Accelerated tumor progression after COVID-19 infection in patients with glioblastoma: A retrospective case-control study.

Background: We observed rapid tumor progression following COVID-19 infection among patients with glioblastoma and sought to systematically characterize their disease course in a retrospective case-control study. Methods: Using an institutional database, we retrospectively identified a series of COVID-19-positive glioblastoma cases and matched them by age and sex 1:2 to glioblastoma controls who had a negative COVID-19 test during their disease course. Demographic and clinical data were analyzed. Hyperprogression was defined using modified response evaluation criteria in solid tumors criteria. Time to progression and overall survival were estimated using the Kaplan-Meier method. Results: Thirty-two glioblastoma cases with positive COVID-19 testing were matched to 64 glioblastoma controls with negative testing; age, sex, and molecular profiles did not differ between groups. Progression events occurred in 27 cases (84%) and 46 controls (72%). Of these, 14 cases (52%) presented with multifocal disease or leptomeningeal disease at progression compared with 10 controls (22%; P = .0082). Hyperprogression was identified in 13 cases (48%) but only 4 controls (9%; P = .0001). Cases had disease progression at a median of 35 days following COVID-19 testing, compared with 164 days for controls (P = .0001). Median survival from COVID-19 testing until death was 8.3 months for cases but 17 months for controls (P = .0016). Median overall survival from glioblastoma diagnosis was 20.7 months for cases and 24.6 months for controls (P = .672). Conclusions: Patients with glioblastoma may have accelerated disease progression in the first 2 months after COVID-19 infection. Infected patients should be monitored vigilantly. Future investigations should explore tumor-immune microenvironment changes linking tumor progression and COVID-19.

Intrathecal topotecan with systemic checkpoint inhibitor therapy for gastroesophageal cancer with leptomeningeal involvement: two case reports and review of the literature.

Background: Leptomeningeal metastases (LM) in gastroesophageal (GE) malignancies are exceedingly rare. Historically, treatment for LM has included steroids, radiation, chemotherapy, and intrathecal (IT) chemotherapy. However, the outcomes in GE malignancies with LM remain poor. Unfortunately, clinical trials in GE malignancies have traditionally excluded those with LM, limiting advances in therapeutic strategies. Given that LM poses potentially devastating neurologic and psychologic sequelae, there is an urgent need for more effective treatments. Case Description: Patient 1 is a 44-year-old woman with localized esophageal adenocarcinoma who undergoes neoadjuvant chemoradiation followed by esophagectomy. Seven months following surgery, she develops ataxia, weakness, and nausea/vomiting. Magnetic resonance imaging (MRI) reveals intracranial disease that is subsequently successfully resected and then treated with gamma knife (GK) radiation. Pathology confirms metastases. Three months later she is found to have LM. She receives palliative whole brain radiation therapy as well as focal radiation to the spine. Following this she transitioned to concurrent IT topotecan plus intravenous (IV) ipilumumab/nivolumab with durable response beyond 14 months. Patient 2 is a 71-year-old man with de novo metastatic esophageal adenocarcinoma with durable response to 5-fluorouracil plus irinotecan. Asymptomatic intracranial metastases are detected on surveillance scans 2 years after initial diagnosis for which he receives GK. Follow up MRI identifies new LM. As such, to treat the LM, he was transitioned to IT topotecan and IV pembrolizumab with good response for 6 months until death from a gastrointestinal bleed. Conclusions: We present two cases of LM in patients with GE adenocarcinoma who had longer survival than what has been reported. They were treated with combination IT topotecan and IV checkpoint inhibition. Further studies evaluating the central nervous system tumor immune-microenvironment can help expand our understanding of how this combination has worked well in our patients and how to care for others with similar scenarios.

Outcomes and Pattern of Care for Spinal Myxopapillary Ependymoma in the Modern Era-A Population-Based Observational Study.

