Development of artificial intelligence prognostic model for surgically resected non-small cell lung cancer.

There are great expectations for artificial intelligence (AI) in medicine. We aimed to develop an AI prognostic model for surgically resected non-small cell lung cancer (NSCLC). This study enrolled 1049 patients with pathological stage I-IIIA surgically resected NSCLC at Kyushu University. We set 17 clinicopathological factors and 30 preoperative and 22 postoperative blood test results as explanatory variables. Disease-free survival (DFS), overall survival (OS), and cancer-specific survival (CSS) were set as objective variables. The eXtreme Gradient Boosting (XGBoost) was used as the machine learning algorithm. The median age was 69 (23-89) years, and 605 patients (57.7%) were male. The numbers of patients with pathological stage IA, IB, IIA, IIB, and IIIA were 553 (52.7%), 223 (21.4%), 100 (9.5%), 55 (5.3%), and 118 (11.2%), respectively. The 5-year DFS, OS, and CSS rates were 71.0%, 82.8%, and 88.7%, respectively. Our AI prognostic model showed that the areas under the curve of the receiver operating characteristic curves of DFS, OS, and CSS at 5 years were 0.890, 0.926, and 0.960, respectively. The AI prognostic model using XGBoost showed good prediction accuracy and provided accurate predictive probability of postoperative prognosis of NSCLC.

Impact of the pretreatment prognostic nutritional index on the survival after first-line immunotherapy in non-small-cell lung cancer patients.

BACKGROUND: Immunotherapy has become a standard-of-care for patients with non-small-cell lung cancer (NSCLC). Although several biomarkers, such as programmed cell death-1, have been shown to be useful in selecting patients likely to benefit from immune checkpoint inhibitors (ICIs), more useful and reliable ones should be investigated. The prognostic nutritional index (PNI) is a marker of the immune and nutritional status of the host, and is derived from serum albumin level and peripheral lymphocyte count. Although several groups reported its prognostic role in patients with NSCLC receiving a single ICI, there exist no reports which have demonstrated its role in the first-line ICI combined with or without chemotherapy. MATERIALS AND METHODS: Two-hundred and eighteen patients with NSCLC were included in the current study and received pembrolizumab alone or chemoimmunotherapy as the first-line therapy. Cutoff value of the pretreatment PNI was set as 42.17. RESULTS: Among 218 patients, 123 (56.4%) had a high PNI (≥42.17), while 95 (43.6%) had a low PNI (<42.17). A significant association was observed between the PNI and both the progression-free survival (PFS; hazard ratio [HR] = 0.67, 95% confidence interval [CI]: 0.51-0.88, p = 0.0021) and overall survival (OS; HR = 0.46, 95% CI: 0.32-0.67, p < 0.0001) in the entire population, respectively. The multivariate analysis identified the pretreatment PNI as an independent prognosticator for the PFS (p = 0.0011) and OS (p < 0.0001), and in patients receiving either pembrolizumab alone or chemoimmunotherapy, the pretreatment PNI remained an independent prognostic factor for the OS (p = 0.0270 and 0.0006, respectively). CONCLUSION: The PNI might help clinicians appropriately identifying patients with better treatment outcomes when receiving first-line ICI therapy.

Skeletal muscle area predicts the outcomes of non-small-cell lung cancer after trimodality therapy.

