Characterizing Genetic Transitions of Copy Number Alterations and Allelic Imbalances in Oral Tongue Carcinoma Metastasis.

Primary tumor (PT) heterogeneity can significantly affect the genetic profile of clones at metastatic sites. To understand the mechanisms underlying metastasis, we compared the genetic profile of paired PT and metastatic lymph node (MLN) samples obtained from patients with oral tongue squamous cell carcinoma (OTSCC). Large-scale genetic profiling was performed on paired PT-MLN samples obtained from 10 OTSCC patients using high-density single-nucleotide polymorphism microarrays. We compared the genetic profile of PT and MLN OTSCC samples to identify common and specific copy number alterations and copy-neutral loss-of-heterozygosity (CN-LOH). Unsupervised hierarchical clustering analysis indicated that 8 of the 10 PT-MLN sample pairs formed clusters, indicating that the primary and metastatic tumors were composed of predominantly genetically similar tumor cells. In 6 of the 10 pairs, 8q11.21, 8q12.2-3, and 8q21.3 gains, and 22q11.23 loss were detected in both the PT and MLN. In addition, 16p11.2 CN-LOH was identified in 9 of the 10 pairs. Conversely, 20q11.2 gain was only observed in the MLNs of 5 of the 10 sample pairs, indicating that genes in this chromosomal region may play a significant role in OTSCC lymph node metastasis. To confirm this, we investigated the expression of two candidate 20q11.2 genes in a separate patient cohort. The expression of one of these genes, E2F1, was significantly increased during the process of metastasis. This study indicates that additional genetic changes, such as 20q11.2 gain, which encodes the E2F1 gene, can be acquired through clonal evolution, and may be required for the metastatic process. © 2016 Wiley Periodicals, Inc.

Clinical Study of 597 Oral Squamous Cell Carcinomas in Our Department - Especially about 318 Tongue Carcinoma.

This clinico-statistical study includes 597 cases of oral squamous cell carcinoma treated at the Maxillofacial Surgery Section of Tokyo Medical and Dental University between January 2002 and December 2011. There were 373 male and 224 female patients (male to female ratio, 1.7 : 1), and the median age was 67 years. The tongue (53.3%) was the most commonly affected site. The 5-year disease-specific survival rate was 84.8%. Survival rates by clinical stage were as follows : Stage 1, 92.1% (n=195).; Stage , 86.0% (n = 221) ; Stage III, 77.7% (n=65) ; and Stage IV, 73.8% (n =116). Survival rates by primary site were as follows: tongue, 85.4% (n=318) ; lower gingiva, 82.8% (n =114) upper gingiva, 83.7% (n=59) ; buccal mucosa, 89.1% (n 54) ; oral floor, 81.4% (n=49) ; and hard palate, 100% (n=3). According to clinical growth patterns of Stage I / I tongue cancer cases, the 5-year disease-specific survival rate was significantly higher for patients with the exophytic/superficial type (97.3%, n =173) than for those with the endophytic type (77.5%, n=145). Among Stage I/II tongue cancer cases, the corresponding survival rate was significantly higher for patients who had not previously undergone invasive treatments (n=201), such as tooth extraction, compared to those who had previously done so (n=54) (92.7% and 79.7%, respectively). In addition, the incidence of secondary cervical lymph node metastasis was significantly higher in patients who had previously undergone invasive treatments.

Determination of Significant Prognostic Factors for Maxillary Gingival Squamous Cell Carcinoma in 90 Cases.

Maxillary gingival squamous cell carcinoma (MGSCC) occurs rather infrequently, compared to tongue and mandibular gingival carcinomas, among the cancers of the oral cavity. Therefore, significant numbers of MGSCC cases have not been statistically analysed. The aim of this study is to clarify the prognostic factors for MGSCC. We performed the statistical analysis of 90 MGSCC cases primarily treated in our department from 1999 to 2014. The patients (male: 36, female: 54) were aged between 38 and 93 years, and the mean age was 68.7 years. The number of patients in each tumour stage according to the TNM classification was as follows: T1: 15 cases, T2: 32 cases, T3: 13 cases, and T4: 30 cases. Forty-two patients were treated only by surgery, 5 only by radiotherapy, 3 by preoperative radiotherapy and surgery, and 40 patients were treated by combination therapy with preoperative chemoradiotherapy and surgery. Neck dissections were performed in 40 cases including 29 cases (11 primary and 18 secondary cases) of histopathologically diagnosed lymph node metastases. Extranodal extension was found in 74.3% cases with metastatic lymph nodes. The 5-year overall survival rate was 81.9%. In univariate analysis, the site of occurrence, stage of tumour, lymph node metastasis, and treatment contributed to the 5-year survival rate. Multivariate analysis demonstrated that the site of occurrence (posterior region) was an independent prognostic factor. Seventeen deaths occurred due to the primary disease, while three deaths were caused by other diseases. The posterior region cancers, according to the classification based on site of occurrence, were independent predictors of poor 5-year overall survival rate.

Prognostic utility of chromosomal instability detected by fluorescence in situ hybridization in fine-needle aspirates from oral squamous cell carcinomas.

