The Effects of Human Papillomavirus Status and Treatment on the Positive Predictive Value of Post-radiotherapy 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Advanced Head and Neck Squamous Cell Carcinoma

AIMS

The high negative predictive value of post-chemoradiation (CRT) positron emission tomography-computed tomography (PET-CT) is well established in head and neck squamous cell cancers (HNSCC). The positive predictive value (PPV) remains under scrutiny, with increasing evidence that it is affected by several factors. The aim of this study was to assess the PPV of post-treatment PET-CT for residual nodal disease when stratified by treatment modality and tumour human papillomavirus (HPV) status.

MATERIALS AND METHODS

This was a retrospective cohort study in a tertiary oncology centre carried out between January 2013 and December 2019. Patients were radically treated with radiotherapy only/CRT for node-positive HNSCC. PET-CT nodal responses were categorised as complete, equivocal (EQR) or incomplete (ICR), and outcomes extracted from electronic records.

RESULTS

In total, 480 patients were evaluated, all had a minimum potential follow-up of 2 years, with a median of 39.2 months. The PPV of 12-week PET-CT was significantly different between HPV-positive (22.5%) and HPV-unrelated (52.7%) disease, P < 0.001. It was also significantly different between the CRT (24.8%) and radiotherapy-only (51.1%) groups, P = 0.001. The PPV of an EQR was significantly less than an ICR, irrespective of HPV status and primary treatment modality. In HPV-positive disease, the PPV of an EQR was 9.0% for the CRT group compared with 21.4% for radiotherapy only, P = 0.278. The PPV in those who achieved an ICR was 34.2% in the CRT group, significantly lower than 70.0% in the radiotherapy-only group, P = 0.03.

CONCLUSION

The PPV of 12-week PET-CT is significantly lower for HPV-positive compared with HPV-unrelated HNSCC. It is poorer in patients with HPV-positive disease treated with CRT compared with radiotherapy alone.

Positron Emission Tomography-Computed Tomography Surveillance after (Chemo)Radiotherapy in Advanced Head and Neck Squamous Cell Cancer: Beyond the PET-NECK Protocol

AIMS

To evaluate the implementation of 18-fluorodeoxyglucose positron emission tomography-computed tomography (FDG PET-CT) surveillance after (chemo)radiotherapy, to compare outcomes for those who achieved a complete (CR), equivocal (EQR) and incomplete (ICR) nodal response on 12-week PET-CT according to their human papillomavirus (HPV) status, and to assess the safety of ongoing surveillance beyond 12 weeks in the HPV-positive EQR group.

MATERIALS AND METHODS

All patients with node-positive head and neck squamous cell carcinoma (HNSCC) treated with (chemo)radiotherapy between January 2013 and September 2017 were identified. PET-CT responses were classified as CR, ICR or EQR. Patient outcomes were obtained from electronic records.

RESULTS

In total, 236 patients with a minimum of 2 years of follow-up were identified. The mean age was 59 years; 79.3% had N2 disease; 77.1% of patients had oropharyngeal cancer and 10.1% had squamous cell carcinoma of unknown primary, of whom 82.0% (169) were HPV positive; 78.0% received chemoradiotherapy. The median time from the end of radiotherapy to PET-CT was 91 days. Of the HPV-related HNSCC, 60.4% achieved CR, 29.0% EQR and 10.6% ICR. With a median follow-up of 41.7 months, there was no difference in survival between patients with HPV-related HNSCC achieving CR and EQR (median overall survival not reached for both, P = 0.67) despite the omission of immediate neck dissection in 98.0% of the EQR group.

CONCLUSION

Patients with HPV-positive HNSCC who have achieved EQR have comparable survival outcomes to those who achieved a CR despite the omission of immediate neck dissections; this shows the safety of ongoing surveillance beyond 12 weeks in this group of patients.

