Refining M1 stage in medulloblastoma: criteria for cerebrospinal fluid cytology and implications for improved risk stratification from the HIT-2000 trial.

BACKGROUND: Medulloblastoma is the most common malignant paediatric brain tumour, and cerebrospinal fluid (CSF) dissemination (M1 stage) is a high-risk prognostic factor. Criteria for CSF evaluation and for differentiating M0 from M1 stage are not clearly defined, and the prognostic significance of M1 stage in this context is unknown. PATIENTS AND METHODS: CSF investigations from 405 patients with medulloblastoma of the prospective multicenter trial HIT-2000 (HIirnTumor-2000) were reviewed. Data from 213 patients aged ≥4 years were related to 5-year progression-free (5y-PFS) and overall survival. RESULTS: Patients with cytological tumour dissemination only (M1 stage only) aged ≥4 years (n = 18) and patients with radiologically detected metastases (M2/3, n = 85) showed a worse 5y-PFS than M0 patients (n = 110) without signs of metastatic disease (5y-PFS 61.1% and 59.6% vs 80.7%; p < 0.02 and p < 0.01, log rank). Patients with positive samples drawn early after surgery who turned negative within 14 days postoperatively (n = 9) and patients with atypical cells (n = 6) showed a 5y-PFS similar to M0 patients. No tumour cells were detected in samples containing <10 nucleated cells. Analysis of cytological criteria showed a better predictive value for tumour cell clusters than ≥2 individual tumour cells. CONCLUSION: Based on our results, we suggest that CSF medulloblastoma staging should be performed 14 days postoperatively by lumbar puncture, and specimens should contain at least 10 nucleated cells. Cytological tumour dissemination alone (M1 stage only) appears a high-risk prognostic factor associated with an outcome comparable to M2/M3 stage. Tumour cell clusters seem to have a greater impact on prognosis than single tumour cells. This should be validated further.

Clinical and molecular characterization of isolated M1 disease in pediatric medulloblastoma: experience from the German HIT-MED studies.

PURPOSE: To evaluate the clinical impact of isolated spread of medulloblastoma cells into cerebrospinal fluid without additional macroscopic metastases (M1-only). METHODS: The HIT-MED database was searched for pediatric patients with M1-only medulloblastoma diagnosed from 2000 to 2019. Corresponding clinical and molecular data was evaluated. Treatment was stratified by age and changed over time for older patients. RESULTS: 70 patients with centrally reviewed M1-only disease were identified. Clinical data was available for all and molecular data for 45/70 cases. 91% were non-WNT/non-SHH medulloblastoma (Grp3/4). 5-year PFS for 52 patients ≥ 4 years was 59.4 (± 7.1) %, receiving either upfront craniospinal irradiation (CSI) or SKK-sandwich chemotherapy (CT). Outcomes did not differ between these strategies (5-year PFS: CSI 61.7 ± 9.9%, SKK-CT 56.7 ± 6.1%). For patients < 4 years (n = 18), 5-year PFS was 50.0 (± 13.2) %. M1-persistence occurred exclusively using postoperative CT and was a strong negative predictive factor (pPFS/OS < 0.01). Patients with additional clinical or molecular high-risk (HR) characteristics had worse outcomes (5-year PFS 42.7 ± 10.6% vs. 64.0 ± 7.0%, p = 0.03). In n = 22 patients ≥ 4 years with full molecular information and without additional HR characteristics, risk classification by molecular subtyping had an effect on 5-year PFS (HR 16.7 ± 15.2%, SR 77.8 ± 13.9%; p = 0.01). CONCLUSIONS: Our results confirm that M1-only is a high-risk condition, and further underline the importance of CSF staging. Specific risk stratification of affected patients needs attention in future discussions for trials and treatment recommendations. Future patients without contraindications may benefit from upfront CSI by sparing risks related to higher cumulative CT applied in sandwich regimen.

Treatment of embryonal tumors with multilayered rosettes with carboplatin/etoposide induction and high-dose chemotherapy within the prospective P-HIT trial.

