Progression to malignancy in oral potentially malignant disorders: a retrospective study of 5,036 patients in Ontario, Canada.

OBJECTIVES: Determine the rate of malignant transformation (MT) of oral potentially malignant disorders (OPMDs) and risk factors for transformation. STUDY DESIGN: The OPMD database (2001-2015) from 2 biopsy services in Ontario, Canada, was linked to the Ontario Cancer Registry to determine the rate of progression to oral squamous cell carcinoma (OSCC). Clinical and histologic features of progressed and non-progressed cases were compared to determine risk factors for progression. RESULTS: The MT rate was 6.4% (322/5,036 cases). The mean time for cancer development was 51.2 months. 33.6% of cases (107/322) progressed after over 60 months. The risk of cancer increased with age and was higher in non-smokers. The MT rate was highest in the tongue (11.4%), followed by the floor of mouth (7.1%) and gingiva (6.5%). Histologic grade was associated with progression to cancer (P < .0001). Atypical verrucous-papillary lesions with no or mild dysplasia predominantly affected older patients' gingiva, and the progression rate was significantly higher than conventional mild dysplasia (9.2% vs 3.2%, P = .0002). CONCLUSIONS: Our population-based retrospective study showed that <10% of OPMDs progressed to cancer, which could take many years. Atypical papillary-verrucous proliferation without high-grade dysplasia is a subtype of OPMD requiring further study.

A 10-Year Review of Intraoral Salivary Gland Tumor Diagnoses: Diagnostic Challenges and Inter-Observer Agreement.

BACKGROUND: Salivary gland tumors (SGT) are a diverse group of neoplasms arising from the major and minor glands. The oral cavity is the most common site for minor SGT (IMSGT), and these lesions frequently pose a challenge to the pathologist due to overlapping histopathological features and limited material for analysis. Our objective was to determine specific clinical and histopathological features associated with challenges in IMSGT diagnoses and pathologists' agreement. METHODS: We conducted a retrospective analysis of 248 IMSGT received between 2010 and 2019. We evaluated the diagnostic challenge of the cases by stratifying according to whether a definitive, favored, or indeterminate (challenging) diagnosis was provided. Inter-observer agreement and concordance of biopsy diagnoses with the final diagnoses after tumor resection were evaluated. RESULTS: Of the 248 biopsies, 191 had a definitive diagnosis, 38 favored diagnoses, and 19 were indeterminate. The predominant diagnoses considered for the indeterminate category were pleomorphic adenoma/myoepithelioma (PA), polymorphous adenocarcinoma (PAC), adenoid cystic carcinoma (AdCC), and low-grade adenocarcinoma. Using multivariate analysis of clinical features, younger patient age, smaller tumor size, and larger biopsy size increased the likelihood of a definitive diagnosis (p = 0.014, p = 0.037, p = 0.012). The inter-observer agreement for 68 representative cases was moderate overall (Fleiss's Kappa 0.575) and good for the 40 cases with a definitive diagnosis (Fleiss's Kappa 0.66). Sixty-five biopsy diagnoses were matched with corresponding tumor resection diagnoses and found to show a good concordance (Cramer's V test 0.76). The discordant diagnoses predominantly involved PA, carcinoma exPA, PAC, AdCC, and adenocarcinoma NOS. CONCLUSION: Diagnostic challenges in IMSGT incisional biopsies were infrequent, especially if multiple pathologists were consulted. PA, PAC, AdCC, and adenocarcinoma NOS were the histologic types more commonly posing diagnostic challenges. Younger patient age, smaller tumor size, and larger biopsy are associated with a definitive diagnosis. This data highlights the importance of appropriate sampling in IMSGT.

Oral Squamous Cell Carcinoma Associated with Precursor Lesions.

