Resistance to Spindle Inhibitors in Glioblastoma Depends on STAT3 and Therapy Induced Senescence.

While mitotic spindle inhibitors specifically kill proliferating tumor cells without the toxicities of microtubule poisons, resistance has limited their clinical utility. Treating glioblastomas with the spindle inhibitors ispinesib, alisertib, or volasertib creates a subpopulation of therapy induced senescent cells that resist these drugs by relying upon the anti-apoptotic and metabolic effects of activated STAT3. Furthermore, these senescent cells expand the repertoire of cells resistant to these drugs by secreting an array of factors, including TGFß, which induce proliferating cells to exit mitosis and become quiescent-a state that also resists spindle inhibitors. Targeting STAT3 restores sensitivity to each of these drugs by depleting the senescent subpopulation and inducing quiescent cells to enter the mitotic cycle. These results support a therapeutic strategy of targeting STAT3-dependent therapy-induced senescence to enhance the efficacy of spindle inhibitors for the treatment of glioblastoma. Highlights: • Resistance to non-microtubule spindle inhibitors limits their efficacy in glioblastoma and depends on STAT3.• Resistance goes hand in hand with development of therapy induced senescence (TIS).• Spindle inhibitor resistant glioblastomas consist of three cell subpopulations-proliferative, quiescent, and TIS-with proliferative cells sensitive and quiescent and TIS cells resistant.• TIS cells secrete TGFß, which induces proliferative cells to become quiescent, thereby expanding the population of resistant cells in a spindle inhibitor resistant glioblastoma• Treatment with a STAT3 inhibitor kills TIS cells and restores sensitivity to spindle inhibitors.

Activation of STAT3 through combined SRC and EGFR signaling drives resistance to a mitotic kinesin inhibitor in glioblastoma.

Inhibitors of the mitotic kinesin Kif11 are anti-mitotics that, unlike vinca alkaloids or taxanes, do not disrupt microtubules and are not neurotoxic. However, development of resistance has limited their clinical utility. While resistance to Kif11 inhibitors in other cell types is due to mechanisms that prevent these drugs from disrupting mitosis, we find that in glioblastoma (GBM), resistance to the Kif11 inhibitor ispinesib works instead through suppression of apoptosis driven by activation of STAT3. This form of resistance requires dual phosphorylation of STAT3 residues Y705 and S727, mediated by SRC and epidermal growth factor receptor (EGFR), respectively. Simultaneously inhibiting SRC and EGFR reverses this resistance, and combined targeting of these two kinases in vivo with clinically available inhibitors is synergistic and significantly prolongs survival in ispinesib-treated GBM-bearing mice. We thus identify a translationally actionable approach to overcoming Kif11 inhibitor resistance that may work to block STAT3-driven resistance against other anti-cancer therapies as well.

Protein kinase Cι and SRC signaling define reciprocally related subgroups of glioblastoma with distinct therapeutic vulnerabilities.

We report that atypical protein kinase Cι (PKCι) is an oncogenic driver of glioblastoma (GBM). Deletion or inhibition of PKCι significantly impairs tumor growth and prolongs survival in murine GBM models. GBM cells expressing elevated PKCι signaling are sensitive to PKCι inhibitors, whereas those expressing low PKCι signaling exhibit active SRC signaling and sensitivity to SRC inhibitors. Resistance to the PKCι inhibitor auranofin is associated with activated SRC signaling and response to a SRC inhibitor, whereas resistance to a SRC inhibitor is associated with activated PKCι signaling and sensitivity to auranofin. Interestingly, PKCι- and SRC-dependent cells often co-exist in individual GBM tumors, and treatment of GBM-bearing mice with combined auranofin and SRC inhibitor prolongs survival beyond either drug alone. Thus, we identify PKCι and SRC signaling as distinct therapeutic vulnerabilities that are directly translatable into an improved treatment for GBM.

Pan-Asian adaptation of the EHNS-ESMO-ESTRO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with squamous cell carcinoma of the head and neck.