OBJECTIVES: Sarcopenia correlates with poor prognosis in various malignancies. However, the prognostic significance of sarcopenia remains to be determined in patients with non-small-cell lung cancer who undergo surgery after receiving neoadjuvant chemoradiotherapy (NACRT). METHODS: We retrospectively reviewed the patients with stage II/III non-small-cell lung cancer who underwent surgery following NACRT. The paravertebral skeletal muscle area (SMA) (cm2) at the 12th thoracic vertebra level was measured. We calculated the SMA index (SMAI) as SMA/squared height (cm2/m2). Patients were divided into low and high SMAI groups, and the association of SMAI with clinicopathological factors and prognosis was assessed. RESULTS: The patients' [men, 86 (81.1%)] median age was 63 (21-76) years. There were 106 patients including 2 (1.9%), 10 (9.4%), 74 (69.8%), 19 (17.9%) and 1 (0.9%) patients with stage IIA, IIB, IIIA, IIIB and IIIC, respectively. Of the patients, 39 (36.8%) and 67 (63.2%) were classified in the low and the high SMAI groups, respectively. Kaplan-Meier analysis showed that the low group had a significantly shorter overall survival and disease-free survival than the high group. Multivariable analysis identified low SMAI as an independent poor prognostic factor for overall survival. CONCLUSIONS: Pre-NACRT SMAI correlates with poor prognosis; therefore, assessing sarcopenia based on pre-NACRT SMAI may help determine optimal treatment strategies and suitable nutritional and exercise interventions.

Preventive effect of tertiary lymphoid structures on lymph node metastasis of lung adenocarcinoma.

BACKGROUND: Ectopic lymphoid formations are called tertiary lymphoid structures (TLSs). TLSs in cancer have been reported to be associated with good prognosis and immunotherapy response. However, the relationship between TLSs and lymph node (LN) metastasis is unclear. METHODS: We analyzed 218 patients with radically resected lung adenocarcinoma. TLSs were defined as the overlap of T cell zone and B cell zone. Granzyme B + cells were defined as cytotoxic lymphocytes. We evaluated phenotypes of lymphocytes in TLSs, tumor-infiltrating lymphocytes (TILs) and LNs by immunohistochemistry. We divided the patients into mature TLS (DC-Lamp high) and immature TLS (DC-Lamp low) groups. The relationship between TLS maturation and clinicopathological factors was analyzed. RESULTS: The mature TLS group was associated with significantly lower frequency of LN metastasis (P < 0.0001) and early cancer stage (P = 0.0049). The mature TLS group had significantly more CD8 + (P = 0.0203) and Foxp3 + (P = 0.0141) cells in TILs than the immature TLS group had. Mature TLSs were independently associated with a favorable overall survival (hazard ratio [HR] = 0.17, P = 0.0220) and disease-free survival (HR = 0.54, P = 0.0436). Multivariate analysis showed that mature TLS was an independent low-risk factor for LN metastasis (odds ratio = 0.06, P = 0.0003). The number of cytotoxic lymphocytes in LNs was higher in the mature TLS group than in the immature group (20.0 vs. 15.1, P = 0.017). CONCLUSION: Mature TLSs were associated with an increased number of cytotoxic lymphocytes in draining LNs, a lower frequency of LN metastasis, and favorable outcomes. Mature TLSs may support antitumor immunity by lymphocyte activation.

Necitumumab plus gemcitabine and cisplatin in previously treated lung squamous cell carcinoma.

BACKGROUND: The efficacy and safety of the anti-EGFR antibody necitumumab combined with gemcitabine and cisplatin (N + GC) in the first-line treatment of advanced lung squamous cell carcinoma (LSCC) have been proven. However, the efficacy and safety of N + GC in the second line or later treatment remain unclear. METHODS: Eleven patients who received N + GC for advanced-stage or recurrent LSCC were enrolled. We retrospectively assessed the patients' clinical characteristics and efficacy and safety of treatment. RESULTS: The median patient age was 73 years (range, 63-77 years). The cohort included nine (81.8%) men and two (18.2%) women. Two (18.2%) patients had postoperative recurrence, and one (9.1%), three (27.3%), one (9.1%), and four (36.4%) patients were diagnosed with stage IIIA, IIIB, IVA, and IVB disease, respectively. Concerning the best overall response, partial response was achieved in five (45.5%) patients, four (36.4%) patients displayed stable disease, and two (18.2%) patients were not evaluable. Median progression-free survival was 6.8 months (range, 1.4-10.3 months). The grade 3 or higher neutropenia, thrombocytopenia, and anemia occurred in six (54.5%), three (27.3%), and two (18.2%) patients, respectively. Additionally, grade 3 skin reaction, rash, lung infection, duodenal ulcer, and febrile neutropenia were observed in one (9.1%) patient each. Two (18.2%) patients required treatment interruption because of adverse events. CONCLUSION: N + GC displayed good efficacy in the second line or later treatment among patients with LSCC. This study suggested that N + GC is a useful option even after second-line treatment of advanced-stage or recurrent LSCC, although the management of adverse events is essential.