Oral squamous cell carcinoma (OSCC) may be associated with precursor lesions known as oral potentially malignant disorders (OPMD). Few studies have reported on how OPMD diagnosis affects early detection and outcome of OSCC. We reviewed a large series of OSCC to determine the proportion that was associated with preceding OPMD and to compare the outcome of OSCC with or without precursor. Cases of oral-oropharyngeal carcinoma diagnosed between 2005 and 2015 were retrieved from the Ontario Cancer Registry (OCR) and matched to records of OPMD between 2001 and 2015 in two large oral pathology diagnostic services and the pathology databases of two hospitals with oral pathology services, to identify cases with precursor. Of 10,987 cancer cases, 378 (3.44%) had a preceding OPMD. Patients living in Central Ontario were more likely to have OPMD diagnosed before carcinoma than those in North Ontario (4.73% vs. 1.63%, P = 0.05). 329 of 5,257 cases of oral cancer were linked to a precursor, compared with 24 of 4,174 cases of oropharyngeal cancer (6.26% vs. 0.57%, P < 0.0001). Oral cancers with precursor were predominantly diagnosed at stage I (49.30%), compared with those without precursor, where stage IV disease predominated (41.28%). Sixty-nine of 309 (22.33%) patients with precursor-associated oral cancer have died of disease, compared with 1,551 of 4,656 (33.31%) patients without a precursor (P = 0.02). We conclude that patients with OSCC associated with a precursor had significantly lower odds of dying from disease. The beneficial effect of precursor lesion diagnosis on outcome is related to a higher proportion of stage I disease. PREVENTION RELEVANCE: OSCC causes significant morbidity and mortality, especially if diagnosed at late stages. Precursor lesions to OSCC can be recognized by clinical examination. Our study shows that early diagnosis of OSCC at the precursor stage can improve the outcome of oral cancer.

Gingival Swelling as the Initial Manifestation of Granulomatosis with Polyangiitis.

We describe a case of granulomatosis with polyangiitis (GPA; formerly named Wegener granulomatosis) that presented initially as florid areas of gingival swelling. The patient also had upper respiratory symptoms that included sinus congestion and cough of recent onset. Clinical-pathologic correlation aided the interpretation of non-specific biopsy findings and immediate referral to an appropriate medical specialist. Treatment was rendered at an early stage of disease with a good response to date. Review of the literature indicates that gingival swelling, often with the characteristic appearance of "strawberry gingivitis" may represent the initial sign of disease in 2% of patients with GPA. Biopsy of gingival lesions often shows a non-specific histologic appearance that should be interpreted in the context of the clinical appearance and pertinent medical history. The clinical investigations that lead to definitive diagnosis and treatment are presented to facilitate the management of this uncommon but potentially fatal condition.

5-Fluorouracil Is Associated With a Decreased Recurrence Risk in Odontogenic Keratocyst Management: A Retrospective Cohort Study.

PURPOSE: The antimetabolite drug, 5-fluorouracil (5-FU), has been suggested as an adjunctive treatment to reduce the recurrence rates of odontogenic keratocysts (OKCs). We report on the use of 5-FU in the management of patients with OKCs as a postenucleation intracavity topical dressing. METHODS: For this retrospective cohort study, we collected all data of sequentially treated cases presenting to the University of Toronto's hospital clinics for the management of biopsy-proven OKCs. Chart reviews were conducted to identify all patients treated with 5-FU cream, and compare them to patients treated with modified Carnoy's solution (MCS). In the treatment group, all patients were treated in an identical manner with enucleation and peripheral ostectomy followed by the application of 5% 5-FU cream for 24 hours. Preoperative and postoperative radiographs were collected to determine the time to recurrence of the disease, and the techniques were compared via a multivariate Cox regression analysis. RESULTS: Seventy patients were found to be eligible for inclusion in this study. Of these, 34 patients were treated with 5% topical 5-FU, and 36 patients were managed with MCS. The median follow-up time in the 5-FU group was 22 months (interquartile range, 36), compared with 27 months (interquartile range, 37) for the MCS group (P = .40). No recurrences were identified in the 5-FU group, compared with 9 recurrences (25%) in patients treated with MCS. 5-FU was shown to be significantly negatively associated with time to disease resolution (P < .01). CONCLUSIONS: Results from this study suggest that when used topically, 5-FU effectively lowers the recurrence rates of OKCs. Further large scale, case-controlled studies are being investigated at our center and are warranted to make definitive conclusions regarding the effectiveness of this novel technique when compared with conventional therapies.