The most recent version of the European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of squamous cell carcinoma (SCC) of the oral cavity, larynx, oropharynx and hypopharynx was published in 2020. It was therefore decided by both the ESMO and the Korean Society of Medical Oncology (KSMO) to convene a special, virtual guidelines meeting in July 2021 to adapt the ESMO 2020 guidelines to consider the potential ethnic differences associated with the treatment of SCCs of the head and neck (SCCHN) in Asian patients. These guidelines represent the consensus opinions reached by experts in the treatment of patients with SCCHN (excluding nasopharyngeal carcinomas) representing the oncological societies of Korea (KSMO), China (CSCO), India (ISMPO), Japan (JSMO), Malaysia (MOS), Singapore (SSO) and Taiwan (TOS). The voting was based on scientific evidence and was independent of the current treatment practices and drug access restrictions in the different Asian countries. The latter was discussed when appropriate. This manuscript provides a series of expert recommendations (Clinical Practice Guidelines) which can be used to provide guidance to health care providers and clinicians for the optimisation of the diagnosis, treatment and management of patients with SCC of the oral cavity, larynx, oropharynx and hypopharynx across Asia.

Myosin 10 Regulates Invasion, Mitosis, and Metabolic Signaling in Glioblastoma.

Invasion and proliferation are defining phenotypes of cancer, and in glioblastoma blocking one stimulates the other, implying that effective therapy must inhibit both, ideally through a single target that is also dispensable for normal tissue function. The molecular motor myosin 10 meets these criteria. Myosin 10 knockout mice can survive to adulthood, implying that normal cells can compensate for its loss; its deletion impairs invasion, slows proliferation, and prolongs survival in murine models of glioblastoma. Myosin 10 deletion also enhances tumor dependency on the DNA damage and the metabolic stress responses and induces synthetic lethality when combined with inhibitors of these processes. Our results thus demonstrate that targeting myosin 10 is active against glioblastoma by itself, synergizes with other clinically available therapeutics, may have acceptable side effects in normal tissues, and has potential as a heretofore unexplored therapeutic approach for this disease.

Ewing Sarcoma With Emphasis on Extra-skeletal Ewing Sarcoma: A Decade's Experience From a Single Centre in India.

INTRODUCTION: The diagnosis of Ewing sarcoma family of tumours (ESFT) is challenging, especially in adults and in extra-skeletal or visceral location. Several morphologic mimics with varied treatment options and prognosis confer diagnostic dilemmas. Application of ancillary diagnostic modalities in surgical pathology in clinical routine has enabled accurate diagnosis of ESFT in bone, soft tissues, and viscera. AIM: The study aims to assess the clinicopathological features including molecular test results of ESFT with emphasis on sex, age, and location, especially extra-skeletal soft tissue and visceral location. MATERIAL AND METHODS: Data of clinicopathological, molecular tests (wherever performed), diagnosis rendered in 302 ESFT over a decade from our centre were reviewed. Statistical comparison of skeletal and extra-skeletal tumours with reference to age and sex was done using SPSS package. The P value of <.05 was considered significant. RESULTS: The cohort included 302 ESFTs with 49% skeletal and 51% extra-skeletal tumours. Thigh was most common site among skeletal tumours; chest wall, paraspinal location, and retroperitoneum among soft tissues (39.4%); and kidney, ovary, and cervix among visceral tumours (11.3%). Fluorescence in situ hybridisation for EWSR1 gene rearrangement was positive in 54 patients and reverse-transcriptase polymerase chain reaction in 19 patients. Predominance of male sex, younger age and location in extremities among skeletal tumours and lack of gender predilection, higher age and axial location in extra-skeletal tumours were noted, which were statistically significant. Molecular tests were performed more frequently in extra-skeletal tumours, especially in visceral tumours to establish the diagnosis. CONCLUSIONS: The study showed statistically significant differences in the age, sex, and location between skeletal and extra-skeletal ESFT. The increased percentage of extra-skeletal tumours especially in viscera was attributed to the increased awareness and availability of ancillary techniques.

Enhancing Brain Retention of a KIF11 Inhibitor Significantly Improves its Efficacy in a Mouse Model of Glioblastoma.