Clinical significance of the combination of preoperative SUVmax and CEA in patients with clinical stage IA lung adenocarcinoma.

BACKGROUND: Preoperative maximum standardized uptake value (SUVmax) of 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography and serum carcinoembryonic antigen (CEA) have been reported as prognostic factors for lung adenocarcinoma. However, the significance of combined SUVmax and CEA in early-stage lung adenocarcinoma is not well known. METHODS: We retrospectively evaluated the relationship between the combination of SUVmax and CEA and the prognosis of 410 patients with clinical stage IA lung adenocarcinoma who underwent resection. The cutoff values for SUVmax and CEA were determined by receiver operating characteristic curve analysis, and patients were categorized into high SC (SUVmax and CEA) group (SUVmax ≥2.96 and CEA ≥5.3), moderate SC group (either SUVmax <2.96 and CEA ≥5.3 or SUVmax ≥2.96 and CEA <5.3) and low SC group (SUVmax <2.96 and CEA <5.3). RESULTS: Kaplan-Meier curve analysis showed that patients with clinical stage IA lung adenocarcinoma in the high SC group had significantly shorter overall survival (OS) and recurrence-free survival (RFS) than the other groups (p = 0.011 and p < 0.0001, respectively). Multivariate analysis showed that high SC was an independent prognostic factor of OS (p = 0.029) and RFS (p < 0.0001). CONCLUSIONS: High values of SUVmax and CEA were associated with poor OS and RFS in patients with stage IA lung adenocarcinoma. Simultaneous evaluation of SUVmax and CEA may be an effective prognostic marker to determine the optimal treatment strategy of early-stage lung adenocarcinoma.

Consideration of the Optimal Surgical Procedure Based on the Risk of Recurrence in Clinical Stage 0 or IA Lung Adenocarcinoma.

BACKGROUND/AIM: Sublobar resection is widely performed for early-stage non-small cell lung cancer in the clinical setting. This study evaluated the optimal surgical procedures of clinical stage 0 or IA adenocarcinoma from the perspective of recurrence. PATIENTS AND METHODS: A total of 508 lung adenocarcinoma patients diagnosed as c-stage 0 or IA were retrospectively investigated. RESULTS: The types of surgical procedures were lobectomy (n=328), segmentectomy (n=73), and wedge resection (n=107). Clinical T descriptors were cTis in 74, cT1mi in 68, cT1a in 94, cT1b in 181 and cT1c in 91 patients. Recurrence was observed in 46 cases (9%), including 3 (3.1%) with cT1a, 23 (12.7%) with cT1b and 20 (22.0%) with cT1c. The patients who received sublobar resection developed recurrence more often than the patients who received lobectomy among cT1b cases (10.1% vs. 21.4%) and cT1c cases (18.0% vs. 46.2%) (p=0.053 and p=0.023). CONCLUSION: The cT1b and cT1c cases should be considered for lobectomy to prevent recurrence.

Prognostic Impact of Albumin-bilirubin (ALBI) Grade on Non-small Lung Cell Carcinoma: A Propensity-score Matched Analysis.

BACKGROUND/AIM: Albumin-bilirubin (ALBI) grade is an indicator of liver dysfunction and is useful for predicting postoperative prognosis of hepatocellular carcinomas. However, the significance of ALBI grade in non-small cell lung carcinoma (NSCLC) has not been elucidated. PATIENTS AND METHODS: We analyzed 947 patients with pStage IA-IIIA NSCLC. We divided patients into ALBI grade 1 and grade 2/3 groups. We then analyzed the association of ABLI grade with clinicopathological characteristics and prognosis in NSCLC by using propensity-score matching. RESULTS: ALBI grade 2/3 was significantly associated with older age, male sex, advanced pT status, and histological type. Even after propensity-score matching, ALBI grade 2/3 patients had significantly worse cancer-specific survival (CSS) than ALBI grade 1 patients (5-year CSS: 87.3% versus 92.8%; p=0.0247). In multivariate analysis, ALBI grade 2/3 was an independent predictor of CSS (HR=1.9; 95%CI=1.11-3.11; p=0.0177). CONCLUSION: ALBI grade was an independent prognostic factor in surgically resected NSCLC.

