Cancer of the base of the tongue: past and future

Squamous–columnar junction of Von Ebner’s glands may be a significant origin of squamous cell carcinomas in the base of the tongue

Objectives

The histological origin of base of the tongue (BOT) carcinomas is still elusive, and most studies have been focusing on the lingual tonsil. In this study, we sought to identify the existence of the squamous–columnar junction (SCJ) in the human Von Ebner’s glandular duct and explored the potential of that in forming squamous cell carcinomas in BOT.

Materials and methods

The specific genomes of BOT carcinoma were acquired and screened out by The Cancer Genome Atlas (TCGA) database analysis. The 4-nitroquinoline-1-oxide (4-NQO)-treated mouse model was used to explore the transformation of SCJ during cancerization. We used immunohistochemistry to confirm the characteristics of SCJ in human Von Ebner’s gland, which were further compared with those in the anus and cervix.

Results

The SCJ in the human Von Ebner’s glandular duct was found to be similar to that of the cervix and anus. The transformation zone in the 4-NQO-treated mouse model had a multilayered epithelium structure similar to that of HPV16-transgenic mice. In human, the transformation zone of Von Ebner’s gland is also similar to that of the cervix and anus.

Conclusion

It is the first time that the existence of SCJ in the opening of the human Von Ebner’s glandular duct was confirmed. The SCJ of Von Ebner’s glands may be a significant origin of squamous cell carcinomas in BOT.

The readiness of dentists to use the autofluorescence method

Background. Head and neck squamous cell carcinoma are the sixth most common cancer in prevalence rate. Early diagnosis significantly reduces morbidity and mortality. Autofluorescence facilitates diagnosis the disease at the early stages, but it depends on the doctor’s skill in interpreting images. The aim of the study: to analyze the results of reading autofluorescence images of the oral mucosa by dentists.Materials and methods. The results of reading 10 autofluorescence images of potentially malignant diseases of the oral mucosa and 10 images of benign lesions and conditions were evaluated. The study involved 308 dentists. The assessment of the ability to recognize autofluorescence images was carried out with respect to gender, age, length of service, qualification category, academic degree, position of the head of the department.Results. On the average, dentists correctly differentiated the results of visualization of potentially malignant diseases of the oral mucosa in 3.85 ± 2.47 cases, benign lesions together with other benign conditions – in 4.56 ± 2.47 cases. Images of benign lesions and conditions were identified by dentists better than images of potentially malignant diseases of the oral mucosa (t = –17.0; p < 0.001). There is a direct correlation between the correct differentiation of visualization of potentially malignant diseases of the oral mucosa with the correct interpretation of benign lesions and conditions (r = 0.956; p < 0.001). The interpretation of potentially malignant diseases of the oral mucosa is not related to gender (t = –1.62; p = 0.306), work experience (r = –0.002; p = 0.977), department head (t = –0.11; p = 0.910), qualification category (t = –0.50; p = 0.574), academic degree (t = –0.34; p = 0.731).Conclusion. Dentists cannot recognize diseases of the oral mucosa well in autofluorescence images. The recognition skill is not related to general professional development.

Coexisting overexpression of STOML1 and STOML2 proteins may be associated with pathology of oral squamous cell carcinoma

OBJECTIVE

The present study aimed to investigate the expression and co-localization of stomatin-like protein-1 (STOML1) and stomatin-like protein-2 (STOML2) in oral squamous cell carcinoma (OSCC) tissues in situ and evaluate their pathologic roles in OSCC.

STUDY DESIGN

STOML1 and STOML2 in human OSCC tissues (n = 109) and normal oral/paracancerous tissues (n = 19) were detected by using multiple immunohistochemistry (IHC) staining. Positive staining scores and clinicopathologic features during the OSCC process were analyzed.

RESULTS

STOML1 and STOML2 were significantly overexpressed in OSCC tissues compared with normal oral tissue/paracancerous tissues (P < .0001 and P < .0001, respectively). Furthermore, both STOML1 and STOML2 were positively associated with pathologic tumor (T) stages. Positive signals of both STOML1 and STOML2 were mainly localized to the cell membrane and the cytoplasm, whereas those of STOML1 were also expressed in the cell nucleus.

CONCLUSIONS

Our results indicated that overexpression of STOML1 and STOML2 was significantly associated with T1 and T2 stages of OSCC. STOML1 and STOML2 were mainly co-localized at the cell membrane and the cytoplasm. These findings suggested that either STOML1 or STOML2 may play critical roles in OSCC development and may serve as potential diagnostic biomarkers and therapeutic targets.

ERK Activation Modulates Cancer Stemness and Motility of a Novel Mouse Oral Squamous Cell Carcinoma Cell Line

We established the NHRI-HN1 cell line from a mouse tongue tumor induced by 4-nitroquinoline 1-oxide (4-NQO)/arecoline, with further selection for cell stemness via in vitro sphere culture, to evaluate potential immunotherapies for oral squamous cell carcinoma (OSCC) in East and Southeast Asia. In vivo and in vitro phenotypic characterization, including tumor growth, immune modulator administration, gene expression, morphology, migration, invasion, and sphere formation assays, were conducted. NHRI-HN1 cells are capable of generating orthotopic tumors in syngeneic mice. Interestingly, immune stimulation via CpG oligodeoxynucleotide (CpG-ODN) dramatically reduced the tumor growth in NHRI-HN1 cell-injected syngeneic mice. The pathways enriched in genes that were differentially expressed in NHRI-HN1 cells when compared to non-tumorigenic cells were similar to those that were identified when comparing human OSCC and non-tumorous tissues. NHRI-HN1 cells have characteristics of epithelial-mesenchymal transition (EMT), including enhanced migration and invasion. NHRI-HN1 cells showed aggressive cell growth and sphere formation. The blockage of extracellular signal-regulated kinase (ERK) activation suppressed cell migration and reduced stemness characteristics in NHRI-HN1 cells, similar to human OSCC cell lines. Our data suggest that NHRI-HN1 cells, showing tumorigenic characteristics of EMT, cancer stemness, and ERK activation, are sufficient in modeling human OSCC and also competent for use in investigating oral cancer immunotherapies.

