P14.04 10 years of weekly web conference for brain tumor of Adolescent/Young Adult (AYA) on behalf of ANOCEF, GO-AJA and SFCE societies

BACKGROUND

The skills of adult versus pediatric neuro-oncologists are not completely similar though additive. Because the tumors and their protocols are different and the tolerance and expected sequelae are specific. Multidisciplinary meetings including adult and pediatric neuro oncologists are warranted to share expertise.

MATERIAL AND METHODS

Since 2008, on behalf of ANOCEF, GO-AJA and SFCE societies, a weekly national web based conference was held in France. Any patient with the following criteria could be discussed: Adolescent and Young Adults aged between 15 and 25 years, and any adult with a pediatric type pathology, including medulloblastoma, germ cell tumors, embryonic tumors, ependymoma, pilocytic astrocytoma.

RESULTS

Number of cases discussed increased from 8 to 202/year, with a mean number of 3 cases (1 to 7) discussed at each meeting. In 2018, 36 meetings were held, with a mean of 8 participants (2 to 14) issued from various French centers. 168 cases were discussed in 2018. Mean age was 30 years old (7 to 67). 45% were discussed at diagnosis; The patients had mostly medulloblastomas (n=47), ependymomas (n=24), low (n=21) or high grade gliomas (n=11), pineal tumors (n=20), germ cell tumors (n=9) and embryonal tumors (n=6). The rate of inclusion in protocols was increased since the opening of this web conference, especially for the germ cell tumor GCT SIOP protocol that is opened without age restriction, and in RSMA standard risk or MEVITEM relapse adult medulloblastoma protocols.

CONCLUSION

Multidisciplinary Web conference for AYAs is feasible and fruitful. It shares knowledge and increases the inclusion rate in protocols. It should be developped further.

OS4.1 MEVITEM: A European, randomized, open-label, Phase I/II study of vismodegib in combination with temozolomide versus temozolomide alone in adult patients with recurrent or refractory medulloblastoma presenting an activation of the Sonic Hedgehog (SHH) pathway

BACKGROUND

Vismodegib (V) suppresses sonic hedgehog (SHH) signaling. We postulated that vismodegib together with chemotherapy may be more efficient than chemotherapy alone in patients (pts) relapsing of a SHH-activated medulloblastoma (MB).

MATERIAL AND METHODS

Adult pts with recurrent SHH-MB not previously exposed to temozolomide (T) were randomly assigned (2:1 ratio) to Arm A (V daily 150mg/d, po) + T (D1-5: 150 mg/m2 for cycle 1 and 200 mg/m2 thereafter; n=up to 25pts) or Am B (T alone; n=up to 13pts). Identification of SHH activation was performed centrally by IHC (GAB1, β-catenin, filamin A, and YAP1). NGS analyses were performed to identify the mutations responsible for SHH activation. Primary objectives were to assess the incidence of severe toxicities (safety run-in based on a 3 + 3 design) and the 6-month non-progression rate (NPR-6m) according to WHO criteria and based on central read tumor assessment (Phase II). A Minimax Simon’s two-stage design was used to detect NPR-6m of 55% (p0: 30%, type I error rate of 5%, power of 80%). At first stage, ≥ 3/9 pts without progression at 6m were required for the accrual of 16 additional pts in Arm A. A 3rd independent and parallel arm with V as single agent (Arm C, n= up to15pts) was added for pts previously treated by T.

RESULTS

24 SHH-MB pts were enrolled (Arm A: 10, Arm B: 5 and Arm C: 9; median age: 37 y [21–55]). At the end of the safety run-in; no major safety concerns were reported. At the end of Stage I: no objective response were reported and 2 pts among 10 were free of progression at 6m among in Arm A. According to statistical rules, the study was definitively closed to enrolment. NGS analyses showed a PTCH1 inactivating mutation in 6 pts (n=4 in arm A; n= 2 in arm B); a SMO activating mutation in 4 pts (n= 3 in Arm A; n=1 in Arm B). For 1 pt in each arm, no tumor sample was available for analysis, for 1 pt in Arm A DNA quality was insufficient, and for 1 patient in each arm no mutations of SMO, PTCH1, SUFU or SHH were found. Out of the 4 pts in Arm A with an inactivating PTCH1 mutation, only 1 was progression free at 6m. PFS and OS data will be presented at the meeting.

