours, chromosome 8 loss was strongly associated with improved survival, which was validated in a non-overlapping cohort (combined cohort HR 0.2, 95% CI 0.1-0.7; p = 0.007). Unlike in pediatric medulloblastoma, whole chromosome 11 loss in Group 4 and chromosome 14q loss in SHH was not associated with improved survival, where MYCN, GLI2 and MYC amplification were rare. In sum, we report unique subgroup-specific cytogenetic features of adult medulloblastoma, which are distinct from those in younger patients, and correlate with survival disparities. Our findings suggest that clinical trials that incorporate new strategies tailored to high-risk adult medulloblastoma patients are urgently needed.

Performance of the McGill Interactive Pediatric OncoGenetic Guidelines for Identifying Cancer Predisposition Syndromes

Importance

Prompt recognition of a child with a cancer predisposition syndrome (CPS) has implications for cancer management, surveillance, genetic counseling, and cascade testing of relatives. Diagnosis of CPS requires practitioner expertise, access to genetic testing, and test result interpretation. This diagnostic process is not accessible in all institutions worldwide, leading to missed CPS diagnoses. Advances in electronic health technology can facilitate CPS risk assessment.

Objective

To evaluate the diagnostic accuracy of a CPS prediction tool (McGill Interactive Pediatric OncoGenetic Guidelines [MIPOGG]) in identifying children with cancer who have a low or high likelihood of having a CPS.

Design, Setting, and Participants

In this international, multicenter diagnostic accuracy study, 1071 pediatric (<19 years of age) oncology patients who had a confirmed CPS (12 oncology referral centers) or who underwent germline DNA sequencing through precision medicine programs (6 centers) from January 1, 2000, to July 31, 2020, were studied.

Exposures

Exposures were MIPOGG application in patients with cancer and a confirmed CPS (diagnosed through routine clinical care; n = 413) in phase 1 and MIPOGG application in patients with cancer who underwent germline DNA sequencing (n = 658) in phase 2. Study phases did not overlap. Data analysts were blinded to genetic test results.

Main Outcomes and Measures

The performance of MIPOGG in CPS recognition was compared with that of routine clinical care, including identifying a CPS earlier than practitioners. The tool's test characteristics were calculated using next-generation germline DNA sequencing as the comparator.

Results

In phase 1, a total of 413 patients with cancer (median age, 3.0 years; range, 0-18 years) and a confirmed CPS were identified. MIPOGG correctly recognized 410 of 412 patients (99.5%) as requiring referral for CPS evaluation at the time of primary cancer diagnosis. Nine patients diagnosed with a CPS by a practitioner after their second malignant tumor were detected by MIPOGG using information available at the time of the first cancer. In phase 2, of 658 children with cancer (median age, 6.6 years; range, 0-18.8 years) who underwent comprehensive germline DNA sequencing, 636 had sufficient information for MIPOGG application. When compared with germline DNA sequencing for CPS detection, the MIPOGG test characteristics for pediatric-onset CPSs were as follows: sensitivity, 90.7%; specificity, 60.5%; positive predictive value, 17.6%; and negative predictive value, 98.6%. Tumor DNA sequencing data confirmed the MIPOGG recommendation for CPS evaluation in 20 of 22 patients with established cancer-CPS associations.

Conclusions and Relevance

In this diagnostic study, MIPOGG exhibited a favorable accuracy profile for CPS screening and reduced time to CPS recognition. These findings suggest that MIPOGG implementation could standardize and rationalize recommendations for CPS evaluation in children with cancer.

Locus-of-care disparities in end-of-life care intensity among adolescents and young adults with cancer: A population-based study using the IMPACT cohort

BACKGROUND

Adolescents and young adults (AYAs) with cancer may experience elevated rates of high-intensity end-of-life (HI-EOL) care. Locus-of-care (LOC) disparities (pediatric vs adult) in AYA end-of-life (EOL) care are unstudied.

METHODS

A decedent population-based cohort of Ontario AYAs diagnosed between 1992 and 2012 at the ages of 15 to 21 years was linked to administrative data. The authors determined the prevalence and associations of a composite outcome of HI-EOL care that included any of the following: intravenous chemotherapy within 14 days of death, more than 1 emergency department visit, more than 1 hospitalization, or an intensive care unit (ICU) admission within 30 days of death. Secondary outcomes included measures of the most invasive EOL care (ventilation within 14 days of death and ICU death) and in-hospital death.

RESULTS

There were 483 decedents: 60.5% experienced HI-EOL care, 20.3% were ventilated, and 22.8% died in the ICU. Compared with patients with solid tumors, patients with hematological malignancies had the greatest odds of HI-EOL care (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.5-3.4), ventilation (OR, 4.7; 95% CI, 2.7-8.3), and ICU death (OR, 4.4; 95% CI, 2.6-4.4). Subjects treated in pediatric centers versus adult centers near death (OR, 2.4; 95% CI, 1.2-4.8) and those living in rural areas (OR, 2.1; 95% CI, 1.1-3.9) were more likely to experience ICU death.

