Salivary gland polymorphous adenocarcinoma: Clinicopathological features and gene alterations in 36 Japanese patients.

BACKGROUND: Polymorphous adenocarcinoma is a common intraoral minor salivary gland carcinoma in Western countries but is extremely rare in Japan. The current study aimed to characterize the clinicopathological features and status of molecular alterations of polymorphous adenocarcinoma-associated genes, such as PRKD1/2/3, ARID1A, and DDX3X, in a large cohort of Japanese patients with polymorphous adenocarcinoma. METHODS: We examined the cases of 36 Japanese patients with salivary gland polymorphous adenocarcinoma and 26 cases involving histopathological mimics. To detect gene splits, fluorescence in situ hybridization was carried out for polymorphous adenocarcinoma-associated genes. Additionally, we applied a SNaPshot multiplex assay to identify PRKD1 hotspot mutations. RESULTS: This study revealed the indolent clinical course of polymorphous adenocarcinoma with a high 10-year overall survival rate (92.9%), accompanied by occasional local recurrences and cervical lymph node metastasis (23.3%). Twenty cases (55.6%) of polymorphous adenocarcinoma (but none of the mimics) exhibited alterations in at least one polymorphous adenocarcinoma-associated gene. Rearrangement of polymorphous adenocarcinoma-associated genes and PRKD1 E710D were identified in 17 (47.2%) and 4 (11.1%) cases, respectively; one case showed coexisting PRKD3 split and PRKD1 E710D. In the multivariate analysis, high clinical stage (p = 0.0005), the presence of prominent nucleoli (p = 0.0003), and ARID1A split positivity (p = 0.004) were independent risk factors for disease-free survival. CONCLUSION: Japanese patients with polymorphous adenocarcinoma showed clinicopathological features similar to those reported in Western countries. This study disclosed that polymorphous adenocarcinoma-associated genetic alterations were common and specific findings in polymorphous adenocarcinomas. The diagnostic role and possible prognostic significance of polymorphous adenocarcinoma-associated genetic alterations in polymorphous adenocarcinomas were suggested.

Porphyromonas gingivalis Lipopolysaccharides Promote Proliferation and Migration of Human Vascular Smooth Muscle Cells through the MAPK/TLR4 Pathway.

Atherosclerosis is a major cause of mortality worldwide. The initial change in atherosclerosis is intimal thickening due to muscle cell proliferation and migration. A correlation has been observed between periodontal disease and atherosclerosis. Here, we investigated the proliferation and migration of human aortic smooth muscle cells (HASMCs) using Porphyromonas gingivalis-derived LPS (Pg-LPS). To elucidate intracellular signaling, toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88) of HASMCs were knocked down, and the role of these molecules in Pg-LPS-stimulated proliferation and migration was examined. The role of mitogen-activated protein kinase (MAPK) in HASMC proliferation and migration was further elucidated by MAPK inhibition. Pg-LPS stimulation increased the proliferation and migration of HASMCs and activated the TLR4/MyD88 pathway. TLR4 knockdown inhibited Pg-LPS stimulated HASMCs proliferation and migration. Pg-LPS stimulation led to the phosphorylation of P38 MAPK, JNK, and ERK, and MyD88 knockdown inhibited the phosphorylation of P38 MAPK and JNK but not ERK. P38 MAPK and SAPK/JNK inhibition did not suppress the proliferation of HASMCs upon Pg-LPS stimulation, but ERK inhibition significantly inhibited proliferation. SAPK/JNK and ERK inhibition suppressed Pg-LPS-stimulated migration of HASMCs. In conclusion, our findings suggest that Pg-LPS may promote atherosclerosis via the activation of MAPK through TLR4.

In Situ PD-L1 Expression in Oral Squamous Cell Carcinoma Is Induced by Heterogeneous Mechanisms among Patients.

