Eduardo Mendez

Gene Expression Profiling Identifies Genes Predictive of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is associated with substantial mortality and morbidity. To identify potential biomarkers for the early detection of invasive OSCC, we compared the gene expressions of incident primary OSCC, oral dysplasia, and clinically normal oral tissue from surgical patients without head and neck cancer or preneoplastic oral lesions (controls), using Affymetrix U133 2.0 Plus arrays. We identified 131 differentially expressed probe sets using a training set of 119 OSCC patients and 35 controls. Forward and stepwise logistic regression analyses identified 10 successive combinations of genes which expression differentiated OSCC from controls. The best model included LAMC2, encoding laminin-γ2 chain, and COL4A1, encoding collagen, type IV α1 chain. Subsequent modeling without these two markers showed that COL1A1, encoding collagen, type I α1 chain, and PADI1, encoding peptidyl arginine deiminase, type 1, could also distinguish OSCC from controls. We validated these two models using an internal independent testing set of 48 invasive OSCC and 10 controls and an external testing set of 42 head and neck squamous cell carcinoma cases and 14 controls (GEO GSE6791), with sensitivity and specificity above 95%. These two models were also able to distinguish dysplasia (n = 17) from control (n = 35) tissue. Differential expression of these four genes was confirmed by quantitative reverse transcription-PCR. If confirmed in larger studies, the proposed models may hold promise for monitoring local recurrence at surgical margins and the development of second primary oral cancer in patients with OSCC. (Cancer Epidemiol Biomarkers Prev 2008;17(8):2152–62)

Cisplatin and Radiotherapy With or Without Erlotinib in Locally Advanced Squamous Cell Carcinoma of the Head and Neck: A Randomized Phase II Trial

PURPOSE The combination of cisplatin and radiotherapy is a standard treatment for patients with locally advanced squamous cell carcinoma of the head and neck (SCCHN). Cetuximab-radiotherapy is superior to radiotherapy alone in this population, validating epidermal growth factor receptor (EGFR) as a target. Erlotinib is a small-molecule inhibitor of EGFR. Adding EGFR inhibition to standard cisplatin-radiotherapy may improve efficacy. PATIENTS AND METHODS Patients with locally advanced SCCHN were randomly assigned to receive cisplatin 100 mg/m(2) on days 1, 22, and 43 combined with 70 Gy of radiotherapy (arm A) or the same chemoradiotherapy with erlotinib 150 mg per day, starting 1 week before radiotherapy and continued to its completion (arm B). The primary end point was complete response rate (CRR), evaluated by central review. The secondary end point was progression-free survival (PFS). Available tumors were tested for p16 and EGFR by fluorescent in situ hybridization. RESULTS Between December 2006 and October 2011, 204 patients were randomly assigned. Arms were well balanced for all patient characteristics including p16, with the exception of more women on arm A. Patients on arm B had more rash, but treatment arms did not differ regarding rates of other grade 3 or 4 toxicities. Arm A had a CRR of 40% and arm B had a CRR of 52% (P = .08) when evaluated by central review. With a median follow-up time of 26 months and 54 progression events, there was no difference in PFS (hazard ratio, 0.9; P = .71). CONCLUSION Erlotinib did not increase the toxicity of cisplatin and radiotherapy in patients with locally advanced HNSCC but failed to significantly increase CRR or PFS.

Developments in reconstruction of midface and maxilla

Loss of the maxilla and midfacial structures after tumour removal has substantial functional and aesthetic consequences. The variable loss of soft tissue, bone, or both, leading to collapse of the lip, cheek, periorbital soft tissues, and palatal competence present a challenging dilemma for reconstructive surgeons. Efforts have been made to classify these midfacial defects and provide appropriate algorithms for optimum reconstruction. Not only does the cavity need to be obliterated and midfacial contours recreated, but swallowing function, phonation, and mastication need to be restored for an ideal result. Traditionally, these defects would have been repaired by a maxillofacial prosthesis but advances in tissue transfers, particularly of microvascular free flaps, have greatly increased reconstructive options. The wide variety of free flaps that contain both soft tissue and bone offer unique properties that could be applicable depending on the defect. Combinations of free tissue transfer, local flaps, and maxillofacial prostheses might achieve a more ideal result than one technique alone. Advances in osseointegration have also enhanced the ability to achieve the best function and form. No one flap or technique is sufficient to reconstruct midface defects in all patients. The choices should be tailored to the bony and soft-tissue needs of each specific defect, denture-bearing potential of the original tissues, and available prosthodontic support. Use of a multidisciplinary approach to reconstruct these defects can yield excellent results. The complexity of the techniques should match the desired goals and needs of each individual patient.

