The effect of the COVID-19 pandemic on the diagnosis and progression of oral cancer

The COVID-19 pandemic placed a significant burden on healthcare resources, limiting care to emergent and essential services only. The objective of this study was to describe the effect of the COVID-19 pandemic on the diagnosis and progression of oral cancer lesions in Montreal, Canada. A retrospective analysis of health records was performed. Patients presenting for a new oncology consultation for an oral lesion suspicious for cancer between March 2018 and March 2022, within the Department of Oral and Maxillofacial Surgery of the McGill University Health Center, were included. Data was collected on sociodemographic characteristics, oral cancer risk behaviors of study participants, oral cancer delays, tumor characteristics, and clinical management. A total of 190 patients were included, 91 patients from the pre-pandemic period and 99 from the pandemic period. The demographic characteristics of the patients in the two periods were comparable. There was no significant difference in the patient, professional, or treatment delay between the two periods. There was a non-significant increase in pathologic tumor size during the pandemic, but the pathologic staging and postoperative outcomes were comparable to those of the pre-pandemic cohort. The results indicate that emergent care pathways for oral cancer treatment were efficiently maintained despite the pandemic shutdown of services.

Gland-sparing neck dissection: oncological and functional outcomes in oral cancer patients

This study was performed to evaluate the subjective and objective functional outcomes of patients who had undergone submandibular gland-sparing neck dissection. All data were obtained from patients treated in a single hospital. Seventy-seven patients who had undergone complete submandibular gland sparing (CSGS) were included in the study. Cancer prognosis items were recorded. The subjective outcomes included patient self-evaluation of mouth dryness and the evaluation of the presence of saliva secretion following the application of digital pressure. Saliva scintigraphy served as the objective test. Self-reported xerostomia was compared between the CSGS patients and a control group of patients who had undergone unilateral submandibular gland removal (USGR; n = 74). In the CSGS group, local recurrence occurred in 3.8% of the 80 cancer sites, and neck recurrence occurred in 5.9% of neck dissection sites. Regarding the subjective measurements, 7.0% of the CSGS patients reported xerostomia and 91.9% demonstrated saliva secretion by digital pressure. Scintigraphy revealed actively secreting glands, with 42.9% of them showing normal gland function; none of the patients had severe xerostomia. The relative risk of dry mouth was significantly higher in the USGR patients than in the CSGS patients (P < 0.001). Submandibular gland sparing during neck dissection was found to result in satisfactory saliva secretion, with a relatively small risk of local or neck recurrence.

Effect of proton radiation therapy on cardiovascular implantable electronic devices [CIED]

Background

The number of cancer patients with CIED receiving radiotherapy has increased dramatically with improving life expectancy in both patients with cardiovascular disease and cancer. The advent of proton therapy adds new concern for potential malfunction in CIED devices, both due to significant neutron scatter and its use of strong magnets to focus radiation beams. Therefore, we aimed to assess the incidence of CIED malfunction secondary to proton therapy in this patient cohort.

Methods

We retrospectively analyzed patients with CIED undergoing proton therapy at our institute between 2011–2021. Each device was programmed pre-treatment and monitored post-treatment according to a special protocol developed in our centre. Treatments were prescribed to doses up to 70 Gy (RBE) and delivered using either passive-scattering or pencil beam techniques. Distances between the CIED and treated volumes ranged from 10–50 cm. We analyzed baseline patient demographics, CIED demographics, CIED outcomes pre-proton therapy as well as post-proton therapy including device reset and requirement for replacement, analyzing up to most recent check.

Results

Fifty-one patients with CIED underwent proton therapy during the study period. Estimated neutron dose ranged from 0.05–2.0 mSv/GyRBE for this patient cohort. Baseline demographics outlines in table 1. Of note 26/51 patients underwent proton therapy for ophthalmic malignancies, 6/51 for brain/skull malignancies. CIED comprised of 39 pacemakers and 12 implantable cardioverter defibrillators. Fourteen patients were pacemaker-dependent. Using 95% Confidence Interval, ventricular threshold, impedance, and amplitude, as well as atrial threshold and amplitude were unchanged, whereas atrial impedance measurements had a change pre- and post-proton therapy (Table 2). No patients had a device reset. One patient had a premature battery depletion three months post-radiotherapy for pancreatic cancer.

Conclusions

Our findings suggest that proton therapy does not significantly impact CIED function. Whilst caution remains as further data is accrued, close monitoring, particularly with the advent of remote monitoring, of these patients should be recommended.