The expression of programmed death ligand-1 (PD-L1) is controlled by complex mechanisms. The elucidation of the molecular mechanisms of PD-L1 expression is important for the exploration of new insights into PD-1 blockade therapy. Detailed mechanisms of the in situ expression of PD-L1 in tissues of oral squamous cell carcinomas (OSCCs) have not yet been clarified. We examined the mechanisms of PD-L1 expression focusing on the phosphorylation of downstream molecules of epidermal growth factor (EGF) and interferon gamma (IFN-γ) signaling in vitro and in vivo by immunoblotting and multi-fluorescence immunohistochemistry (MF-IHC), respectively. The in vitro experiments demonstrated that PD-L1 expression in OSCC cell lines is upregulated by EGF via the EGF receptor (EGFR)/PI3K/AKT pathway, the EGFR/STAT1 pathway, and the EGFR/MEK/ERK pathway, and by IFN-γ via the JAK2/STAT1 pathway. MF-IHC demonstrated that STAT1 and EGFR phosphorylation was frequently shown in PD-L1-positive cases and STAT1 phosphorylation was correlated with lymphocyte infiltration and EGFR phosphorylation. Moreover, the phosphorylation pattern of the related molecules in PD-L1-positive cells differed among the cases investigated. These findings indicate that PD-L1 expression mechanisms differ depending on the tissue environment and suggest that the examination of the tissue environment and molecular alterations of cancer cells affecting PD-L1 expression make it necessary for each patient to choose the appropriate combination drugs for PD-1 blockade cancer treatment.

Oral hygiene status and factors related to oral health in hospitalized patients with schizophrenia.

OBJECTIVE: This study aimed to elucidate the oral hygiene status and the factors associated with poor oral hygiene among patients with schizophrenia. METHODS: The relationships of oral hygiene status (calculus index [CI], debris index [DI]), the mean number of decayed-missing-filled teeth (mean DMFT), and Revised Oral Assessment Guide (ROAG) with related factors (hospitalization, chlorpromazine equivalents [CPZE], age, Barthel Index [BI], frequency of cleaning teeth, and self-oral hygiene ability) among 249 hospitalized schizophrenic patients were investigated. RESULTS: The results for oral hygiene status were as follows: median (range); CI 0.5 (0-6.0), DI 1.7 (0-6.0), ROAG 10.0 (7.0-15.0); and mean DMFT 21.7 ± 7.3. The average CPZE was 524.4 ± 353.6 mg (mean ± SD), and the BI was 76.4 ± 30.7. There was a negative correlation between BI and DI (r = -0.34), and a positive correlation between age and mean DMFT (r = 0.57). Male patients tended to have worse oral conditions (ROAG) than females. The least-squares multiple regression analysis revealed that BI for DI, age for mean DMFT, sex for ROAG, and self-oral hygiene ability for CI, DI, and mean DMFT were factors related to oral health status. CONCLUSION: Patients with schizophrenia tended to have poor oral hygiene. BI, being male, and low activities of daily living were associated with poor oral hygiene. Furthermore, advanced age was associated with an increased risk of dental caries.

Improving function of cytotoxic T-lymphocytes by transforming growth factor-ß inhibitor in oral squamous cell carcinoma.

Immunotherapy with immune-checkpoint therapy has recently been used to treat oral squamous cell carcinomas (OSCCs). However, improvements in current immunotherapy are expected because response rates are limited. Transforming growth factor-ß (TGF-ß) creates an immunosuppressive tumor microenvironment (TME) by inducing the production of regulatory T-cells (Tregs) and cancer-associated fibroblasts and inhibiting the function of cytotoxic T-lymphocytes (CTLs) and natural killer cells. TGF-ß may be an important target in the development of novel cancer immunotherapies. In this study, we investigated the suppressive effect of TGF-ß on CTL function in vitro using OSCC cell lines and their specific CTLs. Moreover, TGFB1 mRNA expression and T-cell infiltration in 25 OSCC tissues were examined by in situ hybridization and multifluorescence immunohistochemistry. We found that TGF-ß suppressed the function of antigen-specific CTLs in the priming and effector phases in vitro. Additionally, TGF-ß inhibitor effectively restored the CTL function, and TGFB1 mRNA was primarily expressed in the tumor invasive front. Interestingly, we found a significant negative correlation between TGFB1 mRNA expression and the CD8+ T-cell/Treg ratio and between TGFB1 mRNA expression and the Ki-67 expression in CD8+ T-cells, indicating that TGF-ß also suppressed the function of CTLs in situ. Our findings suggest that the regulation of TGF-ß function restores the immunosuppressive TME to active status and is important for developing new immunotherapeutic strategies, such as a combination of immune-checkpoint inhibitors and TGF-ß inhibitors, for OSCCs.

p53 and ki67 as biomarkers in determining response to chemoprevention for oral leukoplakia.

