Barbara Rose

Human papillomavirus positivity predicts favourable outcome for squamous carcinoma of the tonsil

Mutations in the p53 and retinoblastoma (pRb) pathways associated with the use of tobacco and alcohol are common in squamous cell carcinoma (SCC) of the head and neck. Cell cycle proteins are also affected by human papillomavirus (HPV), which may also have an aetiological role in cancers at particular sites, most notably the tonsil. Attempts to identify prognostic molecular markers in head and neck cancers have met with conflicting results, but few studies have been undertaken with tumours of known HPV status at a single anatomic site. In our study 86 tonsil cancers were analysed for HPV status by sequence analysis of polymerase chain reaction products and for the expression of cell cycle proteins (p53, p21CIP1/WAF1, pRb, p16INK4A, cyclin D1 and p27KIP1) by immunohistochemistry. The HPV status could be established in 67 of the tumours. Thirty‐one (46%) of these were HPV‐positive, predominantly (28/31) for HPV16. Findings were related to tumour recurrence and patient survival. None of the cell cycle proteins independently predicted recurrence or survival. Patients with HPV‐positive tumours, however, were significantly less likely (p < 0.05) to have recurrence or to die of disease than those with HPV‐negative tumours, after adjusting for the effects of the cell cycle proteins, clinical stage, pathological node status, tumour grade, age, gender and treatment. These findings support the concept that HPV‐positive tonsil cancers may be a distinct biological group with less aggressive characteristics. Screening of tonsil cancers for HPV DNA may help optimise treatment and provide more accurate prognostic information.

Combination antibiotic susceptibility testing to treat exacerbations of cystic fibrosis associated with multiresistant bacteria: a randomised, double-blind, controlled clinical trial

BACKGROUND We did a randomised, double-blind, controlled clinical trial to prospectively assess whether use of combination antibiotic susceptibility testing improved clinical outcomes in patients with acute pulmonary exacerbations of cystic fibrosis who were infected with multiresistant bacteria. METHODS 251 patients with cystic fibrosis who were chronically infected with multiresistant gram negative bacteria gave sputum at 3-month intervals for conventional culture and sensitivity tests and for combination antibiotic susceptibility tests using multiple combination bactericidal antibiotic testing (MCBT). Patients who developed an exacerbation of pulmonary disease were randomised to receive a 14-day course of any two blinded intravenous antibiotics chosen on the basis of either results from conventional sputum culture and sensitivity testing or the result of MCBT. The primary outcome was time from randomisation until the patients next pulmonary exacerbation. Analysis was by intention-to-treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN60187870. FINDINGS 132 patients had a pulmonary exacerbation and were randomised during the 4.5-year study period. The time to next pulmonary exacerbation was not prolonged in the MCBT-treated group (hazard ratio 0.86 in favour of the conventionally-treated group, 95% CI 0.60-1.23, p=0.40). There was no difference between the groups in treatment failure rate. After 14 days of intravenous antibiotic therapy, changes in lung function, dyspnoea, and sputum bacterial density were similar in both groups. INTERPRETATION Antibiotic therapy directed by combination antibiotic susceptibility testing did not result in better clinical and bacteriological outcomes compared with therapy directed by standard culture and sensitivity techniques. The non-bactericidal effects of antibiotic therapy might play an important part in determining improvement in patients with cystic fibrosis pulmonary exacerbations.

Antibiotic Susceptibilities of Pseudomonas aeruginosa Isolates Derived from Patients with Cystic Fibrosis under Aerobic, Anaerobic, and Biofilm Conditions

