Prediction of lymphatic metastasis based on gene expression profile analysis after brachytherapy for early-stage oral tongue carcinoma

Systematic analysis of genes involved in oral cancer metastasis to lymph nodes

Oral cancer remains a deadly disease worldwide. Lymph node metastasis and invasion is one of the causes of death from oral cancer. Elucidating the mechanism of oral cancer lymph node metastasis and identifying critical regulatory genes are important for the treatment of this disease. This study aimed to identify differentially expressed genes (gene signature) and pathways that contribute to oral cancer metastasis to lymph nodes. The GSE70604-associated study compared gene profiles in lymph nodes with metastasis of oral cancer to those of normal lymph nodes. The GSE2280-associated study compared gene profiles in primary tumor of oral cancer with lymph node metastasis to those in tumors without lymph node metastasis. There are 28 common differentially expressed genes (DEGs) showing consistent changes in both datasets in overlapping analysis. GO biological process and KEGG pathway analysis of these 28 DEGs identified the gene signature CCND1, JUN and SPP1, which are categorized as key regulatory genes involved in the focal adhesion pathway. Silencing expression of CCND1, JUN and SPP1 in the human oral cancer cell line OECM-1 confirmed that those genes play essential roles in oral cancer cell invasion. Analysis of clinical samples of oral cancer found a strong correlation of these genes with short survival, especially JUN expression associated with metastasis. Our study identified a unique gene signature - CCND1, JUN and SPP1 - which may be involved in oral cancer lymph node metastasis.

A multiscale and multiparametric approach for modeling the progression of oral cancer

Background

In this work, we propose a multilevel and multiparametric approach in order to model the growth and progression of oral squamous cell carcinoma (OSCC) after remission. OSCC constitutes the major neoplasm of the head and neck region, exhibiting a quite aggressive nature, often leading to unfavorable prognosis.

Methods

We formulate a Decision Support System assembling a multitude of heterogeneous data sources (clinical, imaging tissue and blood genomic), aiming to capture all manifestations of the disease. Our primary aim is to identify the factors that dictate OSCC progression and subsequently predict potential relapses of the disease. The discrimination potential of each source of data is initially explored separately, and afterwards the individual predictions are combined to yield a consensus decision achieving complete discrimination between patients with and without a disease relapse. Moreover, we collect and analyze gene expression data from circulating blood cells throughout the follow-up period in consecutive time-slices, in order to model the temporal dimension of the disease. For this purpose a Dynamic Bayesian Network (DBN) is employed which is able to capture in a transparent manner the underlying mechanism dictating the disease evolvement, and employ it for monitoring the status and prognosis of the patients after remission.

Results

By feeding as input to the DBN data from the baseline visit we achieve accuracy of 86%, which is further improved to complete discrimination when data from the first follow-up visit are also employed.

Conclusions

Knowing in advance the progression of the disease, i.e. identifying groups of patients with higher/lower risk of reoccurrence, we are able to determine the subsequent treatment protocol in a more personalized manner.

Predicting factors for locoregional failure of high-dose-rate brachytherapy for early-stage oral cancer

AIM

Brachytherapy is an alternative to surgery in the treatment of the early stages of oral tongue cancer. The aim of this retrospective study was to analyze the clinical risk factors and possible candidate biomarkers of local and regional tumor control.

PATIENTS & METHODS

Twenty-four patients were treated between the years 2001 and 2010. Median follow-up was 37.4 months. Correlation between disease-free survival and clinical stage, tumor grade, resection margin, depth of invasion, and p16, EGF receptor, NF-κB, HIF-1α, HER2, Ku-80, COX-2 and VEGF expression was evaluated.

RESULTS

The estimated 5-year local control was 81% and locoregional control was 62%. Depth of tumor invasion (p = 0.018) and higher VEGF expression (p = 0.016) were significantly predictive for worse disease-free survival in Cox multivariate analysis.

CONCLUSION

Intensity of VEGF expression and depth of tumor invasion may be significantly negative predictors of disease-free survival in tongue cancer patients treated by brachytherapy alone. Predictive value of VEGF deserves evaluation in larger studies.