BACKGROUND: We performed a randomized controlled chemoprevention trial of oral leukoplakia by administrating a low dose of beta-carotene and vitamin C supplements. 17% of subjects in the experimental arm (4/23) demonstrated clinical remission (complete or partial response) at completion of the trial. The objective of this study was to determine whether baseline expression of p53 and ki67 demonstrated any differences between those responding or not responding to our intervention. A secondary objective was to elucidate any relationship between dietary factors and clinical responses. METHODS: For this biomarker study, we included all subjects in the experimental group (n = 23) who were non-smokers. Among 16 who completed the trial for 1 year of supplementation, there were four responders and 12 non-responders at 1-year follow-up. Following immuno-staining for p53 and ki67, the percentage of positive cell nuclei were analyzed as labeling index (LI). RESULTS: Expression of p53 was greater in basal layers than in para-basal layers. Mean para-basal LI of p53 was higher in non-responding (26.0) than in responding subjects (11.2) (P = 0.028). ki67 LIs were not significantly different in the two groups. CONCLUSIONS: Expression of p53 was inversely related to clinical response to the supplements. Other biomarkers that may recognize subject's responsiveness to chemoprevention require further study.

Impact of TLR9 and TLR7 gene polymorphisms on prognosis and survival of patients with oral squamous cell carcinoma.

Despite significant efforts in developing new diagnostic and therapeutic modalities, oral squamous cell carcinomas (OSCCs) still exhibit a high recurrence rate, a low five-year survival rate, and an increasing prevalence. Toll-like receptors (TLRs), which initiate and perpetuate immune mechanisms upon activation, have been linked to immune surveillance and the antitumor immune response. The aim of this study was to investigate the association between the polymorphisms of the TLR7 rs3853839 and TLR9 rs187084 genes and OSCC risk, clinicopathological features, and survival. Genotyping was assessed by real-time polymerase chain reaction (PCR) in 95 HPV-negative OSCC patients and 107 age- and sex-matched healthy controls. Patients with lymph node metastases had higher frequencies of the TLR9 rs187084 CC variant genotype compared to the major TT genotype (P = 0.020) and to T-allele carriers (combined TT + CT genotypes, P = 0.015). A higher prevalence of advanced stage III was observed in patients with the TLR9 rs187084 variant CC genotype compared to TT (P = 0.047) and to T-allele carriers (TT + CT, P = 0.037). Kaplan-Meier analysis revealed a lower overall survival rate in patients with the TLR9 rs187084 variant CC genotype compared to TT genotype (P = 0.010, log-rank test) and to T-allele carriers (TT + CT, P = 0.002), though it was not an independent predictor of overall survival. Both TLR9 rs187084 and TLR7 rs3853839 polymorphisms were associated with high alcohol consumption (P = 0.027 and P = 0.001, respectively). The investigated genetic variations were not associated with OSCC susceptibility. The variant CC genotype of the TLR9 rs187084 polymorphism might be a marker of poor survival and tumor progression in OSCC.

Novel frameshift variant of WNT10A in a Japanese patient with hypodontia.

Congenital tooth agenesis is caused by the impairment of crucial genes related to tooth development, such as Wnt signaling pathway genes. Here, we investigated the genetic causes of sporadic congenital tooth agenesis. Exome sequencing, followed by Sanger sequencing, identified a novel single-nucleotide deletion in WNT10A (NC_000002.12(NM_025216.3):c.802del), which was not found in the healthy parents of the patient. Thus, we concluded that the variant was the genetic cause of the patient's agenesis.

Three-dimensional imaging evaluation of facial swelling after orthognathic surgery with compression and Kinesio taping therapy: a randomized clinical trial.

Background: Postoperative swelling is a common complication of orthognathic surgery. The authors used three-dimensional (3D) image analysis and body surface temperature to determine the effects of compression taping (CT) and Kinesio taping (KT) by the epidermis, dermis, and fascia method (EDF-KT) on postoperative swelling. Materials and methods: The authors conducted a prospective, parallel-group, randomized controlled trial. Among the 162 patients diagnosed with jaw deformity and who underwent orthognathic surgery from August 2020 to October 2022, 105 patients (men: 36, women: 69, mean age: 28.27±8.92) underwent Le Fort type I + sagittal split ramus osteotomy (SSRO) or SSRO and were included in this study. Patients were randomly divided into three groups: EDF-KT group (n=31), CT group (n=41), and no tape group (control group, n=30). All taping was performed immediately postoperatively and removed on postoperative day (POD) 5. Three-dimensional images of the participants' faces were obtained preoperatively and at PODs 3, 7, 30, and 90 using a hand-held 3D imaging system and infrared thermography. Results: No significant difference was observed in postoperative swelling and postoperative body surface temperature between the groups at each time point. The CT group showed a trend towards reduced swelling on PODs 3 and 7 and a trend toward residual swelling on POD 90. The EDF-KT group showed a trend towards an increase in postoperative body surface temperature. Conclusion: CT taping may not be appropriate for postoperative swelling control, suggesting that EDF-KT may affect body surface temperature. Further validation of the efficacy of KT for jaw deformities is needed.