Genomewide Gene Expression Profiles of HPV-Positive and HPV-Negative Oropharyngeal Cancer: Potential Implications for Treatment Choices

OBJECTIVE To study the difference in gene expression between human papillomavirus (HPV)-positive and HPV-negative oral cavity and oropharyngeal squamous cell carcinoma (OSCC). DESIGN We used Affymetrix U133 plus 2.0 arrays to examine gene expression profiles of OSCC and normal oral tissue. The HPV DNA was detected using polymerase chain reaction followed by the Roche LINEAR ARRAY HPV Genotyping Test, and the differentially expressed genes were analyzed to examine their potential biological roles using the Ingenuity Pathway Analysis Software, version 5.0. SETTING Three medical centers affiliated with the University of Washington. PATIENTS A total of 119 patients with primary OSCC and 35 patients without cancer, all of whom were treated at the setting institutions, provided tissues samples for the study. RESULTS Human papillomavirus DNA was found in 41 of 119 tumors (34.5%) and 2 of 35 normal tissue samples (5.7%); 39 of the 43 HPV specimens were HPV-16. A higher prevalence of HPV DNA was found in oropharyngeal cancer (23 of 31) than in oral cavity cancer (18 of 88). We found no significant difference in gene expression between HPV-positive and HPV-negative oral cavity cancer but found 446 probe sets (347 known genes) differentially expressed in HPV-positive oropharyngeal cancer than in HPV-negative oropharyngeal cancer. The most prominent functions of these genes are DNA replication, DNA repair, and cell cycling. Some genes differentially expressed between HPV-positive and HPV-negative oropharyngeal cancer (eg, TYMS, STMN1, CCND1, and RBBP4) are involved in chemotherapy or radiation sensitivity. CONCLUSION These results suggest that differences in the biology of HPV-positive and HPV-negative oropharyngeal cancer may have implications for the management of patients with these different tumors.

Human papillomavirus-positive oral cavity and oropharyngeal cancer patients do not have better quality-of-life trajectories

Objective. To determine the role of human papillomavirus (HPV) status on quality of life (QOL) in patients with oral cavity and oropharyngeal squamous cell carcinoma (OSCC). Since OSCC that are associated with high-risk HPV have an improved response to treatment and survival, we hypothesized that patients with these tumors would have better QOL trajectories. Study Design. Prospective cohort study. Setting. Tertiary care academic medical center and 2 affiliated hospitals. Subjects and Methods. Head and neck–specific QOL was determined using the University of Washington Quality of Life scale version 4 in patients with newly diagnosed invasive OSSC (N = 228). Results. Pretreatment QOL was higher in patients with high-risk HPV-associated tumors compared with patients with HPV-negative or low-risk HPV-associated tumors (P = .015). Patients with high-risk HPV-associated tumors had larger decreases in QOL from pretreatment to immediate posttreatment compared with patients with HPV-negative or low-risk HPV-associated tumors (P = .041). There was no association between HPV status and 1-year posttreatment QOL. Conclusion. Among OSCC patients, high-risk HPV-associated tumors were associated with higher pretreatment QOL and a larger decrease in QOL from pretreatment to immediate posttreatment, suggesting that treatment intensity in this unique population may adversely affect QOL.

