Impact of COVID-19 pandemic on head-neck cancer referral and treatment pathway in North East London

INTRODUCTION

The COVID-19 pandemic has led to wide-ranging disruption of head-neck cancer (HNC) service provision in the UK. Early reports suggest delays in referral, diagnosis and initiation of treatment for new cancer cases compared with before the pandemic.

METHODS

The HNC service was studied retrospectively for the time-periods between 1 January 2020 to 31 October 2020 (hereafter 'post-COVID') and 1 January 2019 to 31 October 2019 (hereafter 'pre-COVID'). We analysed: (1) the number of cases treated at our centre, (2) stage of disease at presentation and (3) treatment delivery times.

RESULTS

In the post-COVID period, the total number of HNC cases treated decreased (48 vs 56 pre-COVID). There was increase in advanced stage at presentation (58% vs 42% pre-COVID) and a significant increase in the need for airway stabilisation (13 vs 5 pre-COVID; p=0.03). Average time from referral to treatment was significantly prolonged (72.5 days vs 49.23 days pre-COVID; p=0.03). Two-week wait referrals were seen in HNC clinics at median time of 11.9 days, compared with 7.1 days during the pre-COVID period (p=0.07). However, there was no delay in the initiation of first treatment after the decision to treat (29.2 days vs 24.7 days pre-COVID; p=0.58).

CONCLUSION

The results of this study call for early referral at the primary care level and rapid radiopathological confirmation at the tertiary level to prevent delays in diagnosis of new HNC cases.

Head-neck dissection course during COVID-19 pandemic: challenges, adaptations and how we did it

INTRODUCTION

Cadaveric dissection courses have come to a standstill since the onset of the COVID-19 pandemic. In addition to limited operative opportunities, cancellation of such courses has severely impacted surgical training, especially in a craft-based specialty such as head-neck surgery. The aim of this educational project was to: (1) study the feasibility of an in-person head-neck cadaveric dissection course during COVID-19 pandemic; and (2) validate the educational benefit of this teaching method to ear, nose and throat (ENT) trainees.

METHODS

We developed a 2-day head-neck cadaveric dissection course for ENT trainees. The course programme covered essential head-neck open surgical procedures. Content validity (subjective feedback) was assessed using a 5-point Likert scale. Construct validity (objective usefulness) was evaluated via two pre- and post-course questionnaires, estimating knowledge of head-neck surgical anatomy and self-assessment of levels of confidence with head-neck procedures, respectively.

RESULTS

A risk assessment was conducted and a protocol developed (risk was deemed to be low/tolerable). Content validity showed high satisfaction compared with a median Likert score of 3, 'average' (p=0.000002). For construct validity, the mean score per question improved significantly (p=0.001). Overall levels of confidence showed a trend towards improvement (p=0.08). There was significant improvement in laryngectomy (p=0.01) and level I dissection (p=0.01), with an indication of improvement in level II-V dissection (p=0.07).

CONCLUSIONS

We demonstrated that a cadaveric dissection course, using thorough risk assessment and protocol, could be safely conducted with high content and construct validation during these unprecedented times. This is an invaluable learning environment that needs to be encouraged despite infection control restrictions.