Long-term complete response to gefitinib after treatment termination in a patient with recurrent post-operative EGFR-mutated lung adenocarcinoma: case report and literature review.

Non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations is highly sensitive to EGFR-tyrosine kinase inhibitor (EGFR-TKI). However, few cases of advanced NSCLC completely cured by EGFR-TKIs have been reported. We present an extremely rare case of lung adenocarcinoma that was completely cured by gefitinib administration. A 36-year-old Japanese woman was diagnosed with clinical Stage IIIB (T2N3M0) lung adenocarcinoma originating from the left upper lobe in April 2006. After the two cycles of chemotherapy, it was down-staged to ycStage IA (T1N0M0). She underwent a thoracotomy with left upper lobectomy, pulmonary angioplasty, and mediastinal nodal dissection in July 2006 [ypStage IIIA (T3N1M0)]. Eighteen months later, she was found to have lymphadenopathy of the right supraclavicular nodes. Fine needle aspiration cytology of the lymph node indicated adenocarcinoma. She started gefitinib therapy for recurrent lung cancer with EGFR mutation (exon 19 deletion) in January 2008. Four months afterward, computed tomography (CT) showed her right supraclavicular nodes had shrunk dramatically. Treatment with gefitinib was continued. Thereafter, no disease progression was observed throughout her approximately 8-year gefitinib treatment, and gefitinib was terminated in November 2016. Although the patient received no other treatment, she has suffered no recurrence in the 4 years since. A review of the literature, including our case, is also presented.

Interleukin-38 promotes tumor growth through regulation of CD8+ tumor-infiltrating lymphocytes in lung cancer tumor microenvironment.

BACKGROUND: Interleukin (IL)-38 was discovered in 2001 and is a member of the IL-1 family of cytokines. IL-38 shows anti-inflammatory activity in several inflammatory diseases. In lung adenocarcinoma, we previously demonstrated that high IL-38 expression in tumor cells was associated with poor prognosis. However, the role of IL-38 in the tumor microenvironment has not been clarified. METHODS: IL-38-plasmid-transfected Lewis lung carcinoma cells (LLC-IL38) and empty vector-transfected LLC cells (LLC-vector) were established. Cell proliferation in vitro and tumor growth in vivo were examined, and immunohistochemical staining was used to assess tumor-infiltrating lymphocytes (TILs). A CD8+ lymphocyte depletion model was established to show the association between IL-38 and CD8+ lymphocytes. Moreover, we examined the association between IL-38 expression and CD8+ TILs in human samples, analyzing immunohistochemical staining in 226 patients with radically resected lung adenocarcinoma. RESULTS: Tumor growth of LLC-IL38 in vivo was significantly increased compared with that of LLC-vector, although cell proliferation of LLC-IL38 in vitro was lower than that of LLC-vector. CD8+ TILs were significantly decreased in LLC-IL38 tumor compared with LLC-vector tumor. The difference in tumor growth between LLC-IL38 and LLC-vector became insignificant after depletion of CD8+ lymphocytes. In immunohistochemical staining in tissues from patients with lung adenocarcinoma, multivariate analysis showed high IL-38 expression was an independent negative predicter of high density of CD8+ TILs. CONCLUSION: We demonstrated that high IL-38 expression in tumor cells was significantly associated with reduction of CD8+ TILs and tumor progression. These results suggest that IL-38 could be a therapeutic target for lung cancer.

Clinical significance of preoperative inflammatory markers in non-small cell lung cancer patients: A multicenter retrospective study.