CONCLUSIONS

AYAs with cancer experience high rates of HI-EOL care, with patients in pediatric centers and those living in rural areas having the highest odds of ICU death. This study is the first to identify LOC-based disparities in EOL care for AYAs, and it highlights the need to explore the mechanisms underlying these disparities.

Ultra high-risk PFA ependymoma is characterized by loss of chromosome 6q

BACKGROUND

Within PF-EPN-A, 1q gain is a marker of poor prognosis, however, it is unclear if within PF-EPN-A additional cytogenetic events exist which can refine risk stratification.

METHODS

Five independent non-overlapping cohorts of PF-EPN-A were analyzed applying genome-wide methylation arrays for chromosomal and clinical variables predictive of survival.

RESULTS

Across all cohorts, 663 PF-EPN-A were identified. The most common broad copy number event was 1q gain (18.9%), followed by 6q loss (8.6%), 9p gain (6.5%), and 22q loss (6.8%). Within 1q gain tumors, there was significant enrichment for 6q loss (17.7%), 10q loss (16.9%), and 16q loss (15.3%). The 5-year progression-free survival (PFS) was strikingly worse in those patients with 6q loss, with a 5-year PFS of 50% (95% CI 45%-55%) for balanced tumors, compared with 32% (95% CI 24%-44%) for 1q gain only, 7.3% (95% CI 2.0%-27%) for 6q loss only and 0 for both 1q gain and 6q loss (P = 1.65 × 10-13). After accounting for treatment, 6q loss remained the most significant independent predictor of survival in PF-EPN-A but is not in PF-EPN-B. Distant relapses were more common in 1q gain irrespective of 6q loss. RNA sequencing comparing 6q loss to 6q balanced PF-EPN-A suggests that 6q loss forms a biologically distinct group.

CONCLUSIONS

We have identified an ultra high-risk PF-EPN-A ependymoma subgroup, which can be reliably ascertained using cytogenetic markers in routine clinical use. A change in treatment paradigm is urgently needed for this particular subset of PF-EPN-A where novel therapies should be prioritized for upfront therapy.

Canadian Pediatric Neuro-Oncology Standards of Practice

Primary CNS tumors are the leading cause of cancer-related death in pediatrics. It is essential to understand treatment trends to interpret national survival data. In Canada, children with CNS tumors are treated at one of 16 tertiary care centers. We surveyed pediatric neuro-oncologists to create a national standard of practice to be used in the absence of a clinical trial for seven of the most prevalent brain tumors in children. This allowed description of practice across the country, along with a consensus. This had a multitude of benefits, including understanding practice patterns, allowing for a basis to compare in future research and informing Health Canada of the current management of patients. This also allows all children in Canada to receive equivalent care, regardless of location.

LGG-19. SPINAL LOW-GRADE GLIOMAS IN CANADIAN CHILDREN: A MULTI-CENTRE RETROSPECTIVE REVIEW

PURPOSE

Primary spinal low-grade gliomas (LGGs) are rare, can be difficult to treat, and can result in significant morbidity. The management of pediatric spinal LGGs remains controversial.

METHODS

A national multi-centre retrospective review of spinal LGGs diagnosed in children less than 18 years of age between 1990–2015 was undertaken to examine the clinical features, pathological subtypes, and treatment outcomes.

RESULTS

Forty-three patients from five institutions were included. The median age of diagnosis was 5.2 years. All patients were symptomatic at diagnosis. Forty-four percent of patients were diagnosed at least 6 months after symptoms developed. Two patients had metastatic disease at diagnosis. The most common histology was pilocytic astrocytoma (48.8%). Molecular information was available for 15/43 patients: 6 patients had BRAF fusions and 4 patients had BRAF V600E mutations. Gross-total resection was achievable in only 6 patients. Twenty-seven patients were treated with surgery-only and the others received chemotherapy and/or focal radiation. Eleven patients were irradiated. No patients were registered in clinical trials for first-line therapy. Twenty-three patients experienced relapse or progression. Patients were followed for a median of 8.3 years (range, 0.5–20.4 years). Five-year progression-free survival (PFS) and overall survival (OS) rates were 48.3% (95% CI, 32.3% to 62.5%) and 89.7% (95% CI, 74.6% to 96.1%) respectively.

CONCLUSION

There is significant heterogeneity in surgical outcomes and treatment modalities of pediatric spinal LGGs. The PFS and OS rates remain suboptimal, likely due to tumor location. The low clinical trial enrollment rate highlights the paucity of available trials for spinal LGGs.