Characterization of Oral Squamous Cell Carcinoma Associated Inflammation: A Pilot Study.

Background: Oral squamous cell carcinoma (OSCC) is a devastating disease that is usually associated with a dense associated inflammatory infiltrate. Characterizing tumor-associated inflammation is critical to understand the pathogenies of tumor development and progression. Methods: We have tested a protocol to analyze tissue and salivary immune cells and mediators of 37 patients with OSCC at different stages and compared to eight chronic periodontitis patients and 24 healthy controls. Tissue analysis was based on fluorescent immunohistochemistry (FIHC) and inflammatory mediators were analyzed using a Luminex-based 30-Plex panel. Immune cells were analyzed using multichannel flow cytometry including CD45, CD66b, CD3, CD4, CD8, CD25, CD56, CD68, CD138, PD-1, and PD-L1. Results: We show an increase in OSCC-associated inflammation characterized by increased pro-inflammatory cytokines including IL-6, IL-8, TNFα, and GMCSF and increased salivary immune cells. Conclusion: We described a new method to analyze salivary inflammatory markers that can be used in future studies to monitor disease progression and prognosis.

Increase in detection of oral cancer and precursor lesions by dentists: Evidence from an oral and maxillofacial pathology service.

BACKGROUND: Dentists play an important role in the detection and diagnosis of oral diseases, including oral cancer and its precursor lesions. There are few comprehensive reviews in the recent literature that examine the scope and trends of oral disease diagnoses by dentists. METHODS: The authors analyzed all accessions to the Toronto Oral Pathology Service at the Faculty of Dentistry at the University of Toronto in Toronto, Ontario, Canada, from 2005 through 2015 using a custom-built database. They used these data to calculate the temporal trends in the diagnoses of oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). RESULTS: A total of 63,483 biopsy specimens were submitted primarily by dentists from 2005 through 2015. From these, 2,679 cases of OED and 828 OSCC were diagnosed. The authors' results show a 3.8-fold increase in the number of epithelial dysplasias and a 1.8-fold increase in mucosal carcinomas over the study period. The rate of increase of OED and OSCC was significantly higher than the rate of increase of total oral carcinomas diagnosed in the region, the population changes, and the number of dentists in the region. CONCLUSIONS AND PRACTICAL IMPLICATIONS: Within the limitations of a study of a single large oral pathology biopsy service, the analysis of diagnoses shows that dentists are increasingly involved in the detection of oral mucosal carcinoma and precursor lesions. The dental community plays an important and increasing role in the detection of oral cancer and potentially malignant disorders. Increased awareness among oral health care and nonoral health care professionals may increase early detection of OSCC.

V-ATPases Containing a3 Subunit Play a Direct Role in Enamel Development in Mice.

Vacuolar H+ -ATPases (V-ATPases) are ubiquitous multisubunit proton pumps responsible for organellar pH maintenance. Mutations in the a3 subunit of V-ATPases cause autosomal recessive osteopetrosis, a rare disease due to impaired bone resorption. Patients with osteopetrosis also display dental anomalies, such as enamel defects; however, it is not clear whether these enamel abnormalities are a direct consequence of the a3 mutations. We investigated enamel mineralization, spatiotemporal expression of enamel matrix proteins and the a3 protein during tooth development using an osteopetrotic mouse model with a R740S point mutation in the V-ATPase a3 subunit. Histology revealed aberrations in both crown and root development, whereas SEM analysis demonstrated delayed enamel mineralization in homozygous animals. Enamel thickness and mineralization were significantly decreased in homozygous mice as determined by µCT analysis. The expression patterns of the enamel matrix proteins amelogenin, amelotin, and odontogenic ameloblast-associated protein (ODAM) suggested a delay in transition to the maturation stage in homozygous animals. Protein expression of the a3 subunit was detected in ameloblasts in all three genotypes, suggesting that a3-containing V-ATPases play a direct role in amelogenesis, and mutations in a3 delay transition from the secretory to the maturation stage, resulting in hypomineralized and hypoplastic enamel. J. Cell. Biochem. 118: 3328-3340, 2017. © 2017 Wiley Periodicals, Inc.