Childhood Cancer in an LMIC: Navigating the Wilderness

Background and context: When a child has cancer, the entire family is affected. Parents and caregivers lose work days while caring for the child. Many parents blame themselves and wonder if some action or decision of theirs contributed to; or caused the cancer. In addition, and especially for families falling within the low socioeconomic demographic groups, there may be poor understanding of the treatment process and expectations from treatment. Aim: To assess the most common challenges or concerns faced by parents, family members, or caregivers of a child living with cancer in Nigeria. Strategy/Tactics: A series of 10 focus group sessions were held with different groups of parents, family members, or other caregivers of children being treated for cancer at 2 teaching hospitals in Nigeria. Groups consisted of a minimum 8, and maximum of 12 participants in addition to a moderator. At the beginning of every session, participants were asked to submit 2 most pressing questions. Open-ended questions were also used with every attendee given a turn to give their answer. Participants were also given a chance to ask questions or bring up issues they had difficulty with. The single most prevalent concern raised in every focus group was lack of information or understanding. The 2 most common questions were: 1. What is cancer? 2. Why does my child have cancer? Program/Policy process: Data from the sessions were painstakingly compiled. The questions and concerns the attendee raised; and the degree of understanding they had regarding the diagnosis, treatment process, and expectations bring and after treatment. This data were collated and a team of experts including oncologists, nurses, and health workers in cancer were brought together to answer the questions. A compilation was made and a plan to disseminate the information was formulated. This culminated in the publishing of a free childhood cancer handbook; the first of its kind in Nigeria; with plans to translate the handbook into the common colloquial and vernacular languages in Nigeria. Outcomes: Participants of the focus groups were given a handbook, including some whose child had passed on since the sessions were held. 29% of the original participants were unreachable or declined the handbook. They were assessed to see if the handbook provided information that could have eased their cancer journey. 91% of assessed participants responded that having the handbook at diagnosis would have significantly increased their level of information and made the cancer journey easier. [Figure: see text][Figure: see text] The most appreciated information in the handbook was contact details of an organization dedicated to supporting them financially to pay treatment fees. What was learned: Many Nigerian families go through the entire childhood cancer journey completely in the dark. No dedicated information source on child cancer exists in Nigeria. Many parent and caregiver questions remain unanswered, and concerns remain unresolved.[Figure: see text]

Tumour cell-derived extracellular vesicles interact with mesenchymal stem cells to modulate the microenvironment and enhance cholangiocarcinoma growth

The contributions of mesenchymal stem cells (MSCs) to tumour growth and stroma formation are poorly understood. Tumour cells can transfer genetic information and modulate cell signalling in other cells through the release of extracellular vesicles (EVs). We examined the contribution of EV-mediated inter-cellular signalling between bone marrow MSCs and tumour cells in human cholangiocarcinoma, highly desmoplastic cancers that are characterized by tumour cells closely intertwined within a dense fibrous stroma. Exposure of MSCs to tumour cell–derived EVs enhanced MSC migratory capability and expression of alpha-smooth muscle actin mRNA, in addition to mRNA expression and release of CXCL-1, CCL2 and IL-6. Conditioned media from MSCs exposed to tumour cell–derived EVs increased STAT-3 phosphorylation and proliferation in tumour cells. These effects were completely blocked by anti-IL-6R antibody. In conclusion, tumour cell–derived EVs can contribute to the generation of tumour stroma through fibroblastic differentiation of MSCs, and can also selectively modulate the cellular release of soluble factors such as IL-6 by MSCs that can, in turn, alter tumour cell proliferation. Thus, malignant cells can “educate” MSCs to induce local microenvironmental changes that enhance tumour cell growth.

Abstract 182: Increased Adipose-Derived Mesenchymal Stem Cells Counts and Pro-B-Type Natriuretic Peptide in Patients With Critical Limb Ischemia

Mesenchymal stem cells (MSCs) have been shown to improve regeneration of injured tissues in vivo. Several in vitro studies and animal models have demonstrated improvement in MSCs paracrine effects under hypoxic conditions. Moreover, several studies suggested that the pro B-type natriuretic peptide (pro-BNP) could be involved in the stimulation of postischemic vascular regeneration. The purpose of this study was to investigate the effect of critical limb ischemia, in a human model, on in-situ adipose derived mesenchymal stem cells (ADMSCs) and to determine whether serum levels of N-terminal pro-BNP correlate with ADMSCs counts and associated paracrine effects.

Lipoaspirate samples of ≥ 10mL were collected from ischemic limbs (ischemic group) and compared to control (without ischemia). MSCs were characterized by frequency, viability, differentiation potential, cytokines expression, and cell surface markers. Serum NT pro-BNP was measured as well.

MSCs counts were 9-to-10-fold higher in patients with ischemic limbs (mean 7952 MSC/mL ± 542) than controls (mean 790 MSC/mL ± 65). Pro-BNP levels (1878-4757 pg/mL) were approximately 8-to-26-fold higher than in age- and sex-matched controls. Furthermore, there were positive correlations between pro-BNP levels and MSCs counts in the ischemic group.

In conclusion, patients with critical limb ischemia (CLI) have higher levels of pro-BNP and MSCs counts than controls. Increased levels of pro-BNP and MSCs counts can be considered humoral and cellular surrogates of ischemia and hypoxia in patients with CLI. This supports recent studies that suggest that the increase production of peripheral BNP may be a stem cells-mediated response to stimulate angiogenesis in the ischemic skeletal muscles.