Glioblastoma, the most lethal primary brain cancer, is extremely proliferative and invasive. Tumor cells at tumor/brain-interface often exist behind a functionally intact blood-brain barrier (BBB), and so are shielded from exposure to therapeutic drug concentrations. An ideal glioblastoma treatment needs to engage targets that drive proliferation as well as invasion, with brain penetrant therapies. One such target is the mitotic kinesin KIF11, which can be inhibited with ispinesib, a potent molecularly-targeted drug. Although, achieving durable brain exposures of ispinesib is critical for adequate tumor cell engagement during mitosis, when tumor cells are vulnerable, for efficacy. Our results demonstrate that the delivery of ispinesib is restricted by P-gp and Bcrp efflux at BBB. Thereby, ispinesib distribution is heterogeneous with concentrations substantially lower in invasive tumor rim (intact BBB) compared to glioblastoma core (disrupted BBB). We further find that elacridar-a P-gp and Bcrp inhibitor-improves brain accumulation of ispinesib, resulting in remarkably reduced tumor growth and extended survival in a rodent model of glioblastoma. Such observations show the benefits and feasibility of pairing a potentially ideal treatment with a compound that improves its brain accumulation, and supports use of this strategy in clinical exploration of cell cycle-targeting therapies in brain cancers.

Myosin IIA suppresses glioblastoma development in a mechanically sensitive manner.

The ability of glioblastoma to disperse through the brain contributes to its lethality, and blocking this behavior has been an appealing therapeutic approach. Although a number of proinvasive signaling pathways are active in glioblastoma, many are redundant, so targeting one can be overcome by activating another. However, these pathways converge on nonredundant components of the cytoskeleton, and we have shown that inhibiting one of these-the myosin II family of cytoskeletal motors-blocks glioblastoma invasion even with simultaneous activation of multiple upstream promigratory pathways. Myosin IIA and IIB are the most prevalent isoforms of myosin II in glioblastoma, and we now show that codeleting these myosins markedly impairs tumorigenesis and significantly prolongs survival in a rodent model of this disease. However, while targeting just myosin IIA also impairs tumor invasion, it surprisingly increases tumor proliferation in a manner that depends on environmental mechanics. On soft surfaces myosin IIA deletion enhances ERK1/2 activity, while on stiff surfaces it enhances the activity of NFκB, not only in glioblastoma but in triple-negative breast carcinoma and normal keratinocytes as well. We conclude myosin IIA suppresses tumorigenesis in at least two ways that are modulated by the mechanics of the tumor and its stroma. Our results also suggest that inhibiting tumor invasion can enhance tumor proliferation and that effective therapy requires targeting cellular components that drive both proliferation and invasion simultaneously.

Oncological benefits of postoperative radiotherapy in node-negative early stage cancer of the oral cavity with isolated perineural invasion.

Perineural invasion has been widely regarded as a poor prognostic factor in cancer of the oral cavity, but adjuvant treatment based only on this is still debatable. We have made an effort to address the question in a retrospective analysis of data from 2009-15 of patients with early node-negative cancers of the oral cavity. Patients with perineural invasion were divided into those who were treated with radiotherapy and those who were not. The records of a total of 169 patients were analysed, and 118 were given adjuvant radiotherapy and 51 were not. The median (range) duration of follow up was 45 (26-86) months. Of 169 patients, 47 (28%) developed recurrence, 28 in the treated, and 19 in the untreated, group. There was a significant disease-free survival benefit for adjuvant treatment (p = 0.047) but no overall survival benefit (p = 0.54). We conclude that adjuvant radiotherapy should be considered for patients with perineural invasion, even in early cancers of the oral cavity.

Extracapsular extension in oral cavity cancers-predictive factors and impact on recurrence pattern and survival.