Simultaneous Isolation of DNA and RNA from the Same Cell Population Obtained by Laser Capture Microdissection for Genome and Transcriptome Profiling

Laser capture microdissection (LCM) is used extensively for genome and transcriptome profiling. Traditionally, however, DNA and RNA are purified from separate populations of LCM-harvested cells, limiting the strength of inferences about the relationship between gene expression and gene sequence variation. There have been no published protocols for the simultaneous isolation of DNA and RNA from the same cells that are obtained by LCM of patient tissue specimens. Here we report an adaptation of the Qiagen AllPrep method that allows the purification of DNA and RNA from the same LCM-harvested cells. We compared DNA and RNA purified by the QIAamp DNA Micro kit and the PicoPure RNA Isolation kit, respectively, from LCM-collected cells from adjacent tissue sections of the same specimen. The adapted method yields 90% of DNA and 38% of RNA compared with the individual methods. When tested with the GeneChip 250K Nsp Array, the concordance rate of the single nucleotide polymorphism heterozygosity calls was 98%. When tested with the GeneChip U133 Plus 2.0 Array, the correlation coefficient of the raw gene expression was 97%. Thus, we developed a method to obtain both DNA and RNA material from a single population of LCM-harvested cells and herein discuss the strengths and limitations of this methodology.

A Genetic Expression Profile Associated with Oral Cancer Identifies a Group of Patients at High Risk of Poor Survival

Purpose: To determine if gene expression signature of invasive oral squamous cell carcinoma (OSCC) can subclassify OSCC based on survival. Experimental Design: We analyzed the expression of 131 genes in 119 OSCC, 35 normal, and 17 dysplastic mucosa to identify cluster-defined subgroups. Multivariate Cox regression was used to estimate the association between gene expression and survival. By stepwise Cox regression, the top predictive models of OSCC-specific survival were determined and compared by receiver operating characteristic analysis. Results: The 3-year overall mean ± SE survival for a cluster of 45 OSCC patients was 38.7 ± 0.09% compared with 69.1 ± 0.08% for the remaining patients. Multivariate analysis adjusted for age, sex, and stage showed that the 45 OSCC patient cluster had worse overall and OSCC-specific survival (hazard ratio, 3.31; 95% confidence interval, 1.66-6.58 and hazard ratio, 5.43; 95% confidence interval, 2.32-12.73, respectively). Stepwise Cox regression on the 131 probe sets revealed that a model with a term for LAMC2 (laminin γ2) gene expression best identified patients with worst OSCC-specific survival. We fit a Cox model with a term for a principal component analysis-derived risk score marker and two other models that combined stage with either LAMC2 or PCA. The area under the curve for models combining stage with either LAMC2 or PCA was 0.80 or 0.82, respectively, compared with 0.70 for stage alone (P = 0.013 and 0.008, respectively). Conclusions: Gene expression and stage combined predict survival of OSCC patients better than stage alone.

Examination of Oral Cancer Biomarkers by Tissue Microarray Analysis

OBJECTIVE To validate the DNA microarray results on a subset of genes that could potentially serve as biomarkers of oral squamous cell carcinoma (OSCC) by examining their expression with an alternate quantitative method and by assessing their protein levels. DESIGN Based on DNA microarray data from our laboratory and data reported in the literature, we identified 6 potential biomarkers of OSCC to investigate further. We used quantitative real-time polymerase chain reaction to examine expression changes of CDH11, MMP3, SPARC, POSTN, TNC, and TGM3 in OSCC and histologically normal control tissues. We further examined validated markers at the protein level by immunohistochemical analysis of OSCC tissue microarray sections. RESULTS Quantitative real-time polymerase chain reaction analysis revealed upregulation of CDH11, SPARC, POSTN, and TNC gene expression and decreased TGM3 expression in OSCC tissue compared with control tissue; MMP3 was not found to be differentially expressed. In tissue microarray immunohistochemical analyses, SPARC (secreted protein, acidic, rich in cysteine), periostin, and tenascin C exhibited increased protein expression in tumor tissue compared with control tissue, and their expression was primarily localized within tumor-associated stroma rather than tumor epithelium. Conversely, transglutaminase 3 protein expression was found only within keratinocytes in control tissue and was significantly downregulated in cancer cells. CONCLUSIONS Of 6 potential gene markers of OSCC, initially identified by DNA microarray analyses, differential expression of CDH11, SPARC, POSTN, TNC, and TGM3 were validated by quantitative real-time polymerase chain reaction. Differential expression and localization of proteins encoded by SPARC, POSTN, TNC, and TGM3 were clearly shown by tissue microarray immunohistochemical analysis.

