Clinical and genomic features in patients with second primary glioblastoma following first primary renal cell carcinoma.

PURPOSE: To explore the potential pathogenesis and clinical features of second primary glioblastoma (spGBM) following first primary renal cell carcinoma (fpRCC). METHODS: Patients with spGBM after fpRCC were enrolled from our institution and the SEER dataset. Sanger sequencing, whole genome sequencing, and immunehistochemistry were used to detect molecular biomarkers. RESULTS: Four and 122 cases from our institution and the SEER dataset, respectively, were collected with an overall median age of 69 years at spGBM diagnosis following fpRCC. The median interval time between fpRCC and spGBM was 50.7 months and 4 years, for the four and 122 cases respectively. The median overall survival time was 11.2 and 6.0 months for the two datasets. In addition, spGBM patients of younger age (< 75 years) or shorter interval time (< 1 year) had favorable prognosis (p = 0.081 and 0.05, respectively). Moreover, the spGBM cases were molecularly classified as TERT only paired with TP53 mutation, PIK3CA mutation, EGFR alteration, low tumor mutation burden, and stable microsatellite status. CONCLUSIONS: This is the first study to investigate the pathogenesis and clinical features of spGBM following spRCC. We found that spGBMs are old-age related, highly malignant, and have short survival time. Moreover, they might be misdiagnosed and treated as brain metastases from RCC. Thus, the incidence of spGBMs after fpRCC is underestimated. Further studies are needed to investigate the underlying molecular mechanisms and clinical biomarkers for the development of spGBM following fpRCC.

Free Flap Transfer, a Safe and Efficient Method for Reconstruction of Composite Skull Base Defects After Salvage Resection of Advanced Intracranial and Extracranial Communicating Tumors.

OBJECTIVE: Surgical treatment of advanced intracranial and extracranial communicating skull base tumors is challenging, especially for the reconstruction of the large composite defect left by tumor resection. The aim of the study is to evaluate the utility of the free flap reconstruction of the defects resulting from radical resection of these tumors in a single institution. METHODS: The clinical data of 17 consecutive patients who underwent free flap reconstruction for defect left by salvage resection of advanced intracranial and extracranial communicating tumors from 2013 to 2019 were retrospectively collected and analyzed. RESULTS: There were 5 squamous cell carcinomas, 4 adenoid cystic carcinomas, 2 basal cell carcinomas, 2 meningiomas, 1 anaplastic hemangiopericytoma, 1 pleomorphic adenoma, 1 osteosarcoma, and 1 chondrosarcoma. All patients had recurrent neoplasms, 2 of whom had pulmonary metastasis. A modified radical cervical dissection was performed in 6 patients. The anterolateral thigh myocutaneous flap and rectus abdominis myocutaneous flap were used in 15 patients (88.2%) and 2 patients (11.8%), respectively. Complications were seen in 3 of 17 patients (17.6%) with 1 total flap loss. The median progression-free survival duration was 31 months. The 3- and 5-year progression-free survival rates were 0.47 and 0.24, respectively. The mean overall survival duration was 66 months. The 3- and 5-year overall survival rates were 0.85 and 0.68, respectively. CONCLUSIONS: Free flap transfer is a safe and effective method with acceptable complications, useful for reconstruction of large composite skull base defects after salvage resection of advanced intracranial and extracranial communicating tumors. The functional and cosmetic results are satisfying.

Identifying Predictive Gene Expression and Signature Related to Temozolomide Sensitivity of Glioblastomas.

Temozolomide (TMZ) is considered a standard chemotherapeutic agent for glioblastoma (GBM). Characterizing the biological molecules and signaling pathways involved in TMZ sensitivity would be helpful for selecting therapeutic schemes and evaluating prognosis for GBM. Thus, in the present study, we selected 34 glioma cell lines paired with specific IC50 values of TMZ obtained from CancerRxGene and RNA-seq data downloaded from the Cancer Cell Line Encyclopedia to identify genes related to TMZ sensitivity. The results showed that 1,373 genes were related to the response of GBM cells to TMZ. Biological function analysis indicated that epithelial-mesenchymal transition, Wnt signaling, and immune response were the most significantly activated functions in TMZ-resistant cell lines. Additionally, negative regulation of telomere maintenance via telomerase was enriched in TMZ-sensitive glioma cell lines. We also preliminarily observed a synergistic effect of combination treatment comprising TMZ and a telomerase inhibitor in vitro. We identified six genes (MROH8, BET1, PTPRN2, STC1, NKX3-1, and ARMC10) using the random survival forests variable hunting algorithm based on the minimum error rate of the gene combination and constructed a gene expression signature. The signature was strongly related to GBM clinical characteristics and exhibited good prognosis accuracy for both The Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) datasets. Patients in the high score group had a shorter survival time than those in the low score group (11.2 vs. 22.2 months, hazard ratio = 7.31, p = 4.59e-11) of the TCGA dataset. The CGGA dataset was selected as a validation group with 40 patients in the high score set and 43 patients in the low score set (12.5 vs. 28.8 months, hazard ratio = 3.42, p = 8.61e-5). Moreover, the signature showed a better prognostic value than MGMT promoter methylation in both datasets. We also developed a nomogram for clinical use that integrated the TMZ response signature and four other risk factors to individually predict patient survival after TMZ chemotherapy. Overall, our study provides promising therapeutic targets and potential guidance for adjuvant therapy of GBM.