Extracapsular extension (ECE) has long been considered a poor prognostic factor in oral cavity cancer, the presence of which warrants intensification of adjuvant therapy. This study was done to analyze the survival of patients with ECE who received adjuvant chemoradiation. Patients with pathologically confirmed squamous cell carcinoma of the oral cavity, with a minimum of 2 years of follow-up, who were treated at a tertiary cancer centre in New Delhi, India during the years 2009-2017, were included. On multivariate analysis, ECE was significantly associated with depth of invasion >10 mm and tumour deposit size >5 mm. Among the node-positive group, patients without ECE had a 5-year disease-free survival (DFS) and 5-year overall survival (OS) advantage over ECE-positive patients of 7.8% (63.8% vs. 56.0%) and 16.5% (87.2% vs. 70.7%), respectively. For patients with ECE, the hazard ratio for DFS and OS was 1.3 (95% confidence interval 0.97-1.75, P = 0.078) and 2.30 (95% confidence interval 1.35-3.92, P = 0.002), respectively. ECE remains one of the strongest predictors of recurrence and survival in oral cancer patients, and despite aggressive adjuvant therapy, distant recurrence is still significantly high.

Accuracy of core biopsy in predicting pathologic complete response in the breast in patients with complete/near complete clinical and radiological response (Complete Responders in the Breast - CRBr) - Trial design and conduct.

INTRODUCTION: With the advent of taxanes and targeted agents in neoadjuvant chemotherapy (NACT) for breast cancer, the rates of pathologic complete response (pCR) have been steadily increasing. One of the roles of surgery in these women is to serve as a biopsy to confirm or negate a pCR. DESIGN: This is a prospective validation study. All newly diagnosed non-metastatic breast cancers, of any luminal subtype, planned for neoadjuvant chemotherapy (NACT) with a titanium clip placed in the tumor, will be screened. Eligible patients who have a complete/near complete response to NACT as seen on a mammogram and ultrasound of the breast, will undergo multiple core biopsies of the tumor bed under ultrasound guidance as an outpatient procedure. A minimum of four core biopsy specimens will be mandatory. An MRI will also be done for these patients for documentation and analysis. The core biopsy will be compared to the final histopathology report after definitive surgery. OBJECTIVES: The objective is to study the false negative rate and accuracy of ultrasound guided core biopsies of the tumor bed in predicting pCR. Additionally, the correlation of pCR in the breast with axillary response and the incremental benefit of an MRI in predicting pCR will be evaluated. DISCUSSION: The concept of using image guided core biopsies to predict pCR could be useful in designing future studies aimed at avoiding redundant surgery in women with a complete response to NACT. This study is registered with Clinical Trials Registry of India (CTRI/2018/01/011122).

A gland of diverse pathology and unpredictable behaviour: our experience of primary submandibular gland malignancies.

Submandibular gland tumours are relatively uncommon tumours and demonstrate diverse histological types and a variable prognosis. The aim of this study was to analyze our experience with submandibular malignancies over a period of 6 years (January 2009 to December 2015). Patient data from the 6-year period were reviewed retrospectively and 51 patients with submandibular malignancies were identified. Demographic data, clinicopathological details, treatment received, complications, and follow-up were recorded. The mean age of the 51 patients at presentation was 49.1 years. They were followed up for a mean 20.3 months. Nine of 47 patients (19.1%) developed distant metastasis during follow-up, while only three (6.4%) developed local recurrence. Disease-free survival at 2 years was 69.7% and overall survival at the end of 2 years was 77.8%. Actuarial 5-year survival was 57.8% when all subtypes were considered. The overall mean time to recurrence was 10 months (6-24 months). Nodal positivity was the only prognostic factor that was significant on multivariate analysis, while age, sex, perineural invasion, and grade were not. With advances in surgical and radiotherapy techniques, loco-regional control rates have improved greatly; however, effective adjuvant treatment to prevent systemic relapse is still lacking.

Clinical profile and outcomes of patients with Stage IV adenocarcinoma of lung: A tertiary cancer center experience.

