E1B attenuated adenoviral therapy for recurrent squamous cell cancer of the head and neck

Recurrent head and neck cancer is a disease which causes significant morbidity and mortality. Despite advances in surgical reconstruction and in chemotherapy and radiotherapy, current treatments for this disease give poor responses which are of short duration. Because of this, there is a need for new biological therapies to be developed. An example of this is the E1B deleted adenovirus, Onyx-015, which has been shown to selectively replicate in and lyse cells with non-functional p53 (Bischoff et al,1996). This virus may be therapeutically useful in the treatment of a wide range of tumours since p53 abnormalities are very common in human cancer. The aims of this thesis were to determine if this virus would selectively replicate in and lyse head and neck squamous cell carcinoma cell lines with non-functional p53, to determine if the virus could cause tumour regression of subcutaneous tumours derived from human head and neck tumour cell lines in a nude mouse xenograft model, and lastly to determine if this virus could be given safely by intratumoural injection to patients with recurrent head and neck cancer and whether it could produce an anti-tumour response. Using a panel of human head and neck squamous cell carcinoma cell lines of known p53 sequence and function, replication of the E1B attenuated adenovirus, Onyx-015, was tested by cytopathic effect assays, hexon protein staining and quantified by flow cytometry. These assays showed that replication was more efficient in cell lines with non-functional p53 confirming the previously published work in other cell types by Bischoff et al,1996. The cell line BICR16, derived from a patient with recurrent head and neck cancer, was used for in-vivo testing by intratumoural injection of subcutaneous xenografts in nude mice. We showed tumour regression in all virus injected tumours. In contrast, diluent injected tumours continued to grow exponentially. To determine the incidence of p53 inactivation in recurrent head and neck cancer, the p53 status of 22 recurrent head and neck tumours was evaluated by gene sequencing, mdm2 expression and HPV expression. Overall we have shown that there is a greater incidence of p53 mutations in recurrent disease compared to primary disease. However the incidence of HPV infection and mdm2 overexpression was similar to reported studies in primary disease. Nevertheless, we show that the overall incidence of p53 alterations is very high at 95%. This may be one factor which accounts for the poor response of this disease to radiotherapy and chemotherapy and implies new therapies which either restore p53 function or which act in a p53 independent manner may prove to be beneficial in this disease. (Abstract shortened by ProQuest.)

E1B Attenuated Adenoviruses in Genetic Therapy for Cancer

The E1B deleted adenovirus, Onyx-015, has been shown to selectively replicate in and lyse cells with nonfunctional p53 (Bischoff et a1,1996). This virus may be therapeutically useful in the treatment of a wide range of tumours since p53 abnormalities are very common in human cancer. The aims of this thesis were to develop an immunocompetent mouse model to study the role of the immune system in this form of therapy, to further examine the mechanism of selectivity of Onyx-015 for cells with non-functional p53, and lastly to determine whether or not Onyx-015 could increase the cytotoxicity to DNA damaging agents in functional and non-functional p53 cells. We have shown that human adenoviruses will infect rodent cell lines but with variable infectivity. In tissues with high infectivity, productive virus infection only occurs in mouse epidermal cells but is 25 to 50 fold less efficient compared to the human ovarian adenocarcinoma cell line A2780Cp70. The efficiency of replication in mouse epidermal cells is dependent on the expression of the early gene E1A and this correlated with the expression of the nuclear factor ϕAP3 , a transcriptional repressor of the E1A promotor. Replication is shown to be 20 fold greater in squamous (well differentiated ) epidermal cell lines in which there is a high expression of E1A and low ϕAP3 expression compared to clonally related spindle (poorly differentiated) epidermal cell lines. Using mouse epidermal cell lines of known p53 status and function, the selective replication of Onyx-015 for cells with non-functional p53 is in general agreement with that reported in human cell lines. However, some cell lines with wild type p53 function do allow replication of Onyx-015 and we postulate that this is determined by 2 factors, the expression of E1A and the ability for Onyx-015 to repress p21 levels. Using the squamous epidermal cell line PDVc57, in-vivo studies in both nude mouse and syngeneic mouse tumour xenograft models showed decreased tumour growth with intratumoural virus injection compared to diluent injected tumours. However, viral replication is markedly reduced in the syngeneic host suggesting limitation of viral replication by the immune system. Using the paired cell lines A2780 (functional p53) and the cisplatin resistant variant A2780Cp70 (non-functional p53) we have shown that replication is dependent on S-phase entry of the host infected cell and this correlated with E2F induction. In the cell line A2780, S phase entry and viral replication is limited due to virus induced p53 mediated apoptosis. We suggest that this is mediated by E1A induction of p19ARF. In contrast, A2780Cp70 allows a productive virus infection since apoptosis does not occur due to the absence of functional p53 and high expression of the anti-apoptotic factor E1B19kDa. We have shown that in the cell line with nonfunctional p53 (A2780Cp70), cytotoxicity to both cisplatin and radiation is increased by preinfecting cells with Onyx-015. In the cell line with functional p53 (A2780), preinfection with Onyx-015 for 72 hours also resulted in increased cytotoxicity to both cisplain and radiation. In contrast, preinfection of A2780 for 24 hours followed by cisplatin resulted in an antagonistic interaction leading to reduced drug sensitivity. It is suggested that this was due to p21 induction causing a reduction in the S-phase cell population. Further in vivo and clinical studies investigating the role of the immune system in this form of therapy and in the use of combination therapies are therefore warranted