(1) Background: Myxopapillary ependymoma (MPE) is a rare tumor of the spine, typically slow-growing and low-grade. Optimal management strategies remain unclear due to limited evidence given the low incidence of the disease. (2) Methods: We analyzed data from 1197 patients with spinal MPE from the Surveillance, Epidemiology, and End Results (SEER) database (2000-2020). Patient demographics, treatment modalities, and survival outcomes were examined using statistical analyses. (3) Results: Most patients were White (89.9%) with a median age at diagnosis of 42 years. Surgical resection was performed in 95% of cases. The estimated 10-year overall survival was 91.4%. Younger age (hazard ratio (HR) = 1.09, p < 0.001) and receipt of surgery (HR = 0.43, p = 0.007) were associated with improved survival. Surprisingly, male sex was associated with worse survival (HR = 1.86, p = 0.008) and a younger age at diagnosis compared to females. (4) Conclusions: This study, the largest of its kind, underscores the importance of surgical resection in managing spinal MPE. The unexpected association between male sex and worse survival warrants further investigation into potential sex-specific pathophysiological factors influencing prognosis. Despite limitations, our findings contribute valuable insights for guiding clinical management strategies for spinal MPE.

Metastatic extraneural glioblastoma diagnosed with molecular testing.

Glioblastoma, the most common malignant brain tumor in adults, is associated with a median overall survival duration of less than 2 years. Extraneural metastases occur in less than 1% of all patients with glioblastoma. The mechanism of extraneural metastasis is unclear. We present a case of extensive extraneural, extraosseous, epidural, and soft-tissue metastasis of glioblastoma. The diagnosis of metastatic glioblastoma was made only after next-generation sequencing (NGS) of the metastatic paraspinal lesions was completed. The CDK4, pTERT, PTEN, and TP53 molecular alterations seen in the initial intracranial glioblastoma were found in the paraspinal tumor, along with the addition of MYC, which is implicated in angiogenesis and epidermal-to-mesenchymal transition. Immunohistochemical stains showed that neoplastic cells were negative for GFAP. In conclusion, this case raises awareness about the role of NGS in the diagnosis of extraneural glioblastoma. This diagnosis was not possible with histology alone and only became evident after molecular profiling of the metastatic lesions and its comparison to the original tumor.

Genome-wide loss of heterozygosity predicts aggressive, treatment-refractory behavior in pituitary neuroendocrine tumors.

Pituitary neuroendocrine tumors (PitNETs) exhibiting aggressive, treatment-refractory behavior are the rare subset that progress after surgery, conventional medical therapies, and an initial course of radiation and are characterized by unrelenting growth and/or metastatic dissemination. Two groups of patients with PitNETs were sequenced: a prospective group of patients (n = 66) who consented to sequencing prior to surgery and a retrospective group (n = 26) comprised of aggressive/higher risk PitNETs. A higher mutational burden and fraction of loss of heterozygosity (LOH) was found in the aggressive, treatment-refractory PitNETs compared to the benign tumors (p = 1.3 × 10-10 and p = 8.5 × 10-9, respectively). Within the corticotroph lineage, a characteristic pattern of recurrent chromosomal LOH in 12 specific chromosomes was associated with treatment-refractoriness (occurring in 11 of 14 treatment-refractory versus 1 of 14 benign corticotroph PitNETs, p = 1.7 × 10-4). Across the cohort, a higher fraction of LOH was identified in tumors with TP53 mutations (p = 3.3 × 10-8). A machine learning approach identified loss of heterozygosity as the most predictive variable for aggressive, treatment-refractory behavior, outperforming the most common gene-level alteration, TP53, with an accuracy of 0.88 (95% CI: 0.70-0.96). Aggressive, treatment-refractory PitNETs are characterized by significant aneuploidy due to widespread chromosomal LOH, most prominently in the corticotroph tumors. This LOH predicts treatment-refractoriness with high accuracy and represents a novel biomarker for this poorly defined PitNET category.

Prolonged complete response to adjuvant tepotinib in a patient with newly diagnosed disseminated glioblastoma harboring mesenchymal-epithelial transition fusion.