P5472Social economic deprivation and adverse clinical outcomes after acute coronary syndrome

Background

NHS was created in 1948 to redress the healthcare inequality through provision of universal healthcare service in the UK. However even of late, significant health inequality persists. Socioeconomic deprivation is known to result in increased overall morbidity and mortality.

Aim

To assess the impact of socioeconomic deprivation (as categorised by Scottish Index of Multiple Deprivation, SIMD) on the medical management and clinical outcomes of patients with ACS (NSTEMI/STEMI) who were treated with PCI

Methods

A retrospective study of NSTEMI/NSTEMI patients after inpatient treatment with coronary angiogram and PCI. The parameters include basic demographics, risk factors, LV EF on echocardiogram, lipid profile and discharge medication. Individual's socioeconomic deprivation index, as described SIMD was also recorded (1 – most deprived and 10 – least deprived), and accordingly placed into quintile (SIMD 1–2, 3–4, 5–6,7 –8, 9–10). Follow-up for 24 months. Clinical outcome assessed was composite endpoint event of MACE.

Results

357 from the lowest quintile (SIMD 1–2), 319 from SIMD 3–4, 191 from SIMD 5–6, 120 from SIMD 7–8, and 99 from the highest quintile (SIMD 9–10) were included. No statistical difference exists between age or gender. No difference in past medical history (inclusive of hypertension, diabetes, dyslipidemia, family history. No difference in incidence of nicotine use.

Prescription of aspirin, P2Y12 inhibitors (clopidogrel, ticagrelor or prasugrel) as well as secondary prevention medications (such as ace inhibitor/angiotensin II receptor blocker, beta blocker, statin and GTN) were good and not statistically different between all groups.

No statistical difference exists between all groups relating to pre-discharge LV ejection fraction on echocardiogram or random cholesterol level check on admission.

24 months follow-up demonstrated composite endpoint of MACE was statistically higher among patients of lowest socioeconomic quintile (Kaplan Meier plot, p<0.001). Step-wise multiple regression analysis also confirmed multiple socioeconomic deprivation as an independent predictor for more adverse clinical outcomes (p<0.001, R2=14.5%).

Patients from the least deprived quintile possess survival advantage almost 14-folds as compared to those of most deprived group (Odd-ratio 13.8 (95% CI: 39.4–48.5)).

Summary

After an ACS event, despite initial coronary intervention and subsequent optimal prescription of prognostically beneficial secondary prevention medications, patients from the lower socioeconomic group (as described by SIMD) are still more likely to experience readmission for cardiovascular death, non-fatal myocardial infarction and non-fatal stroke. Socioeconomic deprivation has been shown to be an independent predictor of adverse clinical outcome for those who survived initial ACS.

Acknowledgement/Funding

None

Influence of the level of sacrectomy on survival in patients with locally advanced and recurrent rectal cancer

BACKGROUND

Exenterative surgery for locally advanced rectal cancer may involve partial sacrectomy to achieve complete resection. High sacrectomy is technically challenging, and can be associated with high morbidity and mortality rates. The aim of this study was to determine the influence of the level of sacrectomy on the survival of patients with locally advanced rectal cancer.

METHODS

This was an international multicentre retrospective analysis of patients undergoing exenterative abdominosacrectomy between July 2006 and June 2016. High sacrectomy was defined as resection at or above the junction of S2-S3; low sacrectomy was below the S2-S3 junction. Kaplan-Meier survival analysis was used to assess overall survival and cancer-specific survival. Predictive factors were determined using Cox regression analysis.

RESULTS

A total of 345 patients were identified, of whom 91 underwent high sacrectomy and 254 low sacrectomy. There was no difference in 5-year overall survival (53 versus 44·1 per cent; P = 0·216) or cancer-specific survival (60 versus 56·1 per cent; P = 0·526) between high and low sacrectomy. Negative margin rates were similar for primary and recurrent disease: 65 of 90 (72 per cent) versus 97 of 153 (63·4 per cent) (P = 0·143). Level of sacrectomy was not a significant predictor of mortality (P = 0·053). Positive resection margin and advancing age were the only significant predictors for death, with hazard ratios of 2·78 (P < 0·001) and 1·02 (P = 0·020) respectively.