Clinicopathological significance of MAML2 gene split in mucoepidermoid carcinoma.

CRTC1-MAML2 and CRTC3-MAML2 fusions have been associated with favorable clinicopathological features of mucoepidermoid carcinomas. However, the significance of the MAML2 gene split has not been fully clarified. In the present study, 95 mucoepidermoid carcinomas (paraffin-embedded materials) were analyzed for CRTC1-MAML2 and CRTC3-MAML2 fusions by RT-PCR and for the MAML2 gene split by FISH. Quantitative RT-PCR for the CRTC1-MAML2 transcript was performed in selected cases. MLL gene involvement, which has been reported in some leukemia cases, was examined by FISH in fusion partner-unknown cases. CRTC1-MAML2 and CRTC3-MAML2 fusions were detected in 37 and 6 cases, respectively. The MAML2 gene split was detected in 62 cases, which included all CRTC1/3-MAML2 fusion-positive cases. The level of CRTC1-MAML2 transcript expression was highly variable, and its clinicopathological impact was unclear. The MLL gene split was not detected. Mucoepidermoid carcinomas negative for CRTC1/3-MAML2 and positive for the MAML2 gene split (n = 19) showed favorable clinicopathological tumor features similar to those positive for CRTC1/3-MAML2 fusions. Compared with negative cases (n = 33), mucoepidermoid carcinomas positive for the MAML2 split (n = 62) were associated with lower patient age, a mild female predilection, a smaller tumor size, less frequent nodal metastasis, a lower clinical stage, a lower histological grade, and longer overall and disease-free survival. The MAML2 gene split emerged as an independent prognostic factor for both overall and disease-free survival in multivariate prognostic analysis. The presence of the MAML2 gene split defines a distinct mucoepidermoid carcinoma subset that is associated clinicopathologically with favorable tumor features.

MALT lymphoma of the sublingual gland: A case report with current overview of diagnostic and therapeutic strategies.

Extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) is a low-grade B-cell lymphoma. MALT lymphomas involving the sublingual gland are extremely rare. Herein, we report a case of MALT lymphoma of the sublingual gland. Additionally, we discuss challenging diagnostic aspects as well as current treatment strategies.

Cytotoxic, genotoxic, and toxicogenomic effects of heated tobacco products and cigarette smoke in human primary keratinocytes.

INTRODUCTION: Heated tobacco products (HTPs) appear to be less harmful to health than conventional cigarettes (CCs). However, limited analytical data are available to support this claim. This study aimed to compare the cytotoxic, genotoxic, and toxicogenomic effects of HTPs and CCs in carcinogenesis via multistep gene mutations in the oral mucosal cells. METHODS: Cigarette smoke extract (CSE) was obtained from HTPs and CCs. Primary human oral keratinocytes (HOKs) were treated with 5% and 20% CSE from HTPs and CCs. Cell survival rate assays were performed after 6, 12, and 24 h. After 6 h, DNA double-strand breaks (DSBs) were evaluated using anti-γH2AX antibodies with immunohistochemistry. mRNAs expressions of mediator of DNA damage checkpoint 1 (MDC1) and ataxia telangiectasia and Rad3-related protein (ATR), were analyzed. Expressions of miR-22 and miR-185 were analyzed because miR-22 targets MDC1 and miR-185, ATR. RESULTS: The HOKs had equivalent survival rates after exposure to the same concentrations of CSE from CCs and HTPs. HTPs increased foci formation of γH2AX in HOKs, as did CCs (without CSE vs 20% HTP, p<0.05; without CSE vs 20% CC, p<0.05). Expressions of MDC1 and ATR decreased in cells exposed to CSE from CCs and HTPs (MDC1: without CSE vs 20% HTP, p<0.05; without CSE vs 20% CC, p<0.05; ATR: without CSE vs 20% HTP, p<0.05; without CSE vs 20% CC, p<0.05). Expressions of miR-22 and miR-185 were not significantly increased when exposed to CSE from CCs or HTPs. CONCLUSIONS: HTPs and CCs had similar cytotoxic effects. HTPs are genotoxic, can cause DSBs, and have toxicogenomic damage because they inhibit the MDC1 and ATR-CHK1 DNA repair pathways in the oral mucosa. The miRNA-mRNA axis was not related to these inhibitions.

