Preben Homøe

Biofilms in chronic infections – a matter of opportunity – monospecies biofilms in multispecies infections

It has become evident that aggregation or biofilm formation is an important survival mechanism for bacteria in almost any environment. In this review, we summarize recent visualizations of bacterial aggregates in several chronic infections (chronic otitis media, cystic fibrosis, infection due to permanent tissue fillers and chronic wounds) both as to distribution (such as where in the wound bed) and organization (monospecies or multispecies microcolonies). We correlate these biofilm observations to observations of commensal biofilms (dental and intestine) and biofilms in natural ecosystems (soil). The observations of the chronic biofilm infections point toward a trend of low bacterial diversity and sovereign monospecies biofilm aggregates even though the infection in which they reside are multispecies. In contrast to this, commensal and natural biofilm aggregates contain multiple species that are believed to coexist, interact and form biofilms with high bacterial and niche diversity. We discuss these differences from both the diagnostic and the scientific point of view.

Salivary gland carcinoma in Denmark 1990–2005: A national study of incidence, site and histology. Results of the Danish Head and Neck Cancer Group (DAHANCA)

To describe the incidence, site and histology (WHO 2005) of salivary gland carcinomas in Denmark. Nine hundred and eighty-three patients diagnosed from 1990 to 2005 were identified from three nation-wide registries. The associated clinical data were retrospectively retrieved from patient medical records. Histological revision was performed in 886 cases (90%). Based on histological revision, 31 patients (3%) were excluded from the study leaving 952 for epidemiological analysis. The mean crude incidence in Denmark was 1.1/100,000/year. The male vs. female ratio was 0.97 and the median age was 62 years. The parotid gland was the most common site (52.5%) followed by the minor salivary glands of the oral cavity (26.3%). The most frequent histological subtypes were adenoid cystic carcinoma (25.2%), mucoepidermoid carcinoma (16.9%), adenocarcinoma NOS (12.2%) and acinic cell carcinoma (10.2%). The revision process changed the histological diagnosis in 121 out of 886 cases (14%). The incidence of salivary gland carcinoma in Denmark is higher than previously reported. More than half of salivary gland carcinomas are located in the parotid gland with adenoid cystic carcinoma being the most frequent subtype. Histological classification of salivary gland carcinomas is difficult and evaluation by dedicated pathology specialists might be essential for optimal diagnosis and treatment.

Salivary gland carcinoma in Denmark 1990-2005: outcome and prognostic factors. Results of the Danish Head and Neck Cancer Group (DAHANCA).

To describe outcome and prognostic factors in a national Danish series of patients treated for salivary gland carcinoma. From three Danish nation-wide registries and supplementary patient records, 871 patients diagnosed with primary major or minor salivary gland carcinoma in the period from 1990 to 2005 were identified. A total of 796 (91%) histological specimens were revised according to the WHO 2005 classification. The median follow-up time was 78 months. Three hundred and thirty-four patients (38%) experienced recurrence. Crude survival, disease-specific survival and recurrence-free survival after 5 and 10 years were 66%, 76%, 64% and 51%, 69%, 58%, respectively. In multivariate analysis age, latency, stage, microscopic margins, vascular invasion and histological grade were all independent prognostic factors with regards to crude and disease-specific survival. Stage, microscopic margins, vascular invasion and histological grade were independent prognostic factors for recurrence-free survival. Age over 61 years, latency under 8 months, stage 3+4 disease, involved or close microscopic margins, vascular invasion and high histological grade are all independent prognostic factors with a negative impact on survival in salivary gland carcinoma patients. This knowledge can be helpful in guiding clinicians in daily work and choice of treatment across the large variety of salivary gland carcinoma subtypes.

Mucosal biofilm detection in chronic otitis media: a study of middle ear biopsies from Greenlandic patients

The objectives of this study were to examine middle ear biopsies from Greenlandic patients with chronic otitis media (COM) for the presence of mucosal biofilms and the bacteria within the biofilms. Thirty-five middle ear biopsies were obtained from 32 Greenlandic COM patients admitted to ear surgery. All biopsies were examined by means of peptide nucleic acid-fluorescent in situ hybridization (PNA-FISH), and if possible culture and polymerase chain reaction (PCR) of the 16s rDNA and sequencing. Light microscopy and confocal laser scanning microscopy were used. Skin biopsies from 23 of the patients served as controls. PNA-FISH showed morphological signs of biofilms in 15 out of 35 (43xa0%) middle ear biopsies. In the control skin biopsies, there were signs of biofilms in eight out of 23 biopsies (30xa0%), probably representing skin flora. PCR and 16s sequencing detected bacteria in seven out of 20 (35xa0%) usable middle ear biopsies, and in two out of ten (20xa0%) usable control samples. There was no association between biofilm findings and PCR and 16s sequencing. Staphylococci were the most common bacteria in bacterial culture. We found evidence of bacterial biofilms in 43xa0% of middle ear biopsies from patients COM. The findings may indicate that biofilms are a part of the pathogenesis in recurrent episodes of ear discharge in COM, but further investigations are necessary.