Multiparametric decision support system for the prediction of oral cancer reoccurrence

Oral squamous cell carcinoma (OSCC) constitutes the predominant neoplasm of the head and neck region, featuring particularly aggressive nature, associated with quite unfavorable prognosis. In this work we formulate a Decision Support System (DSS) which integrates a multitude of heterogeneous data (clinical, imaging and genomic), thus, framing all manifestations of the disease. Our primary aim is to identify the factors that dictate OSCC progression and subsequently predict potential relapses (local or metastatic) of the disease. The discrimination potential of each source of data is initially explored separately, and afterwards the individual predictions are combined to yield a consensus decision achieving complete discrimination between patients with and without a disease relapse.

Hyperfractionated high-dose rate brachytherapy in the treatment of oral tongue cancer

BACKGROUND

Low-dose rate brachytherapy is a well established treatment modality of oral cancer. Data about high-dose rate (HDR) brachytherapy are still sparse with various fractionation schedules and heterogeneous results.

AIM

The aim of our retrospective study was to evaluate the results of HDR brachytherapy with doses of 3 Gy twice daily.

PATIENTS AND METHODS

Twenty patients with squamous cell tongue cancer were treated in the years 2001-2009 by exclusive HDR BT 18 × 3 Gy twice daily. The plastic tube technique was used. Median follow up was 47 months (7.8-118) since brachytherapy.

RESULTS

The local and locoregional control was 85% and 68%, respectively. Bone necrosis developed in one case treated without mandibular shielding and soft tissue necrosis in 2 cases.

CONCLUSION

It can be concluded that HDR brachytherapy with 18 × 3 Gy twice daily is safe with promising local control. The risk of nodal recurrences is substantial.

An empirical assessment of validation practices for molecular classifiers

Proposed molecular classifiers may be overfit to idiosyncrasies of noisy genomic and proteomic data. Cross-validation methods are often used to obtain estimates of classification accuracy, but both simulations and case studies suggest that, when inappropriate methods are used, bias may ensue. Bias can be bypassed and generalizability can be tested by external (independent) validation. We evaluated 35 studies that have reported on external validation of a molecular classifier. We extracted information on study design and methodological features, and compared the performance of molecular classifiers in internal cross-validation versus external validation for 28 studies where both had been performed. We demonstrate that the majority of studies pursued cross-validation practices that are likely to overestimate classifier performance. Most studies were markedly underpowered to detect a 20% decrease in sensitivity or specificity between internal cross-validation and external validation [median power was 36% (IQR, 21-61%) and 29% (IQR, 15-65%), respectively]. The median reported classification performance for sensitivity and specificity was 94% and 98%, respectively, in cross-validation and 88% and 81% for independent validation. The relative diagnostic odds ratio was 3.26 (95% CI 2.04-5.21) for cross-validation versus independent validation. Finally, we reviewed all studies (n = 758) which cited those in our study sample, and identified only one instance of additional subsequent independent validation of these classifiers. In conclusion, these results document that many cross-validation practices employed in the literature are potentially biased and genuine progress in this field will require adoption of routine external validation of molecular classifiers, preferably in much larger studies than in current practice.

Genome-wide association study of survival in non-small cell lung cancer patients receiving platinum-based chemotherapy

BACKGROUND

Interindividual variation in genetic background may influence the response to chemotherapy and overall survival for patients with advanced-stage non-small cell lung cancer (NSCLC).

METHODS

To identify genetic variants associated with poor overall survival in these patients, we conducted a genome-wide scan of 307,260 single-nucleotide polymorphisms (SNPs) in 327 advanced-stage NSCLC patients who received platinum-based chemotherapy with or without radiation at the University of Texas MD Anderson Cancer Center (the discovery population). A fast-track replication was performed for 315 patients from the Mayo Clinic followed by a second validation at the University of Pittsburgh in 420 patients enrolled in the Spanish Lung Cancer Group PLATAX clinical trial. A pooled analysis combining the Mayo Clinic and PLATAX populations or all three populations was also used to validate the results. We assessed the association of each SNP with overall survival by multivariable Cox proportional hazard regression analysis. All statistical tests were two-sided.