Funding Acknowledgement

Type of funding sources: None.

A positive bacterial culture from allograft bone at implantation does not correlate with subsequent surgical site infection

Fresh-frozen allograft bone is frequently used in orthopaedic surgery. We investigated the incidence of allograft-related infection and analysed the outcomes of recipients of bacterial culture-positive allografts from our single-institute bone bank during bone transplantation. The fresh-frozen allografts were harvested in a strict sterile environment during total joint arthroplasty surgery and immediately stored in a freezer at -78º to -68º C after packing. Between January 2007 and December 2012, 2024 patients received 2083 allografts with a minimum of 12 months of follow-up. The overall allograft-associated infection rate was 1.2% (24/2024). Swab cultures of 2083 allografts taken before implantation revealed 21 (1.0%) positive findings. The 21 recipients were given various antibiotics at the individual orthopaedic surgeon’s discretion. At the latest follow-up, none of these 21 recipients displayed clinical signs of infection following treatment. Based on these findings, we conclude that an incidental positive culture finding for allografts does not correlate with subsequent surgical site infection. Additional prolonged post-operative antibiotic therapy may not be necessary for recipients of fresh-frozen bone allograft with positive culture findings.

Cite this article: Bone Joint J 2015;97-B:427–31.

Cardiac cormorbidities in women with metastatic breast cancer treated with doxorubicin-based and non-doxorubicin-based chemotherapy

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Background: Observational data are sparse regarding cardiac comorbidities in patients with metastatic breast cancer (MBC) newly initiated on chemotherapy. As some MBC treatments are associated with cardiac toxicity, such information would be useful in guiding treatment decisions. The objective of this analysis was to understand the frequency of cardiac comorbidities in MBC patients prior to chemotherapy initiation based on the Medicare 5% standard analytical file (SAF). Methods: The Medicare 5% SAF was used to investigate claims for women with breast neoplasm and > 1 distant metastatic site (based on ICD-9 diagnosis codes) that subsequently received chemotherapy (based on claims with a chemotherapy J code). Cardiac comorbidities [hypertension (HTN), coronary artery disease (CAD), myocardial function (MI), and congestive heart failure (CHF)] prior to initial chemotherapy were reported as non-mutually exclusive categories. The index quarter was based on chemotherapy initiation that occurred between 7/2001 and 12/2006. Patients were categorized based on receipt of non doxorubicin-based chemotherapy (non-DOX) vs DOX-based chemotherapy. Results: The study included 2,587 women with MBC that received cytotoxic chemotherapy subsequent to the diagnosis of MBC. The mean age was higher in the non-DOX group. Both groups reported a significant proportion of patients with cardiac comorbidities prior to chemotherapy, with greater proportions reported in the non-DOX group (table). Conclusions: Cardiac comorbidities were commonly reported in women with MBC prior to chemotherapy. Such information is useful to health care professionals when considering potential interventions for patients with MBC.

[Table: see text]

[Table: see text]

Biochemical genetic analysis of indanocine resistance in human leukemia

Indanocine is a potent tubulin-binding drug that is cytotoxic to multidrug-resistant cancer cell lines. We demonstrated that indanocine specifically induces apoptosis in malignant B cells from patients with chronic lymphocytic leukemia. To address the exact biochemical basis for indanocine toxicity, an indanocine-resistant clone was selected from mutagenized CEM human lymphoblastoid cells. The resistant cells displayed a stable indanocine-resistant phenotype for at least 9 months in drug-free culture. The cloned cells are cross-resistant to colchicine and vinblastine, but not to paclitaxel, and do not have increased expression of the multidrug-resistant p170 glycoprotein. In both parental cells and cell extracts, indanocine treatment caused tubulin depolymerization. In contrast, the tubulin in the resistant clone did not depolymerize under identical conditions. Both extract mixing and cell fusion experiments suggested that a stable structural change in microtubules, rather than a soluble factor, was responsible for indanocine resistance. Sequence analysis of parental and resistant cells revealed a single point mutation in the M40 isotype of beta-tubulin at nucleotide 1050 (G-->T, Lys(350)-->Asn) in the indanocine-resistant clone, in a region close to the putative colchicine binding site.