Topical 5-Fluorouracil is a Novel Targeted Therapy for the Keratocystic Odontogenic Tumor.

PURPOSE: The antimetabolite drug, 5-fluorouracil (5-FU), is used in the treatment of various cancers, including basal cell carcinomas (BCCs). The authors hypothesized that keratocystic odontogenic tumors (KOTs) would respond to 5-FU treatment because of their similarities to BCCs in molecular etiopathogenesis. MATERIALS AND METHODS: An ambispective cohort study of the treatment efficacy of topical 5-FU on KOTs was conducted. Independent variables included the topical application of 5% 5-FU or modified Carnoy's solution (MC) after enucleation and peripheral ostectomy at the University of Toronto from 2006 through 2014. Outcome variables included time to recurrence and peripheral nerve injury. KOT specimens in these patients were immunostained with p53, Ki-67, thymidylate synthetase (TS), thymidylate phosphorylase (TP), and dihydropyrimidine dehydrogenase (DPD) antibodies. Semiquantitative staining scores were calculated for all immunohistochemistry sections examined. Descriptive statistics were computed using Fisher exact test and Kaplan-Meier analysis as appropriate with the P value set at .05. RESULTS: Thirty-two patients with 32 KOTs were reviewed (41% in women and 59% in men). There were no KOT recurrences in the 5-FU group (n = 11), whereas there were 4 recurrences in the MC group (n = 21; P = .190). There was a significantly lower incidence of inferior alveolar nerve paresthesia with 5-FU treatment (P = .039). Immunohistochemical staining showed upregulation of TP (P < .0001) and DPD (P < .0001) and no change in TS (P > .05) in inflamed KOTs. CONCLUSIONS: 5-FU effectively treats KOTs with less postoperative morbidity than conventional treatment with MC. Low TS and upregulated TP expressions in inflamed KOTs suggest increased 5-FU efficacy in inflamed KOTs. Topical 5-FU is a novel therapy for KOTs and provides a targeted molecular approach to treatment.

Unusual presentation of squamous cell carcinoma of the maxilla in an 8-year-old child.

Oral squamous cell carcinoma (OSCC) is extremely rare in patients younger than 20 years of age. We present here a case of OSCC of the maxillary alveolar ridge in an otherwise healthy 8-year-old patient. The clinicohistologic presentation was not typical for mucosal SCC, and the possibility of an intrabony origin from the odontogenic epithelium was considered. The patient was treated with surgical resection, and treatment decisions were made with consideration of the need for eradication of tumor as well as tissue preservation to allow normal growth and development. A review of the literature indicated a preponderance of gingival-alveolar ridge as the site of OSCC in children with no known genetic predisposition to cancer. More studies of this rare subset of OSCC will help understand the underlying biology and guide treatment decisions.

Age-related Epstein-Barr virus-positive mucocutaneous ulcer: a case report.

Key Clinical Message The oral manifestations of EBV-positive mucocutaneous ulcers have a worrisome clinical appearance but relatively benign clinical course, responding well to conservative treatment. Elderly patients who develop an unexplained, persistent ulcer of the oral mucosa should have the lesion examined for EBV.

Neutrophils Increase Oral Squamous Cell Carcinoma Invasion through an Invadopodia-Dependent Pathway.

Neutrophils have recently been shown to promote invasion and correlate with a poor prognosis in different cancers, including head and neck squamous cell carcinomas. In this study, we analyze the effects of neutrophils in the invasion of oral squamous cell carcinoma (OSCC) using a combination of conditioned media, direct and indirect coculture of human peripheral blood neutrophils, and UMSCC47 cells (OSCC cell line). Invasion and matrix degradation were determined using a modified in vitro invasion assay and an invadopodia assay, respectively. UMSCC47 and neutrophil cocultures or conditioned media from cocultures increased UMSCC47 invasion, invadopodia formation, and matrix degradation. Further analysis revealed an increase in TNFα and IL8 in supernatants of cocultures compared with neutrophil or UMSCC47 cultures alone and that inhibition of TNFα and IL8 significantly decreased OSCC invasion. Our results show that neutrophils increase the invasiveness of OSCC through the activation of invadopodia and matrix degradation, suggesting a paracrine activation loop between the two cells. Importantly, the presence of neutrophils in the oral environment may modulate the clinical behavior of OSCC.

