A histological evaluation of the surgical margins from human oral fibrous-epithelial lesions excised with CO2 laser, Diode laser, Er:YAG laser, Nd:YAG laser, electrosurgical scalpel and cold scalpel.

BACKGROUND: We aim to evaluate the presence of histological artefacts in the surgical margins of human oral fibro-epithelial hyperplasias excised with lasers of different wavelengths, and also electrosurgical scalpel and cold scalpel. Moreover, we aim to determine if some of these instruments could impair the normal histological diagnosis of these lesions. MATERIAL AND METHODS: We included 130 consecutive surgical samples of 80 females and 50 males (mean age of 53.82±16.55) with a histological diagnosis of an oral benign fibrous-epithelial hyperplasias. The samples were categorized into 6 groups according to the type of instrument used: CO2 laser group, diode laser group, Er:YAG laser group, Nd:YAG laser group, electrosurgical scalpel group and cold scalpel group. Histological instrument-induced changes were microscopic evaluated and related with clinical and pathological variables. RESULTS: The instrument with highest tissue damage extension (TDE) was the electrosurgical scalpel (1002.2µm±434.92), followed by diode laser (913.73 µm±322.45), Nd:YAG (899.83µm±327.75), CO2 laser (538.37µm±170.50), Er:YAG laser (166.47µm±123.85), and at last with fewer alterations the cold scalpel group (2.36µm±7.27) (P < 0.001). The most regular incision was observed in CO2 laser group, followed by Er:YAG laser, Nd:YAG laser, electrosurgical scalpel and diode laser group with the less regular incision using cold scalpel as comparison (P < 0.001). A correlation was found between the incision score and TDE (P < 0.001). Regarding histological diagnosis, no case showed any limitation of diagnosis related with the use of any instrument evaluated. CONCLUSIONS: Our results suggest that lasers can be used for the excision of oral benign fibrous-epithelial hyperplasias, without hispathological diagnosis limitations, as long as the physical properties of each laser are known and respected. Er:YAG laser have shown to be a laser with few tissue damage extension and with good incision regularity, been a possible instrument of choice for the surgical removal of these lesions.

Phosphorylated EGFR at tyrosine 1173 correlates with poor prognosis in oral squamous cell carcinomas.

OBJECTIVES: To evaluate the expression of epidermal growth factor receptor (EGFR) and phosphorylated EGFR (pEGFR), in oral squamous cell carcinomas (OSCC). We examined their utility as prognostic markers by relating to clinicopathological characteristics and the clinical outcome. MATERIALS AND METHODS: We analysed 74 primary OSCC and examined immunohistochemical expression of EGFR and pEGFR (phosphorylated at tyrosine 1173) using tissue microarray technology. Their role in survival was assessed by Kaplan-Meier method and Cox regression models. RESULTS: Epidermal growth factor receptor expression was observed in all cases, and pEGFR expression was observed in 41.1% of the cases. We found a significant correlation between EGFR and pEGFR expression (P = 0.003). In the multivariable analysis for cause-specific survival, we found an independent prognostic value for pEGFR expression (HR 7.94, 95% CI 2.03-31.06, P = 0.003) and for clinical stage (HR 2.88, 95% CI 1.10-7.53, P = 0.031). For recurrence-free survival, clinical stage (HR 6.59, 95% CI 1.36-31.90, P = 0.019) and tumour grade (HR 3.35, 95% CI 1.07-10.44, P = 0.037) presented independent prognostic value. CONCLUSION: Epidermal growth factor receptor is highly expressed in OSCC and is phosphorylated in more than one-third of the cases. The independent value of pEGFR expression in cause-specific survival of OSCC suggests that this marker may serve as reliable biological marker to identify high-risk subgroups and to guide therapy.