BACKGROUND: Although chromosomal instability (CIN) has been detected in many kinds of human malignancies by means of various methods, there is no practical assessment for small clinical specimens. In this study, we evaluated CIN in fine-needle aspiration (FNA) biopsied oral squamous cell carcinomas (SCCs) using fluorescence in situ hybridization (FISH) analysis, and investigated its prognostic significance. METHODS: To evaluate CIN status of tumors, FISH with genomic probes for the centromeres of chromosomes 7, 9, and 11 was performed on specimens obtained by FNA from 77 patients with primary oral SCCs. RESULTS: High-grade CIN (CIN3) was observed in 11.7% (9/77) of patients with oral SCCs and was associated significantly with reduced disease-free survival (p = .008) and overall survival (p = .003). Multivariate Cox proportional hazards analysis showed that CIN status was significantly correlated with disease-free survival (p = .035) and overall survival (p = .041). CONCLUSION: Analysis of CIN status using FISH on FNA biopsy specimens may be useful in predicting of recurrence and poor prognosis in patients with oral SCCs.

[Prediction of occult cervical lymph node metastasis in patients with stage I -II squamous cell carcinoma of the oral cavity].

The presence of lymph node metastasis is the most important prognostic factor in oral cancer. The purpose of this study was to find useful markers for predicting occult cervical lymph node metastasis in patients with stage I or II squamous cell carcinoma of the oral cavity. We investigated 6 clinicopathologic factors and 2 genetic markers to predict late or occult cervical metastasis in 33 patients with stage I and II oral squamous cell carcinoma who underwent partial glossectomy through the mouth without elective neck dissection. In this study, we performed fluorescence in situ hybridization (FISH) with specimens obtained by fine-needle aspiration biopsies (FNA biopsies) of primary oral cancer material, to investigate numerical aberration of the gene. Late cervical lymph node metastasis occurred in 16 of the 33 patients (48.5%) during follow-up after treatment of the primary tumor. Factors significantly associated with the development of cervical metastasis were the mode of invasion (p = 0.009), cyclin D1 (p = 0.003) and EGFR numerical aberration (p = 0.024). The rate of disease-free survival from metastatic disease was significantly lower in patients with mode of invasion 4 C-4 D than in those with 1-3, and was significantly lower in patients with cyclin D 1 or EGFR gene numerical aberrations than in those without such aberrations (log rank test, p = 0.0064, p = 0.0016 or p = 0.0150). Our results indicate that patients with stage I - II squamous cell carcinoma of the oral cavity with the mode of invasion 4 C or 4 D, cyclin D 1 and EGFR gene numerical aberration should be considered a high-risk group for late cervical lymph node metastasis.

Fluorescence in situ hybridization for detecting genomic alterations of cyclin D1 and p16 in oral squamous cell carcinomas.

BACKGROUND: Cyclin D1 (CCND1) and p16 alterations have been detected in oral squamous cell carcinomas (SCCs), suggesting that abnormalities of these genes may play an important role in the genesis or progression of oral SCCs and serve as independent prognostic indicators. The detection of CCND1 and p16 aberrations using a simple and sensitive method would be valuable for the development of effective treatment modalities for oral cancer. The objective of the current study was to determine whether CCND1 numerical aberrations and p16 deletions in oral SCCs detected by fluorescence in situ hybridization (FISH) have any impact on clinical outcome. METHODS: Using genomic DNA probes for CCND1 and p16, FISH was performed on specimens that were obtained by fine-needle aspiration (FNA) from 57 primary oral SCCs. RESULTS: The CCND1 numerical aberration was observed in 28 of 57 patients (49%) with oral SCCs and was associated significantly with reduced disease-free survival (P = .0004) and overall survival (P = .0179). Conversely, p16 deletion was detected in 22 of 57 patients (39%). The disease-free and overall survival rates for patients with p16 deletion were lower than those among patients without the p16 deletion, although the difference just failed to reach statistical significance (P = .0516 and P = .1878, respectively). The p16 deletion in the presence of the CCND1 numerical aberration conferred significantly worse disease-free survival (P = .0002) and overall survival (P = .0153). CONCLUSIONS: Although the CCND1 numerical aberration was a good predictor of aggressive tumors, recurrence, and poor prognosis in patients with oral SCCs, the authors were able to identify subgroups of patients that had early disease recurrence and a poor prognosis more efficiently by assessment of p16 deletion in addition to CCND1 genetic status using FISH on FNA biopsy samples compared with the analysis of either alteration alone.

Cyclin D1 gene numerical aberration is a predictive marker for occult cervical lymph node metastasis in TNM Stage I and II squamous cell carcinoma of the oral cavity.

BACKGROUND: The management of occult cervical lymph node metastases originating from oral squamous cell carcinomas (OSCCs) remains controversial. The purpose of this study was to evaluate the value of cyclin D1 gene (CCND1) numerical aberrations in predicting the risk of late lymph node metastases. METHODS: Fluorescence in situ hybridization (FISH), using a BAC clone specific for CCND1, was performed on OSCC specimens obtained by fine-needle aspiration (FNA) biopsy from 45 patients with previously untreated TNM Stage I and II (T1-2N0M0) disease who had not undergone elective cervical lymph node dissection. RESULTS: CCND1 numerical aberrations were observed in 15 (33.3%) of the 45 patients and were significantly associated with the mode of invasion of the primary tumor (P = 0.01) and the presence of occult lymph node metastases (P < 0.001). Twelve of these 15 patients (80%) developed late cervical lymph node metastases within 2 years of surgery for primary OSCCs. All patients with cluster-type amplification of CCND1 developed late lymph node metastases. Multivariate analysis showed that only CCND1 numerical aberrations (risk ratio, 8.685%, 95% confidence interval = 2.232-33.802, P = 0.002) independently predicted late cervical lymph node metastasis. CONCLUSIONS: Aberrations in CCND1 numbers appear to be valuable in identifying patients at high risk of late lymph node metastasis in Stage I and II OSCCs. Analysis of CCND1 numerical aberrations using FISH on FNA biopsy specimens may be useful in selecting patients for elective cervical lymph node dissection.