Monocarboxylate Transporter 4 (MCT4) Knockout Mice Have Attenuated 4NQO Induced Carcinogenesis; A Role for MCT4 in Driving Oral Squamous Cell Cancer

Head and neck squamous cell carcinoma (HNSCC) is the 6th most common human cancer and affects approximately 50,000 new patients every year in the US. The major risk factors for HNSCC are tobacco and alcohol consumption as well as oncogenic HPV infections. Despite advances in therapy, the overall survival rate for all-comers is only 50%. Understanding the biology of HNSCC is crucial to identifying new biomarkers, implementing early diagnostic approaches and developing novel therapies. As in several other cancers, HNSCC expresses elevated levels of MCT4, a member of the SLC16 family of monocarboxylate transporters. MCT4 is a H+-linked lactate transporter which functions to facilitate lactate efflux from highly glycolytic cells. High MCT4 levels in HNSCC have been associated with poor prognosis, but the role of MCT4 in the development and progression of this cancer is still poorly understood. In this study, we used 4-nitroquinoline-1-oxide (4NQO) to induce oral cancer in MCT4-/- and wild type littermates, recapitulating the disease progression in humans. Histological analysis of mouse tongues after 23 weeks of 4NQO treatment showed that MCT4-/- mice developed significantly fewer and less extended invasive lesions than wild type. In mice, as in human samples, MCT4 was not expressed in normal oral mucosa but was detected in the transformed epithelium. In the 4NQO treated mice we detected MCT4 in foci of the basal layer undergoing transformation, and progressively in areas of carcinoma in situ and invasive carcinomas. Moreover, we found MCT4 positive macrophages within the tumor and in the stroma surrounding the lesions in both human samples of HNSCC and in the 4NQO treated animals. The results of our studies showed that MCT4 could be used as an early diagnostic biomarker of HNSCC. Our finding with the MCT4-/- mice suggest MCT4 is a driver of progression to oral squamous cell cancer and MCT4 inhibitors could have clinical benefits for preventing invasive HNSCC.

Current mouse models of oral squamous cell carcinoma: Genetic and chemically induced models

Oral squamous cell carcinoma (OSCC) patients have a low 5-year survival rate and poor prognosis. To improve survival and prognosis, the causes and processes involved in lesion development should be evaluated. For this purpose, the use of OSCC mouse models, such as chemically induced mouse models, genetically modified mouse models, and transplanted (xenograft) models, is crucial. These OSCC models exhibit both advantages and disadvantages when studying OSCC development and progression. Until a model resembling human OSCC is developed, both the advantages and disadvantages of each model should be carefully considered. In this review, we discuss OSCC mouse models and their use in cancer research worldwide.

Survival and Functional Outcome after Treatment for Primary Base of Tongue Cancer: A Comparison of Definitive Chemoradiotherapy versus Surgery Followed by Adjuvant Radiotherapy

Purpose

The purpose of this study was to compare the clinical and functional outcomes in patients with primary base of tongue (BOT) cancer who received definitive radiotherapy (RT) or surgery followed by radiotherapy (SRT).

Materials and Methods

Between January 2002 and December 2016, 102 patients with stage I-IVB primary BOT cancer underwent either definitive RT (n=46) or SRT (n=56), and treatment outcomes were compared between two groups. The expression of p16 was also analyzed.

Results

The RT group had more patients with advanced T stage (T3-4) disease (58.7% vs. 35.7%, p=0.021) and who received chemotherapy (91.3% vs. 37.5%, p < 0.001) than the SRT group. At a median follow up of 36.9 months (range, 3.3 to 181.5 months), the 5-year overall survival (OS) and disease-free survival (DFS) were 75.5% and 68.7%, respectively. With respect to treatment group, the 5-year OS and DFS in the RT and SRT groups did not differ significantly (OS, 68.7% vs. 80.5%, p=0.601; DFS, 63.1% vs. 73.1%, p=0.653). In multivariate analysis, OS differed significantly according to p16 expression (p16-negative vs. p16-positive; hazard ratio [HR], 0.145; 95% confidence interval [CI], 0.025 to 0.853; p=0.033). Regarding DFS, p16 expression (p16-negative vs. p16-positive; HR, 0.164; 95% CI, 0.045 to 0.598; p=0.006) showed a significant effect in multivariate analysis. Functional defects (late grade ≥ 3 dysphagia or voice alteration) were more frequently reported in the SRT than in the RT group (16.1% vs. 2.2%, p=0.021).

Conclusion

Despite advanced disease, patients in the RT group showed comparable survival outcomes and better functional preservation than those in the SRT group.

Salivary miR-93 and miR-200a as post-radiotherapy biomarkers in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma is the 6th most malignant tumor entity worldwide and has exhibited a 5-year mortality of approximately 50% for the last fifty years. For the therapy monitoring and successful management of this tumor entity new and easily accessible biomarkers are greatly needed. The aim of the study was to determine whether and to what extent microRNAs, a class of small regulatory RNAs, are detectable in saliva post-radiation therapy. The expression and feasibility as therapy monitoring marker of the microRNAs were analyzed by RT-qPCR in 83 saliva samples from 33 patients collected at several time points pre-, during and post-radiotherapy treatment. Ten head and neck squamous cell carcinoma- or radiation-associated microRNAs (miR-93, miR-125a, miR-142-3p, miR-200a, miR-203, miR-213, let-7a, let-7b, let-7g and let-7i) were analyzed. All were detectable to a different extent in the saliva of the patients. miR-93 and miR-200a were significantly higher expressed 12 months post-radiotherapy than at baseline (p=0.047 and p=0.036). These results point towards miR-93 and miR-200a as biomarkers for the treatment monitoring post-radiation of head and neck squamous cell carcinoma.

Portable LED-induced autofluorescence spectroscopy for oral cancer diagnosis

Oral cancer is a serious and growing problem in many developing and developed countries. To improve the cancer screening procedure, we developed a portable light-emitting-diode (LED)-induced autofluorescence (LIAF) imager that contains two wavelength LED excitation light sources and multiple filters to capture ex vivo oral tissue autofluorescence images. Compared with conventional means of oral cancer diagnosis, the LIAF imager is a handier, faster, and more highly reliable solution. The compact design with a tiny probe allows clinicians to easily observe autofluorescence images of hidden areas located in concave deep oral cavities. The ex vivo trials conducted in Taiwan present the design and prototype of the portable LIAF imager used for analyzing 31 patients with 221 measurement points. Using the normalized factor of normal tissues under the excitation source with 365 nm of the central wavelength and without the bandpass filter, the results revealed that the sensitivity was larger than 84%, the specificity was not smaller than over 76%, the accuracy was about 80%, and the area under curve of the receiver operating characteristic (ROC) was achieved at about 87%, respectively. The fact shows the LIAF spectroscopy has the possibilities of ex vivo diagnosis and noninvasive examinations for oral cancer.