ABSTRACT Recent studies have determined that Pseudomonas aeruginosa can live in a biofilm mode within hypoxic mucus in the airways of patients with cystic fibrosis (CF). P. aeruginosa grown under anaerobic and biofilm conditions may better approximate in vivo growth conditions in the CF airways, and combination antibiotic susceptibility testing of anaerobically and biofilm-grown isolates may be more relevant than traditional susceptibility testing under planktonic aerobic conditions. We tested 16 multidrug-resistant isolates of P. aeruginosa derived from CF patients using multiple combination bactericidal testing to compare the efficacies of double and triple antibiotic combinations against the isolates grown under traditional aerobic planktonic conditions, in planktonic anaerobic conditions, and in biofilm mode. Both anaerobically grown and biofilm-grown bacteria were significantly less susceptible (P < 0.01) to single and combination antibiotics than corresponding aerobic planktonically grown isolates. Furthermore, the antibiotic combinations that were bactericidal under anaerobic conditions were often different from those that were bactericidal against the same organisms grown as biofilms. The most effective combinations under all conditions were colistin (tested at concentrations suitable for nebulization) either alone or in combination with tobramycin (10 μg ml−1), followed by meropenem combined with tobramycin or ciprofloxacin. The findings of this study illustrate that antibiotic sensitivities are dependent on culture conditions and highlight the complexities of choosing appropriate combination therapy for multidrug-resistant P. aeruginosa in the CF lung.

Squamous cell carcinoma of the oropharynx in Australian males induced by human papillomavirus vaccine targets.

This study provides Australian data on the incidence of human papillomavirus (HPV)-related oropharyngeal cancer to aid the debate on extending the HPV vaccination programme to males. The HPV status for 302 oropharyngeal cancers diagnosed between 1987 and 2006 was determined by HPV E6-targeted multiplex real-time PCR/p16 immunohistochemistry. The overall HPV-positivity rate was 36% (94% types 16 and 18). HPV-related cancer increased from 19% (1987-1990) to 47% (2001-2005). HPV data used in conjunction with Australian cancer incidence data 2001-2005 showed that 1.56 cases of oropharyngeal cancer per 100,000 males per year were associated with HPV types targeted by the vaccine. Vaccinating males may substantially reduce the burden of oropharyngeal cancer in Australia.

Human papillomavirus predicts outcome in oropharyngeal cancer in patients treated primarily with surgery or radiation therapy

Objective:This study examines the prognostic significance of human papillomavirus (HPV) in patients with locally advanced oropharyngeal squamous cell carcinoma (SCC) treated primarily with surgery or definitive radiotherapy.Methods:One hundred and ninety-eight patients with Stage 3/4 SCC were followed up for recurrence in any form or death from any cause for between 1 and 235 months after diagnosis. HPV status was determined using HPV E6-targeted multiplex real-time PCR/p16 immunohistochemistry. Determinants of recurrence and mortality hazards were modelled using Coxs regression with censoring at follow-up dates.Results:Forty-two per cent of cancers were HPV-positive (87% type 16). HPV predicted loco-regional control, event-free survival and overall survival in multivariable analysis. Within the surgery with adjuvant radiotherapy (n=110), definitive radiotherapy-alone (n=24) and definitive radiotherapy with chemotherapy (n=47) groups, patients with HPV-positive cancers were one-third or less as likely to have loco-regional recurrence, an event or to die of any cause as those with HPV-negative cancers after adjusting for age, gender, tumour grade, AJCC stage and primary site. The 14 patients treated with surgery alone were considered too few for multivariable analysis.Conclusion:HPV status predicts better outcome in oropharyngeal cancer treated with surgery plus adjuvant radiotherapy as well as with definitive radiation therapy±chemotherapy.

Genetic analysis of Pseudomonas aeruginosa isolates from the sputa of Australian adult cystic fibrosis patients.

ABSTRACT Genetic investigations were carried out with 50 phenotypically selected strains of Pseudomonas aeruginosa from 18 patients attending an Australian cystic fibrosis (CF) center. The isolates were analyzed by restriction fragment length polymorphism (RFLP) analysis by pulsed-field gel electrophoresis (PFGE). Phylogenetic analysis of the macrorestriction patterns showed rates of genetic similarity ranging from 76 to 100%; 24 (48%) of the strains from 11 patients had greater than 90% similarity. A dominant strain emerged: 15 isolates from seven patients had identical PFGE patterns, and 4 other isolates were very closely related. The 50 isolates were grouped into 21 pulsotypes on the basis of visual delineation of a three-band difference. Ten of the 18 (56%) patients were infected with clonal or subclonal strains. Sequence analysis of PCR products derived from the mucA gene showed 20 mutations, with the number of mutations in individual isolates ranging from 1 to 4; 19 of these changes are reported here for the first time. Potentially functional changes were found in 22 (44%) isolates. Eight changes (five transversions and three single base deletions) led to premature stop codons, providing support for the presence of mucA mutations as one pathway to mucoidy. There was a trend toward an association between the dominant strain and lack of potentially functional mucA mutations (P = 0.09 by the χ2 test) but no relationship between genotype and phenotype. This is the first study of genetic variation in P. aeruginosa isolates from adult Australian CF patients. The findings highlight the need for further investigations on the transmissibility of P. aeruginosa in CF patients.