CONCLUSION

There was no survival difference between patients who underwent high or low sacrectomy. In appropriately selected patients, high sacrectomy is feasible and safe.

The relationship of systemic markers of haemostasis with retinal blood vessel responses in cardiovascular disease and/or diabetes

Background Hypercoagulability is a leading factor in diabetes and cardiovascular disease. Retinal vessel responses to flickering light are an important tool for assessing ocular function. We hypothesised a significant relationship between systemic markers of haemostasis and retinal vessel function. Methods Intra-ocular pressure and retinal microcirculation function were measured in 116 patients with diabetes and/or cardiovascular disease using unstimulated and stimulated arterial and venous retinal vessel responses to flickering light. Haemostasis was evaluated by platelet microparticles, soluble P selectin, and five functional markers of fibrin clot formation and lysis, hyperglycaemia by HbA1c. Results Intra-ocular pressure was linked to the rates of clot formation (p = 0.006) and clot dissolution (p = 0.013) whilst central retinal vein equivalent was linked to HbA1c (p = 0.017). In the first of three flickering light cycles only, arterial baseline diameter fluctuation was linked to the lag time to clot formation (p = 0.017), whilst maximum venous dilatation was linked to HbA1c (p = 0.001) and clot density (p = 0.011). HbA1c was linked to venous dilatation amplitude (p = 0.003). There were no significant links between any ocular index and any platelet index. Conclusions In addition to glycaemia, several haemostasis measures, but no measures of platelet activity, are linked to ocular and retinal blood vessel indices in patients with diabetes and/or cardiovascular disease. These associations may have pathophysiological significance.

Laboratory assessment of anti-thrombotic therapy in heart failure, atrial fibrillation and coronary artery disease: insights using thrombelastography and a micro-titre plate assay of thrombogenesis and fibrinolysis

As heart failure, coronary artery disease and atrial fibrillation all bring a risk of thrombosis, anti-thrombotic therapy is recommended. Despite such treatment, major cardiovascular events such as myocardial infarction and stroke still occur, implying inadequate suppression of thrombus formation. Accordingly, identification of patients whose haemostasis remains unimpaired by treatment is valuable. We compared indices for assessing thrombogenesis and fibrinolysis by two different techniques in patients on different anti-thrombotic agents, i.e. aspirin or warfarin. We determined fibrin clot formation and fibrinolysis by a microplate assay and thromboelastography, and platelet marker soluble P selectin in 181 patients with acute or chronic heart failure, coronary artery disease who were taking either aspirin or warfarin. Five thromboelastograph indices and four microplate assay indices were different on aspirin versus warfarin (p < 0.05). In multivariate regression analysis, only microplate assay indices rate of clot formation and rate of clot dissolution were independently related to aspirin or warfarin use (p ≤ 0.001). Five microplate assay indices, but no thrombelastograph index, were different (p < 0.001) in aspirin users. Three microplate assay indices were different (p ≤ 0.002) in warfarin users. The microplate assay indices of lag time and rate of clot formation were abnormal in chronic heart failure patients on aspirin, suggesting increased risk of thrombosis despite anti-platelet use. Soluble P selectin was lower in patients on aspirin (p = 0.0175) but failed to correlate with any other index of haemostasis. The microplate assay shows promise as a tool for dissecting thrombogenesis and fibrinolysis in cardiovascular disease, and the impact of antithrombotic therapy. Prospective studies are required to determine a role in predicting thrombotic risk.

