Numerical aberrations of chromosomes 8, 9, 11, and 17 in squamous cell carcinoma of the pharynx and larynx: a fluorescence in situ hybridization and DNA flow cytometric analysis of 50 cases

Impact of Chromosome 9 Numerical Imbalances in Oral Squamous Cell Carcinoma: A Pilot Grid-Based Centromere Analysis

Oral squamous cell carcinoma (OSCC) is considered an aggressive malignancy, mainly due to its increased propensity to provide local and distant lymph node metastases. Gross chromosome instability (CI; polysomy/aneuploidy/monosomy), combined or not with specific gene alterations, is implicated in the development and progression of solid malignancies, including OSCC. In order to further study the relationship between these genetic alterations and the aggressive biological behavior of OSCCs, we investigated the frequency and impact of chromosome 9 numerical imbalances in these tumors. Fifty (n = 50) formalin-fixed, paraffin-embedded primary OSCC tissue sections were used. Chromogenic in situ hybridization (CISH) was implemented for detecting chromosome 9 (CEN-centromere enumeration) numerical alterations. Concerning the screening process in CISH slides, a novel, real-time reference and calibration grid platform was implemented. Chromosome 9 polysomy was observed in 8/50 (16%) tissue sections, whereas the rest of them demonstrated a normal, diploid pattern (42/50; 84%). Chromosome 9 polysomy was associated with the grade of differentiation of the examined tumors (p = 0.036). Chromosome 9 numerical imbalances (polysomy) were observed in sub-groups of OSCCs correlating with a progressive dedifferentiation of the malignant tissues. Concerning the implementation of the proposed grid-based platform as described above on CISH slides, it provides a novel, fast, and accurate screening mapping mechanism for detecting chromosome numerical imbalances.

Genetic gains and losses in oral squamous cell carcinoma: impact on clinical management

PURPOSE

The identification of genetic markers associated with oral cancer is considered essential to improve the diagnosis, prognosis, early tumor and relapse detection and, ultimately, to delineate individualized therapeutic approaches. Here, we aimed at identifying such markers.

METHODS

Multiplex Ligation-dependent Probe Amplification (MLPA) analyses encompassing 133 cancer-related genes were performed on a panel of primary oral tumor samples and its corresponding resection margins (macroscopically tumor-free tissue) allowing, in both types of tissue, the detection of a wide arrange of copy number imbalances on various human chromosomes.

RESULTS

We found that in tumor tissue, from the 133 cancer-related genes included in this study, those that most frequently exhibited copy number gains were located on chromosomal arms 3q, 6p, 8q, 11q, 16p, 16q, 17p, 17q and 19q, whereas those most frequently exhibiting copy number losses were located on chromosomal arms 2q, 3p, 4q, 5q, 8p, 9p, 11q and 18q. Several imbalances were highlighted, i.e., losses of ERBB4, CTNNB1, NFKB1, IL2, IL12B, TUSC3, CDKN2A, CASP1, and gains of MME, BCL6, VEGF, PTK2, PTP4A3, RNF139, CCND1, FGF3, CTTN, MVP, CDH1, BRCA1, CDKN2D, BAX, as well as exon 4 of TP53. Comparisons between tumor and matched macroscopically tumor-free tissues allowed us to build a logistic regression model to predict the tissue type (benign versus malignant). In this model, the TUSC3 gene showed statistical significance, indicating that loss of this gene may serve as a good indicator of malignancy.

CONCLUSIONS

Our results point towards relevance of the above mentioned cancer-related genes as putative genetic markers for oral cancer. For practical clinical purposes, these genetic markers should be validated in additional studies.

Genetic model of transformation and neoplastic progression in laryngeal epithelium

BACKGROUND

The aim of this study was to analyze genetic alterations in the transformation-progression model of laryngeal tumors.

METHODS

Copy number changes of 37 genes were analyzed by multiple ligation-dependent probe amplification (MLPA) in 94 tissue samples.

RESULTS

In the smoker normal mucosa group TP53 loss was predominant, whereas in the precursor lesions CDKN2A loss and CDKN2D gain were most frequent. Precursor lesions with progression presented CTNNB1 loss. In the carcinoma group the most common changes were CDKN2A, MLH1, CTNNB1, and CASP6 losses and RECQL4, CCND1, and EMS1 gains. Positive lymph node primary tumors were related to TP53, IL1A, and RB1 losses and STK11 gain. The lymph node metastases differed from their corresponding primary tumor in LMNA, RECQL4, and IGF1R losses, and N33 and CDKN2D gains.

CONCLUSIONS

Genetic changes and new key genes were found to be associated with specific steps. We included new steps, not presented in the classic models: normal mucosa tobacco exposed, positive lymph node primary tumor, and corresponding lymph node metastases.

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.

