COX-2 as a determinant of lower disease-free survival for patients affected by ameloblastoma

Ameloblastoma is a locally aggressive neoplasm with a poorly understood pathogenesis. Therefore, the aim of this study is to investigate whether COX-2 expression is associated with ameloblastoma microvascular density (MVD) and with tumor aggressiveness. Sixty-three cases of primary ameloblastomas arranged in tissue microarray were submitted to immunohistochemistry against cyclooxigenase-2 (COX-2) and CD34. Clinicopathological parameters regarding sex, age, tumour size, tumour duration, tumour location, treatment, recurrences, radiographic features, vestibular/lingual and basal cortical disruption and follow-up data were obtained from patients’ medical records and correlated with the proteins expression. The results on BRAF-V600E expression were obtained from our previous study and correlated with COX-2 and CD34 expressions. Log-rank univariate analysis and multivariate Cox regression model were done to investigate the prognostic potential of the molecular markers. Twenty-eight cases (44.4%) exhibited cytoplasmic positivity for COX-2, predominantly in the columnar peripheral cells, with a mean MVD of 2.2 vessels/mm². COX-2 was significantly associated with recurrences (p?<?0.001) and BRAF-V600E expression (p?<?0.001), whereas lower MVD was associated with the use of conservative therapy (p?=?0.004). Using univariate and multivariate analyses, COX-2 was significantly associated with a lower 5-year disease-free survival (DFS) rate (p?<?0.001 and p?=?0.012, respectively), but not with a higher MVD (p?=?0.68). In conclusion, COX-2 expression in ameloblastomas is not associated with MVD, but it is significantly associated with recurrences and with a lower DFS.     

The use of optical fiber in endodontic photodynamic therapy. Is it really relevant?

This study analyzed the necessity of use of an optical fiber/diffusor when performing antimicrobial photodynamic therapy (PDT) associated with endodontic therapy. Fifty freshly extracted human single-rooted teeth were used. Conventional endodontic treatment was performed using a sequence of ProTaper (Dentsply Maillefer Instruments), the teeth were sterilized, and the canals were contaminated with Enterococcus faecalis 3 days’ biofilm. The samples were divided into five groups: group 1—ten roots irradiated with a laser tip (area of 0.04 cm²), group 2—ten roots irradiated with a smaller laser tip (area of 0.028 cm²), and group 3—ten teeth with the crown, irradiate with the laser tip with 0.04 cm² of area. The forth group (G4) followed the same methodology as group 3, but the irradiation was performed with smaller tip (area of 0.028 cm²) and G5 ten teeth with crown were irradiated using a 200-mm-diameter fiber/diffusor coupled to diode laser. Microbiological samples were taken after accessing the canal, after endodontic therapy, and after PDT. Groups 1 and 2 showed a reduction of two logs (99%), groups 3 and 4 of one log (85% and 97%, respectively), and group 5 of four logs (99.99%). Results suggest that the use of PDT added to endodontic treatment in roots canals infected with E. faecalis with the optical fiber/diffusor is better than when the laser light is used directed at the access of cavity.     

Simple bone cyst: possible misdiagnosis in periapical pathology

Simple bone cysts are non-neoplastic bone lesions, classified as intraosseous pseudocysts without epithelial lining, that can be empty or filled by fluid and display uncommon clinical and radiographic features. This article presents an unusual case of a simple bone cyst with clinical and radiographic features similar to chronic apical periodontitis. A general dentist referred an 18-year-old man for endodontic treatment after the patient complained of pain in the mandibular right second molar, which displayed a significant bony radiolucency. Chronic periapical lesion was excluded after detailed clinical and radiographic examinations. During surgical exploration, an empty bone cavity was observed and curetted before wound closure. One year later, complete healing was observed.     

Cadherin-catenin adhesion system and mucin expression: a comparison between young and older patients with gastric carcinoma

BACKGROUND: Young patients are thought to develop gastric carcinomas with a molecular genetic profile that is distinct from that of gastric carcinomas occurring at a later age. The aim of this study was to compare the clinicopathological features and expression patterns of the markers E-cadherin and beta-catenin, and mucins (MUC1, MUC2, MUC5AC, and MUC6) in young and older patients. METHODS: The clinicopathological features and overall survival data of 62 young patients (age 40 years). A tissue microarray method and immunohistochemistry were used in order to analyze marker expression in paraffin-embedded tissue blocks obtained from both groups. RESULTS: The young group presented a higher percentage of diffuse-type tumors in comparison to the older group (P<0.01). The rates of positivity for E-cadherin and beta-catenin membranous expression patterns and mucin (MUC2, MUC5AC and MUC6) positivity were higher in the young group (P<0.01). Although young patients showed a lower frequency of alterations in marker expression and had significantly better survival rates than the older patients, neither age nor the marker expression pattern were found to be independent prognostic factors of survival. Only stage, tumor size, and tumor location persisted as prognostic factors for patients with gastric cancer. CONCLUSION: Biological markers of cellular adhesion and gastric differentiation were differently expressed in young and older patients. Our findings support the hypothesis that young patients develop carcinomas with a different genetic pathway compared to the pathway of tumors occurring at a later age, and we suggest further investigations to assess the prognostic relevance of the markers to specific subgroups.     

Isolated limb perfusion with hyperthermia and chemotherapy: predictive factors for regional toxicity

OBJECTIVE:

Isolated limb perfusion combined with melphalan is an accepted treatment for obtaining locoregional control in advanced melanoma of the extremities and other malignant neoplasias restricted to the limb. This study aims to examine the factors associated with toxicity caused by the regional method. We considered the technical aspects of severe complications associated with the procedure in an attempt to diminish the patient morbidity that occurs during the learning curve.

METHODS:

We conducted a retrospective analysis of the records of patients who underwent perfusion at the AC Camargo Hospital in São Paulo, Brazil between January 2000 and January 2009. The Wieberdink scale was applied to classify local toxicity and its relation to clinical and laboratory variables.

RESULTS:

Fifty-eight perfusions were performed in 55 patients. Most patients (86.2%) presented a toxicity level between I and III. Grade V toxicity was seen in five cases (8.6%), four of which occurred in the first 2 years. Creatine phosphokinase, an important predictive factor for toxicity, had an average value of 231.8 for toxicity grades I-III and 1286.2 for toxicity grades IV-V (p = 0.001). There was a relationship between the melphalan dose and toxicity, which was 77 mg (25 to 130 mg) for toxicity grades I-II and 93.5 mg (45 to 120 mg) for toxicity grades IV-V (p = 0.0204).

CONCLUSION:

It is possible to prevent the toxicity associated with melphalan by adjusting the dose according to the patient''s body weight (especially for women and obese patients) and the creatine phosphokinase values in the postoperative period.