Feasibility of oral microbiome profiles associated with oral squamous cell carcinoma.

Objective: Recently, the possibility that oral microbiomes is associated with oral squamous cell carcinoma (OSCC) initiation and progression has attracted attention; however, this association is still unclear. Here, we comprehensively analyze the microbiome profiles of saliva samples using next-generation sequencing followed by determining the association between oral microbiome profiles and OSCC. Materials and Methods: Microbiome profiles in saliva samples from patients with OSCC, oral leukoplakia (OLK), and postoperative OSCC (Post) were analyzed. Candidate OSCC-associated bacteria were identified by comparing the bacterial diversity and relative abundance of each group based on these microbiome profiles, and their applicability as OSCC detection tools were evaluated. Results: There were significant differences in genus abundances (Streptococcus, Aggregatibacter, and Alloprevotella) among the groups from saliva samples. In the OSCC group, compared with the OLK and Post groups, abundances of the genus Fusobacterium, phylum Fusobacteria and phylum Bacteroidetes were markedly increased and that of the genus Streptococcus and phylum Firmicutes were decreased. Conclusion: The results suggested a strong association of these bacteria with OSCC. Especially, phylum Fusobacterium was significantly associated with early recurrence of OSCC. Thus, oral microbiome analysis may have a potential of novel OSCC detection and prognostic tool.

Impact of CRTC1/3-MAML2 fusions on histological classification and prognosis of mucoepidermoid carcinoma.

AIMS: The aim of study was to evaluate the impact of CRTC1-MAML2 and CRTC3-MAML2 fusions on the histological classification of mucoepidermoid carcinoma (MEC) of the salivary glands and on the prognosis of patients. METHODS AND RESULTS: MEC cases (n = 111) were screened for CRTC1-MAML2 and CRTC3-MAML2 fusions by reverse transcription polymerase chain reaction. We developed a system of 'molecular Armed Forces Institute of Pathology (AFIP) classification' that combined the AFIP histological classification proposed by Goode et al. and the presence of CRTC1-MAML2 or CRTC3-MAML2 fusions. MEC cases positive for CRTC1-MAML2 or CRTC3-MAML2 fusion formed a favourable tumour subset that was distinct from fusion-negative cases. When positive for the fusions, 'high-risk' patients, including those with a higher histological grade or an advanced clinical stage, showed an excellent prognosis. For overall survival, 'molecular AFIP classification' was selected as a powerful independent prognostic factor (P=0.0038), as was the clinical stage (P =0.0032). For disease-free survival, 'molecular AFIP classification' was also selected as an independent prognostic factor (P = 0.0006). CONCLUSIONS: Molecular AFIP classification may be useful in predicting the prognosis of patients with MEC.

Relationship between age and sex and the numbers of ingestions and swallows for foods of different textures among healthy adults.

BACKGROUND: The number of swallows needed per single ingestion of food is an important index when assisting a patient with dysphagia in eating. While providing meal assistance, the caregiver may assume that one ingestion is completed with one swallow and then may administer the next ingestion even if the individual's mouth still has remaining food from the previous ingestions, increasing the risk for aspiration and choking. OBJECTIVE: The objective of this pilot study was to clarify the differences in foods ingested and swallowed because of influencing factors such as age and gender among healthy adults. METHODS: The study enrolled 110 healthy adults (47.4 ± 15.8 years; 57 males, 53 females). The numbers of ingestions and swallows were counted and evaluated by food type (pilaf, 100 g; yogurt 80 g; and sponge cake, 35 g) and participant age and sex and analyzed by least-squares multiple regression analysis. RESULTS: The mean numbers of ingestion/swallows were pilaf, 12.5 ± 3.2/13.4 ± 4.2; yogurt, 8.8 ± 2.1/10.8 ± 2.1; and sponge cake, 5.8 ± 2.1/7.0 ± 2.1. The mean number of ingestions and swallows for all foods were higher for female participants compared with male participants. Statistical analysis identified sex as a significant influencing factor for the number of ingestion for all foods. For the number of swallows, the significant influencing factors were sex for sponge cake and age for pilaf and yogurt. CONCLUSION: For the test foods of different textures, sex and age were significant influencing factors for the numbers of ingestions and swallows. Further research is needed to elucidate the problem areas in this pilot study.