The prognosis of patients with glioblastoma (GBM) remains poor despite current treatments. Targeted therapy in GBM has been the subject of intense investigation but has not been successful in clinical trials. The reasons for the failure of targeted therapy in GBM are multifold and include a lack of patient selection in trials, the failure to identify driver mutations, and poor blood-brain barrier penetration of investigational drugs. Here, we describe a case of a durable complete response in a newly diagnosed patient with GBM with leptomeningeal dissemination and PTPRZ1-MET fusion who was treated with tepotinib, a brain-penetrant MET inhibitor. This case of successful targeted therapy in a patient with GBM demonstrates that early molecular testing, identification of driver molecular alterations, and treatment with brain-penetrant small molecule inhibitors have the potential to change the outcome in select patients with GBM.

Therapeutic Strategies for Gliomas Associated With Cancer Predisposition Syndromes.

PURPOSE: The purpose of this article was to provide an overview of syndromic gliomas. DESIGN: The authors conducted a nonsystematic literature review. RESULTS: Cancer predisposition syndromes (CPSs) are genetic conditions that increase one's risk for certain types of cancer compared with the general population. Syndromes that can predispose one to developing gliomas include neurofibromatosis, Li-Fraumeni syndrome, Lynch syndrome, and tuberous sclerosis complex. The standard treatment for sporadic glioma may involve resection, radiation therapy, and/or alkylating chemotherapy. However, DNA-damaging approaches, such as radiation and alkylating agents, may increase the risk of secondary malignancies and other complications in patients with CPSs. In some cases, depending on genetic aberrations, targeted therapies or immunotherapeutic approaches may be considered. Data on clinical characteristics, therapeutic strategies, and prognosis of syndromic gliomas remain limited. CONCLUSION: In this review, we provide an overview of syndromic gliomas with a focus on management for patients with CPSs and the role of novel treatments that can be considered.

The risk and burden of thromboembolic and hemorrhagic events in patients with malignant gliomas receiving bevacizumab.

PURPOSE: Bevacizumab has evolved as an integral treatment option for patients with high-grade gliomas. Little is known about clinical risk factors that predispose patients with high-grade gliomas receiving bevacizumab to VTE or ICH. We sought to characterize the clinical risk factors associated with risk of either event. METHODS: In this multi-institutional retrospective study, we first evaluated patients with high-grade gliomas who were treated with bevacizumab at University of Texas MD Anderson Cancer Center from 2015-2021. We compared clinical and treatment-related factors among three cohorts: those who developed VTE, ICH, or neither. We further compared survival outcomes of these patients from the time of bevacizumab initiation. Then to further confirm our results in a non-cancer center hospital setting we evaluated patients from two Ascension Seton Hospitals in Austin, Texas which are affiliated with Dell Medical School at the University of Texas at Austin from 2017-2022. RESULTS: We found that the presence of cerebral macrobleeding, defined as a magnetic susceptibility of > 1 cm3 on magnetic resonance imaging, was highly associated with risk of developing ICH after initiation of bevacizumab. Development of ICH was significantly associated with poorer survival outcomes. We did not find a statistically significant effect of VTE on survival after bevacizumab initiation. CONCLUSION: In order to stratify the risk for developing ICH before the initiation of bevacizumab, we recommend to assess for the presence of cerebral macrobleeding as it is associated with ICH development.

The Role of Immunotherapy in the Treatment of Rare Central Nervous System Tumors.

Establishing novel therapies for rare central nervous system (CNS) tumors is arduous due to challenges in conducting clinical trials in rare tumors. Immunotherapy treatment has been a rapidly developing field and has demonstrated improvements in outcomes for multiple types of solid malignancies. In rare CNS tumors, the role of immunotherapy is being explored. In this article, we review the preclinical and clinical data of various immunotherapy modalities in select rare CNS tumors, including atypical meningioma, aggressive pituitary adenoma, pituitary carcinoma, ependymoma, embryonal tumor, atypical teratoid/rhabdoid tumor, and meningeal solitary fibrous tumor. Among these tumor types, some studies have shown promise; however, ongoing clinical trials will be critical for defining and optimizing the role of immunotherapy for these patients.

Recent Therapeutic Advances in Pituitary Carcinoma.

