The predictive value of mandibular advancement maneuvers during drug-induced sleep endoscopy for treatment success of oral appliance treatment in obstructive sleep apnea: a prospective study

STUDY OBJECTIVES

To prospectively validate drug-induced sleep endoscopy with mandibular advancement maneuvers as a prediction tool for treatment success of oral appliance treatment (OAT).

METHODS

Seventy-seven patients diagnosed with moderate obstructive sleep apnea were included and underwent drug-induced sleep endoscopy. The upper airway collapse was assessed using the VOTE classification. Additionally, three mandibular advancement maneuvers were performed to predict treatment success of OAT. If the maneuver was negative, the level and degree and configuration of the persistent collapse was described according to the VOTE classification. All patients were treated with OAT and completed a follow-up sleep study with OAT in situ without regard to their anticipated response to treatment.

RESULTS

Sixty-four patients completed 6-month follow up. A positive jaw thrust maneuver proved to be significantly associated with favorable OAT response, whereas the chin lift maneuver and the vertical chin lift maneuver were not. Additionally, a persistent lateral oropharyngeal collapse when performing any mandibular advancement maneuver was significantly associated with unfavorable OAT response.

CONCLUSIONS

The current findings suggest that a jaw thrust maneuver should be preferred over the chin lift maneuver for predicting OAT response. Patients with a positive jaw thrust maneuver should be counseled toward favorable OAT response, whereas those with persistent lateral oropharyngeal collapse should be advised about the likelihood of unfavorable OAT response. A negative jaw thrust maneuver did not prove to be a significant predictor for unfavorable response to OAT. Consequently, uncertainties arise regarding the justification of performing drug-induced sleep endoscopy solely for predicting the efficacy of OAT. However, the results of the current study could be influenced by heterogeneity in the assessment of respiratory parameters, variability in the performance of the mandibular advancement maneuvers, and the instability of bolus technique sedation.

CLINICAL TRIAL REGISTRATION

Registry: Netherlands Trial Register; Name: Drug-induced Sleep Endoscopy: a prediction tool for success rate of oral appliance treatment; Identifier: NL8425; URL: https://www.onderzoekmetmensen.nl/en/trial/20741.

CITATION

Veugen CCAFM, Kant E, Kelder JC, Schipper A, Stokroos RJ, Copper MP. The predictive value of mandibular advancement maneuvers during drug-induced sleep endoscopy for treatment success of oral appliance treatment in obstructive sleep apnea: a prospective study. J Clin Sleep Med. 2024;20(3): 353-361.

Treatment of a floppy epiglottis with upper airway stimulation therapy

PURPOSE

To evaluate the efficacy of upper airway stimulation therapy in patients with a floppy epiglottis who have experienced continuous positive airway pressure failure or intolerance.

METHODS

A retrospective single-center cohort study was conducted. Patients who received an Inspire Upper Airway Stimulation system and had a 1-year follow-up were included. Baseline and one-year in-laboratory polysomnography examinations were performed. Patient characteristics, Epworth Sleepiness Scale scores and upper airway stimulation device settings were collected.

RESULTS

A total of 75 patients were included, of whom 10 had a floppy epiglottis. Patients with a floppy epiglottis had a significant therapeutic response to upper airway stimulation therapy, similar to patients without a floppy epiglottis. According to the Sher's success criteria, 90% of patients with a floppy epiglottis and 68% of patients without a floppy epiglottis were responders to therapy (p = 0.149). In the floppy epiglottis group, the apnea-hypopnea index decreased from 35.1 ± 5.5 events/hour to 11.2 ± 11.3 events/hour (95% CI (15.0, 32.9), p < 0.001), similarly in the non-floppy epiglottis group, the decline was from 36.4 ± 8.3 events/hour to 14.4 ± 9.5 events/hour (95% CI (18.6, 25.2), p < 0.001, between groups p = 0.659). Comparable reductions were observed for the other respiratory parameters.

CONCLUSION

Treatment of patients with obstructive sleep apnea and a floppy epiglottis can be challenging. Continuous positive airway pressure may aggravate the epiglottis collapse. Upper airway stimulation therapy can be considered an effective alternative treatment option for patients with a floppy epiglottis who have encountered either continuous positive airway pressure failure or intolerance.

The effect of velar collapse patterns on unilateral upper airway stimulation therapy

PURPOSE

Hypoglossal nerve stimulation is a promising alternative therapy for patients with obstructive sleep apnea with continuous positive airway pressure intolerance or failure. Previous studies concluded that a velar complete concentric collapse might prohibit a good therapeutic outcome. However, certain patients have an upper velar anteroposterior collapse and a lower velar complete concentric collapse. The effect of this velar collapse pattern is unknown, preventing evidence-based decision-making for these patients. This study aimed to compare the results of upper airway stimulation therapy in these patients to patients with a pure anteroposterior velar collapse.

METHODS

A retrospective single-center cohort study was performed. Patients were included who were implanted with an upper airway stimulation device and had a 1-year follow-up.

RESULTS

Of 66 patients, 10 had an upper velar anteroposterior collapse and lower velar complete concentric collapse. Fifty-six patients had a complete or partial velar anteroposterior collapse. At follow-up, all respiratory outcomes were similarly changed between the two groups. The mean apnea and hypopnea index reduced equally (26.9 events/hour vs. 23.9 events/hour, 95% CI (-5.0, 11.0), p = 0.46). A similar decrease in the oxygen desaturation index of ≥ 4% was observed (12.0/hour versus 11.5/hour, 95% CI (-8.7, 9.7) p = 0.92) CONCLUSION: Patients with an upper velar anteroposterior collapse and a lower velar complete concentric collapse are suitable candidates for upper airway stimulation therapy. In these patients, the lower velum may represent a transition zone between the anteroposterior collapse of the upper velum and the lateral collapse of the oropharynx, instead of being a real concentric collapse.

Upper Airway Stimulation in Patients with Obstructive Sleep Apnea: Long-Term Surgical Success, Respiratory Outcomes, and Patient Experience

Introduction  Upper airway stimulation (UAS) with electric activation of the hypoglossal nerve has emerged as a promising treatment for patients with moderate-to-severe obstructive sleep apnea. Objective  To retrospectively analyze objective and subjective outcome measures after long-term follow-up in obstructive sleep apnea patients receiving upper airway stimulation. Methods  An observational retrospective single-center cohort study including a consecutive series of patients diagnosed with obstructive sleep apnea receiving upper airway stimulation. Results  Twenty-five patients were included. The total median apnea-hypopnea index (AHI) significantly decreased from 37.4 to 8.7 events per hour at the 12-month follow-up ( p  < 0.001). The surgical success rate was 96%. Adverse events were reported by 28% of the patients. Conclusion  Upper airway stimulation is an effective and safe treatment for obstructive sleep apnea in patients with continuous positive airway pressure (CPAP) failure or intolerance. However, it is possible that the existing in and exclusion criteria for UAS therapy in the Netherlands have positively influenced our results.

Drug-induced Sleep Endoscopy: Are there Predictors for Failure of Oral Appliance Treatment?

Introduction In the literature, evidence is lacking on the predictive value of drug-induced sleep endoscopy (DISE) for oral appliance treatment (OAT).

Objectives The aim of the present study is to evaluate whether DISE with concomitant mandibular advancement maneuver can predict failure of OAT.

Methods An observational retrospective study including patients diagnosed with obstructive sleep apnea (OSA) who previously received OAT. Results of DISE were analyzed in a group with documented OAT failure (apnea-hypopnea index [AHI] > 10 events/hour or < 50% reduction) and a group with OAT benefit (AHI <10 events/hour or > 50% reduction). The upper airway was assessed using the velum, oropharynx, tongue base, epiglottis (VOTE) classification. Additionally, a mandibular advancement maneuver, manually protruding the mandible by performing a jaw thrust, was performed to mimic the effect of OAT.

Results The present study included 50 patients with OAT failure and 20 patients with OAT benefit. A subgroup analysis of patients with OAT failure and an AHI < 30 events/hour included 26 patients. In the OAT failure group, 74% had a negative jaw thrust maneuver. In the subgroup with an AHI < 30 events/hour, 76.9% had a negative jaw thrust maneuver. In the OAT benefit group, 25% had a negative jaw thrust maneuver (p < 0.001).

Conclusions A negative jaw thrust maneuver during DISE can be a valuable predictor for OAT failure, independent of AHI. Drug-induced sleep endoscopy should be considered as a diagnostic evaluation tool before starting OAT.

Prediction of obstructive sleep apnea: comparative performance of three screening instruments on the apnea-hypopnea index and the oxygen desaturation index

Purpose

To evaluate the performance of the NoSAS (neck, obesity, snoring, age, sex) score, the STOP-Bang (snoring, tiredness, observed apneas, blood pressure, body mass index, age, neck circumference, gender) questionnaire, and the Epworth sleepiness score (ESS) as a screening tool for obstructive sleep apnea (OSA) severity based on the apnea-hypopnea index (AHI) and the oxygen desaturation index (ODI).

Methods

Data from 235 patients who were monitored by ambulant polysomnography (PSG) were retrospectively analyzed. OSA severity was classified based on the AHI; similar classification categories were made based on the ODI. Discrimination was assessed by the area under the curve (AUC), while predictive parameters were calculated by four-grid contingency tables.

Results

The NoSAS score and the STOP-Bang questionnaire were both equally adequate screening tools for the AHI and the ODI with AUC ranging from 0.695 to 0.767 and 0.684 to 0.767, respectively. Both questionnaires perform better when used as a continuous variable. The ESS did not show adequate discrimination for screening for OSA (AUC ranging from 0.450 to 0.525). Male gender, age, and BMI proved to be the strongest individual predictors in this cohort.

Conclusion

This is the first study to evaluate the predictive performance of three different screening instruments with respect to both the AHI and the ODI. This is important, due to increasing evidence that the ODI may have a higher reproducibility in the clinical setting. The NoSAS score and the STOP-Bang questionnaire proved to be equally adequate to predict OSA severity based on both the AHI and the ODI.

Electronic supplementary material

The online version of this article (10.1007/s11325-020-02219-6) contains supplementary material, which is available to authorized users.

Drug-induced sleep endoscopy while administering CPAP therapy in patients with CPAP failure

Study objectives

To study the pattern of upper airway collapse in patients with CPAP failure by performing DISE while administering CPAP therapy and to determine the reason for CPAP failure accordingly.

Methods

This observational retrospective study comprised 30 patients diagnosed with OSA and CPAP failure, who underwent DISE while administering CPAP therapy. During DISE, the upper airway was assessed with and without CPAP therapy using the VOTE classification. Additionally, a jaw thrust maneuver was performed, in order to mimic the effect of an additional mandibular advancement device (MAD) in combination with CPAP therapy. Consequently, the outcome of DISE was translated into a clinically relevant categorization.

Results

Eleven patients (37%) had a persistent anteroposterior (AP) collapse, including a collapse at velum, tongue base, or epiglottis level and multilevel collapse. Eight patients (27%) had a floppy epiglottis. Five patients (17%) had a persistent complete concentric collapse (CCC) and three patients had a persistent laryngeal collapse (10%). In three patients (10%), no airway collapse was found after CPAP administration.

Conclusions

Based on the results of the reported study, in most cases, the potential cause of CPAP failure can be determined by this new diagnostic method. Consequently, suggestions can be made for additional therapy.

[Obstructive sleep apnoea]

Obstructive sleep apnoea Obstructive sleep apnoea (OSA) is a complex condition with many different phenotypes. Historically, OSA has been defined using the apnoea-hypopnoea index (AHI). However, because there is no clear relationship between the AHI and the severity of symptoms and comorbidities the degree of hypoxia is increasingly being used to define OSA severity. To reach a diagnosis of obstructive sleep apnoea syndrome (OSAS), it has to be shown that symptoms improve with therapy. The treatment of first choice for patients with severe OSA is continuous positive airway pressure (CPAP) therapy. The indication for other therapies depends upon the patient's characteristics and preferences. Treatment with a position trainer and implantation of a hypoglossal nerve stimulator are relatively new therapies. OSA is a cardiovascular risk factor, but the effect of OSA treatment on cardiovascular outcome measures and mortality has not been shown in clinical trials.

Monitoring microcirculatory alterations in oral squamous cell carcinoma following photodynamic therapy

BACKGROUND

One of the mechanisms through which photodynamic therapy (PDT) is thought to elicit tumour destruction is by producing microvascular damage and obstruction of nutritive blood flow. The aim of this study was to directly monitor and quantify microcirculatory changes following tissue illumination by PDT for oral squamous cell carcinoma.

METHODS

Ten consecutive patients receiving PDT for a carcinoma in situ, a T1 or T2 tumour in the oral cavity without evidence of lymph node metastasis were selected for this study. Tumour and marginal healthy mucosa total capillary density (TCD) and functional capillary density (FCD) inside the field of illumination were measured and compared using sidestream dark-field (SDF) imaging prior to tissue illumination, immediately after PDT, and again after 15min.

RESULTS

Baseline mean tumour TCD was 21.2±5capillaries per square millimetres (cpll/mm²) and 24.9±19cpll/mm² in the surrounding marginal healthy tissue; there were no significant differences between tumour and healthy tissue or time points. Comparisons between baseline and post-illumination time points revealed significant differences in both tumour and healthy tissue FCD (P<0.05). No significant differences in FCD were observed between the two tissues.

CONCLUSIONS

Our findings using SDF imaging demonstrate that PDT significantly attenuates tumour and marginal healthy tissue perfusion by directly disrupting the functionality of the microcirculation.

Photodynamic therapy of early stage oral cavity and oropharynx neoplasms: an outcome analysis of 170 patients

The indications of photodynamic therapy (PDT) of oral cavity and oropharynx neoplasms are not well defined. The main reason is that the success rates are not well established. The current paper analyzes our institutional experience of early stage oral cavity and oropharynx neoplasms (Tis-T2) to identify the success rates for each subgroup according to T stage, primary or non-primary treatment and subsites. In total, 170 patients with 226 lesions are treated with PDT. From these lesions, 95 are primary neoplasms, 131 were non-primaries (recurrences and multiple primaries). The overall response rate is 90.7% with a complete response rate of 70.8%. Subgroup analysis identified oral tongue, floor of mouth sites with more favorable outcome. PDT has more favorable results with certain subsites and with previously untreated lesions. However, PDT can find its place for treating lesions in previously treated areas with acceptable results.

Photodynamic therapy in the treatment of multiple primary tumours in the head and neck, located to the oral cavity and oropharynx

OBJECTIVES

Multiple primary tumours are a common problem in the head and neck cancer patients. Curative surgery or radiotherapy of these tumours can be very mutilating or even impossible. This study aims at evaluating meta-tetrahydroxy-phenyl chlorin-mediated photodynamic therapy for second or multiple primary tumours in the head and neck.

DESIGN

Retrospective study of all patients with second or multiple primary tumours treated by photodynamic therapy over a 10-year period.

SETTING

All patients were treated in the Netherlands Cancer Institute, a tertiary referral centre for the head and neck cancer patients.

PARTICIPANTS

A total of 27 patients with 42 the second or the multiple primary head and neck tumours were treated by photodynamic therapy (0.15 mg/kg meta-tetrahydroxy-phenyl chlorin).

MAIN OUTCOMES MEASURES

Cure rates.

RESULTS

Twenty-eight of 42 tumours were cured (67%). Cure rates for stage I or in situ disease were 85%versus 38% for stage II/III.

CONCLUSIONS

Cure rates for photodynamic therapy of the multiple primary head and neck tumours were lower than previously described for first primaries, but were still very encouraging for this difficult patient population. The high cure rate obtained in stage I multiple primaries emphasises the importance of a meticulous follow-up of patients treated for the head and neck cancer to detect new tumours at a curable stage.

Surgical technique—unwrapping the neck node levels around a sternocleidomastoid muscle bar: A systematic way of performing (modified) radical neck dissection

AIM

Description of a systematic approach to the neck for removal of lymph node bearing tissues in levels I-V.

METHOD

A (modified) radical neck dissection is divided in three steps: (1) Dissection of levels I-IV, (2) dissection of level V and (3) transection of SCM bar and finalisation of the dissection. The sternocleidomastoid muscle (SCM) is used as a "bar", around which the different neck levels can be systematically unwrapped, warranting permanent cranio-caudal tension of the neck specimen, while anatomical relations remain intact.

RESULTS

In a group of 115 (modified) radical en bloc neck dissections with or without post-operative radiotherapy 10% regional recurrences, 2% post-operative chylous fistulas and < 5% post-operative wound infections occurred. The overall 5 years survival was 45% (95% confidence interval: 36-54%).

CONCLUSION

A systematic unwrapping of lymph node levels around the sternocleidomastoid bar provides a reliable systematic method for performing (modified) radical neck dissections without a negative influence on clinical outcome.

The AMORE protocol as salvage treatment for non-orbital head and neck rhabdomyosarcoma in children

AIM

To investigate the feasibility and outcome of the AMORE protocol as salvage treatment in paediatric head and neck rhabdomyosarcoma (HNRMS).

METHODS

The AMORE protocol is a local treatment regimen, consisting of Ablative surgery, Moulage technique brachytherapy and surgical Reconstruction, scheduled in 1 week. Patients with recurrent or residual non-orbital HNRMS were eligible for AMORE salvage treatment.

RESULTS

The procedure was feasible in nine out of 11 eligible patients. Five patients were treated for recurrent or residual parameningeal RMS after prior chemoradiation. Local complete remission was achieved in all five patients and maintained in four. Three patients are without evidence of RMS with a follow-up duration of 4-10 years. Two patients developed a distant relapse, together with a local recurrence in one. Both patients died of their disease. Four patients were included for recurrent non-parameningeal HNRMS. Long-term local control at the site of recurrence was obtained in all four patients (follow-up 5-10 years).

CONCLUSIONS

The AMORE protocol is a feasible salvage strategy for non-orbital HNRMS even after external beam radiotherapy. The local salvage rate in this series is promising.

A novel local treatment strategy for advanced stage head and neck rhabdomyosarcomas in children: results of the AMORE protocol

The AMORE protocol is a local treatment regimen for head and neck rhabdomyosarcomas (HNRMS), consisting of Ablative surgery, Moulage technique brachytherapy and surgical Reconstruction. The aim of AMORE is to intensify local treatment for children with HNRMS and to avoid external beam radiation therapy (EBRT) and its long-term sequelae. All children with primary irresectable, non-orbital HNRMS in whom EBRT was indicated, were evaluated for the feasibility of AMORE. In 20 children, AMORE was performed (15 with parameningeal disease and five with non-parameningeal disease). Complete remission was achieved in all 20 patients. Local complications were limited. 5 patients experienced a local relapse and 1 patient developed distant metastases. Estimated 5-year OS and EFS were 67.5 and 64.1% for the entire group, and 64.2 and 60.0% for the parameningeal subgroup. We conclude that the AMORE protocol is a feasible strategy, with a good local control rate. Long-term sequelae of EBRT might be avoided although, to date, the follow-up is too short for definitive conclusions regarding these sequelae.

Meta-tetra(hydroxyphenyl)chlorin photodynamic therapy in early-stage squamous cell carcinoma of the head and neck

OBJECTIVE

Photodynamic therapy (PDT) is a relatively new treatment modality for various types of cancer, including cancer of the head and neck. The advent of the second-generation photosensitizers such as meta-tetra(hydroxyphenyl)chlorin (mTHPC) (Foscan; Scotia Pharmaceuticals, Stirling, Scotland), which are more effective and less phototoxic to the skin than their forerunners, now makes this treatment a feasible alternative to surgery or radiotherapy in specific cases. To evaluate the long-term outcome of this therapy for squamous cell carcinomas of the head and neck, we treated patients with PDT using mTHPC.

DESIGN

Prospective study.

SETTING

Tertiary cancer referral center.

PATIENTS

Twenty-five patients with 29 T1-T2 N0 tumors of the oral cavity and/or oropharynx.

INTERVENTION

Photodynamic therapy.

MAIN OUTCOME MEASURE

Complete local tumor remission.

RESULTS

The mean follow-up of the patients after treatment was 37 months. In 25 (86%) of 29 tumors, a complete remission of the primary tumor was obtained. In the 4 recurrences, salvage was achieved by conventional therapy. In none of the patients was any long-term functional deficit detected.

CONCLUSIONS

This study confirms that PDT is a powerful treatment modality that could be considered as an alternative to surgery or radiotherapy in specific cases of head and neck cancer. The major advantage of PDT over these conventional therapies is the reduction in long-term morbidity. Radiotherapy or surgery could be reserved for salvage therapy in the event of a recurrence or second primary tumors.

[Early diagnosis and prevention of malignant tumors in the head and neck region]

In the Netherlands more than 2000 new patients with head and neck cancer are diagnosed annually. Most of these cancers are squamous cell carcinomas. The use of tobacco and alcohol are well established aetiologic factors. Head and neck cancers usually affect patients above the age of 40 years and are somewhat more common in men than in women. The type of the initial symptoms of head and neck cancer depends largely on the exact location. Often, these symptoms are rather aspecific. However, laryngeal cancer is an exception. In this site cancer usually presents at an early stage with sudden hoarseness. Hoarseness of more than three weeks' duration requires laryngoscopic examination. Particularly the cancers of the floor of the mouth and the borders on the tongue can be detected early because of the accessibility of these sites, which allows proper inspection and palpation. The most common clinical manifestation of oral cancer is an indurated ulcer. An oral ulcer present for more than three weeks is an indication for biopsy. The prognosis of head and neck cancer in general depends largely on the stage at diagnosis. Small cancers carry a much better prognosis after surgical removal or radiotherapy than larger ones.

Effect of cigarette smoking on gastropharyngeal and gastroesophageal reflux

Gastropharyngeal reflux appears to be associated with various otolaryngological complaints. Cigarette smoking is known to affect adversely the defense mechanisms against reflux of acid gastric contents into the esophagus. To study the relationship between gastropharyngeal, as well as gastroesophageal, reflux and cigarette smoking, 15 subjects underwent 24-hour double-probe pH monitoring while smoking their daily amount of cigarettes. The percentage of time the pH was below 4 during the smoking period was significantly higher than the percentage of time the pH was below 4 during the nonsmoking period, proximal, at the level of the upper esophageal sphincter, as well as distal, above the lower esophageal sphincter. These findings demonstrate that smoking increases gastropharyngeal and gastroesophageal reflux. Smokers with complaints and disorders caused by reflux should therefore be advised to stop smoking in order to reduce reflux.

Lymphoma in the ear

BACKGROUND

Malignant tumors of the ear are rare. The most common malignant tumors are squamous cell carcinomas and adenocarcinomas. Lymphoma in the ear is rare.

METHODS

We report 2 cases of a primary presentation of a lymphoma of the ear. The literature since 1947 is reviewed.

RESULTS

An 83-year-old woman with an anaplastic large cell lymphoma of the skin of the external auditory meatus and a 75-year-old man with a B-cell non-Hodgkin's lymphoma of the mastoid process are presented. The literature review shows that only 16 cases of lymphomas of the ear have been reported so far.

CONCLUSIONS

In a case of therapy-resistant otitis and/or peripheral facial paralysis malignancy should be excluded by computer tomography of the mastoid. For histopathological diagnosis unfixed specimens are preferable. Uniform treatment of lymphomas of the ear has not been established.

High incidence of laryngopharyngeal reflux in patients with head and neck cancer

OBJECTIVES

Laryngopharyngeal reflux may play a role in the etiology of squamous cell cancer of the head and neck and contribute to complications in head and neck cancer patients after surgery or during radiotherapy.

STUDY DESIGN

Prospective study.

METHODS

To investigate the incidence of laryngopharyngeal and gastroesophageal reflux in patients with head and neck cancer, ambulatory 24-hour double-probe pH monitoring was performed in 24 untreated patients with laryngeal or pharyngeal squamous cell carcinoma. In addition, 10 patients who had been irradiated in the head and neck area were analyzed for reflux to study the effect of radiotherapy on reflux.

RESULTS

Only 4 of the 24 head and neck cancer patients (17%) had neither pathological laryngopharyngeal nor gastroesophageal reflux. Esophageal acid exposure was abnormal in five patients and acid exposure at the level of the upper esophageal sphincter was abnormal in four patients. Eleven patients had pathological reflux in both areas. Irradiated patients did not differ from the untreated patients considering the incidence of pathological laryngopharyngeal or gastroesophageal reflux.

CONCLUSIONS

The data obtained in this study indicate that reflux is a common event in head and neck cancer patients.

Evidence for recurrent laryngeal nerve contribution in motor innervation of the human cricopharyngeal muscle

OBJECTIVE

To study the functional motor nerve supply of the upper esophageal sphincter in humans.

STUDY DESIGN

Intraoperative electromyographic study.

METHODS

The contribution of the recurrent laryngeal nerve and the pharyngeal plexus in the motor nerve innervation of the cricopharyngeal muscle and the inferior pharyngeal constrictor muscle was examined intraoperatively.

RESULTS

Electromyography showed that there is a considerable overlap in the innervation of the cricopharyngeal muscle and the inferior pharyngeal constrictor muscle. The recurrent laryngeal nerve functionally contributes to the motor innervation of the cricopharyngeal muscle in all patients and contributes to the motor innervation of the inferior pharyngeal constrictor muscle in most patients. The pharyngeal plexus functionally contributes to the motor innervation of the inferior pharyngeal constrictor muscle but does not always contribute to the motor innervation of the cricopharyngeal muscle.

CONCLUSIONS

This is the first report which provides evidence that the recurrent laryngeal nerve functionally contributes to the motor innervation of the cricopharyngeal and inferior pharyngeal constrictor muscle. Furthermore, this study shows that intraoperative electromyography in humans is a feasible method to analyze the physiology of the motor innervation of the upper esophageal sphincter.

Plasma retinoid levels in head and neck cancer patients: a comparison with healthy controls and the effect of retinyl palmitate treatment

Vitamin A and related compounds, also known as retinoids are thought to play a role in the development of head and neck cancer. We measured levels of the major retinoids, retinol, all-trans retinoic acid, 13-cis retinoic acid and 13-cis-4-oxo retinoic acid in plasma of head and neck cancer patients in comparison with controls without cancer. No differences were found between plasma levels of these retinoids between 25 head and neck cancer patients and 21 controls. Mean baseline levels for the patients were 2458. 6.0, 6.4 and 8.6 nM for retinol, all-trans retinoic acid, 13-cis retinoic acid and 13-cis-4-oxo retinoic acid, respectively. In addition, we selected 10 patients from the chemoprevention trial Euroscan and measured the effect on retinoid levels of 300,000 I.U. daily retinyl palmitate intake during 1 month. Medication caused significant elevations in retinol levels (1.2 fold), all-trans retinoic acid (2.2 fold) and its metabolites 13-cis retinoic acid (5.8 fold) and 13-cis-4-oxo retinoic acid (8.9 fold). Because of its high increase in levels, 13-cis-4-oxo retinoic acid seems a good candidate to serve as a suitable marker to monitor patient compliance in future chemo-prevention trials involving retinoids. No relations were found between the occurrence of side-effects of retinyl palmitate and retinoid levels during treatment. However, the two patients who developed side-effects had the highest pre-treatment levels of 13-cis retinoic acid and 13-cis-4-oxo retinoic acid, suggesting that retinoid toxicity is associated with relatively high basal retinoid metabolism.

Exfoliated oral cell messenger RNA: suitability for biomarker studies

The efficacy of chemoprevention trials can be improved by the use of biomarkers of carcinogenesis that serve as surrogate end points. The aim of this study was to assess the perspectives of using mRNA isolated from oral exfoliated cells for biomarker research in chemoprevention of upper aerodigestive tract cancer. When using reverse transcription-PCR in combination with Southern blotting and hybridization, it was possible to detect transcripts from only five cells. With the quantitative RNase protection assay, we could only detect highly abundant transcripts. The integrity of the RNA was verified by Northern blotting, which showed a variable degree of degradation, depending on the gene studied. Interestingly, although specific transcripts were found to be intact to a certain extent, the rRNA appeared to be completely degraded, suggesting that a specific protein synthesis shut-off mechanism exists in terminally differentiated oral epithelial cells. Altogether, this differential RNA degradation makes accurate measurement of transcript levels of most genes, as determined in exfoliated oral cells, unreliable. Because this RNA degradation process is likely to start before the cells are shed from the tissue, the results of measurements of transcript levels in biopsies of oral tissue should be interpreted with caution.

All-trans retinoic acid induced gene expression and growth inhibition in head and neck cancer cell lines

Retinoids are natural and synthetic analogues of vitamin A and have proven activity in various types of cancer. As for head and neck squamous cell cancer (HNSCC), retinoids are especially active in leukoplakia and in preventing second primary cancers. The aim of this study was to assess the growth inhibiting activity of all-trans retinoic acid (all-trans RA) in a panel of six head and neck squamous cell cancer cell lines and to correlate this response to the mRNA expression of factors related to differentiation and receptor mediated signal transduction. Three lines showed minimal, two moderate and one strong growth inhibition after 72 h exposure to all-trans RA. Three lines with a dissimilar response were selected for further studies, the measurement of mRNA expression by northern blotting. It was found that neither the expression nor the induction of retinoic acid receptor (RAR)-alpha and -gamma and retinoic X receptor-alpha mRNA war related to sensitivity. The mRNA expression of RAR-beta was too low to be measured in the three cell lines. The most sensitive cell line was, however, the only one that expressed mRNA of squamous differentiation markers. These data suggest a relationship between the retinoid sensitivity profile and the degree of cellular differentiation.

Simultaneous analysis of retinol, all-trans- and 13-cis-retinoic acid and 13-cis-4-oxoretinoic acid in plasma by liquid chromatography using on-column concentration after single-phase fluid extraction

A reversed-phase high-performance liquid chromatographic method for the simultaneous analysis of retinol, all-trans-retinoic acid, 13-cis-retinoic acid and 13-cis-4-oxoretinoic acid in human plasma and cell culture medium is described. Sample preparation involves precipitation of proteins and extraction of retinoids with 60% acetonitrile. After centrifugation, the acetonitrile content of the supernatant is reduced to 45%, allowing on-column concentration of analytes. Injection volumes up to 2.0 ml (equivalent to 0.525 ml of sample) can be used without compromising chromatographic resolution of all-trans-retinoic acid and 13-cis-retinoic acid. Retinoids were stable in this extract and showed no isomerization when stored in the dark in a cooled autosampler, allowing automated analysis of large series of samples. Recoveries from spiked plasma samples were between 95 and 103%. Although no internal standard was used, the inter-assay precision for all retinoids was better than 6% and 4% at concentrations of 30 nM and 100 nM, respectively. The method is a valuable tool for the study of cellular metabolism of all-trans-retinoic acid, as polar metabolites of this compound can be detected with high sensitivity in cell culture media.

Retinoid metabolism and all-trans retinoic acid-induced growth inhibition in head and neck squamous cell carcinoma cell lines

Retinoids can reverse potentially premalignant lesions and prevent second primary tumours in patients with head and neck squamous cell carcinoma (HNSCC). Furthermore, it has been reported that acquired resistance to all-trans retinoic acid (RA) in leukaemia is associated with decreased plasma peak levels, probably the result of enhanced retinoid metabolism. The aim of this study was to investigate the metabolism of retinoids and relate this to growth inhibition in HNSCC. Three HNSCC cell lines were selected on the basis of a large variation in the all-trans RA-induced growth inhibition. Cells were exposed to 9.5 nM (radioactive) for 4 and 24 h, and to 1 and 10 microM (nonradioactive) all-trans RA for 4, 24, 48 and 72 h, and medium and cells were analysed for retinoid metabolites. At all concentrations studied, the amount of growth inhibition was proportional to the extent at which all-trans-, 13- and 9-cis RA disappeared from the medium as well as from the cells. This turnover process coincided with the formation of a group of as yet unidentified polar retinoid metabolites. The level of mRNA of cellular RA-binding protein II (CRABP-II), involved in retinoid homeostasis, was inversely proportional to growth inhibition. These findings indicate that for HNSCC retinoid metabolism may be associated with growth inhibition.

Standardization of counting micronuclei: definition of a protocol to measure genotoxic damage in human exfoliated cells

The proportion of exfoliated buccal mucosal cells with micronuclei gives the opportunity to assess sensitivity to gamma-radiation and genotoxic compounds and in addition to monitor the effectiveness of cancer intervention strategies. So far, results on counting micronuclei in various publications are difficult to compare because of differences in methods used, especially with regard to microscopical magnification used and number of cells counted. The aims of this study were (i) to define a protocol for counting micronuclei; (ii) to assess the feasibility of manually counting micronuclei; and (iii) the assessment of inter- and intra-patient variability of the number of micronuclei. We propose the definition of a strict protocol on counting micronuclei, with regard to cytological preparation, definition of micronuclei, instrumentation, sampling of cells in a cytological specimen and sample size. Such a strict protocol is a prerequisite for counting micronuclei in exfoliated cells to get a reproducible and sensitive indicator of exposure and for cancer risk. Although the inter- and intra-observer reproducibility of counting micronuclei per 1000 cells using such a protocol is well, we show that the variability among 10 assessments of micronuclei per 1000 cells taken sequentially from a sample size of 10,000 nuclei of the same specimen can be enormous (coefficients of variation varied in seven individuals studied between 42.1 and 102.9%). Based on the observed low frequencies varying from 1.2 to 5.2 micronuclei per 1000 cells and the variation found, we conclude that at least 10,000 exfoliated cells should be screened to monitor a significant reduction of 50% in the number of micronuclei (for a patient with an initial frequency in the micronuclei frequency range given). Since it takes approximately 7 h to evaluate this number of cells, it is also concluded that counting of micronuclei requires automation.

[Life-threatening angioedema as a side effect of angiotensin-converting-enzyme (ACE) inhibitors]

During the past years, angioedema occurring in association with angiotensin converting enzyme (ACE) inhibitors is seen more and more often. This is due to the increasing use of these drugs for hypertension and congestive heart failure. If the diagnosis is missed and prescription of the ACE inhibitor is prolonged, recurrent and more severe episodes of angioedema may occur. In case of involvement of the upper airway and respiratory distress, the condition may be life-threatening. We demonstrate three such patients, men of 84, 73 and 63 years old. First of all, the airway should be secured. Administration of epinephrine may be indicated. Further use of ACE inhibitors is contraindicated.

Role of genetic factors in the etiology of squamous cell carcinoma of the head and neck

OBJECTIVE

To determine the role of genetic predisposition in the etiology of head and neck squamous cell carcinoma.

DESIGN

Retrospective study.

SETTING

The outpatient clinics of the departments of otorhinolaryngology and maxillofacial surgery.

PATIENTS

First-degree relatives of patients with new head and neck cancer, with first-degree relatives of the patients' spouses as controls.

MAIN OUTCOME MEASURE

Occurrence of cancer of the respiratory and upper digestive tract in relatives of patients with head and neck cancer and controls.

RESULTS

First-degree relatives (n = 617) of 105 patients with head and neck cancer had 31 cases of cancer of the respiratory and upper digestive tract vs 10 cases in the control group (n = 618) (relative risk, 3.5; P = .0002). This higher rate of cancer was even larger in siblings (16 vs 2, relative risk, 14.6; P = .0001).

CONCLUSIONS

Genetic predisposition is an important risk factor for squamous cell carcinoma of the head and neck.

Increased mutagen sensitivity in head-and-neck squamous-cell carcinoma patients, particularly those with multiple primary tumors

Mutagen sensitivity is a constitutional factor which may be used to identify head-and-neck squamous-cell carcinoma (HNSCC) patients at high risk for the development of multiple primary tumors (MPT). In this retrospective study, mutagen sensitivity was measured in HNSCC patients with a single primary tumor (SPT), HNSCC patients who have already developed MPT and control subjects with no tumor history. In vitro, lymphocytes were challenged with bleomycin and chromosomal damage was quantified by scoring chromatid breaks of 100 cells. A significant difference in the mean number of breaks per cell (b/c) was found between SPT patients and controls. Patients with MPT showed a significantly higher mean b/c value than SPT patients. This increase in mutagen sensitivity in HNSCC patients was not related to well-known cancer risk factors such as age, or life-style factors such as smoking and alcohol drinking habits. In addition, tumor site but not tumor stage was found to be related to mutagen sensitivity. On the basis of our findings, we propose that mutagen sensitivity is not an independent risk factor but a constitutional factor which reflects the way in which genotoxic compounds are dealt with and is thereby directly related to cancer risk.

A panel of biomarkers of carcinogenesis of the upper aerodigestive tract as potential intermediate endpoints in chemoprevention trials

BACKGROUND

Patients with squamous cell carcinoma of the head and neck have a 10-30% risk of developing a second primary tumor. The concept of "field cancerization" assumes that the whole upper aerodigestive tract is affected and prone to malignant transformation. This study was undertaken to investigate the value of a panel of monoclonal antibodies to identify biomarkers in oral mucosa associated with cancer risk. Such biomarkers may be suitable candidates to serve as intermediate endpoints in cancer chemoprevention trials.

METHODS

As a model, the expression of antigens was assessed in cytologic preparations obtained from macroscopically normal oral mucosa of patients with tongue carcinoma and of controls. The panel consisted of antibodies against cytokeratin 8, 10, 13, and 19 and the monoclonal antibodies designated K931, K984, E48, Ki-67, and UM-A9.

RESULTS

Oral mucosa of cancer patients had a more than threefold increased expression of cytokeratin 19 as compared with controls (36.0 versus 11.3%; P < 0.01).

CONCLUSION

Cytokeratin 19 is a potential intermediate endpoint in head and neck cancer chemopreventive trials.