Post-GWAS: where next? More samples, more SNPs or more biology?

The power of genome-wide association studies (GWAS) rests on several foundations: (i) there is a significant amount of additive genetic variation, (ii) individual causal polymorphisms often have sizable effects and (iii) they segregate at moderate-to-intermediate frequencies, or will be effectively 'tagged' by polymorphisms that do. Each of these assumptions has recently been questioned. (i) Why should genetic variation appear additive given that the underlying molecular networks are highly nonlinear? (ii) A new generation of relatedness-based analyses directs us back to the nearly infinitesimal model for effect sizes that quantitative genetics was long based upon. (iii) Larger effect causal polymorphisms are often low frequency, as selection might lead us to expect. Here, we review these issues and other findings that appear to question many of the foundations of the optimism GWAS prompted. We then present a roadmap emerging as one possible future for quantitative genetics. We argue that in future GWAS should move beyond purely statistical grounds. One promising approach is to build upon the combination of population genetic models and molecular biological knowledge. This combined treatment, however, requires fitting experimental data to models that are very complex, as well as accurate capturing of the uncertainty of resulting inference. This problem can be resolved through Bayesian analysis and tools such as approximate Bayesian computation-a method growing in popularity in population genetic analysis. We show a case example of anterior-posterior segmentation in Drosophila, and argue that similar approaches will be helpful as a GWAS augmentation, in human and agricultural research.

Therapeutic apheresis: when things go wrong

Therapeutic apheresis medicine requires in-depth knowledge of physiology, disease mechanisms as well as a thorough understanding of the parameters that can be adjusted in the instrument that are used. We report two cases where critical decision making was crucial during management of patients being treated with therapeutic apheresis. Case 1 involves an adult patient with severe circulating cryoglobulins and Case 2 describes a patient with Waldenström's macroglobulinemia and hyperviscosity. Both cases demonstrate the importance of readily available expert supervision of therapeutic apheresis procedures.

Early neutrophil engraftment following autologous BMT provides a functional predictor of long-term hematopoietic reconstitution

BACKGROUND

Previous studies have demonstrated that the number of CD34+ progenitor cells in the stem cell graft is highly predictive of the rapidity of short-term hematopoietic engraftment. The aim of this study was to identify factors that predict long-term hematopoietic reconstitution (LHR) following autologous BMT.

STUDY DESIGN AND METHODS

To identify predictors of LHR, peripheral blood counts and marrow biopsies were evaluated at 1 year after transplant in 81 patients with B-cell non-Hodgkin's lymphoma (NHL) or chronic lymphocytic leukemia who underwent autologous BMT. Results were correlated with CD34+ cell dose, granulocyte-monocyte colony-forming units (CFU-GM) infused, and time to neutrophil engraftment (TNE).

RESULTS

Total MNC dose, CD34+ cell dose, and CFU-GM infused were significantly associated with TNE (p = 0.011, p < 0.0001, and p = 0.078, respectively). Patients with chronic lymphocytic leukemia were more likely to have received a low CD34+ cell dose than patients with B-cell non-Hodgkin's lymphoma (p = 0.01). Among the four principal predictors, only TNE showed consistent significant correlation with WBC, absolute neutrophil, and platelet count at 1 year after transplant. Logistic regression model showed that TNE was a more sensitive predictor of LHR than either CD34+ cell dose or CFU-GM infused.

CONCLUSION

TNE is an in vivo functional measure of LHR and is a more sensitive predictor of LHR at 1 year after BMT than either CD34+ cell dose or CFU-GM infused.