Inflammatory biomarkers have been associated with clinical outcomes in non-small cell lung cancer (NSCLC). However, the best prognostic marker(s) has not been identified, and the association between inflammatory markers and clinical characteristics is poorly understood. We selected 1,237 patients with resected NSCLC from Kyushu University (2003-2015) and Kyushu Cancer Center (2009-2015) in Japan. Pearson product-moment correlation coefficient among inflammatory markers and area under curve (AUC) of receiver operating characteristic (ROC) curve analyses for overall survival (OS) were calculated. We analyzed the associations between inflammatory markers and clinical factors using Student's t-test. Univariate and multivariate analyses with Cox proportional hazards regression analyses were performed to evaluate the relationship between survival and clinical factors. The cut-off values for neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR), platelet-lymphocyte ratio, and derived NLR (dNLR) were determined by ROC curve analyses for OS. We found a strong positive correlation between NLR and dNLR (r = 0.9629). The AUC of LMR was the highest amongst the measured metrics, and the AUC of NLR was higher than dNLR. Levels of some inflammatory markers were associated with sex, smoking, squamous cell carcinoma, and pathological stage. LMR ≥ 5.11 and lactate dehydrogenase (LDH) concentration ≥ 222 (U/L) were independent predictors of both disease-free survival (DFS) and OS (LMR; P = 0.0009 and 0.0008, LDH; P = 0.0195 and 0.0187, respectively). Certain inflammatory markers, potentially linked to smoking, were associated with an advanced pathological stage in NSCLC. LMR and LDH were independent predictors of both DFS and OS.

Combined Evaluation of Tumor-Infiltrating CD8 + and FoxP3 + Lymphocytes Provides Accurate Prognosis in Stage IA Lung Adenocarcinoma.

BACKGROUND: Immunotherapy has become a standard treatment option for non-small cell lung cancer (NSCLC), with the tumor microenvironment attracting significant attention. CD8 + and forkhead box protein P3 + (FoxP3 +) tumor-infiltrating lymphocytes (TILs) influence the tumor microenvironment, but the clinical significance of CD8 + and FoxP3 + TILs in stage IA lung adenocarcinoma (LAD) is poorly understood. METHODS: We analyzed 203 patients with stage IA primary LAD who had undergone surgery at Kyushu University from January 2003 to December 2012. We evaluated CD8 + and FoxP3 + TILs by immunohistochemistry. We set the cutoff values at 50 cells/0.04 mm2 for CD8 + TILs and 20 cells/0.04 mm2 for FoxP3 + TILs, respectively. We divided the patients into four groups: CD8-Low/FoxP3-Low; CD8-High/FoxP3-Low; CD8-Low/FoxP3-High; and CD8-High/FoxP3-High. We compared clinical outcomes among them. Programmed cell death ligand-1 (PD-L1) expression by tumor cells was also evaluated as previously reported. RESULTS: Respectively, 104 (51.2%), 46 (22.7%), 22 (10.8%), and 31 (15.3%) patients were classified as CD8-Low/FoxP3-Low, CD8-High/FoxP3-Low, CD8-Low/FoxP3-High, and CD8-High/FoxP3-High. Both disease-free survival (DFS) and overall survival (OS) were significantly worse in the CD8-Low/FoxP3-High group than the other groups (5-year DFS: 66.3% vs. 90.5%; P = 0.0007, 5-year OS: 90.9% vs. 97.0%; P = 0.0077). In the multivariate analysis, CD8-Low/FoxP3-High and PD-L1 expression were independent prognostic factors of DFS, and lymphatic invasion, surgical procedure, and PD-L1 expression were independent prognostic factors of OS. CONCLUSIONS: CD8-Low/FoxP3-High was an independent prognostic factor of DFS (hazard ratio: 3.22; 95% confidence interval: 1.321-7.179; P = 0.0121) in stage IA LAD. Immunosuppressive conditions were associated with poor prognosis in stage IA LAD.

Impact of Preoperative Ultrasonography Screening for Carotid Artery Stenosis in Lung Cancer Patients.

