Occult nodal metastases in T1-T2cN0 oral squamous cell carcinoma: Correlation between sentinel node positivity and completion neck dissection analysis.

OBJECTIVES: Sentinel node procedure (SN) is a standard procedure that has shown its safety and effectiveness for T1/T2 cN0 oral squamous cell carcinoma (OSCC), with completion neck dissection (CND) for patients with positive SN. The aim of this study was to characterize the nodal involvement in a cohort of SN + OSCC. MATERIALS AND METHODS: Patients with T1/T2 cN0 OSCC with positive SN with CND were included in this single-center, prospective cohort study between 2000 and 2013. RESULTS: 54/301 patients had at least one positive SN. In 43/54 (80 %) cases, only the SN(s) were invaded; with only one SN involved (SN+=1) in 36/54 (67 %) cases. No predictive factors of nodal involvement in the CND were found considering the followings: SN micro/macrometastases, primary tumor's depth of invasion (DOI), perineural spread, lymphovascular involvement, primary tumor location, T stage and extranodal extension. The SN micrometastatic involvement (n = 22) was significantly associated with only one SN + CND- (p = 0.017). In the group of patients with unique micrometastatic involvement in the SN (n = 20/54), there was a higher isolated nodal recurrence free time (p = 0.017). CONCLUSION: 80% of T1/T2 cN0 OSCC with positive SN had no other lymph node metastases in the CND, questioning the potential benefits of this procedure. Predictive factors such as the size of the SN metastasis need to be tested to stratify the risk of positive non-SN lymph nodes leading to a personalized treatment, lowering the therapeutic morbidity while maintaining the oncologic safety.

Replacement of lip-split mandibulotomy by pull-through approach for T3-4 oral carcinomas.

At the study hospital, the lip-split mandibulotomy (LSM) has progressively been replaced by a pull-through (PT) approach. This study compared the outcomes of the LSM and PT approaches in a series of 192 patients with T3-T4a oral tongue and floor of the mouth squamous cell carcinoma treated over the two last decades. No difference in margin status (P = 0.254), rate of early complications (local infections) (P = 0.867), haematoma/haemorrhage (P = 0.221), delayed wound healing (P = 0.438), re-operation (P = 0.083), or Clavien-Dindo classification (P= 0.5281) was found. The LSM approach was associated with a higher rate of late complications such as pseudarthrosis (14.5% vs 0.9%; OR 17.89, P = 0.0005) and trismus (35% vs 13.8%; OR 3.32, P = 0.025), and a trend towards a higher rate of fistulas (24.6% vs 13.1%; OR 2.16, P = 0.088). The quality of life of long-term survivors (median 132 months) was similar in the two groups, with a mean QLQC30 score of 59.7 (P = 0.099) and mean MDADI score of 57.4 (P = 0.213). The 5-year local control rate was 86.4% in the PT group and 86.2% in the LSM group (P = 0.878), while the 5-year overall survival rates were 50.0% and 48.3%, respectively (P = 0.68). In our experience, replacement of LSM by a PT approach in oral carcinoma was associated with decreased rates of late complications such as pseudarthrosis, fistula, and trismus, without any difference in oncological outcomes.

French consensus on management of head and neck cancer surgery during COVID-19 pandemic.

In the context of the current pandemic, there is a need for specific advice concerning treatment of patients with Head and Neck cancers. The rule is to limit as much as possible the number of patients in order to reduce the risks of contamination by the SARS-Cov-2 virus for both patients and the caregivers, who are particularly exposed in ENT. The aim is to minimize the risk of loss of opportunity for patients and to anticipate the increased number of cancer patients to be treated at the end of the pandemic, taking into account the degree of urgency, the difficulty of the surgery, the risk of contaminating the caregivers (tracheotomy) and the local situation (whether or not the hospital and intensive care departments are overstretched).

Vocal fold mobility as the main prognostic factor of treatment outcomes and survival in stage II squamous cell carcinomas of the glottic larynx.