American Brachytherapy Society Task Group Report: Combined external beam irradiation and interstitial brachytherapy for base of tongue tumors and other head and neck sites in the era of new technologies

Irradiation plays an important role in the treatment of cancers of the head and neck providing a high locoregional tumor control and preservation of organ functions. External beam irradiation (EBI) results in unnecessary radiation exposure of the surrounding normal tissues increasing the incidence of side effects (xerostomy, osteoradionecrosis, and so forth). Brachytherapy (BT) seems to be the best choice for dose escalation over a short treatment period and for minimizing radiation-related normal tissue damage due to the rapid dose falloff around the source. Low-dose-rate BT is being increasingly replaced by pulsed-dose-rate and high-dose-rate BT because the stepping source technology offers the advantage of optimizing dose distribution by varying dwell times. Pulsed-dose and high-dose rates appear to yield local control and complication rates equivalent to those of low-dose rate. BT may be applied alone; but in case of high risk of nodal metastases, it is used together with EBI. This review presents the results and the indications of combined BT and EBI in carcinoma of the base of tongue and other sites of the head and neck region, as well as the role BT plays among other-normal tissue protecting-modern radiotherapy modalities (intensity-modulated radiotherapy, stereotactic radiotherapy) applied in these localizations.

Treatment outcomes of external-beam radiotherapy for squamous cell carcinoma of the base of the tongue

PURPOSE

To evaluate definitive external-beam radiotherapy (EBRT) for patients with base of the tongue (BOT) cancers.

METHODS

We reviewed results for 26 patients with BOT cancers who were treated with EBRT. Clinical stages T1, T2, T3, and T4a were observed for 10, 7, 4, and 5 patients, respectively, and stages N0, N1, N2a, N2b, N2c, and N3 were observed for 4, 2, 5, 6, 8, and 1 patients, respectively. More than half of the patients (n = 19) were stage IVA. Standard total delivered doses were 70 Gy to primary tumors and cervical lymph node (CLN) metastases and 40-46 Gy to elective nodal regions. Eleven patients with advanced loco-regional disease received concurrent or neoadjuvant chemotherapy. Four T3 patients and one T2 patient received 2 or 3 cycles of concurrent intra-arterial cisplatin with EBRT (RADPLAT).

RESULTS

Three-year overall survival was 69 % (95 % CI 47-83 %), with a median follow-up period of 33 months. Three-year local control was 100, 86, 100, and 20 % for T1, T2, T3, and T4 patients, respectively. Three-year regional control was 100 % for N0, N1, and N2a, 83 % for N2b, 75 % for N2c, and 0 % for N3 patients. Treatment failed for 7 patients. All 5 patients undergoing RADPLAT achieved complete responses and did not develop local recurrence.

CONCLUSIONS

We achieved favorable outcomes for patients with T1-T3 BOT cancers by use of definitive EBRT with or without chemotherapy.

Recurrent genomic alterations in sequential progressive leukoplakia and oral cancer: drivers of oral tumorigenesis?

A significant proportion (up to 62%) of oral squamous cell carcinomas (OSCCs) may arise from oral potential malignant lesions (OPMLs), such as leukoplakia. Patient outcomes may thus be improved through detection of lesions at a risk for malignant transformation, by identifying and categorizing genetic changes in sequential, progressive OPMLs. We conducted array comparative genomic hybridization analysis of 25 sequential, progressive OPMLs and same-site OSCCs from five patients. Recurrent DNA copy number gains were identified on 1p in 20/25 cases (80%) with minimal, high-level amplification regions on 1p35 and 1p36. Other regions of gains were frequently observed: 11q13.4 (68%), 9q34.13 (64%), 21q22.3 (60%), 6p21 and 6q25 (56%) and 10q24, 19q13.2, 22q12, 5q31.2, 7p13, 10q24 and 14q22 (48%). DNA losses were observed in >20% of samples and mainly detected on 5q31.2 (35%), 16p13.2 (30%), 9q33.1 and 9q33.29 (25%) and 17q11.2, 3p26.2, 18q21.1, 4q34.1 and 8p23.2 (20%). Such copy number alterations (CNAs) were mapped in all grades of dysplasia that progressed, and their corresponding OSCCs, in 70% of patients, indicating that these CNAs may be associated with disease progression. Amplified genes mapping within recurrent CNAs (KHDRBS1, PARP1, RAB1A, HBEGF, PAIP2, BTBD7) were selected for validation, by quantitative real-time PCR, in an independent set of 32 progressive leukoplakia, 32 OSSCs and 21 non-progressive leukoplakia samples. Amplification of BTBD7, KHDRBS1, PARP1 and RAB1A was exclusively detected in progressive leukoplakia and corresponding OSCC. BTBD7, KHDRBS1, PARP1 and RAB1A may be associated with OSCC progression. Protein–protein interaction networks were created to identify possible pathways associated with OSCC progression.

Robotic surgery for oropharynx cancer: promise, challenges, and future directions

Epidemiologic studies have shown a rise in the incidence of oropharyngeal cancer without a corresponding increase in oral cavity cancers. These diverging trends are explained by human papilloma virus, which preferentially affects the oropharynx. Cancers resulting from this viral infection bear a better prognosis than those that are smoking-related. Treatment of oropharyngeal cancers has typically involved the use of radiation and chemotherapy to avoid the morbidity of mandibular splitting surgery. The use of transoral robotic surgery (TORS) has obviated the need for large-scale open approaches but still provides the pathologic staging data that is unavailable from non-surgical approaches. Although TORS is in its infancy, early functional and oncologic outcome data are promising. The complex management of oropharyngeal cancers should utilize the available treatment modalities to optimize outcomes and stratify patients to different treatment based on risk status.

Improved survival among patients with base of tongue and tonsil cancer in the United States

OBJECTIVE

To examine if survival has changed over the last 20 years in patients with base of tongue and tonsil cancers in the United States.

METHODS

Using SEER data, we employed Kaplan-Meier method to draw survival curves and calculate survival rates, and estimated adjusted hazard ratios (HR).