BACKGROUND: Stroke is a major cause of morbidity or death after lung operations. Carotid artery screening (CAS) is useful for detecting carotid artery stenosis, which is one of the causes of stroke. This study investigated the frequency of and risk factors for preoperative carotid artery stenosis to determine whether CAS with ultrasonography contributes to preventing postoperative stroke or cardiovascular comorbidities in lung cancer patients. METHODS: This retrospective study included 1,676 consecutive lung cancer patients who underwent surgical resection. RESULTS: Of the 1,342 patients who underwent CAS, 173 (12.9%) had carotid artery stenosis. Significant associations with carotid artery stenosis were found for older patients (p < 0.0001), men (p < 0.0001), smoking history (p < 0.0001), history of stroke (p = 0.0037), cardiovascular diseases (p < 0.0001), hypertension (p = 0.0353), diabetes mellitus (p = 0.0037), and peripheral vascular diseases (p < 0.0001). Patients with the three independent risk factors of age, male sex, and history of cardiovascular diseases had a 6.43-fold higher prevalence of carotid artery stenosis (odds ratio, 6.43; 95% confidence interval, 3.80 to 10.89) than those with none of these factors. Propensity score-matched analysis showed that incidences of postoperative stroke and cardiovascular comorbidities were both lower in patients who underwent CAS and received appropriate anticoagulant therapy than in those who did not (p = 0.0619 and p = 0.0319, respectively). CONCLUSIONS: Preoperative CAS is a simple and useful tool for detecting carotid artery stenosis. Administration of perioperative anticoagulant therapy to preoperative patients with lung cancer and carotid artery stenosis identified by CAS may prevent postoperative stroke and cardiovascular events.

Postoperative Management of Multiple Primary Cancers Associated with Non-small Cell Lung Cancer.

BACKGROUND/AIM: Modern treatment for primary cancers has improved survival. Therefore, increased numbers of patients with multiple primary cancers (MPC) associated with lung cancer may be expected. The aim of the present study was to report MPC associated with lung cancer and discuss patients' characteristics and postoperative management. PATIENTS AND METHODS: Overall, 973 consecutive patients who underwent surgery for non-small cell lung cancer (NSCLC) were retrospectively studied. RESULTS: NSCLC with MPC was observed in 148 patients (15.2%). MPC comprised 24 synchronous (2.5%) and 124 metachronous (12.7%) diseases. Of the 124 metachronous patients, NSCLC was detected before cancers were detected in other organs (lung cancer first (LCF)) in 25 (20.2%) patients and subsequently in other organs after treatment (other organs, primary cancer-first (OCF)) in 99 (79.8%) patients. MPC was significantly associated with advanced age (p<0.0001) and chronic obstructive pulmonary disease (COPD) (p=0.0040). The leading sites of MPC in patients with synchronous tumors and those with OCF were the digestive organs. In contrast, the leading site of MPC in patients with LCF was the lung. In the latter, at least two primary lung cancers were detected within 5 years as well as 5 years after surgery for the treatment of the first detected lung cancer, while primary cancers of other organs were detected within 5 years. CONCLUSION: Advanced age and COPD may represent a high-risk of MPCs. Therefore, we recommend careful follow-up to detect MPC in the lung as well as the digestive organs beyond 5 years after treatment of the first cancer.

Expression of heparanase: a possible role in invasiveness and aggressive clinical behavior of ameloblastomas.

Heparanase is an endoglycosidase that cleaves heparan sulfate (HS), thus participating in degradation and remodeling of the extracellular matrix (ECM). Heparanase up-regulation is correlated with lymph node and distant metastasis, microvessel density and reduced postoperative survival of cancer patients. In the present study, we carried out an immunohistochemical investigation of heparanase to extend and confirm present knowledge regarding its expression in ameloblastomas (AMs), which are characterized by locally aggressive behavior. Paraffin-embedded tissue specimens of 53 AMs were stained using an antibody against heparanase. Immunohistochemical reactivity for heparanase was detected in 94.3% of the AMs examined. Heparanase was expressed strongly in peripheral columnar cells and slightly in central stellate reticulum-like cells. Small tumor nests and budding epithelial branches showed a stronger staining pattern. Stromal cells were negative for heparanase, or showed diffuse expression. However, an enhanced positive immunoreaction was present specifically near osseous tissue and adjacent to the invasive front of tumor nests. Areas of cystic degeneration showed intense heparanase immunoreactivity. The enzyme may facilitate the function of HS-binding growth factors that elicit an angiogenic response and favor osteoclastogenesis in AM.