CONCLUSION

The combination of vismodegib with monthly T failed to demonstrate superior activity as compared with T alone. Further studies are warranted to refine therapeutic indication for vismodegib

Diffusion-weighted imaging in brain aspergillosis

Brain aspergillosis is a rare pathology, occurring mainly in immunocompromised patients, responsible for multiple cerebral septic infarctions. Some researchers have described magnetic resonance (MR) findings in cerebral invasive aspergillosis, but diffusion-weighted imaging (DWI) has rarely been reported, especially in typical non-enhancing lesions, while it may be helpful for early differential diagnosis and may allow earlier antifungal treatment. We describe three cases of patients presenting brain aspergillosis, with MR imaging including diffusion-weighted sequences and apparent diffusion coefficient (ADC) cartography. The three patients described in this study presented a total of 23 circular lesions, and one patient presented an infarction area in the territory of the right middle cerebral artery. Lesions were ring-enhancing for one patient, and presented no enhancement for the other two. Eleven lesions were very bright on DWI, with reduced ADC values. Twelve lesions, either enhancing or not enhancing, presented a 'target-like' aspect with central and peripheral hypointense areas on DWI, corresponding to higher ADC value areas, and intermediate marked hypersignal on DWI. This typical aspect of aspergillosis lesions on DWI may allow early diagnosis and treatment of cerebral aspergillosis, and is helpful for differentiating aspergillosis lesions from other infectious or malignant lesions affecting immunocompromised patients.

Ultrastructural pathology of prion diseases revisited: brain biopsy studies

We report here a detailed ultrastructural comparison of brain biopsies from 13 cases of Creutzfeldt-Jakob disease (CJD) and from one case of fatal familial insomnia (FFI). The latter disease has not heretofore benefited from ultrastructural study. In particular, we searched for tubulovesicular structures (TVS), 35-nm particles regarded as the only disease-specific structures at the level of thin-section electron microscopy. Our material consisted of brain biopsies obtained by open surgery from one FFI case from a new French family, one case of variant CJD (vCJD), nine cases of sporadic CJD (sCJD), two cases of iatrogenic (human growth hormone) CJD and one case of hereditary CJD (Val203Iso). The ultrastructural picture of the cerebral cortex of the FFI patient was virtually indistinguishable from that of CJD. TVS were found, albeit only after prolonged search. Typical spongiform change was observed, consisting of intracellular membrane-bound vacuoles containing secondary chambers (vacuoles within vacuoles) and amorphous material. Neuronal degeneration was widespread: some processes contained degenerating mitochondria and lysosomal electron-dense bodies and these met the criteria for neuroaxonal dystrophy. Other processes contained branching cisterns; still others were filled with electron-dense masses and amorphous vesicles. The overall ultrastructural appearance of variant CJD was similar to that of FFI cerebral cortex, except for a much higher number of cellular processes containing TVS. We detected TVS in the majority of sCJD cases that, in addition to typical spongiform change and robust astrocytic reaction, showed widespread neuritic and synaptic degeneration and autophagic vacuoles. We conclude that TVS are readily found in FFI, vCJD and sCJD and that widespread neuritic degeneration is a part of ultrastructural pathology in prion diseases.

Circumstances of death and gross and microscopic observations in a series of 200 cases of sudden death associated with arrhythmogenic right ventricular cardiomyopathy and/or dysplasia

BACKGROUND

Sudden death is a possible consequence of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D). Prevalence of ARVC/D in unexpected sudden cardiac death (USCD), however, remains imprecise, as do circumstances of death and ARVC/D-associated gross and microscopic findings, especially His bundle anomalies.

METHODS AND RESULTS

We reviewed 14 000 forensic autopsies required by judicial authorities from January 1980 to January 1999 in a 2 000 000-resident area. Age, gender, and circumstances of death were recorded. Hearts were examined macroscopically and microscopically. In this series, the ARVC/D group accounted for 200 consecutive cases (10.4%) of USCD, including 108 males and 92 females (average age 32.5 and 34.5 years, respectively). Nearly one third of deaths occurred during the fourth decade of life. Circumstances of death were various, but 75.6% occurred during everyday life events (at home, 63.1%; in the street, 6.6%; or at work, 6.1%); only 7 cases (3.5%) occurred during sports activity. Nineteen cases (9.5%) happened during the perioperative period. Adipose infiltration of the right ventricle was either isolated (20%) or associated with fibrosis (74.5%) and lymphocytes (5.5%). A total of 14.5% of cases had cardiac hypertrophy, assessed by an increase in heart weight and/or left ventricular wall thickness. In most cases, the His bundle and its branches were abnormal either because of infiltration of adipose tissue (8.1%), fibrosis (54.3%), or both (5.6%).

CONCLUSIONS

In ARVC/D, both sexes are equally affected, and there is a peak of risk during the fourth decade. Death most frequently occurs during sedentary activity. His abnormalities and left ventricular hypertrophy may be associated with ARVC/D.