Pituitary carcinoma (PC) is a rare, aggressive malignancy that comprises 0.1-0.2% of all pituitary tumors. PC is defined anatomically as a pituitary tumor that metastasizes outside the primary intrasellar location as noncontiguous lesions in the central nervous system or as metastases to other organs. Similar to pituitary adenoma, PC originates from various cell types of the pituitary gland and can be functioning or nonfunctioning, with the former constituting the majority of the cases. Compression of intricate skull-based structures, excessive hormonal secretion, impaired pituitary function from therapy, and systemic metastases lead to debilitating symptoms and a poor survival outcome in most cases. PC frequently recurs despite multimodality treatments, including surgical resection, radiotherapy, and biochemical and cytotoxic treatments. There is an unmet need to better understand the pathogenesis and molecular characterization of PC to improve therapeutic strategies. As our understanding of the role of signaling pathways in the tumorigenesis of and malignant transformation of PC evolves, efforts have focused on targeted therapy. In addition, recent advances in the use of immune checkpoint inhibitors to treat various solid cancers have led to an interest in exploring the role of immunotherapy for the treatment of aggressive refractory pituitary tumors. Here, we review our current understanding of the pathogenesis, molecular characterization, and treatment of PC. Particular attention is given to emerging treatment options, including targeted therapy, immunotherapy, and peptide receptor radionuclide therapy.

Characterization of industry relationships in oncology.

BACKGROUND: Collaborative relationships between academic oncology and industry (pharmaceutical, biotechnology, "omic," and medical device companies) are essential for therapeutic development in oncology; however, limited research on engagement in and perceptions of these relationships has been done. METHODS: Survey questions were developed to evaluate relationships between academic oncology and industry. An electronic survey was delivered to 1000 randomly selected members of the American Society of Clinical Oncology, a professional organization for oncologists, eliciting respondents' views around oncology-industry collaborations. The responses were analyzed according to prespecified plans. RESULTS: There were 225 survey respondents. Most were from the United States (70.0%), worked at an academic institution (60.1%), worked in medical oncology (81.2%), and had an active relationship with industry (85.8%). One quarter (26.7%) of respondents reported difficulty establishing a relationship with industry collaborators, and most respondents (75%) did not report having had mentorship in developing these relationships. The majority (85.3%) of respondents considered these collaborations important to their careers. Respondents generally thought that scientific integrity was preserved (92%), and most respondents (95%) had little concern over the quality of the collaborative product. Many (60%) shared concerns over potential conflict of interest if an individual with a compensated relationship promoted an industry product for clinical care/research, yet most respondents (67%) stated these relationships did not shape their interactions with patients. CONCLUSIONS: This study provides novel data characterizing the nature of collaborative relationships between clinicians, researchers, and industry in oncology. Although respondents considered these collaborations an important part of clinical and academic oncology, formal education or mentorship around these relationships was rare. Conflicting findings around conflict of interest highlight the importance of more dedicated research in this area. PLAIN LANGUAGE SUMMARY: Business enterprises in health care play a central role in cancer research and care, driving the development of new medical testing, drugs, and devices. Effective working relationships among clinicians, researchers, and these industry partners can promote innovative research and enhance patient care. Study of these collaborations has been limited to date. Through distribution of a questionnaire to cancer clinicians and researchers, we found that most participants consider these relationships valuable, though they find establishing such relationships challenging partly because of gaps in educational programs in this area. Our findings also highlight the need for further policy around the potential bias these relationships can introduce.

Characterization of recurrence patterns and outcomes of medulloblastoma in adults: The University of Texas MD Anderson Cancer Center experience.