Enhanced expression of podoplanin in ameloblastomas.

OBJECTIVE: Podoplanin, a mucin-type transmembrane glycoprotein, is specifically expressed by lymphatic but not blood vascular endothelial cells, and is also widely expressed in various specialized cell types throughout the body. Recent studies have demonstrated that it mediates a pathway leading to collective cell migration and invasion in vivo and in vitro. In the present study, we carried out an immunohistochemical investigation of podoplanin to clarify whether it is expressed in human ameloblastomas (AMs), which are characterized by locally aggressive behavior with a high rate of recurrence. In addition, we examined the localization of the epithelial marker E-cadherin and the mesenchymal marker vimentin to clarify whether AMs show epithelial-mesenchymal transition (EMT). METHODS: Paraffin-embedded tissue specimens of 38 AMs were examined immunohistochemically using antibodies against podoplanin, E-cadherin, and vimentin. RESULTS: Immunohistochemical reactivity for podoplanin was detected in the cell membrane and cytoplasm of most odontogenic tumor epithelial cells in AMs. Podoplanin was expressed strongly in peripheral columnar cells and slightly in central stellate reticulum-like cells. E-cadherin was expressed in central stellate reticulum-like cells and showed decreased expression in peripheral columnar cells. Immunoreactivity for E-cadherin was weak or negative in keratinizing cells of acanthomatous AMs, suggesting terminal differentiation of the tumor cells. Immunohistochemical reactivity for vimentin was found in stromal cells, but partial or no reaction was observed in neoplastic cells. CONCLUSION: Expression of podoplanin in AMs is considered to be associated with neoplastic odontogenic tissues; this molecule might play a role in the collective cell migration of tumor nests in AMs. The pattern of expression of E-cadherin and vimentin suggests that invasion in AMs occurs in the absence of EMT. The migration and invasion mediated by podoplanin in AMs could be related to cytoskeletal reorganization.

Significance of podoplanin expression in keratocystic odontogenic tumor.

BACKGROUND: The most important clinical features of the keratocystic odontogenic tumor (KCOT) are its potential for locally destructive behavior, a tendency to recur, and its origin in the odontogenic epithelium. The clinical features of KCOT are similar to those of ameloblastoma (AM). Histologically, KCOT is distinguished from jaw cyst with keratinization (orthokeratinized odontogenic cyst; OOC). However, current scientifically based clinical parameters cannot predict any potential for neoplastic behavior, or aggressive and localized invasiveness, in patients with KCOT. We have shown that podoplanin, a lymphatic endothelial marker, is highly expressed in AM. The purpose of this study was to determine the usefulness of podoplanin for reclassification of the odontogenic keratocyst (OKC) from cyst to tumor status. METHODS: Paraffin-embedded tissue specimens of 57 OKCs (46 KCOTs and 11 OOCs) and 15 dentigerous cysts (DCs) were immunohistochemically examined using antibody against podoplanin. RESULTS: Immunohistochemical reactivity for podoplanin was detected in the cell membrane and cytoplasm of most of the basal and suprabasal layer, areas of budding basal cell proliferation, epithelial nests and peripheral cells of daughter cysts in the stromal connective tissue in KCOTs. In the case of OOC and DC, only cases associated with inflammation were positive for podoplanin. CONCLUSION: Podoplanin is strongly expressed in KCOTs in comparison with OOCs. The pattern of staining for podoplanin in KCOT could be related to its neoplastic nature, and suggests a role of the protein in tumor invasiveness.

Keratocystic odontogenic tumor: a retrospective study of 183 cases.