Association of human papilloma virus with atypical and malignant oral papillary lesions.

OBJECTIVE: This study aimed to examine atypical and malignant papillary oral lesions for low- and high-risk human papillomavirus (HPV) infection and to correlate HPV infection with clinical and pathologic features. STUDY DESIGN: Sections of 28 atypical papillary lesions (APLs) and 14 malignant papillary lesions (MPLs) were examined for HPV by in situ hybridization and for p16 and MIB-1 by immunohistochemistry; 24 conventional papillomas were studied for comparison. RESULTS: Low-risk HPV was found in 10 of 66 cases, including 9 APLs and 1 papilloma. All low-risk HPV-positive cases showed suprabasilar MIB-1 staining, and the agreement was statistically significant (P < .0001). Diffuse p16 staining combined with high-risk HPV was not seen in any of the cases. A subset of HPV(-) APLs progressed to carcinoma. CONCLUSIONS: Oral papillary lesions are a heterogeneous group. Low-risk HPV infection is associated with a subset of APLs with a benign clinical course. Potentially malignant APLs and MPLs are not associated with low- or high-risk HPV.

Recurrent genomic alterations in sequential progressive leukoplakia and oral cancer: drivers of oral tumorigenesis?

A significant proportion (up to 62%) of oral squamous cell carcinomas (OSCCs) may arise from oral potential malignant lesions (OPMLs), such as leukoplakia. Patient outcomes may thus be improved through detection of lesions at a risk for malignant transformation, by identifying and categorizing genetic changes in sequential, progressive OPMLs. We conducted array comparative genomic hybridization analysis of 25 sequential, progressive OPMLs and same-site OSCCs from five patients. Recurrent DNA copy number gains were identified on 1p in 20/25 cases (80%) with minimal, high-level amplification regions on 1p35 and 1p36. Other regions of gains were frequently observed: 11q13.4 (68%), 9q34.13 (64%), 21q22.3 (60%), 6p21 and 6q25 (56%) and 10q24, 19q13.2, 22q12, 5q31.2, 7p13, 10q24 and 14q22 (48%). DNA losses were observed in >20% of samples and mainly detected on 5q31.2 (35%), 16p13.2 (30%), 9q33.1 and 9q33.29 (25%) and 17q11.2, 3p26.2, 18q21.1, 4q34.1 and 8p23.2 (20%). Such copy number alterations (CNAs) were mapped in all grades of dysplasia that progressed, and their corresponding OSCCs, in 70% of patients, indicating that these CNAs may be associated with disease progression. Amplified genes mapping within recurrent CNAs (KHDRBS1, PARP1, RAB1A, HBEGF, PAIP2, BTBD7) were selected for validation, by quantitative real-time PCR, in an independent set of 32 progressive leukoplakia, 32 OSSCs and 21 non-progressive leukoplakia samples. Amplification of BTBD7, KHDRBS1, PARP1 and RAB1A was exclusively detected in progressive leukoplakia and corresponding OSCC. BTBD7, KHDRBS1, PARP1 and RAB1A may be associated with OSCC progression. Protein-protein interaction networks were created to identify possible pathways associated with OSCC progression.

Association of high-risk human papillomavirus infection with oral epithelial dysplasia.

OBJECTIVE: The aim of this study was to evaluate cases of oral epithelial dysplasia for biologically significant human papillomavirus (HPV) infection. STUDY DESIGN: Forty consecutive cases of high-grade dysplasia and 37 cases of low-grade dysplasia were examined for p16(INK4a) expression by immunohistochemistry. High-risk HPV infection was assessed in p16-positive cases using in situ hybridization. Proliferation index was assessed with MIB-1 immunohistochemistry. RESULTS: Eleven of 40 high-grade dysplasias and one of 37 low-grade dysplasias were p16 positive. High-risk HPV was detected in seven cases of p16-positive high-grade dysplasia. The difference between high- and low-grade dysplasia was statistically significant (P = .01). HPV-positive high-grade dysplasias showed a distinctive histologic appearance and MIB-1 labeling pattern. Most high-risk HPV-positive cases were seen in the floor of mouth. CONCLUSION: High-risk HPV was associated with a subset of cases of severe epithelial dysplasia/carcinoma in situ that demonstrated diffuse loss of squamous differentiation and a high proliferation index.