Background: Medulloblastoma in adults is rare and treatment decisions are largely driven from pediatric literature. We sought to characterize recurrent medulloblastoma in adults. Methods: From a single-institution dataset of 200 adult patients diagnosed with medulloblastoma during 1978-2017, those with recurrence were analyzed for clinical features, treatment, and outcome. Results: Of the 200 patients, 82 (41%) with median age of 29 years (18-59) had recurrence after a median follow-up time of 8.4 years (95% CI = 7.1, 10.3). Of these, 30 (37%) were standard-risk, 31 (38%) were high-risk, and 21 (26%) had unknown-risk diseases at the time of initial diagnosis. Forty-eight (58%) presented with recurrence outside the posterior fossa, of whom 35 (43%) had distant recurrence only. Median Progression-free survival (PFS) and OS from initial surgery were 33.5 and 62.4 months, respectively. Neither PFS nor OS from initial diagnosis differed between the standard-risk and high-risk groups in those who experience recurrence (P = .505 and .463, respectively). Median OS from first recurrence was 20.3 months, also with no difference between the standard-risk and high-risk groups (P = .518). Recurrences were treated with combinations of re-resection (20 patients; 25%), systemic chemotherapy (61 patients; 76%), radiation (29 patients; 36%), stem cell transplant (6 patients; 8%), and intrathecal chemotherapy (4 patients; 5%). Patients who received radiation at recurrence had better OS (32.9 months) than those who did not (19.2 months) (P = .034). Conclusions: Recurrent medulloblastoma in adults has a poor prognosis irrespective of initial risk stratification. Recurrence commonly arises outside the posterior fossa years after initial diagnosis.

Preclinical Models of Low-Grade Gliomas.

Diffuse infiltrating low-grade glioma (LGG) is classified as WHO grade 2 astrocytoma with isocitrate dehydrogenase (IDH) mutation and oligodendroglioma with IDH1 mutation and 1p/19q codeletion. Despite their better prognosis compared with glioblastoma, LGGs invariably recur, leading to disability and premature death. There is an unmet need to discover new therapeutics for LGG, which necessitates preclinical models that closely resemble the human disease. Basic scientific efforts in the field of neuro-oncology are mostly focused on high-grade glioma, due to the ease of maintaining rapidly growing cell cultures and highly reproducible murine tumors. Development of preclinical models of LGG, on the other hand, has been difficult due to the slow-growing nature of these tumors as well as challenges involved in recapitulating the widespread genomic and epigenomic effects of IDH mutation. The most recent WHO classification of CNS tumors emphasizes the importance of the role of IDH mutation in the classification of gliomas, yet there are relatively few IDH-mutant preclinical models available. Here, we review the in vitro and in vivo preclinical models of LGG and discuss the mechanistic challenges involved in generating such models and potential strategies to overcome these hurdles.

A first-in-human Phase I trial of the oral p-STAT3 inhibitor WP1066 in patients with recurrent malignant glioma.

Aim: To ascertain the maximum tolerated dose (MTD)/maximum feasible dose (MFD) of WP1066 and p-STAT3 target engagement within recurrent glioblastoma (GBM) patients. Patients & methods: In a first-in-human open-label, single-center, single-arm 3 + 3 design Phase I clinical trial, eight patients were treated with WP1066 until disease progression or unacceptable toxicities. Results: In the absence of significant toxicity, the MFD was identified to be 8 mg/kg. The most common adverse event was grade 1 nausea and diarrhea in 50% of patients. No treatment-related deaths occurred; 6 of 8 patients died from disease progression and one was lost to follow-up. Of 8 patients with radiographic follow-up, all had progressive disease. The longest response duration exceeded 3.25 months. The median progression-free survival (PFS) time was 2.3 months (95% CI: 1.7 months-NA months), and 6-month PFS (PFS6) rate was 0%. The median overall survival (OS) rate was 25 months (95% CI: 22.5 months-NA months), with an estimated 1-year OS rate of 100%. Pharmacokinetic (PK) data demonstrated that at 8 mg/kg, the T1/2 was 2-3 h with a dose dependent increase in the Cmax. Immune monitoring of the peripheral blood demonstrated that there was p-STAT3 suppression starting at a dose of 1 mg/kg. Conclusion: Immune analyses indicated that WP1066 inhibited systemic immune p-STAT3. WP1066 had an MFD identified at 8 mg/kg which is the target allometric dose based on prior preclinical modeling in combination with radiation therapy and a Phase II study is being planned for newly diagnosed MGMT promoter unmethylated glioblastoma patients.

Molecular, Histological, and Clinical Characteristics of Oligodendrogliomas: A Multi-Institutional Retrospective Study.