RESULTS

SNP rs1878022 in the chemokine-like receptor 1 (CMKLR1) was statistically significantly associated with poor overall survival in the MD Anderson discovery population (hazard ratio [HR] of death = 1.59, 95% confidence interval [CI] = 1.32 to 1.92, P = 1.42 × 10(-6)), in the PLATAX clinical trial (HR of death = 1.23, 95% CI = 1.00 to 1.51, P = .05), in the pooled Mayo Clinic and PLATAX validation (HR of death = 1.22, 95% CI = 1.06 to 1.40, P = .005), and in pooled analysis of all three populations (HR of death = 1.33, 95% CI = 1.19 to 1.48, P = 5.13 × 10(-7)). Carrying a variant genotype of rs10937823 was associated with decreased overall survival (HR of death = 1.82, 95% CI = 1.42 to 2.33, P = 1.73 × 10(-6)) in the pooled MD Anderson and Mayo Clinic populations but not in the PLATAX trial patient population (HR of death = 0.96, 95% CI = 0.69 to 1.35).

CONCLUSION

These results have the potential to contribute to the future development of personalized chemotherapy treatments for individual NSCLC patients.

Gene expression profiling towards the prediction of oral cancer reoccurrence

In this work we perform gene expression profiling on tissue specimen obtained from patients with oral squamous cell carcinoma with a twofold aim: i) to identify a limited number of genes that capture perturbations at molecular level dictating the development of a potential disease relapse after remission, and ii) to employ these genes in order to build a classifier that is able to calculate the probability of disease reoccurrence for new patients, subsequently discriminating patients into high and low risk groups based on reoccurrence probability. The proposed analysis yielded 94% overall accuracy, 100% sensitivity and 89% specificity, for discriminating patients with and without a disease relapse.

Gene Expression Signatures of Lymph Node Metastasis in Oral Cancer: Molecular Characteristics and Clinical Significances

Even though lymph node metastasis accounts for the vast majority of cancer death in patients with oral cancer (OC), the molecular mechanisms of lymph node metastasis remain elusive. Genome-wide microarray analyses and functional studies in vitro and in vivo, along with detailed clinical observations, have identified a number of molecules that may contribute to lymph node metastasis. These include lymphangionenic cytokines, cell adhesion molecules, basement membrane-interacting molecules, matrix enzymes and relevant downstream signaling pathways. However, defined gene signatures from different studies are highly variable, which hinders their translation to clinically relevant applications. To date, none of the identified signatures or molecular biomarkers has been successfully implemented as a diagnostic or prognostic tool applicable to routine clinical practice. In this review, we will first introduce the significance of lymph node metastasis in OC, and clinical/experimental evidences that support the underlying molecular mechanisms. We will then provide a comprehensive review and integrative analysis of the existing gene expression studies that aim to identify the metastasis-related signatures in OC. Finally, the remaining challenges will be discussed and our insights on future directions will be provided.

Interstitial HDR brachytherapy (HDR-BT) in early stage mobile tongue cancers in young patients - Gliwice experience

Purpose

In early stage mobile tongue cancer radical radiotherapy offers good local control and organ preservation, which is especially important in the group of young patients. In our department, for many years HDR-BT has been performed in mobile tongue cancers as a sole treatment or as a “boost” with EBRT. The aim of the study was to show our experience with HDR-BT in early stage mobile tongue cancers among young patients.

Material and methods

From 2001 to 2006 in Maria Skłodowska-Curie Memorial Cancer Centre and Institute of Oncology, Gliwice Branch, five patients under 45 years with mobile tongue cancer were treated with HDR brachytherapy (T1N0M0 – 3/5 and T2N0M0 – 2/5); 4 with HDR brachytherapy “boost” and 1 as a sole treatment. One woman was previously treated with tumour resection, but because of positive surgical margins was referred for radiotherapy. All patients had clinically negative lymph nodes, without dissection. They were treated with interstitial HDR-BT (3-8 catheters). In 4 patients treated with HDR-BT as a “boost”, total doses ranged from 18 to 21 Gy given in 6-7 fractions (twice a day, 3 Gy per fraction). Total doses in EBRT (to local lymph nodes and tumour bed) ranged from 50 to 60 Gy (1.8-2 Gy per fraction 5 days/week). One patient, treated with radical HDR brachytherapy, received 45 Gy in 10 fractions and 50 Gy in EBRT to regional lymph nodes.

Results

We did not notice local recurrences or distant metastases in our group of patients. Median follow-up was 67 months (range 47-79 months). All patients preserved normal tongue function. A severe late complication occurred in 1 patient – fracture of the mandible.

Conclusions

In the analysed group of young patients with mobile tongue cancer interstitial HDR brachytherapy in combination with EBRT was an effective and well tolerated treatment modality which allowed preservation of the tongue and its function.