EWSR1-ATF1 fusion is a novel and consistent finding in hyalinizing clear-cell carcinoma of salivary gland.

Hyalinizing clear-cell carcinoma (HCCC) is a rare, low-grade salivary gland tumor with distinctive clear-cell morphology and pattern of hyalinization as well as focal mucinous differentiation. However, histological overlap exists with other salivary gland tumors, such as epithelial-myoepithelial carcinoma (EMCa), salivary myoepithelial carcinoma, and mucoepidermoid carcinoma (MEC). The potential relationship between HCCC and its morphological mimics has not been yet investigated at the genetic level. In this study, we conducted a molecular analysis for the presence of rearrangements in MAML2, commonly seen in MECs, and EWSR1, involved in "soft tissue myoepithelial tumors" (SMET) by fusion with POU5F1, PBX1, or ZNF444. Fluorescence in situ hybridization (FISH) was performed on 23 HCCC cases for abnormalities in MAML2, EWSR1, FUS, POU5F1, PBX1, and ZNF444. FISH for MAML2 was negative in all cases (0 of 14), including those with mucinous differentiation (0 of 7). An EWSR1 rearrangement was identified in 18 of 22 HCCCs (82%), while no break-apart signals were seen in FUS, POU5F1, PBX1, or ZNF444. 3'RACE on an EWSR1 rearranged HCCC identified an EWSR1-ATF1 fusion, which was confirmed by RT-PCR. ATF1 involvement was further confirmed by FISH analysis in 13 of 14 EWSR1-rearranged HCCC cases (93%). In contrast, all control cases tested, including among others 5 EMCa and 3 MEC with clear cells, were negative for EWSR1 and ATF1 rearrangements. The presence of EWSR1-ATF1 fusion in most HCCCs reliably separates these tumors from its histological mimics. The distinction from MEC is particularly important, as conventional MEC grading schemes overgrade these indolent HCCCs, potentially impacting on treatment.

SNAI1 expression and the mesenchymal phenotype: an immunohistochemical study performed on 46 cases of oral squamous cell carcinoma.

BACKGROUND: SNAI1 can initiate epithelial-mesenchymal transition (EMT), leading to loss of epithelial characteristics and, in cancer, to invasion and metastasis. We hypothesized that SNAI1 reactivation occurs in oral squamous cell carcinoma (OSCC) where it might also be associated with focal adhesion kinase (FAK) expression and p63 loss. METHODS: Immunohistochemistry was performed on 46 tumors and 26 corresponding lymph node metastases. Full tissue sections were examined to account for rare and focal expression. Clinical outcome data were collected and analyzed. RESULTS: SNAI1-positivity (nuclear, >/= 5% tumor cells) was observed in 10 tumors and 5 metastases (n = 12 patients). Individual SNAI1(+) tumor cells were seen in primary tumors of 30 patients. High level SNAI1 expression (>10% tumor cells) was rare, but significantly associated with poor outcome. Two cases displayed a sarcomatoid component as part of the primary tumor with SNAI1(+)/FAK(+)/E-cadherin(-)/p63(-) phenotype, but disparate phenotypes in corresponding metastases. All cases had variable SNAI1(+) stroma. A mesenchymal-like immunoprofile in primary tumors characterized by E-cadherin loss (n = 29, 63%) or high cytoplasmic FAK expression (n = 10, 22%) was associated with N(+) status and tumor recurrence/new primary, respectively. CONCLUSIONS: SNAI1 is expressed, although at low levels, in a substantial proportion of OSCC. High levels of SNAI1 may herald a poor prognosis and circumscribed SNAI1 expression can indicate the presence of a sarcomatoid component. Absence of p63 in this context does not exclude squamous tumor origin. Additional EMT inducers may contribute to a mesenchymal-like phenotype and OSCC progression.