Comparative studies on the effects of green tea extracts and individual tea catechins on human CYP1A gene expression

Green tea possesses significant anticancer activity in numerous experimental animal models, including demonstrated protection against aryl hydrocarbon induced cancers. The aryl hydrocarbon receptor (AhR) mediates the transcriptional activation of CYP1A1 and CYP1A2. In the present study, we investigated the effects of commercially available green tea extracts (GTEs) and individual tea catechins on the function of the AhR and on CYP1A gene expression in human hepatoma HepG2 cells and primary cultures of human hepatocytes. GTEs inhibited the transcription of a human CYP1A1 promoter-driven reporter gene induced by the AhR ligand 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) in a concentration-dependent manner and inhibited the induced accumulation of both CYP1A1 and CYP1A2 mRNAs. GTEs blocked TCDD-induced binding of the AhR to DNA in HepG2 cells and in vitro in isolated hepatic cytosol. To determine if the observed effects were due to a single green tea component, we examined the four major catechins present in GTEs. Only (-)-epigallocatechin gallate (EGCG), the most abundant catechin in green tea, was able to inhibit TCDD-induced binding of the AhR to DNA and subsequent CYP1A transcription, however EGCG alone was less effective than GTEs. We next examined GTEs and catechins for AhR agonist activity. GTEs caused a concentration-dependent increase in CYP1A1-promoter driven reporter gene activity and caused accumulation of CYP1A1 mRNA and protein, but we found that individual catechins were unable to induce the expression of CYP1A1. Our results demonstrate that GTEs as a whole exert mixed agonist/antagonist activity on the AhR, while EGCG functions as a strict AhR antagonist. Therefore, modulation of human CYP1A expression by green tea extracts can not be attributed to the action of a single tea catechin, but rather is due to the effects of a complex mixture. These findings may be useful in future studies concerning green tea as a cancer preventive agent.

Rational design, synthesis and structure-activity relationships of antitumor (E)-2-benzylidene-1-tetralones and (E)-2-benzylidene-1-indanones

Novel substituted 6,7-dimethoxy-1-tetralones and 5,6-dimethoxy-1-indanones have been synthesized and evaluated for their cytotoxicity. Compounds with 3'-lipophilic, 3',5'-dilipophilic, or 3',5'-dilipophilic-4'-hydrophilic substituents on (E)-2-benzylidene moiety showed highly cytotoxic effects. The unique structure of 42 possibly matches the pharmacophore features for these cytotoxic compounds.

Indanocine, a microtubule-binding indanone and a selective inducer of apoptosis in multidrug-resistant cancer cells

BACKGROUND

Certain antimitotic drugs have antitumor activities that apparently result from interactions with nontubulin components involved in cell growth and/or apoptotic cell death. Indanocine is a synthetic indanone that has been identified by the National Cancer Institute's Developmental Therapeutics Program as having antiproliferative activity. In this study, we characterized the activity of this new antimitotic drug toward malignant cells.

METHODS

We tested antiproliferative activity with an MTT [i.e., 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay, mitochondrial damage and cell cycle perturbations with flow cytometry, caspase-3 activation with fluorometry, alterations of the cytoskeletal components with immunofluorescence, and antimicrotubule activity with a tubulin polymerization assay.

RESULTS/CONCLUSIONS

Indanocine is a cytostatic and cytotoxic indanone that blocks tubulin polymerization but, unlike other antimitotic agents, induces apoptotic cell death in stationary-phase multidrug-resistant cancer cells at concentrations that do not impair the viability of normal nonproliferating cells. Of the seven multidrug-resistant cell lines tested, three (i.e., MCF-7/ADR, MES-SA/DX5, and HL-60/ADR) were more sensitive to growth inhibition by indanocine than were their corresponding parental cells. Confluent multidrug-resistant cells (MCF-7/ADR), but not drug-sensitive cancer cells (MCF-7) or normal peripheral blood lymphocytes, underwent apoptotic cell death 8-24 hours after exposure to indanocine, as measured by sequential changes in mitochondrial membrane potential, caspase activity, and DNA fragmentation. Indanocine interacts with tubulin at the colchicine-binding site, potently inhibits tubulin polymerization in vitro, and disrupts the mitotic apparatus in dividing cells.

IMPLICATIONS

The sensitivity of stationary multidrug-resistant cancer cells to indanocine suggests that indanocine and related indanones be considered as lead compounds for the development of chemotherapeutic strategies for drug-resistant malignancies.

