Metastases and death rates after primary enucleation of unilateral retinoblastoma in the USA 2007-2017.

BACKGROUND/AIMS: Enucleation for retinoblastoma is performed less often in the past decade due to increasingly widespread alternative therapies, but enucleation remains an important option. There is a paucity of reports on the current incidence of metastases and metastatic deaths in unilateral retinoblastoma from US centres. METHODS: Retrospective chart review at five tertiary retinoblastoma centres in the USA for unilateral retinoblastoma patients treated with primary enucleation, 2007-2017, with >1 year of follow-up or treatment failure. RESULTS: Among 228 patients (228 eyes), there were nine metastases (3.9%) and four deaths (1.7%). The Kaplan-Meier estimate at 5 years for metastasis-free survival was 96% (95% CI, 94% to 99 %), and for overall survival was 98% (95% CI 96% to 100%). All metastases were evident within 12 months. Histopathology revealed higher risk pathology (postlaminar optic nerve and/or massive choroidal invasion) in 62 of 228 eyes (27%). Of these higher risk eyes, 39 received adjuvant chemotherapy. There were four subsequent metastases in this higher risk pathology with adjuvant chemotherapy group, with three deaths. Of the nine overall with metastases, seven (78%) showed higher risk pathology. All metastatic patients were classified as Reese-Ellsworth V and International Classification of Retinoblastoma Groups D or E. Initial metastases presented as orbital invasion in seven of nine cases. CONCLUSIONS: Primary enucleation for unilateral retinoblastoma results in a low rate of metastatic death, but is still associated with a 3.9% chance of metastases within a year of enucleation. Most but not all patients who developed metastases had higher risk histopathological findings.

Novel activating BRAF fusion identifies a recurrent alternative mechanism for ERK activation in pediatric Langerhans cell histiocytosis.

Langerhans cell histiocytosis (LCH) is an inflammatory myeloid neoplasm characterized by constitutive activation of extracellular signal-regulated kinase (ERK). Genomic characterization has identified activating point mutations including mutually exclusive BRAFV600E and activating MAP2K1 mutations to be responsible for ERK activation in a majority of pediatric LCH patients. Here, we report the discovery of a novel BRAF kinase fusion, PACSIN2-BRAF, in a child with multisystem LCH. This is the second reported case of an activating BRAF kinase fusion and indicates a recurrent pathologic mechanism. Genomic evaluation for activating kinase fusions should be strongly considered in pediatric LCH patients lacking more common mutations.

Disease control and ototoxicity using intensity-modulated radiation therapy tumor-bed boost for medulloblastoma.

PURPOSE: We previously reported excellent local control for treating medulloblastoma with a limited boost to the tumor bed. In order to decrease ototoxicity, we subsequently implemented a tumor-bed boost using intensity-modulated radiation therapy (IMRT), the clinical results of which we report here. PATIENTS AND METHODS: A total of 33 patients with newly diagnosed medulloblastoma, 25 with standard risk, and 8 with high risk, were treated on an IMRT tumor-bed boost following craniospinal irradiation (CSI). Six standard-risk patients were treated with an institutional protocol with 18 Gy CSI in conjunction with intrathecal iodine-131-labeled monoclonal antibody. The majority of patients received concurrent vincristine and standard adjuvant chemotherapy. Pure-tone audiograms were graded according to National Cancer Institute Common Terminology Criteria for Adverse Events version 3.0. RESULTS: Median age was 9 years old (range, 4-46 years old). Median follow-up was 63 months. Kaplan-Meier estimates of progression-free survival (PFS) and overall survival (OS) rates for standard-risk patients who received 23.4 or 36 Gy CSI (not including those who received 18 Gy CSI with radioimmunotherapy) were 81.4% and 88.4%, respectively, at 5 years; 5-year PFS and OS rates for high-risk patients were both 87.5%. There were no isolated posterior fossa failures outside of the boost volume. Posttreatment audiograms were available for 31 patients, of whom 6%, at a median follow-up of 19 months, had developed Grade 3 hearing loss. CONCLUSION: An IMRT tumor-bed boost results in excellent local control while delivering a low mean dose to the cochlea, resulting in a low rate of ototoxicity.

Brainstem primitive neuroectodermal tumors (bstPNET): results of treatment with intensive induction chemotherapy followed by consolidative chemotherapy with autologous hematopoietic cell rescue.

We have evaluated the response rate and survival utilizing intensified chemotherapy followed by myeloablative chemotherapy with autologous hematopoietic cell rescue (AuHCR) and adjuvant radiation therapy in six young children with newly diagnosed brainstem primitive neuroectodermal tumors (bstPNET). Following maximum surgical resection of the tumor, patients received high dose induction chemotherapy including vincristine, cisplatin, cyclophosphamide, and etoposide. Eligible patients received a single cycle of myeloablative chemotherapy followed by AuHCR. Two patients survive at least 32 months with stable disease. This approach provides an alternative for young patients with bstPNET who in prior reports have had a uniformly fatal prognosis.