OBJECTIVE: This study aimed to assess the influence of supra- and subglottic extensions and vocal fold mobility on outcome in a large monocentric cohort of 148 patients treated for tumour-node-metastasis stage T2N0 glottic carcinomas. METHODS: In all, 107 glottic carcinoma patients had normal vocal fold mobility (T2aN0), and 41 had impaired vocal fold mobility (T2bN0). Treatment decisions were made by a multidisciplinary team. RESULTS: Vocal fold mobility was associated with overall survival, disease-free survival, local control, larynx preservation and laryngectomy-free survival. For patients with T2a lesions, local control, laryngectomy-free survival and disease-free survival improved after surgery but overall survival did not. For patients with T2b lesions, local control, laryngectomy-free survival, disease-free survival and overall survival were all higher after surgery than after radiotherapy. CONCLUSION: This study highlights for the first time the importance of vocal fold mobility in treatment outcomes and is the first to assess its influence on survival. Updated tumour-node-metastasis classifications should consider the distinction between T2a and T2b lesions.

New insights into peripherin expression in cochlear neurons.

Peripherin is an intermediate filament protein that is expressed in peripheral and enteric neurons. In the cochlear nervous system, peripherin expression has been extensively used as a differentiation marker by preferentially labeling the type II neuronal population at adulthood, but yet without knowing its function. Since the expression of peripherin has been associated in time with the process of axonal extension and during regeneration of nerve fibers in other systems, it was of interest to determine whether peripherin expression in cochlear neurons was a static phenotypic trait or rather prone to modifications following nerve injury. In the present study, we first compared the expression pattern of peripherin and beta III-tubulin from late embryonic stages to the adult in rat cochlea. The staining for both proteins was seen before birth within all cochlear neurons. By birth, and for 2 or 3 days, peripherin expression was gradually restricted to the type II neuronal population and their projections. In contrast, from postnatal day (P) 10 onwards, while the expression of beta III-tubulin was still found in projections of all cochlear neurons, only the type I population had beta III-tubulin immunoreactivity in their cell bodies. We next investigated the expression of peripherin in axotomized cochlear neurons using an organotypic explant model. Peripherin expression was surprisingly re-expressed in a vast majority of neurons after axotomy. In parallel, the expression and localization of beta III-tubulin and peripherin in dissociated cultures of cochlear neurons were studied. Both proteins were distributed along the entire neuronal length but exhibited complementary distribution, especially within the projections. Moreover, peripherin immunoreactivity was still abundant in the growth cone, whereas that of beta III-tubulin was decreasing at this compartment. Our findings are consistent with a model in which peripherin plays an important structural role in cochlear neurons and their projections during both development and regenerative processes and which is compatible with the assumption that frequently developmentally regulated factors are reactivated during neuronal regeneration.

Supernumerary outer hair cells arise external to the last row of sensory cells in the organ of corti.

During the development of the mammalian inner ear, the number of hair cells produced is highly regulated and remains constant throughout life. The mechanism underlying this regulation is beginning to be understood although many aspects still remain obscure. When late embryonic or early postnatal rat organs of Corti were cultured, the production of supernumerary hair cells was observed. This overproduction of sensory cells could be modulated by the addition of several growth factors. In this study, we examined explants of rat organs of Corti that produced supernumerary hair cells. In the supernumerary hair cell region, up to two rows of inner hair cells and five rows of outer hair cells were observed. Morphological evaluation of these specimens revealed that less mature hair cells were located in the most external rows of these sensory cells. When a supernumerary hair cell was produced, a supporting cell (i.e. Deiters' cell) was also produced, strongly suggesting that the conversion of a Deiters' cell into a hair cell was not the mechanism that produced these extra hair cells. Based on these results, we propose that prosensory cells located at the external edge of the organ of Corti retain a capacity to form hair cells and that it is these prosensory cells that differentiate into supernumerary hair cells and Deiters' cells.