Differential effects of flavonoid compounds on tumor promoter-induced activation of the human CYP1A2 enhancer

Flavonoids, a family of naturally occurring polyphenolic compounds found in many fruits, nuts, vegetables, and beverages, appear to inhibit tumor promotion as part of their chemopreventive properties. To investigate at the molecular level the ability of flavonoids to inhibit tumor-promoting activity, we developed a cell line designed to screen for flavonoids that block the tumor promoter-mediated induction of activator protein-1 (AP-1) transcriptional activity. This cell line, T2Luc, is a HepG2-derived cell line stably integrated with a region of the human CYP1A2 5'-flanking gene containing two AP-1 binding sites linked to the thymidine kinase promoter-driven firefly luciferase reporter gene. Treatment of T2Luc with a commercial extract of green tea alone had no effect on luciferase activity, but did block the induction of luciferase when cells were further challenged with the tumor promoter phorbol 12-O-tetradecanoate 13-acetate (TPA). In contrast, treatment of cells with the flavonoid quercetin alone activated luciferase activity in a concentration-dependent manner and enhanced the TPA-induced transcription of luciferase. Gel mobility shift assays using nuclear extracts from cells treated with green tea extracts or TPA alone revealed induced binding of AP-1 proteins to the CYP1A2 3'AP-1 site. Pretreatment with green tea extracts did not inhibit the TPA-induced formation of AP-1 complexes. Quercetin treatment alone slightly enhanced binding of AP-1 complexes to this site. Our results suggest that these dietary chemopreventive agents may work through different pathways to modulate gene expression.

Substituted isoquinolines and quinazolines as potential antiinflammatory agents. Synthesis and biological evaluation of inhibitors of tumor necrosis factor alpha

A series of isoquinolin-1-ones and quinazolin-4-ones and related derivatives were prepared and evaluated for their ability to inhibit tumor necrosis factor alpha (TNFalpha) production in human peripheral blood monocytes stimulated with bacterial lipopolysaccharide (LPS). In an effort to optimize the TNFalpha inhibitory activity, a homologous series of N-alkanoic acid esters was prepared. Several electrophilic and nucleophilic substitutions were also carried out. Alkanoic acid esters of four carbons were found to be optimum for activity in both the isoquinoline and quinazoline series. Ring substituents such as fluoro, bromo, nitro, acetyl, and aminomethyl on the isoquinoline ring resulted in a significant loss of activity. Likewise, similar groups on the quinazoline ring also reduced inhibitory activity. However, the 6- and 7-aminoquinazoline derivatives, 75 and 76, were potent inhibitors, with IC(50) values in the TNFalpha in vitro assay of approximately 5 microM for each. An in vivo mouse model of pulmonary inflammation was then used to evaluate promising candidate compounds identified in the primary in vitro assay. Compound 75 was selected for further study in this inhalation model, and was found to reduce the level of TNFalpha in brochoalveolar lavage fluid of LPS-treated mice by about 50% that of control mice. Thus, compounds such as 75, which can effectively inhibit proinflammatory cytokines such as TNFalpha in clinically relevant animal models of inflammation and fibrosis, may have potential as new antiinflammatory agents. Finally, a quinazoline derivative suitable to serve as a photoaffinity radiolabeled compound was prepared to help identify the putative cellular target(s) for these TNFalpha inhibitors.

Species differences in hepatocyte induction of CYP1A1 and CYP1A2 by omeprazole

Omeprazole, a proton pump inhibitor therapeutically administered for the treatment of gastric ulcers, induces the expression of cytochromes P4501A1/2 (CYP1A1/2) through transcriptional activation mediated by the Ah-dioxin)-receptor. Primary cultures of hepatocytes isolated from rabbit, rat, mouse and human livers were compared for CYP1A1/2 mRNA inducibility by omeprazole (1 to 100 microM). Primary cultures of human hepatocytes were the most sensitive to the inducing effects of omeprazole. Rabbit hepatocytes were the only other cells studied that showed induced CYP1A1/2 mRNA expression from a concentration lower than 100 microM (i.e., 10 microM). Rat hepatocytes were the least sensitive to omeprazole induction. The response of mouse hepatocytes to omeprazole treatment was variable, with CYP1A1/2 mRNA expression being induced in only two of the three cultures examined. Differences in the time dependence of CYP1A1/2 mRNA expression were observed between species. In general, after treatment of hepatocytes with omeprazole the levels of CYP1A1 mRNA peaked prior to that of CYP1A2 mRNA. Due to the interspecific variability of CYP1A mRNA inducibility by omeprazole, we conclude that human hepatocytes in culture are probably the only appropriate animal model for prediction of CYP1A induction in humans.