Role of human papillomavirus in the etiology of head and neck cancer.

Head and neck cancer is the worlds sixth most common cancer, but despite advances in treatment, there has been no significant decline in the mortality rate. In recent years, there has been mounting epidemiologic and experimental evidence of a role for human papillomavirus (HPV) as the etiologic agent of a subset of head and neck cancers. The association is strongest for oropharyngeal cancers, especially those of the tonsil. HPV 16 is invariably the predominant type. HPV‐positive cancers have been shown to be biologically distinct, clustering among nonsmokers and light drinkers, and have been associated with a favorable prognosis. This review examines the current findings of HPV in head and neck cancers and discusses implications for developing new treatments.

The Expression Of Key Cell Cycle Markers And Presence Of Human Papillomavirus In Squamous Cell Carcinoma Of The Tonsil.

Chemical carcinogens induce squamous cell carcinoma (SCC) of the head and neck by targeting the p53 and the retinoblastoma (pRb) pathways. Human papillomavirus (HPV) might have an etiologic role in these cancers at particular sites. Few studies have compared cell cycle protein expression in HPV‐positive and HPV‐negative tumors in this region.

Evidence for spread of a clonal strain of Pseudomonas aeruginosa among cystic fibrosis clinics

Recent advances in molecular typing techniques have led to the identification of a dominant clonal strain of Pseudomonas aeruginosa within several cystic fibrosis (CF) clinics ([2][1]-[6][2], [8][3], [9][4]). These strains have been described as “hypertransmissible,” and “patient-to-patient

Cough-generated aerosols of Pseudomonas aeruginosa and other Gram-negative bacteria from patients with cystic fibrosis

Background: Pseudomonas aeruginosa is the most common bacterial pathogen in patients with cystic fibrosis (CF). Current infection control guidelines aim to prevent transmission via contact and respiratory droplet routes and do not consider the possibility of airborne transmission. It was hypothesised that subjects with CF produce viable respirable bacterial aerosols with coughing. Methods: A cross-sectional study was undertaken of 15 children and 13 adults with CF, 26 chronically infected with P aeruginosa. A cough aerosol sampling system enabled fractioning of respiratory particles of different sizes and culture of viable Gram-negative non-fermentative bacteria. Cough aerosols were collected during 5 min of voluntary coughing and during a sputum induction procedure when tolerated. Standardised quantitative culture and genotyping techniques were used. Results: P aeruginosa was isolated in cough aerosols of 25 subjects (89%), 22 of whom produced sputum samples. P aeruginosa from sputum and paired cough aerosols were indistinguishable by molecular typing. In four cases the same genotype was isolated from ambient room air. Approximately 70% of viable aerosols collected during voluntary coughing were of particles ⩽3.3 μm aerodynamic diameter. P aeruginosa, Burkholderia cenocepacia, Stenotrophomonas maltophilia and Achromobacter xylosoxidans were cultivated from respiratory particles in this size range. Positive room air samples were associated with high total counts in cough aerosols (p = 0.003). The magnitude of cough aerosols was associated with higher forced expiratory volume in 1 s (r = 0.45, p = 0.02) and higher quantitative sputum culture results (r = 0.58, p = 0.008). Conclusion: During coughing, patients with CF produce viable aerosols of P aeruginosa and other Gram-negative bacteria of respirable size range, suggesting the potential for airborne transmission.