The relationship of systemic markers of renal function and vascular function with retinal blood vessel responses

PURPOSE

To test the hypothesis of a significant relationship between systemic markers of renal and vascular function (processes linked to cardiovascular disease and its development) and retinal microvascular function in diabetes and/or cardiovascular disease.

METHODS

Ocular microcirculatory function was measured in 116 patients with diabetes and/or cardiovascular disease using static and continuous retinal vessel responses to three cycles of flickering light. Endothelial function was evaluated by von Willebrand factor (vWf), endothelial microparticles and soluble E selectin, renal function by serum creatinine, creatinine clearance and estimated glomerular filtration rate (eGFR). HbA1c was used as a control index.

RESULTS

Central retinal vein equivalence and venous maximum dilation to flicker were linked to HbA1c (both p < 0.05). Arterial reaction time was linked to serum creatinine (p = 0.036) and eGFR (p = 0.039); venous reaction time was linked to creatinine clearance (p = 0.018). Creatinine clearance and eGFR were linked to arterial maximum dilatation (p < 0.001 and p = 0.003, respectively) and the dilatation amplitude (p = 0.038 and p = 0.048, respectively) responses in the third flicker cycle. Of venous responses to the first flicker cycle, HbA1c was linked to the maximum dilation response (p = 0.004) and dilatation amplitude (p = 0.017), vWf was linked to the maximum constriction response (p = 0.016), and creatinine clearance to the baseline diameter fluctuation (p = 0.029). In the second flicker cycle, dilatation amplitude was linked to serum creatinine (p = 0.022).

CONCLUSIONS

Several retinal blood vessel responses to flickering light are linked to glycaemia and renal function, but only one index is linked to endothelial function. Renal function must be considered when interpreting retinal vessel responses.

One-stage posterior decompression and fusion using a Luque rod for occipito-cervical instability and neural compression

STUDY DESIGN

Original article.

OBJECTIVE

The authors present seven cases who underwent one-stage suboccipital, C1 and/or C2 posterior decompression and fusion by Luque rod, wiring and autogenic bone graft for occipito-cervical instability and neural compression.

SETTING

Chang Gung University and Medical Center at Kaohsiung, Taiwan.

METHOD

Since January 1996, 20 cases of craniovertebral and upper cervical spinal instability were encountered. Seven of these cases had no neurological improvment under Cone-Barton Skeletal traction. Imaging studies revealed poor reduction with persistent neural compression. One patient underwent unsuccessful anterior trans-oral vertebrectomy for decompression. All patients underwent posterior suboccipital craniectomy, C1 and/or C2 laminectomy for decompression. Contoured Luque rod with wiring and autogeneic bone graft was used for craniocervical fusion. After surgical treatment, halo-vest or sterno-occipito-mandibular immobilizer (SOMI) was used for 3-6 months.

RESULTS

Suboccipital craniectomy and C1 laminectomy could afford a 30-50% increment of anteroposterior diameter in the neural canal and effective decompression of the low medulla and cord. All patients made neurological improvement. The ASIA-MIS scores improved from pre-operative 49 (mean) to 78. Four patients can walk without any support. There were no major complications except for one case requiring readjustment of the halo-vest brace.

CONCLUSION

The authors recommend this procedure as one choice for relieving craniocervical instability with neurological compromise. A programmed rehabilitation will afford better neurological improvement.

Study of low-temperature thermoplastic modified custom-molded cervical orthosis for cervical spine fixation

The purpose of this experiment is to use a low-temperature thermoplastic material (Aquaplast) to make a modified custom-molded cervical orthosis. Sixteen normal young subjects who do not have previous cervical problems are tested in this study. This modified orthosis is applied on these volunteers so that external fixation of the cervical spine can be tested. Various roentgenograms for cervical flexion and extension, as well as neutral position and lateral bending, are taken to determine the fixation property of the cervical spine. A study of rotation of the cervical spine is also carried out through goniometer measurements. This clinical study proves that this low-temperature thermoplastic cervical orthosis provides good fixation for the cervical spine, especially in flexion and rotation, but is not suitable for C1- and C2-injured patients.