RESULTS

From the 1980s to the 2000s, the 5-year overall survival rates statistically significantly improved by 100% from 25 to 51% among patients with one primary base of tongue cancer and 28-60% among those with one primary tonsil cancer (p values for trend <0.001). In addition, the 5-year cancer-specific survival improved by 222.4 and 276%, respectively, among two types of patients. Survival improvement was more pronounced among male patients than among female patients regardless of young or old age, while the improvement was generally consistent among patients with different tumor stages and treatment methods. In contrast, however, those patients with subsequent multiple cancers showed no improvement in overall survival over time.

CONCLUSIONS

The survival of patients with base of tongue and tonsil cancer has significantly improved over the last decades in the United States. Whether the improvement is associated with HPV infection, screening, or early detection is worthy to study in future.

Efficacy of tissue autofluorescence imaging (VELScope) in the visualization of oral mucosal lesions

BACKGROUND

Technology that highlights potentially malignant oral lesions in a highly sensitive and specific manner will aid clinicians in early diagnosis of these conditions. This study assessed the efficacy of direct tissue autofluorescence imaging Visually Enhanced Lesion Scope (VELScope) in the detection of oral mucosal lesions.

METHODS

One hundred twelve patients referred with a potentially malignant oral mucosal lesion were examined under routine incandescent light, and then with VELScope, noting loss of autofluorescence and presence of blanching. Incisional biopsies were performed to provide definitive histopathological diagnoses.

RESULTS

VELScope enhanced the visibility of 41 lesions and helped uncover 5 clinically undetected lesions. VELScope examination alone showed a sensitivity of 30% and a specificity of 63%. Its accuracy at identifying dysplasia was 55%.

CONCLUSION

VELScope examination cannot provide a definitive diagnosis regarding the presence of epithelial dysplasia. Loss of autofluorescence is not useful in diagnosing epithelial dysplasia in its own right without relevant clinical interpretation.

Chemoradiotherapy for locoregionally advanced squamous cell carcinoma of the base of tongue

BACKGROUND

Our aim was to report the outcomes of base of tongue cancers treated with chemoradiotherapy.

METHODS

Between 1990 and 2004, 127 patients with stage III or IV base of tongue cancer were treated with chemoradiotherapy on protocol. Indications included nodal involvement, T3/T4 tumors, positive margins, those patients refusing surgery, or were medically inoperable. The most common regimen was paclitaxel (100 mg/m2 on day 1), infusional 5-fluorouracil (600 mg/m2/day × 5 days), hydroxyurea (500 mg prescribed orally [PO] 2 × daily [BID]), and 1.5 Gy twice daily irradiation followed by a 9-day break without treatment.

RESULTS

Median follow-up was 51 months. The median dose to gross tumor was 72.5 Gy (range, 40-75.5 Gy). Five-year locoregional progression-free survival, overall survival, and disease-free survival was 87.0%, 58.2%, and 46.0%, respectively.

CONCLUSION

Concurrent chemoradiotherapy results in promising locoregional control for base of tongue cancer. As distant relapse was common, further investigation of systemic therapy with novel agents may be warranted.

Mutational analyses of the BRAF, KRAS, and PIK3CA genes in oral squamous cell carcinoma

OBJECTIVES

The development of oral squamous cell carcinoma (OSCC) is a complex, multistep process. To date, numerous oncogenes and tumor-suppressor genes have been implicated in oral carcinogenesis. Of particular interest in this regard are genes involved in cell cycling and apoptosis, such BRAF, KRAS, and PIK3CA genes.

STUDY DESIGN

Mutations of BRAF, KRAS, and PIK3CA were evaluated by direct genomic sequencing of exons 1 of KRAS, 11 and 15 of BRAF, and 9 and 20 of PIK3CA in OSCC specimens.

RESULTS

Both BRAF and KRAS mutations were detected with a mutation frequency of 2% (1/42). PIK3CA mutations were detected at 3% (1/35).

CONCLUSIONS

This is the first report implicating BRAF mutation in OSCC. Our study supports that mutations in the BRAF, KRAS, and PIK3CA genes make at least a minor contribution to OSCC tumorigenesis, and pathway-specific therapies targeting these 2 pathways should be considered for OSCC in a subset of patients with these mutations.

Recent advances in managing human papillomavirus-positive oropharyngeal tumors

Human papillomavirus (HPV) is detected in a subset of patients with head and neck squamous cell carcinoma, most frequently in tumors in the Waldeyer's ring (palatine tonsil and base of tongue). Several studies suggest that patients with HPV-positive tumors have better survival with either concurrent chemoradiation therapy or surgery followed by radiation compared with HPV-negative patients. However, some possible confounding clinicopathologic variables may challenge the validity of this statement, for example, some authors used the TNM (tumor, node, metastasis) grouping stage while others used the primary tumor (T stage), and other studies have demonstrated that tumors with advanced T stage were less likely to be infected with HPV. A large clinical trial with stratification of patients according to all known tumor prognostic factors is crucial to solve the question.

Transoral resection of tonsillar squamous cell carcinoma

OBJECTIVES

The tonsillar fossa is the most common subsite of the oropharynx to be afflicted with squamous cell carcinoma (SCCA). Accepted treatments include any combination of surgery, radiotherapy, and chemotherapy. We review the oncologic and functional outcomes of patients with tonsillar carcinoma who underwent transoral tumor resection and neck dissection with or without postoperative radiotherapy or chemoradiotherapy.

STUDY DESIGN

Retrospective chart review.

METHODS

From 1996 through January 2005, 102 patients with tonsillar SCCA underwent transoral resection. Overall survival, disease-specific survival, local control, and locoregional control rates were analyzed using the Kaplan-Meier method. Immediate and long-term speech and swallowing function and treatment-related morbidity were analyzed.

RESULTS

Twenty-six patients had surgery only, 71 had surgery and radiotherapy, and five had surgery and chemoradiotherapy. Twenty patients had stage III disease, 63 had stage IVA disease, and two had stage IVB disease. The Kaplan-Meier overall survival estimate was 92.2% at 2 years and 85.0% at 5 years. The 5-year local control estimate was 91.8%, and the 5-year Kaplan-Meier disease-specific survival estimate was 93.9%. The median hospital stay was 3 days. Tracheostomy was required for 14 patients, and 13 of these patients had decannulation. Temporary feeding tubes were placed in 35 patients. Sixteen patients received a percutaneous endoscopic gastrostomy tube; of these, 12 had the tubes removed.

CONCLUSIONS

Transoral resection of tonsillar SCCA with or without postoperative adjuvant therapy provided excellent locoregional control and minimized treatment-related morbidity. We believe that transoral resection is the optimal treatment for patients with oropharyngeal SCCA.