A rare case of odontogenic keratocyst extending into the sphenoid bone from the maxilla.

BACKGROUND: Odontogenic keratocyst (OKC) is the third most common odontogenic cyst which arises from cell rests of dental lamina, and usually observed in the jaws. Because OKC is noted for its high rate of recurrence, there are various treatment strategies. Here, we present a rare case of OKC which occupied the entire maxillary sinus and pterygoid process of the sphenoid bone extending nearly to the skull base. CASE PRESENTATION: The patient was a 21-year-old male and underwent surgical removal of the cyst using the Caldwell-Luc procedure which in this case extended the surgical approach to the pterygoid process of the sphenoid bone via the pterygomaxillary junction. However, we found a recurrent lesion in the posterior wall of the maxillary sinus 20 months after the surgery and subsequently performed a secondary cystectomy. Surgical specimens showed positive bcl-2 staining of OKC and negative cytokeratin-10 on immunohistochemistry for both primary and recurrent lesions. CONCLUSION: OKC rarely occurs in the maxillary sinus and extends to the deep maxillary structure and the skull base. In order to prevent recurrence, it is necessary to recognize the exact location of the entire lesion. Careful examination of preoperative CT images is needed to make a complete surgical planning and to perform a reliable surgical procedure.

Salivary NUS1 and RCN1 Levels as Biomarkers for Oral Squamous Cell Carcinoma Diagnosis.

BACKGROUND/AIM: Oral cancer may become advanced because of delay in diagnosis. In order to promote oral cancer screening, simple and highly reliable screening methods that can be implemented at general dental clinics are required. Herein we investigated differential salivary gene expression between oral squamous cell carcinoma (OSCC) patients and healthy volunteers (HV) to identify new biomarkers for OSCC detection. MATERIALS AND METHODS: Candidate genes were selected by microarrays, nuclear undecaprenyl pyrophosphate synthase 1 (NUS1) and reticulocalbin 1 (RCN1) were selected for further investigation. We used real-time quantitative reverse transcription PCR (qRT-PCR) to determine NUS1 and RCN1 expression levels in saliva and tissues. RESULTS: qRT-PCR analysis of clinical samples revealed that OSCC patients had significantly higher expression of salivary NUS1 and RCN1 than HV. CONCLUSION: A combination of NUS1 and RCN1 accurately distinguished patients from controls, and this combination can be implemented as a screening test for OSCC.

Clinicopathological significance of the CRTC3-MAML2 fusion transcript in mucoepidermoid carcinoma.

Mucoepidermoid carcinoma is the most common primary malignancy of the salivary gland. We and others showed that CRTC1-MAML2 gene fusion was associated with favorable clinicopathological tumor features. Recently, a novel gene fusion, CRTC3-MAML2, was reported as a rare gene alteration in a case of mucoepidermoid carcinoma. However, its frequency and clinicopathological significance remains unclear. In all, 101 cases of mucoepidermoid carcinoma and 89 cases of non-mucoepidermoid carcinoma of the salivary gland were analyzed, and RNA was extracted from formalin-fixed, paraffin-embedded specimens. In the CRTC family, there have been three genes, CRTC1, CRTC2, and CRTC3. We developed reverse transcription-polymerase chain reaction (RT-PCR) assays for CRTC1-MAML2, CRTC2-MAML2, and CRTC3-MAML2 fusions. Clinicopathological data of the patients were obtained from their clinical records. Of 101 cases of mucoepidermoid carcinoma, 34 (34%) and 6 (6%) were positive for CRTC1-MAML2 and CRTC3-MAML2 fusion transcripts. However, in the 89 cases of non-mucoepidermoid carcinoma, neither transcript was noted. In the former cases, CRTC1-MAML2 and CRTC3-MAML2 fusions were mutually exclusive. The other fusion, CRTC2-MAML2, was not detected. We confirmed that the clinicopathological features of CRTC1-MAML2-positive mucoepidermoid carcinomas indicated an indolent course. CRTC3-MAML2-positive mucoepidermoid carcinomas also had clinicopathologically favorable features; all cases showed a less advanced clinical stage, negative nodal metastasis, no high-grade tumor histology, and no recurrence or tumor-related death after surgical resection of the tumor. It is interesting to note that patients with CRTC3-MAML2-positive tumors (mean 36 years of age) were significantly younger that those with the CRTC1-MAML2 fusion (55 years) and those with fusion-negative tumors (58 years). In conclusion, CRTC3-MAML2 fusion, which is mutually exclusive with CRTC1-MAML2 fusion and specific to mucoepidermoid carcinoma, may be detected more frequently than previously expected. Mucoepidermoid carcinomas possessing CRTC3-MAML2 fusion may be associated with favorable clinicopathological features and patients may be younger than those with CRTC1-MAML2 fusion or those with no detectable gene fusion.

