Proof-of-Concept for Liquid Biopsy Disease Monitoring of MYC-Amplified Group 3 Medulloblastoma by Droplet Digital PCR.

BACKGROUND: Liquid biopsy diagnostic methods are an emerging complementary tool to imaging and pathology techniques across various cancer types. However, there is still no established method for the detection of molecular alterations and disease monitoring in MB, the most common malignant CNS tumor in the pediatric population. In the presented study, we investigated droplet digital polymerase chain reaction (ddPCR) as a highly sensitive method for the detection of MYC amplification in bodily fluids of group 3 MB patients. METHODS: We identified a cohort of five MYC-amplified MBs by methylation array and FISH. Predesigned and wet-lab validated probes for ddPCR were used to establish the detection method and were validated in two MYC-amplified MB cell lines as well as tumor tissue of the MYC-amplified cohort. Finally, a total of 49 longitudinal CSF samples were analyzed at multiple timepoints during the course of the disease. RESULTS: Detection of MYC amplification by ddPCR in CSF showed a sensitivity and specificity of 90% and 100%, respectively. We observed a steep increase in amplification rate (AR) at disease progression in 3/5 cases. ddPCR was proven to be more sensitive than cytology for the detection of residual disease. In contrast to CSF, MYC amplification was not detectable by ddPCR in blood samples. CONCLUSIONS: ddPCR proves to be a sensitive and specific method for the detection of MYC amplification in the CSF of MB patients. These results warrant implementation of liquid biopsy in future prospective clinical trials to validate the potential for improved diagnosis, disease staging and monitoring.

Improved Long-Term Survival of Patients with Recurrent Medulloblastoma Treated with a "MEMMAT-like" Metronomic Antiangiogenic Approach.

Medulloblastoma (MB) recurrence is usually incurable despite intensive therapy including high-dose chemotherapy. An evolving alternative approach to conventional chemotherapy aims at interfering with tumor angiogenesis at different levels. We report on a novel combinatorial metronomic antiangiogenic approach. The study is a retrospective observational study of 29 consecutive patients with first or multiple recurrences prospectively treated according to the MEMMAT strategy ("MEMMAT-like") before the formal protocol (MEMMAT; ClinicalTrials.gov Identifier: NCT01356290) started. The study period was 11/2006 to 06/2016. Treatment consisted of daily oral thalidomide, fenofibrate, celecoxib, and alternating 21-day cycles of low-dose oral etoposide and cyclophosphamide supplemented by IV bevacizumab and intraventricular therapy consisting of alternating etoposide and liposomal cytarabine. Median overall survival (OS) after recurrence for the whole group was 29.5 months, OS was 48.3 ± 9.3% at three years and 34.5 ± 8.8% at five years, and progression-free survival was 42.0 ± 9.5% at three years and 29.4 ± 9% at five years. As of 07/2022, 9/29 patients are alive 86 to 164 months after the recurrence that prompted the "MEMMAT-like" therapy. Treatment was primarily out-patient and generally well-tolerated. Toxicities did occur but were manageable. In conclusion, antiangiogenic therapy according to the MEMMAT strategy increased median OS of patients with recurrent MB and may lead to long-term survival. Adherence to the protocol, including intraventricular therapy, appears important.

First-Time Diagnosis After an Emergency Presentation in Children With Cancer.

AIM: To determine the prevalence rate of cancer diagnoses by an emergency route, the related risk factors and whether the emergency diagnosis was associated with poorer outcome. METHODS: Retrospective observational study with identification of patients diagnosed at the Pediatric Oncology Unit of "Sapienza" University between 2008 and 2018. The percentage of patients who received a first-time diagnosis after an emergency presentation was determined. Two-year survival and clinical factors, such as sex, age and histology, associated to emergency presentation were evaluated. RESULTS: Of 207 patients (109 girls and 98 boys; median age, 120 months), with a first-time diagnosis of solid tumor, 5.8% were diagnosed during an emergency admission after a median latency time of 2.5 days. Cases with an emergency diagnosis were younger compared with those who were diagnosed electively (median age, 30 months vs 120 months, P < 0.005). Higher prevalence rate of emergency presentation was detected in patients with lymphoma compared with those with no lymphoma disease (28.6% vs 4.1%; P < 0.0001). All patients were managed to overcome their emergency presentation, 33.3% of these died later. No statistically significant difference for 2-year overall survival was found between patients with an emergency diagnosis and those with elective diagnosis (66.7% vs 81.0%; odds ratio, 2.1; confidence interval, 0.6-7.5; P = 0.22). CONCLUSIONS: A minor but not negligible number of pediatric patients come to a first-time diagnosis of cancer as result of a life-threatening event; risk factors were younger age and lymphoma disease. The emergency event can be successfully treated, and it was not related to a poorer survival.