Amplification and overexpression of PPFIA1, a putative 11q13 invasion suppressor gene, in head and neck squamous cell carcinoma

Chromosomal amplifications of the 11q13 genomic region are frequent in head and neck squamous cell carcinoma (HNSCC). To identify novel 11q13 amplification targets, we integrated high-resolution array-based comparative genomic hybridization and Affymetrix gene-expression profiling of eight HNSCC cell lines. We found that PPFIA1 was the highest upregulated gene in the 11q13 amplicon of HNSCC cell lines when compared with HNSCC lines without 11q13 amplification and confirmed the upregulation of PPFIA1 in primary HNSCCs by real-time PCR. Using siRNA knockdown, we investigated PPFIA1 function in three HNSCC lines using both in vitro invasion assays and wound-healing assays. Surprisingly, we found that cancer cells become more invasive when the PPFIA1 protein levels were reduced, suggesting that PPFIA1 may act as an invasion inhibitor in HNSCC. This unexpected result suggests that the 11q13 amplicon may comprise both positive and negative regulators involved in HNSCC. Our study is the first to evaluate the role of PPFIA1 in head and neck carcinogenesis and suggests a potential link between PPFIA1 activity and cell-extracellular matrix interactions. This article contains supplementary material available via the Internet at http://www.interscience.wiley.com/jpages/1045-2257/suppmat.

Cytokeratin fragments in the serum: their utility for the management of oral cancer

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy and is a major cause of cancer morbidity and mortality worldwide. Oral cancer is the most predominant malignancy in the Indian subcontinent due to the widespread habits of chewing tobacco and related products. Patients with oral tumours have a high risk of early locoregional relapse. Early detection of disease progression remains a challenging task mainly due to the lack of adequate early prognostic markers. CEA, SCC Ag, CA-125, serum cytokeratin (CK) fragments, Cyfra 21-1 (CK 19), TPS (CK 18), TPA (CK 8, 18, and 19) etc. are being used as serum markers for the prediction of prognosis of various malignancies. This review presents the available literature on serum CK markers in different malignancies evaluates their utility in the management of oral cancer, and identifies the lacunae which need to be addressed to develop sensitive and specific assays for early detection of recurrence, prognosis, and treatment monitoring.

Are we influencing outcome in oropharynx cancer with intensity-modulated radiotherapy? An inter-era comparison

PURPOSE

To analyze the outcome in all oropharynx cancer patients treated at the University of Wisconsin during 1995-2005 and highlight the methodologic challenge in comparing outcome after intensity-modulated radiotherapy (IMRT) with that of historical controls.

METHODS AND MATERIALS

Outcomes were compared in 195 oropharynx cancer patients after definitive radiotherapy with curative intent in the pre-IMRT era (pre-IMRT, n = 105), after IMRT (IMRT+, n = 52) or after non-IMRT techniques during the IMRT era (IMRT-, n = 38).

RESULTS

With a median follow-up of 30.4 months, the 3-year overall survival rate in IMRT+, IMRT-, and pre-IMRT patients was 88.2%, 81.1%, and 67.7%, respectively; and for locoregional control was 96.1%, 78.1%, and 81.1%. Patients from the IMRT era more frequently received concurrent chemotherapy (67% vs. 6%, p < 0.001) and underwent adjuvant neck dissection (52% vs. 29%, p = 0.002). Patients with T3-4 disease and bilateral neck disease were significantly less likely to receive IMRT. Cox regression analysis identified IMRT as a significant prognostic factor (p = 0.04); however, after including T stage in the model, IMRT lost independent significance (p = 0.2). Analysis of a potential effect of IMRT on Grade 3+ mucositis or skin reaction was also hampered by the change in other treatment characteristics.

CONCLUSIONS

Outcomes in oropharynx cancer have improved at our institution since the introduction of IMRT. However, multiple factors have contributed to this improvement, and presentation of IMRT outcomes without the full context of historical and contemporary controls may yield data that overstate outcome after IMRT.

Treatment results for 84 patients with base of tongue cancer

CONCLUSIONS

For T2 tumors, surgery was indicated if functional preservation was possible. For T3/T4 tumors, the rate of primary disease control was not high and surgery frequently involved total laryngectomy. Points that surgeons must heed when performing such surgery were delineated.

OBJECTIVES

Because tumors originating from the base of the tongue are rare, few large-scale studies of such tumors have been performed. We reviewed treatments and outcomes at our department to establish effective future therapeutic plans.

PATIENTS AND METHODS

From 1971 to 2000, 84 patients with previously untreated and resectable squamous cell carcinoma of the base of the tongue were treated at the Head and Neck Department of the Cancer Institute Hospital, Tokyo. Treatment selection and results were investigated.

RESULTS

The main treatment options were radiotherapy for primary lesions < or = T2 and surgery for primary lesions > or = T3. Overall disease-specific 5-year cumulative survival rate was 59.8%, but there was no significant difference in survival rate at each stage between the two treatments. Among patients who died of the primary disease, the area that was most difficult to control was the superior margin of the lateral wall of the oropharynx (n=7). The incidence of contralateral or retropharyngeal lymph node metastasis was low if tumors neither crossed the midline nor infiltrated the lateral wall. While total laryngectomy was performed on 48 patients, the larynx was operatively preserved in 5 T3 patients and one T4 patient.

Treatment of oropharyngeal squamous cell carcinoma with external beam radiation combined with interstitial brachytherapy

BACKGROUND

We reviewed the outcomes of oropharyngeal squamous cell carcinoma treated with external beam radiation and interstitial brachytherapy.

METHODS

Ninety patients with squamous cell carcinoma of the oropharynx were treated with interstitial brachytherapy at the University of Utah between 1984 and 2001. Seventy-two patients received external beam radiotherapy (EBRT) followed by brachytherapy boost, 11 had surgery followed by EBRT and brachytherapy, 4 had surgery and brachytherapy, and 3 were treated with brachytherapy alone. Median doses for EBRT and brachytherapy were 50 and 24 Gy, respectively.

RESULTS

Median follow-up after brachytherapy was 48.3 months for all patients. Five-year local control, disease-free survival, and overall survival were 76%, 61%, and 55%. For T1, T2, T3, and T4, 5-year local control rates were 83%, 79%, 79%, and 64%, respectively. Severe complications occurred in 13 patients, including 2 treatment-related deaths.

CONCLUSIONS

EBRT combined with interstitial brachytherapy provide good local control rates for locally advanced oropharyngeal squamous cell carcinoma.