Radiological imaging of the neck for initial decision-making in oral squamous cell carcinomas-A questionnaire survey in the Nordic countries

Background. Fast and accurate work-up is crucial to ensure the best possible treatment and prognosis for patients with head and neck cancer. The presence or absence of neck lymph node metastases is important for the prognosis and the choice of treatment. Clinical lymph node (N)-staging is done by palpation and diagnostic imaging of the neck. We investigated the current practice of the initial radiological work-up of patients with oral squamous cell carcinomas (OSCC) in the Nordic countries. Methods. A questionnaire regarding the availability and use of guidelines and imaging modalities for radiological N-staging in OSCC was distributed to 21 Head and Neck centres in Denmark (n = 4), Finland (n = 5), Iceland (n = 1), Norway (n = 4) and Sweden (n = 7). We also asked for a description of the radiological criteria for determining the lymph nodes as clinical positive (cN+) or negative (cN0). Results. All 21 Head and Neck centres responded to the questionnaire. Denmark and Finland have national guidelines, while Norway and Sweden have local or regional guidelines. Seventeen of the 19 centres with available guidelines recommended computed tomography (CT) of the cN0 neck. The waiting time may influence the imaging modalities used. Lymph node size was the most commonly used criteria for radiological cN+, but the cut-off measures vary from 0.8 to 2.0 cm. Conclusion. Overall, CT is the most commonly recommended and used imaging modality for OSCC. Despite availability of national guidelines the type and number of radiological examinations vary between centres within a country, but the implementation of a fast-track programme may facilitate fast access to imaging. The absence of uniform criteria for determining the lymph nodes of the neck as cN+ complicates the comparison of the accuracy of the imaging modalities. Well-defined radiological strategies and criteria are needed to optimise the radiological work-up in OSCC.

Risk factors for postoperative complications after total laryngectomy following radiotherapy or chemoradiation: a 10-year retrospective longitudinal study in Eastern Denmark.

To determine the rates of and risk factors for postoperative complications following total laryngectomy in patients treated with radiotherapy or chemoradiation.

Prognostic factors for survival after salvage total laryngectomy following radiotherapy or chemoradiation failure: a 10-year retrospective longitudinal study in eastern Denmark.

The primary aims were to determine the rates of and prognostic factors for overall survival, disease‐specific survival and disease‐free survival following salvage total laryngectomy.

Ten-year retrospective study of head and neck carcinoma in situ: incidence, treatment, and clinical outcome

OBJECTIVESnTo examine the management and clinical outcome for patients with primary head and neck carcinoma in situ (CIS) and to estimate the incidence in the referral population.nnnSTUDY DESIGNnA retrospective study from 2000-2009 of patients with head and neck CIS referred for treatment at Rigshospitalet. The referral area was East Denmark and Greenland with a population of 2.4 million.nnnRESULTSnFifty-five patients with primary CIS were identified: 21 oral cavity, 7 pharynx, 25 larynx, 2 nasal cavity/paranasal sinuses. The median annual incidence was 0.24/100,000. Eleven patients (20%) had T-site recurrence. The 5-year disease-specific survival rate and 5-year recurrence-free survival rate were 98% and 74% respectively.nnnCONCLUSIONSnThe annual incidence of primary head and neck CIS was low and in accordance with previous findings reported in the literature. We recommend that CIS lesions should be treated on T-site and surveilled as T1/T2 head and neck carcinomas.

A Spectrum of Basaloid Morphology in a Subset of EBV-Associated “Lymphoepithelial Carcinomas” of Major Salivary Glands

Nasopharyngeal carcinomas of the undifferentiated or lymphoepithelial type are most commonly seen in South East Asians. Identical tumors have also been described at a variety of other sites including lung, skin and salivary gland and have been referred to by a number of names including lymphoepithelial carcinoma (LEC). LECs of major salivary gland are extremely rare. They are particularly common amongst the Inuit populations of the arctic region including Greenland (Denmark), Canada and Alaska, as well as South East Asians. Within the Inuit group, this tumor represents the majority of all salivary gland carcinomas. Amongst primary LEC of major salivary gland, most cases reported in the literature have represented typical nasopharynx-like tumors. Variants of Epstein–Barr Virus (EBV) associated LEC have not been described previously, to the best of our knowledge. In this report, we describe 4 EBV-associated major salivary gland LECs with prominent basaloid morphology, which represent 22xa0% of a cohort of 18 salivary LECs from an Inuit population in Greenland. The features described in these cases raise a differential diagnosis of other basaloid tumors, particularly in light of the salivary gland location. A basaloid variant of LEC in major salivary gland should be recognized, especially in highly prone populations, to avoid misdiagnosis of other more common salivary tumors.

The relation of biofilms to chronic otitis media and other ear related chronic infections

Ear, nose and throat infections (rhinitis, rhinosinusitis, otitis media, adenoiditis and tonsillitis), also termed, upper respiratory tract infections (URTI) are extremely frequent diseases worldwide, especially in childhood. The diseases are caused by viruses or bacteria and occur in both acute and chronic forms.