BACKGROUND: Reports suggest that phosphatidylinositol 3-kinase pathway alterations confer increased risk of progression and poor prognosis in oligodendroglioma, IDH-mutant, and 1p/19q-codeleted molecular oligodendrogliomas (mODG). However, factors that affect prognosis in mODG have not been thoroughly studied. In addition, the benefits of adjuvant radiation and temozolomide (TMZ) in mODGs remain to be determined. OBJECTIVE: To evaluate the role of PIK3CA mutations in mODGs. METHODS: One hundred seven mODGs (2008-2019) diagnosed at 2 institutions were included. A retrospective review of clinical characteristics, molecular alterations, treatments, and outcomes was performed. RESULTS: The median age was 37 years, and 61 patients (57%) were male. There were 64 (60%) World Health Organization (WHO) grade 2 and 43 (40%) WHO grade 3 tumors. Eighty-two patients (77%) were stratified as high risk (age 40 years or older and/or subtotal resection per Radiation Treatment Oncology Group-9802). Gross-total resection was achieved in 47 patients (45%). Treatment strategies included observation (n = 15), TMZ (n = 11), radiation (n = 13), radiation/TMZ (n = 62), and others (n = 6). Our results show a benefit of TMZ vs observation in progression-free survival (PFS). No difference in PFS or overall survival (OS) was observed between radiation and radiation/TMZ. PIK3CA mutations were detected in 15 (14%) mODG, and shorter OS was observed in PIK3CA-mutant compared with PIK3CA wild-type mODGs (10.7 years vs 15.1 years, P = .009). WHO grade 3 tumors showed a shorter PFS, but no significant difference in OS was observed between WHO grades. CONCLUSION: Our findings suggest that mODGs harboring PIK3CA mutations have worse OS. Except for an advantage in PFS with TMZ treatment, adjuvant TMZ, radiation, or a combination of the two showed no significant improvement in OS.

Intrinsic Interferon Signaling Regulates the Cell Death and Mesenchymal Phenotype of Glioblastoma Stem Cells.

Interferon (IFN) signaling contributes to stemness, cell proliferation, cell death, and cytokine signaling in cancer and immune cells; however, the role of IFN signaling in glioblastoma (GBM) and GBM stem-like cells (GSCs) is unclear. Here, we investigated the role of cancer-cell-intrinsic IFN signaling in tumorigenesis in GBM. We report here that GSCs and GBM tumors exhibited differential cell-intrinsic type I and type II IFN signaling, and high IFN/STAT1 signaling was associated with mesenchymal phenotype and poor survival outcomes. In addition, chronic inhibition of IFN/STAT1 signaling decreased cell proliferation and mesenchymal signatures in GSCs with intrinsically high IFN/STAT1 signaling. IFN-ß exposure induced apoptosis in GSCs with intrinsically high IFN/STAT1 signaling, and this effect was abolished by the pharmacological inhibitor ruxolitinib and STAT1 knockdown. We provide evidence for targeting IFN signaling in a specific sub-group of GBM patients. IFN-ß may be a promising candidate for adjuvant GBM therapy.

Clinical characterization of adult medulloblastoma and the effect of first-line therapies on outcome; The MD Anderson Cancer Center experience.

BACKGROUND: Adult medulloblastoma (MB) is rare, and management guidelines are largely based on pediatric clinical trials and retrospective series. Limited data exist with respect to clinical characteristics, prognostic factors, and outcomes based on first-line treatments. METHODS: Two hundred adults with MB seen at a single institution from January 1978 to April 2017 were identified and followed for a median of 8.4 y (7.1, 10.3). RESULTS: Patient's median age at diagnosis was 29 y (18, 63). One hundred eleven (55.5%) were standard-risk, 59 (29.5%) were high-risk, and 30 (15.0%) were indeterminate. Most received post-operative radiation (RT) (184 [92.0%]), and 105 (52.5%) received first-line chemotherapy. Median overall survival (OS) was 8.8 y (7.2, 12.2) and median progression-free survival (PFS) was 6.6 y (4.9, 11.2). High-risk patients had inferior OS (Hazard ratio [HR] = 2.5 [1.5, 4.2], P = .0006) and PFS (HR = 2.3 [1.3, 3.9], P = .002) compared to standard-risk patients. Age, sex, and metastatic disease were not associated with survival. After adjusting for risk status, those who received RT plus adjuvant chemotherapy had superior PFS compared to RT plus neoadjuvant chemotherapy [HR = 0.46 (0.22, 0.95), P = .0357]. Within a subgroup for whom detailed clinical data were available, those who received RT plus adjuvant chemotherapy had improved PFS compared to RT only [HR = 0.24 (0.074-0.76), P = .016]. The substitution of cisplatin for carboplatin and the elimination of vincristine did not negatively affect outcomes. CONCLUSION: This is the largest single-institution retrospective study of adult MB to our knowledge and identifies standard-risk status, first-line RT and adjuvant chemotherapy as factors associated with improved outcomes.