Carcinoma of the Tongue Base Treated by Transoral Laser Microsurgery, Part One: Untreated Tumors, a Prospective Analysis of Oncologic and Functional Outcomes

OBJECTIVES

To report the oncologic and functional outcomes of transoral laser microsurgery (TLM) in the management of untreated primary carcinoma of the tongue base.

STUDY DESIGN

A two center prospective case series analysis.

METHODS

Fifty-nine patients with pathologically confirmed squamous cell carcinoma of the tongue base were treated with TLM between 1997 and 2005. The pathological T stage distribution was: T1, 16; T2, 23; T3, 12 and T4, 8. Thirty-six patients presented with stage IV disease, 12 with stage III, 7 with stage II and 4 with stage I disease. Neck dissections were performed in 49 patients (83%). Twenty-eight patients (47%) underwent adjuvant radiotherapy. End points analyzed were local control, loco regional control, disease specific survival, and overall survival. Organ function was assessed before and after treatment using a clinical Functional Outcome Swallowing Scale (FOSS) and Communication Scale (CS) staging system.

RESULTS

The mean follow up for all patients was 31 months. The 2 and 5-year Kaplan-Meier estimates were: local control, both 90%; loco-regional control, both 88%; recurrence free survival, both 84% and overall survival 91% and 69% respectively. For all patients the median stay in hospital was 4 days. The median length of hospital visit for TLM alone was 2.5 days and 4 days for TLM with neck dissection. Three patients (5%) suffered minor post-operative hemorrhage. The median pre-operative FOSS stage was 0 (normal function.) The median post-operative FOSS stage was stage 1 (Normal function with episodic or daily symptoms of dysphagia.) There were no clinically significant changes in communication function after treatment.

CONCLUSIONS

Transoral laser surgery is a safe and effective treatment for select early and advanced previously untreated squamous cell cancer of the tongue base. In addition, the low morbidity and mortality and shortened duration of hospitalization associated with TLM make it an attractive therapeutic alternative.

Fragile Histidine Triad Expression in Oral Squamous Cell Carcinoma and Precursor Lesions

PURPOSE

Fragile histidine triad (FHIT) expression in precursor oral lesions (POL) and oral squamous cell carcinomas (OSCC) was studied with regard to (a) the frequency of loss of FHIT expression, (b) whether loss of FHIT expression correlates with degree of dysplasia in POLs, (c) whether FHIT loss predicts high-risk POLs that are more likely to transform, and (d) whether FHIT loss in OSCCs correlates with survival.

EXPERIMENTAL DESIGN

Ninety-four POLs and 86 OSCCs were immunostained for FHIT. Survival analysis was done for cases with validated clinical outcomes.

RESULTS

By optimizing the immunostaining protocol, we found that FHIT is expressed in a distinctive strong nuclear and weak cytoplasmic pattern in oral tissues. Loss of FHIT expression was found in 42 of 94 (45%) POLs and in 66 of 86 (77%) OSCCs. We observed a statistically significant positive correlation between frequency of FHIT loss and increasing grade of dysplasia (chi2=13.8; degrees of freedom=4; P=0.008). Loss of FHIT expression in POLs that progressed to malignancy was more frequent than in those that did not [17 of 25 (68%) versus 12 of 29 (41.4%), respectively]. This difference was statistically significant (chi2=3.8; degrees of freedom=1; P=0.046). In OSCCs, loss of FHIT staining indicated a worse prognosis (survival rate, 36.2%) than when positive FHIT staining was observed (survival rate, 50%), but the difference was not statistically significant (P=0.546, Kaplan-Meier, log-rank).

CONCLUSIONS

FHIT seems to localize to both nuclear and cytoplasmic domains. FHIT inactivation occurs early in oral carcinogenesis and may be useful molecular marker for progressive dysplastic oral lesions.

4-nitroquinoline-1-oxide induced experimental oral carcinogenesis

Human oral cancer is the sixth largest group of malignancies worldwide and single largest group of malignancies in the Indian subcontinent. Seventy percent of premalignant cancers appear from premalignant lesions. Only 8-10% of these lesions finally turn into malignancy. The appearance of these premalignant lesions is one distinct feature of human oral cancer. At present there is dearth of biomarkers to identify which of these lesions will turn into malignancy. Regional lymph node metastasis and locoregional recurrence are the major factors responsible for the limited survival of patients with oral cancer. Paucity of early diagnostic and prognostic markers is one of the contributory factors for higher mortality rates. Cancer is a multistep process and because of constrain in availability of human tissues from multiple stages of oral carcinogenesis including normal tissues, animal models are being widely used, aiming for the development of diagnostic and prognostic markers. A number of chemical carcinogens like coal tar, 20 methyl cholanthrene (20MC), 9,10-dimethyl-1,2-benzanthracene (DMBA) and 4-nitroquinoline-1-oxide (4NQO) have been used in experimental oral carcinogenesis. However, 4NQO is the preferred carcinogen apart from DMBA in the development of experimental oral carcinogenesis. 4NQO is a water soluble carcinogen, which induces tumors predominantly in the oral cavity. It produces all the stages of oral carcinogenesis and several lines of evidences suggest that similar histological as well as molecular changes are observed in the human system. In the present review an attempt has been made to collate the information available on mechanisms of action of 4NQO, studies carried out for the development of biomarkers and chemopreventives agents using 4NQO animal models.

Ablation of advanced tongue or base of tongue cancer and reconstruction with free flap: Functional outcomes

AIM

To evaluate the functional outcomes of patients who underwent total or nearly total glossectomy for advanced tongue or base of tongue cancer.

MATERIAL AND METHODS

We used the radial forearm free flap (RFFF), anterior lateral thigh flap (ALTF) or fibular osteocutaneous flap (FOCF) to reconstruct the oral defect after radical resection in 39 patients undergoing total or nearly total glossectomy with laryngeal preservation.

RESULTS

Good functional outcomes, measured by independent feeding, speech and swallowing were achieved in 35, 36 and 35 patients, respectively. The cumulative 4-year survival rates were 63.8% for tongue cancer and 42.9% for base of tongue cancer.

CONCLUSION

Reconstruction with free flaps is a feasible method to restore the functional outcomes in speech and deglutition among patients who undergo total or nearly total glossectomy with laryngeal preservation.