Periodontal pathogens are a risk factor of oral cavity squamous cell carcinoma, independent of tobacco and alcohol and human papillomavirus

Over the past decade, there has been a change in the epidemiology of oral cavity squamous cell cancer (OC-SCC). Many new cases of OC-SCC lack the recognized risk factors of smoking, alcohol and human papilloma virus. The aim of this study was to determine if the oral microbiome may be associated with OC-SCC in nonsmoking HPV negative patients. We compared the oral microbiome of HPV-negative nonsmoker OC-SCC(n = 18), premalignant lesions(PML) (n = 8) and normal control patients (n = 12). Their oral microbiome was sampled by oral wash and defined by 16S rRNA gene sequencing. We report that the periodontal pathogens Fusobacterium, Prevotella, Alloprevotella were enriched while commensal Streptococcus depleted in OC-SCC. Based on the four genera plus a marker genus Veillonella for PML, we classified the oral microbiome into two types. Gene/pathway analysis revealed a progressive increase of genes encoding HSP90 and ligands for TLRs 1, 2 and 4 along the controls→PML → OC-SCC progression sequence. Our findings suggest an association between periodontal pathogens and OC-SCC in non smoking HPV negative patients

Taselisib (GDC-0032), a Potent -Sparing Small Molecule Inhibitor of PI3K, Radiosensitizes Head and Neck Squamous Carcinomas Containing Activating PIK3CA Alterations

Activating PIK3CA genomic alterations are frequent in head and neck squamous cell carcinoma (HNSCC), and there is an association between phosphoinositide 3-kinase (PI3K) signaling and radioresistance. Hence, we investigated the therapeutic efficacy of inhibiting PI3K with GDC-0032, a PI3K inhibitor with potent activity against p110α, in combination with radiation in HNSCC

Outcomes of multimodal therapy in a large series of patients with anaplastic thyroid cancer

Background The role of radiotherapy (RT) in the treatment of patients with anaplastic thyroid cancer (ATC) for local tumor control is critical because mortality often is secondary to complications of tumor volume rather than metastatic disease. Herein, the authors report the long-term outcomes of RT for patients with ATC. Methods A total of 104 patients with histologically confirmed ATC were identified who presented to the study institution between 1984 and 2017 and who received curative-intent or postoperative RT. Locoregional progression-free survival (LPFS), overall survival (OS), and distant metastasis-free survival were assessed. Results The median age of the patients was 63.5 years. The median follow-up was 5.9 months (interquartile range, 2.7-17.0 months) for the entire cohort and 10.6 months (interquartile range, 5.3-40.0 months) for surviving patients. Thirty-one patients (29.8%) had metastatic disease prior to the initiation of RT. Concurrent chemoradiation was administered in 99 patients (95.2%) and 53 patients (51.0%) received trimodal therapy. Systemic therapy included doxorubicin (73.7%), paclitaxel with or without pazopanib (24.3%), and other systemic agents (2.0%). The 1-year OS and LPFS rates were 34.4% and 74.4%, respectively. On multivariate analysis, RT >= 60 Gy was associated with improved LPFS (hazard ratio [HR], 0.135; P = .001) and improved OS (HR, 0.487; P = .004), and trimodal therapy was associated with improved LPFS (HR, 0.060; P = .017). The most commonly observed acute grade 3 adverse events included dermatitis (20%) and mucositis (13%), with no grade 4 subacute or late adverse events noted (adverse events were graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0]). Conclusions RT appears to demonstrate a dose-dependent, persistent LPFS and OS benefit in patients with locally advanced ATC with an acceptable toxicity profile. Aggressive RT should be strongly considered for the treatment of patients with ATC as part of a trimodal treatment approach