Observed-to-expected incidence ratios of second malignant neoplasms after radiation therapy for medulloblastoma: A Surveillance, Epidemiology, and End Results analysis.

BACKGROUND: The authors analyzed the incidence and types of second malignant neoplasms (SMNs) in patients treated for medulloblastoma. METHODS: The authors compared the incidence of SMNs after radiotherapy (RT) for medulloblastoma in patients treated in 1973-2014 with the incidence in the general population with the multiple primary-standardized incidence ratio function of Surveillance, Epidemiology, and End Results 9. Observed-to-expected incidence (O/E) ratios and 95% confidence intervals (CIs) were reported for the entire cohort and by disease site according to age at diagnosis, treatment era, and receipt of chemotherapy. P values < .05 were considered statistically significant. RESULTS: Of the 1294 patients with medulloblastoma who received RT, 68 developed 75 SMNs. The O/E ratio for SMNs among all patients was 4.49 (95% CI, 3.53-5.62; P < .05). The site at highest risk was the central nervous system (CNS; O/E, 40.62; 95% CI, 25.46-61.51), which was followed by the endocrine system (O/E, 15.95; 95% CI, 9.12-25.91), bone (O/E, 14.45; 95% CI, 1.75-52.21), soft tissues (O/E, 9.01; 95% CI, 1.09-32.56), the digestive system (O/E, 5.03; 95% CI, 2.51-9.00), and the lymphatic/hematopoietic system (O/E, 3.37; 95% CI, 1.35-6.94). The O/E ratio was higher for patients given chemotherapy and RT (O/E, 5.52; 95% CI, 3.75-7.83) than for those given RT only (O/E, 3.96; 95% CI, 2.88-5.32). CONCLUSIONS: Patients with medulloblastoma are at elevated risk for SMNs in comparison with the general population. Variations in O/E for SMNs by organ systems were found for treatment modality, age at diagnosis, and time of diagnosis. The most common site, the CNS, was involved more often in younger patients and those given chemotherapy with RT.

The promise of DNA damage response inhibitors for the treatment of glioblastoma.

Glioblastoma (GBM), the most aggressive primary brain tumor, has a dismal prognosis. Despite our growing knowledge of genomic and epigenomic alterations in GBM, standard therapies and outcomes have not changed significantly in the past two decades. There is therefore an urgent unmet need to develop novel therapies for GBM. The inter- and intratumoral heterogeneity of GBM, inadequate drug concentrations in the tumor owing to the blood-brain barrier, redundant signaling pathways contributing to resistance to conventional therapies, and an immunosuppressive tumor microenvironment, have all hindered the development of novel therapies for GBM. Given the high frequency of DNA damage pathway alterations in GBM, researchers have focused their efforts on pharmacologically targeting key enzymes, including poly(ADP-ribose) polymerase (PARP), DNA-dependent protein kinase, ataxia telangiectasia-mutated, and ataxia telangiectasia and Rad3-related. The mainstays of GBM treatment, ionizing radiation and alkylating chemotherapy, generate DNA damage that is repaired through the upregulation and activation of DNA damage response (DDR) enzymes. Therefore, the use of PARP and other DDR inhibitors to render GBM cells more vulnerable to conventional treatments is an area of intense investigation. In this review, we highlight the growing body of data behind DDR inhibitors in GBM, with a focus on putative predictive biomarkers of response. We also discuss the challenges involved in the successful development of DDR inhibitors for GBM, including the intracranial location and predicted overlapping toxicities of DDR agents with current standards of care, and propose promising strategies to overcome these hurdles.