Oral cancer prevention and the evolution of molecular-targeted drug development

The multifaceted rationale for molecular-targeted prevention of oral cancer is strong. Oral cancer is a major global threat to public health, causing great morbidity and mortality rates that have not improved in decades. Oral cancer development is a tobacco-related multistep and multifocal process involving field carcinogenesis and intraepithelial clonal spread. Biomarkers of genomic instability, such as aneuploidy and allelic imbalance, can accurately measure the cancer risk of oral premalignant lesions, or intraepithelial neoplasia (IEN). Retinoid-oral IEN studies (eg, of retinoic acid receptor-beta, p53, genetic instability, loss of heterozygosity, and cyclin D1) have advanced the overall understanding of the biology of intraepithelial carcinogenesis and of preventive agent molecular mechanisms and targets-important advances for monitoring preventive interventions and assessing cancer risk and pharmacogenomics. Clinical management of oral IEN varies from watchful waiting to complete resection, although complete resection does not prevent oral cancer in high-risk patients. New approaches, such as interventions with molecular-targeted agents and agent combinations in molecularly defined high-risk oral IEN patients, are urgently needed to reduce the devastating worldwide consequences of oral cancer.

Management of cancer of the base of tongue

The management of base of tongue cancer has evolved steadily over time. Organ preservation with primary radiation therapy has produced excellent oncologic and functional outcomes. Concomitant chemotherapy has become important in patients with locoregionally advanced disease. Planned neck dissection after organ preservation therapy continues to be an integral step for regional control. This article reports the results of a literature review of base of tongue cancer emphasizing a multidisciplinary approach to obtain optimal results in terms of cure and quality of life.

Novel management of oral cancer: a paradigm of predictive oncology

The rationale for molecular-targeted prevention of oral cancer is strong. Oral cancer is a major global threat to public health with 300,000 new cases diagnosed worldwide on an annual basis. Notably, the great morbidity and mortality rates of this devastating disease have not improved in decades. Oral cancer development is a tobacco-related multistep and multifocal process involving field carcinogenesis and intraepithelial clonal spread. Biomarkers of genomic instability, such as aneuploidy and allelic imbalance, can accurately measure the cancer risk of oral premalignant lesions or intraepithelial neoplasia (IEN). Retinoid-oral IEN studies (e.g., retinoid acid receptor-beta, p53, genetic instability, loss of heterozygosity, and cyclin D1) have advanced the overall understanding of the biology of intraepithelial carcinogenesis and preventive agent molecular mechanisms and targets, important advances for monitoring preventive interventions, assessing cancer risk, and pharmacogenomics. Clinical management of oral IEN varies from watchful waiting to complete resection, although complete resection does not prevent oral cancer in high-risk patients. New approaches, such as interventions with molecular-targeted agents and agent combinations in molecularly defined high-risk oral IEN patients, are urgently needed to reduce the devastating worldwide consequences of oral cancer.

Quality of life following resection, free flap reconstruction and postoperative external beam radiotherapy for squamous cell carcinoma of the base of tongue1

This study was conducted to evaluate quality of life in a cohort of patients with squamous cell carcinoma of the tongue base, treated with primary surgery, reconstruction and postoperative radiotherapy. Twelve patients were assessed in a cross-sectional study using the University of Washington Quality of Life Instrument (UW-QOL). All patients underwent external beam irradiation following primary resection of their tumour and reconstruction. Patients on average reported their overall and health related QOL to be good. Functionally they had good pain control, speech intelligibility, activity and recreational levels. There were some limitations in chewing, swallowing and taste. The results suggest that surgical resection can offer good functional and overall QOL results for advanced tumours when combined with reconstruction. The morbidity associated with postoperative radiotherapy includes reduced swallowing, taste, saliva production and difficulty chewing.

Current philosophy on the management of cancer of the base of the tongue

Cancer of the base of the tongue is a challenging disease for the head and neck surgeon, radiation oncologist and medical oncologist. However, over the last 10-15 years, improved treatment strategies have evolved which offer patients high probability of loco-regional control, survival, and good quality of life. The ability to offer patients good oncologic and functional outcomes serves as a paradigm for the successful application of multidisciplinary care, and the emphasis on quality of life in head and neck cancer treatment. This review provides an overview of the treatment options that exist, their advantages and disadvantages, and hopefully provides proper guidelines for the current management of this challenging disease.

Neck dissection prior to radiation therapy for squamous cell carcinoma of tongue base

BACKGROUND

Squamous cell carcinoma of the tongue base can be treated with comparable control and survival rates when neck dissection (ND) is performed before radiation therapy (RT).

METHODS

Fourteen patients were treated between 1990 and 2000. Tumor stage on presentation was: T2, 6; T3, 4; T4, 4. Average radiation dose was 7,268 cGy. Follow-up ranged from 2 to 11 years (median, 50 months). Ten patients (71.4%) who presented with cervical metastases underwent neck dissection. All neck dissections were performed prior to RT.

RESULTS

The initial local control rate was 85.7%. The 10-year survival rate was 62.8%. Patients tolerated their procedure well and were ready for RT within 2 to 4 weeks.

CONCLUSIONS

Our preliminary data indicate that our treatment protocol results in control and survival rates which are comparable with other regimens. It is our impression that in contrast to patients undergoing ND after radiation, our patients tolerated their initial ND well and were better prepared for the second part of the treatment. Future studies will use quality-of-life research methods to study this aspect of the treatment protocol.

Surgical treatment of squamous cell carcinoma of the base of tongue

INTRODUCTION

Squamous cell carcinoma (SSC) of the tongue base has historically been shown to be associated with a poor prognosis. We reviewed our experience with primary surgery followed by postoperative radiation therapy (XRT) to determine the impact of our treatment protocols on outcome.

METHODS

We retrospectively reviewed the records of all patients presenting to the University of Pittsburgh with previously untreated SSC of the tongue base between 1980-1997. Patients who were treated nonoperatively were excluded from analysis. Surgical excision of the primary was performed with ipsilateral neck dissection. The contralateral neck was dissected when the primary lesion was located in the midline or for clinically positive contralateral neck nodes. Postoperatively, most patients (93%) received XRT to the primary site and neck. Adjuvant chemotherapy was offered if histologic signs of aggressive behavior were identified (multiple nodes or extracapsular spread).