BACKGROUND: There is limited Indian data on clinical profile and treatment outcomes for patients with Stage IV adenocarcinoma of lung. AIM: We aimed to prospectively study the clinical profile and treatment outcomes for patients with Stage IV adenocarcinoma of lung at a tertiary cancer center. MATERIALS AND METHODS: One hundred and ninetyfour patients with Stage IV adenocarcinoma of lung were prospectively analyzed for demographic and molecular profile (epidermal growth factor receptor [EGFR] and echinodermal microtubuleassociated proteinlike 4anaplastic lymphoma kinase [EML4ALK] mutations). Patients with EGFR and EML4ALK mutations were treated with tyrosine kinase inhibitors. Patients without these mutations were treated with standard chemotherapy regimens. Maintenance chemotherapy was offered to patients as per standard guidelines. Clinical outcomes measured were response rate (RR), progressionfree survival (PFS), and overall survival (OS). RESULTS: Median age of patients was 56 years (range, 26-82) with a male:female ratio of 2.3:1. EGFR and ALK mutation testing was feasible in 169 (87.1%) and 164 (84.5%), respectively, and detected in 37.9% and 5.5% patients, respectively. Overall RR, PFS and OS of whole cohort were 44.3%, 6.9, and 15.5 months, respectively. PFS and OS of mutated group (EGFR, EML4ALK) were longer than nonmutated group (10.5 vs. 5.4 months, P < 0.0001 and 21.5 vs. 11 months, P = 0.0001, respectively). PFS and OS of patients who received pemetrexed maintenance were longer than those who did not receive maintenance (8.5 vs. 6.5 months, P = 0.1613 and 18.5 vs. 12.5 months, P = 0.0219, respectively). CONCLUSIONS: Mutation testing at diagnosis is feasible in the vast majority of patients with Stage IV adenocarcinoma of the lung. Patients with EGFR or EML4ALK mutation and those who received pemetrexed maintenance had better clinical outcomes.

Anaplastic lymphoma kinase status in lung cancers: An immunohistochemistry and fluorescence in situ hybridization study from a tertiary cancer center in India.

BACKGROUND AND OBJECTIVES: Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) have shown good concordance for the detection of echinoderm microtubule-associated protein-like 4 and anaplastic lymphoma kinase (ALK) rearrangement. Since studies reporting FISH/IHC concordance, clinicopathological features, and clinical outcomes of ALK-positive patients from India are lacking, this study was undertaken. MATERIALS AND METHODS: This is a retrospective, observational study of patients with adenocarcinoma of the lung on whom ALK test was performed between March 2013 and December 2015. ALK status was assessed in 341 patients by FISH using Vysis ALK Dual Color Break Apart Rearrangement Probe and IHC using ALK D5F3 clone. Clinicopathological features were noted. Patients were managed as per the standard guidelines. Clinical outcomes - response rate (RR) and progression-free survival (PFS) - were measured. RESULTS: ALK rearrangement was positive in 37 patients (10.9%). ALK positivity was observed more commonly in younger patients with no predilection for any gender or any specific histological subtype. ALK by IHC was highly sensitive (100%), compared to FISH with concordance rate of 94.4%. Thirty one of thirty seven (31 of 37) patients received therapy of which 3 patients received palliative chemotherapy and 28 patients received tyrosine kinase inhibitors (crizotinib/ceritinib). Overall RR observed was 77.4%, and median PFS had not been reached at a median follow-up of 12.5 months. INTERPRETATION AND CONCLUSIONS: We report higher frequency of ALK positivity (10.9%) in patients with adenocarcinoma of the lung. ALK by IHC is more sensitive than FISH for ALK detection with high concordance. These patients had good clinical outcome with TKIs targeting ALK fusion protein.

BIRC3 is a biomarker of mesenchymal habitat of glioblastoma, and a mediator of survival adaptation in hypoxia-driven glioblastoma habitats.

Tumor hypoxia is an established facilitator of survival adaptation and mesenchymal transformation in glioblastoma (GBM). The underlying mechanisms that direct hypoxia-mediated survival in GBM habitats are unclear. We previously identified BIRC3 as a mediator of therapeutic resistance in GBM to standard temozolomide (TMZ) chemotherapy and radiotherapy (RT). Here we report that BIRC3 is a biomarker of the hypoxia-mediated adaptive mesenchymal phenotype of GBM. Specifically, in the TCGA dataset elevated BIRC3 gene expression was identified as a superior and selective biomarker of mesenchymal GBM versus neural, proneural and classical subtypes. Further, BIRC3 protein was highly expressed in the tumor cell niches compared to the perivascular niche across multiple regions in GBM patient tissue microarrays. Tumor hypoxia was found to mechanistically induce BIRC3 expression through HIF1-alpha signaling in GBM cells. Moreover, in human GBM xenografts robust BIRC3 expression was noted within hypoxic regions of the tumor. Importantly, selective inhibition of BIRC3 reversed therapeutic resistance of GBM cells to RT in hypoxic microenvironments through enhanced activation of caspases. Collectively, we have uncovered a novel role for BIRC3 as a targetable biomarker and mediator of hypoxia-driven habitats in GBM.