In 2005, the WHO Working Group considered odontogenic keratocyst (OKC) to be a tumor and recommended the term keratocystic odontogenic tumor (KCOT), separating the lesion from the orthokeratinizing variant, which is now considered an odontogenic cyst. We analyzed the clinicopathological features of KCOTs encountered over a period of 28 years at Meikai University Hospital. The diagnosis was confirmed by reevaluation of hematoxylin and eosin-stained slides on the basis of the 2005 WHO Classification. Clinical history was also taken into consideration. A total of 183 KCOTs were found, and the two genders were affected almost evenly (51.3% male; 48.7% female; male to female ratio 1.05 to 1). Patient age at the time of diagnosis ranged from 6 to 78 years, with a peak in the third decade of life (mean age: 32.8 years). The mandible was the site of occurrence of 70.5% of tumors; 16.4% occurred in the maxilla and 13.1% in both. Association with the nevoid basal cell carcinoma syndrome (NBCCS) was found in 6.0% of all tumors, and recurrence was found in 13.1% of patients. We found that tumors that initially appeared in the maxilla alone had a higher recurrence rate than those that first appeared in the mandible alone. Pathological examination of KCOT is important to avoid misdiagnosis and provide appropriate treatment and follow-up.

Expression of CYLD, NF-kappaB and NF-kappaB-related factors in salivary gland tumors.

The cylindromatosis (CYLD) gene was originally identified as a tumor suppressor that is mutated in familial cylindromatosis, an autosomal dominant condition that confers a predisposition to multiple tumors of the skin appendages. CYLD has deubiquitinating enzyme activity and inhibits the activation of transcription factor NF-kappaB. Therefore, loss of CYLD function correlates with tumorigenesis. Expression of CYLD has been detected in various organs, but its expression in salivary gland tumor (SGT) is still unknown. Adenoid cystic carcinoma (ACC) is a well known and typical malignant SGT ACC was previously known as cylindroma in view of its marked histological resemblance to dermal cylindroma. In this study, the expressions of CYLD and NF-kappaB mRNA in HSG, a human SGT cell line, were found to be increased by TNF-alpha stimulation. Immunohistochemistry clearly demonstrated the expression of CYLD and NF-kappaB-related factors in ACC tissue.

Induction of apoptosis in human salivary gland tumor cells by anti-NCAM antibody.

Neural cell adhesion molecule (NCAM) is a type of cell surface glycoprotein and a member of the immunoglobulin superfamily. It has been reported that NCAM may be associated with perineural invasion by malignant salivary gland tumors such as adenoid cystic carcinoma. We have previously demonstrated that NCAM is constitutively expressed in the human salivary gland tumor cell line HSG, in vitro. In the present study, we have aimed to clarify the hypothesis that NCAM-mediated inhibition of salivary gland tumor proliferation is caused by homophilic binding and involves the prevention of signal transduction for perineural invasion using HSG cells. NCAM mRNA and protein expression was found to decrease in a dose-dependent manner upon treatment with the anti-NCAM antibody (MAb NCAM) for 24 h. The MTT assay showed a significant reduction in the number of viable HSG cells. Confocal laser microscopy showed that HSG cells underwent apoptosis after treatment with MAb NCAM. The activation of caspases 3, 7 and 9 was observed in HSG cells after treatment with MAb NCAM, thus confirming that apoptosis was induced by the activated caspases. Apaf-1 activity was also detected in HSG cells in a dose-dependent manner after treatment with MAb NCAM. The up-regulation of TGF-beta1-mediated NCAM expression appeared to lead to the activation of homophilic NCAM binding, further accelerating HSG cell proliferation. In addition, the localization of NCAM in adenoid cystic carcinomas (ACCs) was examined using an immunohistochemical method. NCAM was slightly to moderately positive in 9 of 13 cases (69.2%) of ACC. These findings suggest that NCAM is associated not only with a cell-to-cell adhesion mechanism, but also with tumorigenesis, including growth, development and perineural invasion in human salivary gland tumors.