Oral Microbiome Profiles: 16S rRNA Pyrosequencing and Microarray Assay Comparison

The human oral microbiome is potentially related to diverse health conditions and high-throughput technology provides the possibility of surveying microbial community structure at high resolution. We compared two oral microbiome survey methods: broad-based microbiome identification by 16S rRNA gene sequencing and targeted characterization of microbes by custom DNA microarray.Oral wash samples were collected from 20 individuals at Memorial Sloan-Kettering Cancer Center. 16S rRNA gene survey was performed by 454 pyrosequencing of the V3–V5 region (450 bp). Targeted identification by DNA microarray was carried out with the Human Oral Microbe Identification Microarray (HOMIM). Correlations and relative abundance were compared at phylum and genus level, between 16S rRNA sequence read ratio and HOMIM hybridization intensity.; Correlation = 0.70–0.84).Microbiome community profiles assessed by 16S rRNA pyrosequencing and HOMIM were highly correlated at the phylum level and, when comparing the more commonly detected taxa, also at the genus level. Both methods are currently suitable for high-throughput epidemiologic investigations relating identified and more common oral microbial taxa to disease risk; yet, pyrosequencing may provide a broader spectrum of taxa identification, a distinct sequence-read record, and greater detection sensitivity

Association of the Genomic Profile of Medullary Thyroid Carcinoma with Tumor Characteristics and Clinical Outcomes in an International Multicenter Study

Purpose: The prognostic importance of RET and RAS mutations and their relationship to clinicopathologic parameters and outcomes in medullary thyroid carcinoma (MTC) need to be clarified. Experimental Design: A multicenter retrospective cohort study was performed utilizing data from 290 patients with MTC. The molecular profile was determined and associations were examined with clinicopathologic data and outcomes. Results: RET germ line mutations were detected in 40 patients (16.3%). Somatic RET and RAS mutations occurred in 135 (46.9%) and 57 (19.8%) patients, respectively. RETM918T was the most common somatic RET mutation (n = 75). RET somatic mutations were associated with male sex, larger tumor size, advanced American Joint Committee Cancer (AJCC) stage, vascular invasion, and high International Medullary Thyroid Carcinoma Grading System (IMTCGS) grade. When compared with other RET somatic mutations, RETM918T was associated with younger age, AJCC (eighth edition) IV, vascular invasion, extrathyroidal extension, and positive margins. RET somatic or germ line mutations were significantly associated with reduced distant metastasis-free survival on univariate analysis, but there were no significant independent associations on multivariable analysis, after adjusting for tumor grade and stage. There were no significant differences in outcomes between RET somatic and RET germ line mutations, or between RETM918T and other RET mutations. Other recurrent molecular alterations included TP53 (4.2%), ARID2 (2.9%), SETD2 (2.9%), KMT2A (2.9%), and KMT2C (2.9%). Among them, TP53 mutations were associated with decreased overall survival (OS) and disease-specific survival (DSS), independently of tumor grade and AJCC stage. Conclusions: RET somatic mutations were associated with high-grade, aggressive primary tumor characteristics, and decreased distant metastatic-free survival but this relationship was not significant after accounting for tumor grade and disease stage. RETM918T was associated with aggressive primary tumors but was not independently associated with clinical outcomes. TP53 mutation may represent an adverse molecular event associated with decreased OS and DSS in MTC, but its prognostic value needs to be confirmed in future studies

Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

Peer reviewe

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AIM: The SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery. METHODS: This was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin. RESULTS: Overall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P < 0.001). After adjustment, delay was not associated with a lower rate of complete resection (OR 1.18, 95% CI 0.90-1.55, P = 0.224), which was consistent in elective patients only (OR 0.94, 95% CI 0.69-1.27, P = 0.672). Longer delays were not associated with poorer outcomes. CONCLUSION: One in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease