One-year swallowing outcomes following transoral laser microsurgery +/- adjuvant therapy versus primary chemoradiotherapy for advanced stage oropharyngeal squamous cell carcinoma

OBJECTIVES

To assess the between-group change in swallowing function from baseline to 12 months following treatment, for patients treated for resectable stage III and IVA oropharyngeal squamous cell carcinoma. To assess the within-group change in swallowing function between 3 and 12 months following treatment.

DESIGN

Non-randomised cohort study.

SETTING

A single head and neck cancer unit with oncology services held at the nearby regional treatment centre.

PARTICIPANTS

Twenty-five patients treated with Transoral Laser Microsurgery +/- adjuvant (chemo)radiotherapy (Transoral Laser Microsurgery) observed alongside an historic cohort of 33 patients treated with (chemo)radiotherapy.

MAIN OUTCOME MEASURES

The patient reported MD Anderson Dysphagia Inventory (MDADI), an objective timed Water Swallow Test, and the clinician rated normalcy of diet subsection of the Performance of Swallowing Scale .

RESULTS

Between baseline and 12 months, patients treated with primary (chemo)radiotherapy demonstrated greater deterioration in swallowing function compared to Transoral Laser Microsurgery for all 3 swallowing measures. Between 3 and 12 months, the only significant change was an improvement in Performance of Swallowing Scale scores in the (chemo)radiotherapy group.

CONCLUSIONS

This is the first study to report the results of a complimentary set of swallowing measures for patients treated with Transoral Laser Microsurgery, observed alongside a cohort of (chemo)radiotherapy patients. The preliminary results suggest a benefit in swallowing function for Transoral Laser Microsurgery over (chemo)radiotherapy during the year following treatment.

Brain natriuretic peptide and NT-proBNP levels reflect pulmonary artery systolic pressure in trekkers at high altitude

Our objective was to evaluate the utility of the natriuretic peptides BNP (brain natriuretic peptide) and NT-proBNP as markers of pulmonary artery systolic pressure (PASP) in trekkers ascending to high altitude (HA). 20 participants had BNP and NT-proBNP assayed and simultaneous echocardiographic assessment of PASP performed during a trek to 5150 m. PASP increased significantly (p=0.006) with ascent from 24+/-4 to 39+/-11 mm Hg at 5150 m. At 5150 m those with a PASP>/=40 mm Hg (n=8) (versus those with PASP<40 mm Hg) had higher post-exercise BNP (pg/ml): 54.5+/-36 vs. 13.4+/-17 (p=0.012). Their resting BNP at 5150 m was also higher: 57.3+/-43.4 vs. 12.6+/-13 (p=0.017). In those with a pathological (>/=400 pg/ml) rise in NT-proBNP at 5150 m (n=4) PASP was significantly higher: 45.9+/-7.5 vs. 32.2+/-6.2 mm Hg (p=0.015). BNP and NT-proBNP may reflect elevated PASP, a central feature of high altitude pulmonary oedema, at HA.

Abstract P6-04-21: AIB1 expression specifically predicts breast cancer patient response to aromatase inhibitor therapy

Aromatase inhibitors (AI) have evolved over the last decade into an effective therapeutic regime for postmenopausal women with primary or advanced breast cancer. Despite their remarkable success in the clinic, intrinsic resistance to therapy occurs in a proportion of patients, while other patients who respond initially to treatment will relapse with recurrent disease. Previous studies suggest that this may be due, at least in part to estrogen receptor (ER) hypersensitivity.

We undertook ER ChIPseq analysis on AI resistant cell model and data for this suggests that ER transcriptional regulation alone may not be responsible for the development of the resistant phenotype. We examined the role of the established ER coactivator protein AIB1. AIB1 has previously been associated with initiation of breast cancer and resistance to endocrine therapy. In tamoxifen treated patients, expression of AIB1 in conjunction with an activated HER2 cascade has been associated with treatment resistance and early disease recurrence. By contrast, we have observed that AIB1 alone can predict response to AIs. In our TMA the expression of AIB1 associated with disease recurrence (p = 0.025) and reduced disease free survival time (p = 0.0471) in patients treated with AIs as first-line therapy. Reflecting increased growth factor activity reported in AI resistance, AIB1 expression associated with the growth factor second messenger signaling proteins, p-Src and pERK1/2, but not the receptor HER2. These results suggest that AIB1 may utilize additional transcription factors other than ER to drive endocrine resistance. Additionally, we show that AIB1 is highly expressed in AI resistant metastases; therefore, monitoring AIB1 expression may be useful to screen for disease progression and detect disease advancement before metastases appear.

Our studies of cell line models of AI resistance suggest that AIB1 may play a functional role in aggressive, migratory, phenotype of AI resistance. We have generated cell line models of resistance to letrozole (LetR) and anastrozole (AnaR). Our resistance models have higher levels of AIB1 and have increased migratory capacity. Interestingly, knockdown of AIB1 reduces the migratory capacity of the resistant cells.

Furthermore, we have observed that AIB1 regulation of ER target genes is selectively enhanced in AI resistant cells in a promoter specific context. AIB1 recruitment to ER target genes such as pS2 and Myc becomes insensitive to letrozole. By contrast, AIB1 recruitment to cyclinD1 retained letrozole sensitivity. Our evidence suggests that steroidal regulation of transcription factors such as Jun and Fos may contribute to this promoter-specific regulation of ER target genes.

We establish a role for AIB1 in AI-resistant breast cancer and describe a new mechanism of ERalpha/AIB1 gene regulation which could contribute to the development of an aggressive tumour phenotype. We provide evidence of a central role for AIB1 in regulating selective ER transcriptional activity and driving tumour recurrence in AI treated patients. Tackling the emerging problem of AI resistance in a timely fashion will enable us to tailor existing therapies and improve outcome in specific patient groups before disease recurrence becomes a clinical issue.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-04-21.

Abstract P1-05-06: A novel mutation in the tyrosine kinase domain of ErbB2: molecular and proteomic investigation of its role in breast cancer invasion

Introduction: A landmark genomic study revealed 17 somatic coding mutations in a lobular metastatic breast tumor, none of which were present in the patient's primary tumor. Among these was a novel mutation in the tyrosine kinase domain of ErbB2, a gene often amplified in breast cancer. Other mutations in this domain have been shown to stimulate transformation, growth and invasion in breast cancer cells. We hypothesize that an accumulation of mutations in the primary tumor over time preceded the development of an invasive clone, which allowed it to metastasise. Therefore, we investigated the specific effects of ErbB2 on cellular signalling and invasion, in conjunction with proteomic analyses to show its effects on global protein expression.

Methods: Wild-type and mutant ErbB2 cDNAs were cloned into V180 pLP 3X FLAG-tagged expression vectors. T47D breast cancer cells were transfected with one of these constructs. Protein was detected by immunoblotting with an anti-ErbB2 antibody. Membranes were then immunoblotted with an anti-phospho-ERK1/2 antibody. Transfected cells were seeded onto Matrigel; cells that migrated through the matrix were stained and counted after 48h.

To identify global proteomic changes caused by mutant ErbB2, T47D cells transfected with mutant/wild-type ErbB2 or vector control, were differentially labeled by growing them in medium containing various lysine/arginine isotopes (known as stable isotope labeling of amino acids in cell culture; SILAC). Protein lysates were mixed and subjected to LC-MS/MS mass spectrometry. Proteomic changes were analysed using MaxQuant and DAVID software.

Results: Overexpression of the wild-type or mutant ErbB2 genes produced protein expression in T47D, a non-invasive breast cancer cell line, confirmed by western blotting. To measure signalling downstream of ErbB2, we measured levels of the MAP kinase phospho-ERK1/2. Increased phosphorylation of ERK1/2 was demonstrated in cells expressing mutated ErbB2, compared with cells transfected with wild-type. This indicates increased activation of mutant ErbB2, demonstrating distinct phenotypic effects between wild-type and mutant ErbB2 in breast cancer cells. To analyze whether increased activation was accompanied by enhanced invasive properties, invasion assays were performed using Matrigel. A greater number of cells (1.5-fold increase) expressing mutant ErbB2 migrated across this matrix compared with wild-type-expressing cells.

Global proteomic analysis of T47D cells overexpressing wild-type or mutant ErbB2 yielded 1,357 total proteins, of which 543 could be quantified. Two subsets of proteins were identified, whose levels were either increased or decreased, in the mutant versus wild-type-transfected lysates (compared to control ratios). Proteins elevated in the mutant-expressing cells included candidates involved in cell migration, inhibition of apoptosis and promotion of cellular survival. Proteins showing reduced expression were involved in pathways including adhesion and DNA damage response.

Conclusion: This previously undescribed mutation in the tyrosine kinase domain of ErbB2 differentially effects downstream signalling pathways and may play a role in invasion of breast cancer cells.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-05-06.

The prevalence, influential factors and mechanisms of relative age effects in UK Rugby League

Relative age effects (RAEs), reflecting observed inequalities in participation and attainment as a result of annual age-grouping policies in youth sport, are common in most team sports. The aims of this study were to determine if and when RAEs become apparent in Rugby League, determine how influential variables (e.g., gender) lead and clarify whether player retention at junior representative levels can explain persistent RAEs. Player data were collected for the male and female community games ranging from Under 7s to Senior (N=15,060) levels, junior representative selections (i.e., Regional) and professional players (N=298). Chi-square analyses found significant (P<0.05) uneven birth date distributions beginning at the earliest stages of the game and throughout into senior professionals. In junior representative selections, 47.0% of Regional and 55.7% of National representative players were born in Quartile 1, with RAE risk increasing with performance level. Gender and nationality were also found to moderate RAE risk. When tracking representative juniors, over 50% were retained for similar competition the following season. Findings clearly demonstrate that RAEs exist throughout Rugby League with early selection, performance level and retention processes, appearing to be key contributing factors responsible for RAE persistence.

Laser bladder perforation from photoselective vaporization of prostate resulting in rhabdomyolysis induced acute renal failure

Hyponatremia and its related comorbidities remain a concern after traditional transurethral resection of the prostrate (TURP). Photoselective vaporization of the prostate (PVP) laser coagulation therapy is a new, relatively bloodless procedure for treatment of benign prostatic hyperplasia (BPH). Perceived benefits with PVP laser TURP include excellent visualization of the operative field during urethral prostatic tissue vaporization and the reduced incidence of laser penetration through the prostatic capsular fibers once the capsule is reached. Theoretically, this would provide a low risk method of perforation during laser TURP. After literature review, we report this as the first case of laser bladder perforation as a complication arising from PVP therapy. This case report discusses the management of acute hyponatremic induced rhabdomyolysis with acute renal failure (ARF) and the recommendation to use sodium chloride vs. sterile water for bladder irrigation during PVP TURP procedures.

The significance of MRI findings for non-rhinological disease

OBJECTIVES

Mucosal changes in the paranasal sinuses are detected in 30-50% of scans for non-rhinological disease. This study assesses the relationship between symptoms of rhinosinusitis and radiological evidence of sinus pathology in patients undergoing magnetic resonance imaging (MRI) scans for unrelated pathology.

DESIGN

Prospective observational study, evaluating symptoms of rhinosinusitis in patients undergoing MRI scanning of the internal acoustic meati. A visual analogue scale (VAS) of rhinological symptoms was completed immediately before scanning, specifying symptoms present at the time of completing the questionnaire. Symptom scores were recorded by one of the investigators, blinded to the MRI images. Two investigators independently rated sinus mucosal thickening for each scan, both of whom were blinded to the symptom scores. Lund and Mackay scoring systems were used for both symptom and radiological scores, which were then compared.

SETTING

Otolaryngology and Radiology Departments in a large teaching hospital.

PARTICIPANTS

Fifty consecutive patients were recruited over a 2-month period.

MAIN OUTCOME MEASURES

Visual analogue scale symptom scores were compared with radiological scores for sinus mucosal thickening.

RESULTS

No statistically significant relationship was demonstrated between rhinological symptoms and radiological features suggestive of rhinosinusitis in patients undergoing MRI scanning for non-rhinological disease.

CONCLUSIONS

The relationship between rhinological symptoms and MRI findings of sinus pathology is not straightforward. Management decisions should be made on the basis of nasal history and endoscopy, rather than radiological findings. This is the first study assessing this relationship by documenting symptoms on the day of scanning, using a validated scoring system.

"Post-nasal drip syndrome": most patients with purulent nasal secretions do not complain of chronic cough

INTRODUCTION

Post-nasal drip syndrome (PNDS) is quoted as a common cause of chronic cough. However, there is little evidence to explain the mechanism by which PNDS may stimulate the cough reflex. This cohort study looks at patients with purulent nasal secretions, who may best represent any potential candidate for PNDS, and observes the frequency of symptomatic coughing.

METHODS

One-hundred and eight consecutive patients referred to a rhinology clinic with symptoms of chronic infective rhinosinusitis, all with purulent nasal secretions identified on nasendoscopy, were observed through investigation and treatment. Patients were initially treated with broad-spectrum antibiotics and nasal douching. The frequency of coughing was recorded pre- and post- treatment.

RESULTS

Eighty-nine percent of patients complained of post-nasal secretions. Twenty-three (21%) patients complained of cough. Eight had co-existing asthma, 3 had bronchiectasis, 1 had sarcoid and 2 had had a recent respiratory tract infection. Therefore 9 patients (8%) had purulent nasal secretions and a cough with no other discernable pathology. Cough improved in 8 of the 9 patients following treatment. Cough improved in 9 of the 14 patients with other possible co-existing causes for cough.

CONCLUSIONS

Only a small proportion of patients with purulent rhinosinusitis without coexisting chest disease complain of cough. Although nasal disease may be a genuine cause for chronic cough it is unlikely to be as common a cause as has been reported. Postnasal secretions do not appear to be an adequate cause for cough and the term 'PNDS' should be replaced by rhinosinusitis when nasal disease is the cause of chronic cough.

The aetiology of chronic cough: a review of current theories for the otorhinolaryngologist

Most studies agree that post-nasal drip syndrome (PNDS), asthma, gastroesophageal reflux disease (GORD), and laryngopharyngeal reflux (LPR) are the commonest causes of chronic cough in the immunocompetent, non-smoking patient who is not taking an angiotensin-converting enzyme inhibitor. No diagnostic test has been found to define those who are said to have PNDS other than a response to a first-generation antihistamine. Examining the available evidence suggests that mechanical stimulation of the pharynx by mucus is not an adequate theory for the production of cough. Inflammatory mediators in the lower airways are raised in PNDS, cough variant asthma and GORD, and the theory that an inflammatory process is affecting 'one airway' is a plausible one. Nasal disease is more likely to result in cough from the co-existing involvement of the lower airways through an as yet undefined pathway, and eosinophil and mast cell mediation appear a likely mechanism.