Nitrate removal by simultaneous sulfur utilizing autotrophic and heterotrophic denitrification under different organics and alkalinity conditions: batch experiments

The effect of various organic compounds were tested using lab-scale batch reactors. At sufficient alkalinity, the initial nitrate nitrogen concentration of 100 mg/L was completely reduced in all batch reactors. Sulfate production decreased by the addition of organics. The concentration range of organics used in this experiment did not inhibit autotrophic denitrification except for propionate. Propionate inhibited autotrophic denitrification a little, indicated by a lower sulfate production rate. Biomass in suspension increased with higher initial organic concentrations, showing higher DOC consumption. As the concentration of organics increased, alkalinity increased accordingly. Under the conditions of low alkalinity, in the case of a control reactor without organics, only about 30% of the initial nitrate was reduced. With half the theoretically required dosage of methanol, the denitrification rates increased slightly. When ethanol, acetate, and propionate were used, denitrification went to completion. When excess organics was added, however, sulfate production was significantly decreased. Interestingly, even when small amounts of organics were added, autotrophic denitrification was promoted as indicated by the sulfate production.

[Effect of iron compounds on the treatment of fat-containing wastewaters]

Effects of iron compounds on methanogenic fermentation the water polluted with fatty acids were studied. A natural readily available source of iron applicable to biological treatment of liquid wastes was searched for. A positive effect of iron on the methanogenic fermentation of fats and their degradation products--long-chain fatty acids--in aqueous media was demonstrated. It is recommended to add iron-containing clay, as an inexpensive and easily available iron source, in amounts providing the binding of the long-chain fatty acids present in wastewaters.

Two Listeria monocytogenes vaccine vectors that express different molecular forms of human papilloma virus-16 (HPV-16) E7 induce qualitatively different T cell immunity that correlates with their ability to induce regression of established tumors immortalized by HPV-16

Two recombinant Listeria monocytogenes (rLm) strains were produced that secrete the human papilloma virus-16 (HPV-16) E7 protein expressed in HPV-16-associated cervical cancer cells. One, Lm-E7, expresses and secretes E7 protein, whereas a second, Lm-LLO-E7, secretes E7 as a fusion protein joined to a nonhemolytic listeriolysin O (LLO). Lm-LLO-E7, but not Lm-E7, induces the regression of the E7-expressing tumor, TC-1, established in syngeneic C57BL/6 mice. Both recombinant E7-expressing rLm vaccines induce measurable anti-E7 CTL responses that stain positively for H-2D(b) E7 tetramers. Depletion of the CD8+ T cell subset before treatment abrogates the ability of Lm-LLO-E7 to impact on tumor growth. In addition, the rLm strains induce markedly different CD4+ T cell subsets. Depletion of the CD4+ T cell subset considerably reduces the ability of Lm-LLO-E7 to eliminate established TC-1 tumors. Surprisingly, the reverse is the case for Lm-E7, which becomes an effective anti-tumor immunotherapeutic in mice lacking this T cell subset. Ab-mediated depletion of TGF-beta and CD25+ cells improves the effectiveness of Lm-E7 treatment, suggesting that TGF-beta and CD25+ cells are in part responsible for this suppressive response. CD4+ T cells from mice immunized with Lm-E7 are capable of suppressing the ability of Lm-LLO-E7 to induce the regression of TC-1 when transferred to tumor-bearing mice. These studies demonstrate the complexity of L. monocytogenes-mediated tumor immunotherapy targeting the human tumor Ag, HPV-16 E7.

Evaluation of a recombinant Listeria monocytogenes expressing an HIV protein that protects mice against viral challenge

Vaccine strategies that utilize cell mediated immunity to control infection will be a necessary component of human immunodeficiency virus (HIV) vaccines. In previous studies we have shown that a Listeria monocytogenes recombinant expressing HIV-Gag elicits strong CD8+ and CD4+ T cell responses against HIV Gag in addition to its own secreted proteins. Here, we show that Lm-Gag can protect mice against a viral challenge with a recombinant vaccinia virus expressing Gag, in an antigen specific manner, and that this protection is T cell mediated. These results further support the use of L. monocytogenes as a vaccine approach for HIV through the induction of T cell immunity.

Expression of alpha-melanocyte stimulating hormone and the invasive ability of the B16 murine melanoma

The expression of alpha melanocyte stimulating hormone (MSH) has been investigated in two variants of the B16 murine melanoma. The presence of MSH was demonstrated by immunohistochemical methods using anti-MSH antibodies. The low metastasis variant B16-F1, which grows as an encapsulated non-invasive tumour, showed no alpha-MSH immunoreactivity. In contrast, the high metastasis variant BL6 was found to be alpha-MSH positive and the immunoreactivity was found predominantly in the peripheral invading zones of the tumour.