RESULTS

Of 87 patients identified, 39 (45%) were initially seen with T1 or T2 tumors. Seventy-nine patients (91%) were initially seen with stage III or IV disease. Contralateral neck dissection was performed in 36 patients (41%). Metastatic disease was demonstrated in 84% of ipsilateral neck nodes and in 47% of contralateral neck nodes. Occult metastases were found in 61% of clinically N0 necks. Local recurrence occurred in 5 patients, regional recurrence occurred in 12 patients, and distant metastases developed in 22 patients. Overall and disease-specific survival rates at 5 years for all patients were 49% and 56%, respectively. The 5 year disease-specific survival rates for stage I, stage II, stage III, and stage IV disease were 100%, 86%, 62%, and 48%. The 5-year disease-specific survival rate was 88% for T1 lesions, 64% for T2 lesions, 58% for T3 lesions, and 30% for T4 lesions (p <.05, log-rank test).

CONCLUSIONS

Surgical treatment of SCC of the tongue base is highly effective in achieving local disease control and disease-free survival for early lesions. Because both functional outcome and survival are poor after surgical treatment of advanced lesions, we now offer brachytherapy with XRT or participation in a combined chemoradiation protocol rather than primary surgical therapy to patients with advanced disease. Prospective studies are needed to compare the effect of these organ-preserving therapies with traditional combined surgery and XRT to determine the effect on functional outcome and quality of life.

Comparison of histological grading and large-scale genomic status (DNA ploidy) as prognostic tools in oral dysplasia

Approximately one in ten oral white patches (leukoplakia) are histologically classified as dysplasia, with a well-documented potential for developing into oral squamous cell carcinoma (OSCC). Histological grading in oral dysplasia has limited prognostic value, whereas large-scale genomic status (DNA ploidy, nuclear DNA content) is an early marker of malignant transformation in several tissues. Biopsies from 196 patients with oral leukoplakia histologically typed as dysplasia were investigated. Inter-observer agreement among four experienced pathologists performing a simplified grading was assessed by Cohen's kappa values. For 150 of the 196 cases, it was also possible to assess large-scale genomic status and compare its prognostic impact with that of histological grading. Disease-free survival was estimated by life-table methods, with a mean follow-up time of 103 months (range 4-165 months). The primary considered end-point was the subsequent occurrence of OSCC. For grading of the total of 196 cases, kappa values ranged from 0.17 to 0.33 when three grading groups (mild, moderate, and severe dysplasia) were considered, and from 0.21 to 0.32 when two groups (low grade and high grade) were considered (p=0.41). For the 150 cases in which large-scale genomic status was also assessed, kappa values for the histological grading ranged from 0.21 to 0.33 for three grading groups and from 0.27 to 0.34 for two grading groups (p=0.47). In survival analysis, histological grading was without significant prognostic value for any of the four observers (p 0.14-0.44), in contrast to DNA ploidy (p=0.001). It is concluded that DNA ploidy in oral dysplasia has a practical prognostic value, unlike histological grading of the same lesions.

DNA content as a prognostic marker in patients with oral leukoplakia

BACKGROUND

Oral leukoplakia may develop into squamous-cell carcinoma, which has a poor prognosis. Risk factors for oral carcinoma have been identified, but there are no reliable predictors of the outcome in individual patients with oral leukoplakia.

METHODS

We identified 150 patients with oral leukoplakia that was classified as epithelial dysplasia and measured the nuclear DNA content (ploidy) of the lesions to determine whether DNA ploidy could be used to predict the clinical outcome. Biopsy specimens obtained at annual follow-up visits were graded histologically and classified with respect to DNA content in a blinded fashion. Disease-free survival was assessed in relation to DNA ploidy and the histologic grade. The mean duration of follow-up was 103 months (range, 4 to 165).

RESULTS

Among 150 patients with verified epithelial dysplasia, a carcinoma developed in 36 (24 percent). Of the 150 patients, 105 (70 percent) had diploid (normal) lesions, 20 (13 percent) had tetraploid (intermediate) lesions, and 25 (17 percent) had aneuploid (abnormal) lesions at the time of the initial diagnosis. A carcinoma developed in 3 of the 105 patients with diploid lesions (3 percent), as compared with 21 of the 25 patients with aneuploid lesions (84 percent), yielding a negative predictive value of 97 percent with respect to the diploid lesions and a positive predictive value of 84 percent with respect to the aneuploid lesions. Carcinoma developed in 12 of 20 patients with tetraploid lesions (60 percent). The mean time from the initial assessment of the DNA content to the development of a carcinoma was 35 months (range, 4 to 57) in the group with aneuploid lesions and 49 months (range, 8 to 78) in the group with tetraploid lesions (P=0.02). The cumulative disease-free survival rate was 97 percent among the group with diploid lesions, 40 percent among the group with tetraploid lesions, and 16 percent among the group with aneuploid lesions (P<0.001).

CONCLUSIONS

The DNA content in cells of oral leukoplakia can be used to predict the risk of oral carcinoma.

Prognostic value of graph theory-based tissue architecture analysis in carcinomas of the tongue

Several studies on oral squamous cell carcinomas (OSCC) suggest that the clinical value of traditional histologic grading is limited both by poor reproducibility and by low prognostic impact. However, the prognostic potential of a strictly quantitative and highly reproducible assessment of the tissue architecture in OSCC has not been evaluated. Using image analysis, in 193 cases of T1-2 (Stage I-II) OSCC we retrospectively investigated the prognostic impact of two graph theory-derived structural features: the average Delaunay Edge Length (DEL_av) and the average homogeneity of the Ulam Tree (ELH_av). Both structural features were derived from subgraphs of the Voronoi Diagram. The geometric centers of the cell nuclei were computed, generating a two-dimensional swarm of point-like seeds from which graphs could be constructed. The impact on survival of the computed values of ELH_av and DEL_av was estimated by the method of Kaplan and Meier, with relapse-free survival and overall survival as end-points. The prognostic values of DEL_av and ELH_av as computed for the invasive front, the superficial part of the carcinoma, the total carcinoma, and the normal-appearing oral mucosa were compared. For DEL_av, significant prognostic information was found in the invasive front (p < 0.001). No significant prognostic information was found in superficial part of the carcinoma (p = 0.34), in the carcinoma as a whole (p = 0.35), or in the normal-appearing mucosa (p = 0.27). For ELH_av, significant prognostic information was found in the invasive front (p = 0.01) and, surprisingly, in putatively normal mucosa (p = 0.03). No significant prognostic information was found in superficial parts of the carcinoma (p = 0.34) or in the total carcinoma (p = 0.11). In conclusion, strictly quantitative assessment of tissue architecture in the invasive front of OSCC yields highly prognostic information.