Prognostic factors for keratocystic odontogenic tumor (odontogenic keratocyst): analysis of clinico-pathologic and immunohistochemical findings in cysts treated by enucleation.

BACKGROUND: The purpose of this study was to determine prognostic factors for the recurrence of keratocystic odontogenic tumors (KCOTs) following simple enucleation by examining clinico-pathologic and immunohistochemical findings. METHODS: Following enucleation, the frequency of recurrence among 32 subjects diagnosed with KCOT was analyzed for tumor site, radiographic and histologic features, and immunopositivity for Ki-67 and p53. RESULTS: Keratocystic odontogenic tumors in four out of 32 subjects (12.5%) recurred during the follow-up period (median: 33 months, range: 7-114 months). Three out of four subjects (75.0%) among recurrent group showed high expression of Ki-67 (LI >10%) in basal layer and four (4/28; 14.3%) among non-recurrence group (P = 0.025). Expression of p53 among non-recurrent group was observed in 11 subjects (11/28; 39.3%), and in three subjects (3/4; 75.0%) among the recurrent group (P = 0.295). Hazard risk for the recurrence of KCOT was 4.02 (95% CI 1.42-18.14) for high Ki-67 expression in the basal layer by the Cox proportional hazard model (P = 0.009). In our study, none of the other clinico-pathologic variables were associated with the recurrence of KCOT. CONCLUSION: The results suggested that the evaluation of Ki-67 expression in KCOT at the time of pathological diagnosis might be helpful for consideration of appropriate adjunctive surgical procedures to avoid a recurrence and may serve as a prognostic marker.

Prognostic significance of p27Kip1, Ki-67, and CRTC1-MAML2 fusion transcript in mucoepidermoid carcinoma: a molecular and clinicopathologic study of 101 cases.

PURPOSE: Mucoepidermoid carcinoma (MEC) is the most frequently detected primary malignancy of the salivary gland and is characterized by a marked variation in prognosis. In the present study, we investigated the prognostic significance of p27Kip1, Ki-67, and CRTC1 (also called MECT1, TORC1, and WAMTP1)-MAML2 fusion in MEC. MATERIALS AND METHODS: MEC cases (n = 101) were examined for p27Kip1 and Ki-67 expression using immunohistochemistry and for CRTC1-MAML2 fusion transcript using reverse transcriptase-polymerase chain reaction. RESULTS: p27Kip1, Ki-67, and the CRTC1-MAML2 fusion transcript were expressed in 71, 31, and 34 of the 101 cases, respectively. p27Kip1 and CRTC1-MAML2 fusion were associated with favorable clinicopathologic tumor features and Ki-67 with aggressive clinicopathologic features. Multivariate survival analyses were performed that included the following 10 clinicopathologic factors: age, gender, tumor site, tumor size, nodal metastasis, clinical stage, histologic grade, p27 expression, Ki-67 expression, and CRTC1-MAML2 fusion. For disease-free survival, only p27Kip1 expression was significant as an independent prognostic factor. For overall survival, p27Kip1 expression, CRTC1-MAML2 fusion, and tumor size were significant. In each analysis, p27Kip1 and CRTC1-MAML2 fusion were independent of the clinical stage. Ki-67 expression was not selected in either multivariate analysis. CONCLUSIONS: p27Kip1 and CRTC1-MAML2 fusion were associated with favorable clinicopathologic tumor features, and both were useful in predicting the overall survival of patients with MEC. For disease-free survival, p27Kip1 might be the most useful prognostic factor. In contrast, Ki-67 might not be a very powerful prognostic indicator for either survival point.