Prevalence and predictors of high-intensity end-of-life care among adolescents and young adults with cancer in Ontario: a population-based study using the IMPACT cohort

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Background: End-of-life (EOL) care in adolescents and young adults (AYA) with cancer is poorly characterized, though this group may be at risk of elevated rates of high-intensity (HI) care and consequently, increased EOL suffering. Few population-based studies exist, and are limited by incomplete clinical information. AYA care patterns can vary by locus of care (LOC – pediatric v. adult), but LOC disparities in AYA EOL care are unstudied. Methods: We conducted a retrospective decedent population-based cohort study of all Ontario AYA diagnosed between 15-21 years of age with 6 prevalent primary cancers between 1992-2012, who died ≤5 years from diagnosis. Chart-abstracted clinical data were linked to health services data. The primary composite outcome (HI-EOL care) included any of: intravenous chemotherapy ≤14 days from death; > 1 emergency department visit ≤30 days from death; or > 1 hospitalization or intensive care unit (ICU) admission ≤30 days from death. Secondary outcomes included measures of the most invasive (MI) EOL care: mechanical ventilation ≤14 days from death, and death in the ICU. Factors associated with HI-EOL were examined. Results: Of 483 patients, 292 (60.5%) experienced HI-EOL care, 98 (20.3%) were mechanically ventilated ≤14 days from death, and 110 (22.8%) died in the ICU. Patients with hematological malignancies (v. solid tumors) were at greatest risk of HI-EOL care (OR, 2.3; 95CI, 1.5-3.5, p < 0.01), mechanical ventilation (OR, 5.4; 95CI, 3.0-9.7, p < 0.01), and death in an ICU (OR, 4.9; 95CI, 2.8-8.5, p < 0.01). AYA who died in a pediatric center were substantially more likely to experience MI-EOL measures compared to those dying in adult centers (mechanical ventilation, OR 3.2, 95CI 1.3-7.6, p = 0.01). Assessment of interactions showed LOC-based disparities widening over the study period (ICU death in pediatric v. adult centres: early period OR 0.9, 95CI 0.3-2.9, p = 0.91; late period OR 3.3, 95CI 1.2-9.2, p = 0.02; interaction term p = 0.04). AYA living in rural areas were also at higher risk of experiencing mechanical ventilation (OR, 2.0; 95CI, 1.0-3.8, p = 0.04) and death in ICU (OR, 2.1; 95CI, 1.1-4.0, p = 0.02). Conclusions: AYA with cancer experience high rates of HI-EOL care, with patients in pediatric centers and those living in rural areas at highest risk of MI-EOL care. Our study is the first to identify LOC-based disparities in AYA EOL care. Future studies should explore mechanisms underlying these disparities, including potential differences in palliative care services.

Cancer risk in children and young adults born preterm: A systematic review and meta-analysis

Introduction

Risk of developing a malignancy when born premature is unknown. We hypothesised that risk of certain cancers might be increased in youth born preterm versus term. We therefore performed a systematic review and meta-analysis to evaluate the incidence of malignancy in the context of preterm birth, according to various cancer types.

Methods

The study was designed per MOOSE and PRISMA guidelines. Articles were identified through November 2015. Observational studies exploring the association between childhood malignancy and birth characteristics were included. Of the 1658 records identified, 109 full text articles were evaluated for eligibility. Random effects meta-analyses were conducted on 10/26 studies retained; 95% confidence intervals were computed and adjusted following sensitivity analysis. Publication bias was evaluated using funnel plots, Begg’s and Egger’s tests.

Results

No differences in risk of primary central nervous system tumor [OR 1.05; 95% CI 0.93–1.17, 5 studies, 580 cases] and neuroblastoma [OR 1.09; 95% CI 0.90–1.32, 5 studies, 211 cases] were observed in individuals born <37 versus ≥37 weeks’ gestation. Preterm birth was consistently associated with hepatoblastoma [ORs 3.12 (95% CI 2.32–4.20), 1.52 (95% CI 1.1–2.1), 1.82 (95% CI 1.01–3.26), and 2.65 (95% CI 1.98–3.55)], but not leukemia, astrocytoma, ependymoma, medulloblastoma, lymphoma, nephroblastoma, rhabdomyosarcoma, retinoblastoma or thyroid cancer.

Conclusions

Children born premature may be at increased risk for hepatoblastoma but there is no strong evidence of an increased risk of primary central nervous system tumours or neuroblastoma. There is insufficient evidence to conclude whether prematurity modulates the risk of other childhood cancers.

The McGill Interactive Pediatric OncoGenetic Guidelines: An approach to identifying pediatric oncology patients most likely to benefit from a genetic evaluation

Identifying cancer predisposition syndromes in children with tumors is crucial, yet few clinical guidelines exist to identify children at high risk of having germline mutations. The McGill Interactive Pediatric OncoGenetic Guidelines project aims to create a validated pediatric guideline in the form of a smartphone/tablet application using algorithms to process clinical data and help determine whether to refer a child for genetic assessment. This paper discusses the initial stages of the project, focusing on its overall structure, the methodology underpinning the algorithms, and the upcoming algorithm validation process.