Simultaneous over activation of EGFR, telomerase (h TERT), and cyclin D1 correlates with advanced disease in larynx squamous cell carcinoma: a tissue microarray analysis

Overexpression of Epidermal Growth Factor Receptor (EGFR) and also of cell cycle control proteins, such as cyclin D1 is a frequent event in squamous cell carcinoma of the larynx (LSSC). Our aim was to correlate their protein levels with telomerase catalytic subunit (h-TERT) expression. Using tissue microarray technology, fifty-five paraffin embedded histologically confirmed primary LSSCs and also ten dysplastic lesions were cored at a diameter of 1.5 mm. Immunohistochemistry (IHC) was performed by the use of anti-EGFR, anti-cyclin D1, and anti-h TERT monoclonal antibodies. Chromogenic in situ hybridization (CISH) analysis was also applied using EGFR gene and chromosome 7 probes, respectively. EGFR, cyclin D1 and h-TERT protein overexpression was observed in 48/55 (87.2%), 19/55 (34.5%) and 21/55 (38.1%) carcinoma cases, respectively. EGFR protein expression was statistically associated with grade (P=0.01), and also with stage (P=0.001) of the examined tumors. Borderline statistical significance was assessed correlating overall cyclin D1 expression to h TERT expression (P=0.06). Simultaneous up regulation of the three proteins was established in 7/55 (12.7%) cases, correlated to the stage of the tumors (P=0.05). EGFR gene amplification was observed in 7/65 (10.7%) carcinomas and dysplasias, whereas chromosome 7 aneuploidy was detected in 4/65 (6.1%) of those cases.Simultaneous up regulation of EGFR, cyclin D1 and h TERT proteins correlates with advanced stage in LSCC. EGFR gene amplification and not only protein over expression maybe is the eligible criterion for targeted therapeutic strategies in those patients.

Genetic differences between primary larynx and pharynx carcinomas and their matched lymph node metastases by multiplex ligation-dependent probe amplification

Lymph nodes metastasis is a major risk factor related to poor survival in larynx and pharynx carcinomas. The aim of this study is to search for markers of lymph node involvement analyzing the genetic differences between primary larynx and pharynx squamous cell carcinomas and their corresponding lymph node metastases. Twenty-five primary tumors and their corresponding lymph node metastases were examined. DNA copy number changes of 37 genes were analyzed by multiplex ligation-dependent probe amplification (MLPA). Loss of CDKN2A (9p21) occurred in 14 out of 25 pairs (56%) of primary tumor and lymph node metastases. Loss of LMNA (1q21) was exclusively detected in 8 lymph node samples (32%). Loss of CTNNB1 (3p22) and gain of CDKN2D (19p13) were also significantly more frequent in lymph node metastases. Other aberrations related to lymph node metastases were loss of MFHAS1 (8p23), RECQL4 (8q24) and gain of N33 (8p22) and TP53 (17p13). Primary tumor and corresponding lymph node metastases showed common genetic changes. However, the lymph node metastases presented with a number of additional alterations. Acquisition of these alterations may play a role in lymphatic metastasis development.

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.

Alterations of the CCND1 and HER-2/neu (ERBB2) proteins in esophageal and gastric cancers

We evaluated the relationship of amplification and polysomy of both the CCND1 and the ERBB2 (alias HER-2/NEU) genes to the overexpression of their proteins in esophageal and gastric cancers and also their association with clinicopathological features. CCND1 gene amplification (45%) was more prevalent than polysomy (25%) in esophageal carcinoma, but the pattern observed was similar in gastric adenocarcinoma (10% amplification, 15% polysomy). For ERBB2, polysomy was a more frequent mechanism than amplification in both esophageal (32.5 vs. 7.5%) and gastric (15 vs. 5%) cancers. Overexpression of cyclin D1 protein was identified in 37.5% of the specimens of esophageal tumors and 35% of gastric tumors, and overexpression of Her-2/neu protein in 12.5 and 7.5%, respectively. The kappa-statistics revealed a fair agreement in both types of tumors only in overexpression and amplification of the CCND1 gene; the ERBB2 gene showed a fair agreement in amplification and polysomy and the level of protein expression in gastric adenocarcinoma. Thus, polysomy 17 could contribute to a high Her-2/neu protein level, at least in gastric cancer. Our data indicated an association with alcohol consumption and the CCND1 gene or protein levels, in both esophageal and gastric cancers.

Heterogeneity, histological features and DNA ploidy in oral carcinoma by image-based analysis

Oral squamous carcinomas appear heterogeneous on DNA ploidy analysis. However, this may be partly a result of sample dilution or the detection limit of techniques. The aim of this study was to determine whether oral squamous carcinomas are heterogeneous for ploidy status using image-based ploidy analysis and to determine whether ploidy status correlates with histological parameters. Multiple samples from 42 oral squamous carcinomas were analysed for DNA ploidy using an image-based system and scored for histological parameters. 22 were uniformly aneuploid, 1 uniformly tetraploid and 3 uniformly diploid. 16 appeared heterogeneous but only 8 appeared to be genuinely heterogeneous when minor ploidy histogram peaks were taken into account. Ploidy was closely related to nuclear pleomorphism but not differentiation. Sample variation, detection limits and diagnostic criteria account for much of the ploidy heterogeneity observed. Confident diagnosis of diploid status in an oral squamous cell carcinoma requires a minimum of 5 samples.