Neuroblast differentiation during development and in neuroblastoma requires KIF1Bß-mediated transport of TRKA.

We recently identified pathogenic KIF1Bß mutations in sympathetic nervous system malignancies that are defective in developmental apoptosis. Here we deleted KIF1Bß in the mouse sympathetic nervous system and observed impaired sympathetic nervous function and misexpression of genes required for sympathoadrenal lineage differentiation. We discovered that KIF1Bß is required for nerve growth factor (NGF)-dependent neuronal differentiation through anterograde transport of the NGF receptor TRKA. Moreover, pathogenic KIF1Bß mutations identified in neuroblastoma impair TRKA transport. Expression of neuronal differentiation markers is ablated in both KIF1Bß-deficient mouse neuroblasts and human neuroblastomas that lack KIF1Bß. Transcriptomic analyses show that unfavorable neuroblastomas resemble mouse sympathetic neuroblasts lacking KIF1Bß independent of MYCN amplification and the loss of genes neighboring KIF1B on chromosome 1p36. Thus, defective precursor cell differentiation, a common trait of aggressive childhood malignancies, is a pathogenic effect of KIF1Bß loss in neuroblastomas. Furthermore, neuropathy-associated KIF1Bß mutations impede cargo transport, providing a direct link between neuroblastomas and neurodegeneration.

Oncogenic drivers in nonsmall cell lung cancer and resistance to epidermal growth factor receptor tyrosine kinase inhibitors.

Nonsmall cell lung cancer (NSCLC) is increasingly being treated with targeted therapies. Epidermal growth factor receptor (EGFR) has been extensively studied in NSCLC as an oncogenic driver. However, the efficacy of the EGFR tyrosine kinase inhibitors (TKIs) is adversely impacted by the development of resistance. The occurrence of de novo resistance to EGFR TKIs is attributed to multiple mechanisms such as point mutations of oncogenes and chromosomal rearrangements. The development of acquired resistance to EGFR TKIs is facilitated by secondary mutations, phenotypical transformation, aberrance of downstream pathways, and activation of alternate signaling pathways. The T790M mutation is the most common mutation that accounts for about half of the acquired resistance to EGFR TKIs. This review article provides an overview of the common oncogenic drivers, targeted therapies for NSCLC, and the established mechanisms implicated in the development of resistance to the EGFR TKIs.

Oncology Gold Standard™ practical consensus recommendations 2016 for treatment of advanced clear cell renal cell carcinoma.

The Oncology Gold Standard (OGS) Expert Group on renal cell carcinoma (RCC) developed the consensus statement to provide community oncologists practical guidelines on the management of advanced clear cell (cc) RCC using published evidence, practical experience of experts in real life management, and results of a nationwide survey involving 144 health-care professionals. Six broad question categories containing 33 unique questions cover major situations in the routine management of RCC. This document serves as a ready guide for the standard of care to optimize outcome. The table of "Take Home Messages" at the end is a convenient tool for busy practitioners.

A rare case of leptomeningeal carcinomatosis in a patient with uveal melanoma: case report and review of literature.

Uveal melanoma is a rare subtype of melanoma, accounting for only 3-5% of all melanoma cases in the USA. Although fewer than 4% of uveal melanoma patients present with metastasis at diagnosis, approximately half will develop metastasis, more than 90% of which disseminate to the liver. Infrequently, a number of malignancies can lead to leptomeningeal metastases, a devastating and terminal complication. In this case report, we present an exceedingly rare case of a patient with uveal melanoma who developed leptomeningeal carcinomatosis as the sole site of metastasis. After conventional methods to diagnose leptomeningeal carcinomatosis fell short, a diagnosis was confirmed on the basis of identification and genomic analysis of melanoma circulating tumor cells in the cerebrospinal fluid.