Robotic surgery for primary head and neck squamous cell carcinoma of unknown site

IMPORTANCE Identification of the primary site in head and neck squamous cell carcinoma (HNSCC) is crucial because it improves the patients prognosis and minimizes morbidity from treatment. OBJECTIVES To determine the efficacy of transoral robotic surgery (TORS) in identifying unknown primary sites of head and neck squamous cell carcinoma. DESIGN, SETTING, AND PARTICIPANTS Retrospective, multi-institutional case series from January 1, 2010, to February 28, 2013, in which data were pooled from the following 6 institutions: University of Washington Medical Center, The University of Texas MD Anderson Cancer Center, University of Alabama-Birmingham Hospital, The University of Texas Medical School at Houston, Johns Hopkins Hospital, and Oregon Health Sciences University. All patients diagnosed as having HNSCC of an unknown primary site who underwent TORS to identify the primary site were included in the study. We excluded those with recurrent disease, a history of radiation therapy to the head and neck, or evidence of a primary tumor site based on previous biopsy results. MAIN OUTCOME AND MEASURE Identification of the primary tumor site. RESULTS Forty-seven patients were eligible for the study. The tumor site was identified by TORS in 34 of 47 patients (72.3%). The primary site was located in the base of tongue for 20 patients (58.8%) and the palatine tonsil for 13 patients (38.2%), with 1 patient having a primary site in both the base of tongue and the palatine tonsil. Suspicious physical examination findings were present in 23 of 47 patients (48.9%), with positive and negative predictive values of 56.5% and 25.0%, respectively. Of those who underwent any imaging, 16 patients had suspicious findings, with positive and negative predictive values of 50.0% and 16.7%, respectively. In 18 of 47 patients (38.3%), both preoperative radiographic and physical examination failed to suggest a primary site. Of these 18 patients, 13 (72.2%) were identified after undergoing TORS. CONCLUSIONS AND RELEVANCE We demonstrate that TORS is a useful approach to identify and treat the primary site in patients with HNSCC who present with an unknown primary site.

Functional Kinomics Identifies Candidate Therapeutic Targets in Head and Neck Cancer

Purpose: To identify novel therapeutic drug targets for p53-mutant head and neck squamous cell carcinoma (HNSCC). Experimental Design: RNAi kinome viability screens were performed on HNSCC cells, including autologous pairs from primary tumor and recurrent/metastatic lesions, and in parallel on murine squamous cell carcinoma (MSCC) cells derived from tumors of inbred mice bearing germline mutations in Trp53, and p53 regulatory genes: Atm, Prkdc, and p19Arf. Cross-species analysis of cell lines stratified by p53 mutational status and metastatic phenotype was used to select 38 kinase targets. Both primary and secondary RNAi validation assays were performed on additional HNSCC cell lines to credential these kinase targets using multiple phenotypic endpoints. Kinase targets were also examined via chemical inhibition using a panel of kinase inhibitors. A preclinical study was conducted on the WEE1 kinase inhibitor, MK-1775. Results: Our functional kinomics approach identified novel survival kinases in HNSCC involved in G2–M cell-cycle checkpoint, SFK, PI3K, and FAK pathways. RNAi-mediated knockdown and chemical inhibition of the WEE1 kinase with a specific inhibitor, MK-1775, had a significant effect on both viability and apoptosis. Sensitivity to the MK-1775 kinase inhibitor is in part determined by p53 mutational status, and due to unscheduled mitotic entry. MK-1775 displays single-agent activity and potentiates the efficacy of cisplatin in a p53-mutant HNSCC xenograft model. Conclusions: WEE1 kinase is a potential therapeutic drug target for HNSCC. This study supports the application of a functional kinomics strategy to identify novel therapeutic targets for cancer. Clin Cancer Res; 20(16); 4274–88. ©2014 AACR.