Control of Rancidity in Frozen Pacific Herring, Clupea harengus pallasi: Use of Sodium Erythorbate

The effectiveness of 1% sodium erythorbate (NaER) and other treatments for retarding the development of rancidity was studied in Pacific herring, Clupea harengus pallasi, fillets stored at −28 °C. Dipping of fillets in NaER significantly decreased fat oxidation. Glazing with NaER was more effective than a water glaze alone. The addition of NaER to water used for enclosing fillets in ice blocks increased the protection against rancidity. All tested NaER applications were less effective in retarding rancidity than the vacuum packaging. Erythorbic acid uptake by the flesh reaching 0.2% caused a deterioration of the flavor, whereas uptake of 0.05% or less led to no discernible alterations in flavor or appearance. Therefore, when used at low levels (uptake ≤0.05%), NaER has a potential value for extending the storage life of frozen herring. Key words: Pacific herring, Clupea harengus pallasi, control of rancidity, sodium erythorbate, frozen storage

Time--concentration studies by high-performance liquid chromatography of metabolites removed during hemodialysis

Reversed-phase high-performance liquid chromatography was used to study the efficiency of hemodialysis. The method, previously used to study uremic hemodialysate, was also found useful for analyzing other uremic biofluids, such as serum and urine. Samples of blood (centrifuged to obtain cell-free serum) and hemodialysate were simultaneously collected from selected patients at regular intervals during the entire 6-hour hemodialysis treatment. These samples were filtered through membranes to remove particulates and proteins and were then analyzed by use of a 60-cm muBondapak-C18 column, an aqueous sodium acetate/methanol gradient, and detection at 254 nm. The identification of components in the eluate was based on retention times, ultraviolet absorption spectra, and mass spectra. From the amounts of several metabolites in the various physiological fluid pools during hemodialysis, we concluded that they mostly originate from tissue fluids. We also observed that the concentrations of most components in serum and hemodialysate fluctuated regularly with time.

Time--concentration studies by high-performance liquid chromatography of metabolites removed during hemodialysis

Reversed-phase high-performance liquid chromatography was used to study the efficiency of hemodialysis. The method, previously used to study uremic hemodialysate, was also found useful for analyzing other uremic biofluids, such as serum and urine. Samples of blood (centrifuged to obtain cell-free serum) and hemodialysate were simultaneously collected from selected patients at regular intervals during the entire 6-hour hemodialysis treatment. These samples were filtered through membranes to remove particulates and proteins and were then analyzed by use of a 60-cm muBondapak-C18 column, an aqueous sodium acetate/methanol gradient, and detection at 254 nm. The identification of components in the eluate was based on retention times, ultraviolet absorption spectra, and mass spectra. From the amounts of several metabolites in the various physiological fluid pools during hemodialysis, we concluded that they mostly originate from tissue fluids. We also observed that the concentrations of most components in serum and hemodialysate fluctuated regularly with time.

Chill Stowage and Development of Rancidity in Frozen Pacific Herring, Clupea harengus pallasi

Freshly caught Pacific herring, Clupea harengus pallasi, were stowed in ice or refrigerated seawater (RSW) at −0.8 °C for 0, 2, and 4 d and were then filleted and stored frozen (−28 °C) for up to 11 mo. The development of rancidity was determined using the peroxide value and the thiobarbituric acid number. During the chill stowage before freezing, the lipids from the flesh were not subjected to any significant oxidation. In Cryovac-vacuum-packed fillets the rancidity remained at low levels during the duration of frozen storage. If oxygen was present during frozen storage, chill stowage accelerated the development of rancidity and this effect was more pronounced in the case of RSW than ice, especially after 4 d of stowage. Key words: Pacific herring, Clupea harengus pallasi, rancidity, icing, refrigerated seawater, frozen storage