BACKGROUND: Embryonal tumors with multilayered rosettes (ETMR) are highly aggressive tumors occurring in early childhood. Published clinical data refer to retrospective, heterogeneously treated cohorts. Here, we describe the outcome of patients treated according to the prospective P-HIT trial and subsequent HIT2000-interim-registry. PATIENTS AND METHODS: Age-stratified treatment included carboplatin/etoposide induction, tandem high-dose chemotherapy ("CARBO/ETO + HDCT"), and response-stratified radiotherapy. Patients with centrally reviewed neuropathological and molecularly confirmed diagnosis of ETMR recruited within the P-HIT trial (2001-2011; n = 19), the HIT2000-interim-registry (2012-2014; n = 12), and earlier HIT trials (n = 4) were selected for analysis. RESULTS: Age-adjusted incidence rate was 1.35 per 1 million children (aged 1-4 years) in the years 2012-2014. Median age at diagnosis for 35 patients was 2.9 years. Metastases at diagnosis were detected in 9 patients. One patient died due to postoperative complications. For 30 patients with non-brainstem tumor location, 5-year progression-free survival (PFS) and overall survival (OS) were 35% and 47% after treatment with CARBO/ETO + HDCT (n = 17), compared to 0% and 8% with other treatments (n = 13, P[OS] = .011). All 4 patients with brainstem tumor died within 10 months after diagnosis. By multivariable analysis, supratentorial location: (HR [PFS]: 0.07 [95%CI: 0.01-0.38], P = .003), localized disease (M0): (HR [OS] M0, no residual tumor: 0.30 [95%CI: 0.009-1.09], P = .068; M0, residual tumor: 0.18 [95%CI: 0.04-0.76], P = .020), and CARBO/ETO + HDCT treatment (HR [OS]: 0.16 [95%CI: 0.05-054], P = .003) were identified as independent prognostic factors. Of 9 survivors, 6 were treated with radiotherapy (craniospinal 4; local 2). CONCLUSIONS: Our data indicate improved survival with intensified chemotherapy (CARBO/ETO + HDCT). However, despite intensive treatment, the outcome was poor. Thus, innovative therapies need to be evaluated urgently in an upfront setting.

Evaluation of age-dependent treatment strategies for children and young adults with pineoblastoma: analysis of pooled European Society for Paediatric Oncology (SIOP-E) and US Head Start data.

Background: Pineoblastoma is a rare pineal region brain tumor. Treatment strategies have reflected those for other malignant embryonal brain tumors. Patients and Methods: Original prospective treatment and outcome data from international trial groups were pooled. Cox regression models were developed considering treatment elements as time-dependent covariates. Results: Data on 135 patients with pineoblastoma aged 0.01-20.7 (median 4.9) years were analyzed. Median observation time was 7.3 years. Favorable prognostic factors were age ≥4 years (hazard ratio [HR] for progression-free survival [PFS] 0.270, P < .001) and administration of radiotherapy (HR for PFS 0.282, P < .001). Metastatic disease (HR for PFS 2.015, P = .006), but not postoperative residual tumor, was associated with unfavorable prognosis. In 57 patients <4 years old, 5-year PFS/overall survival (OS) were 11 ± 4%/12 ± 4%. Two patients survived after chemotherapy only, while 3 of 16 treated with craniospinal irradiation (CSI) with boost, and 3 of 5 treated with high-dose chemotherapy (HDCT) and local radiotherapy survived. In 78 patients aged ≥4 years, PFS/OS were 72 ± 7%/73 ± 7% for patients without metastases, and 50 ± 10%/55 ± 10% with metastases. Seventy-three patients received radiotherapy (48 conventionally fractionated CSI, median dose 35.0 [18.0-45.0] Gy, 19 hyperfractionated CSI, 6 local radiotherapy), with (n = 68) or without (n = 6) chemotherapy. The treatment sequence had no impact; application of HDCT had weak impact on survival in older patients. Conclusion: Survival is poor in young children treated without radiotherapy. In these patients, combination of HDCT and local radiotherapy may warrant further evaluation in the absence of more specific or targeted treatments. CSI combined with chemotherapy is effective for older non-metastatic patients.

Cell-specific expression of uptake transporters--a potential approach for cardiovascular drug delivery devices.

Enhanced proliferation of human coronary artery smooth muscle cells (HCASMCs) and thereby formation of neointima is one of the factors contributing to failure of coronary stents. Even if the use of drug eluting stents (DES) and thereby the local delivery of cytotoxic compounds has significantly improved the clinical outcome, unselective cytotoxic effects are assumed to hamper clinical success. Novel pharmacological approaches are required to enhance cellular selectivity of locally delivered drugs. Cell specific overexpression of a drug transporter could be used to enhance cellular accumulation and therefore cell specificity. In the herein reported study we tested the possibility of cell specific transporter expression to enhance drug effects in HCASMCs. We generated adenoviral constructs to overexpress the organic cation transporter 1 (OCT1) under control of the promoter of SM22α, which had been previously reported as muscle cell specific gene. First the activity of the SM22α-promoter was assessed in various cell types supporting the notion of muscle cell specificity. Subsequently, the activity of the transporter was compared in infected HCAECs and HCASMCs revealing enhanced accumulation of substrate drugs in HCASMCs in presence of the SM22α-promoter. Testing the hypothesis that this kind of targeting might serve as a mechanism for cell-specific drug effects, we investigated the impact on paclitaxel treatment in HCASMC and HCAECs, showing significantly increased antiproliferative activity of this substrate drug on muscle cells. Taken together, our findings suggest that cell-specific expression of transport proteins serves as mechanism governing the uptake of cytotoxic compounds for a selective impact on targeted cells.