Treatments Before Frozen Storage Affecting Thaw Drip Formation in Pacific Salmon

Freshly caught chum salmon, Oncorhynchus keta, were stored in ice or refrigerated seawater for 0.3 and 10 days and were then gutted and frozen at two different rates (1 or 14.5 h through the temperature range of 0 to −5 °C). The amount of thaw drip (TD) was determined in steaks following 1.5, 4, 8, and 12 mo of storage at −28 °C. A significant increase in TD occurred with the slow freezing rate or with a delay before freezing. These effects were not suppressed by a prolonged frozen storage, which also produced an increase in TD. There was no marked difference between fish held in ice and refrigerated seawater before freezing. Similar results were obtained with coho salmon, O. kisutch, frozen without prior chill stowage. Key words: Pacific salmon, thaw drip, chill stowage, freezing rates Oncorhynchus keta, O. kisutch

Lysosomal Triglyceride Lipase from the Lateral Line Tissue of Rainbow Trout (Salmo gairdneri)

An acid lipase active toward tripalmitin and having the characteristics of lysosomal enzymes was shown to occur in the red lateral line tissue of rainbow trout (Salmo gairdneri). The enzyme showed maximum activity at pH 4–4.5. Triton X-100 (0.2–2.0%) strongly stimulated the activity of the acid lipase, but it inhibited markedly the lipolytic activity above pH 7. NaF (20 mM) and Na-p-chloromercuriphenyl-sulfonate (1 mM) partially inhibited the acid lipase. Fractionation of the total homogenate by differential centrifugation in 0.25 M sucrose showed that the acid lipase was present at highest concentration in the light mitochondrial fraction. Palmitic acid and dipalmitin were the two main products of hydrolysis of tripalmitin.

Identification and characterization of phospholipase D in a unicellular red alga (Porphyridium cruentum)

Axenically cultured cells of Porphyridium cruentum were assayed for enzymes catalyzing the hydrolysis of lecithin. The sonicated cells showed virtually exclusive and complete conversion of 14C-choline-labelled lecithin to 14C-choline, with no significant formation of glycerylphosphorylcholine or phosphorylcholine. The enzymatic activity showed a sharp pH optimum at 7.0, and was strongly inhibited by chelating agents (two types), sulfhydryl-group binding reagents (three types), and surface-active agents (anionic and non-ionic). The inhibition from ethylenediamine tetraacetate (EDTA) was reversed by Ca2+ or Sr2+ but not by Mg2+ or Ba2+, and that from —SH binding reagents was reversed by dithiothreitol. Heavy metal ions (Zn2+, Cu2+, Ba2+, Co2+, Mn2+, Fe2+) inhibited the activity, Ca2+ caused stimulation, while Mg2+ and Sr2+ had little effect. The results indicate the occurrence of a pH and heavy-metal ion sensitive, Ca2+-(or Sr2+-) requiring phospholipase D in the red alga, and the involvement of sulfhydryl groups in the expression of its activity. The algal enzyme resembles those from higher plants in its Ca2+ requirement and sensitivity to EDTA and organomercurial sulfhydryl binding reagent, but differs markedly in its optimum pH and several other properties.

Lipolytic Activity Toward Long-Chain Triglycerides in Lateral Line Muscle of Rainbow Trout (Salmo gairdneri)

Lipolytic activity toward long-chain triglycerides was studied in the lateral line muscle of rainbow trout (Salmo gairdneri) by use of tissue slices. Emulsification of substrates with phospholipids was found to be necessary to demonstrate lipolysis, which occurred in decreasing intensity with tripalmitin, triolein, and tristearin. The lipolytic activity showed optimum activity at pH 7.3 and it was inhibited by NaF, protamine, and p-chloromercuriphenyl sulfonate. Albumin had little effect on the activity. Epinephrine did not stimulate lipolysis, but it reduced loss of activity during preincubation.