Overexpression of p53 in squamous cell carcinoma of the tongue in young patients with no known risk factors is not associated with mutations in exons 5-9

Unusual Presentation of Squamous Cell Carcinoma in a Young Male: Clinicopathological Insights and Considerations

Cancer of the oral cavity is the most common cancer in males in India, and lip cancer comprises approximately 25% of all oral cancers. Squamous cell carcinoma of lip usually occurs in middle-aged male with history of tobacco use or smoking. Its occurrence in a young, non-smoker male with no associated known predisposing risk factors for carcinoma is very rare. We present a case of a 21-year-old male student who presented with a painless, gradually increasing, occasionally bleeding, nodulo-ulcerated lower lip lesion. The lesion was removed 3 months back with a carbon dioxide laser, and this was a recurrent lesion. We did lesion biopsy which confirmed squamous cell carcinoma. The patient started treatment at the T2N0M0 stage. Patient has responded well to the radiotherapy treatment. Our case had no known predisposing risk factors for carcinoma. For etiopathogenesis in this case, role of prior lesion removal with carbon dioxide laser is debatable. As laser treatment does not spare tissue for histopathology, so confirmatory diagnosis prior to laser removal remains unknown. Treating clinicians should always send a tissue biopsy for histopathology for definitive diagnosis and choose such a treatment modality where the tissue for histopathological diagnosis is preserved irrespective of clinical diagnosis. Future studies to find out exact etiopathogenesis in such cases need to be accelerated.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13193-024-01931-z.

Stage-Specific Survival in Young Patients With Oral Tongue Squamous Cell Carcinoma

OBJECTIVE

To determine demographic factors and clinicopathologic characteristics associated with survival in young patients (age <45 years) with early- (I-II) or late-stage (III-IV) oral tongue squamous cell carcinoma (OTSCC).

STUDY DESIGN

Retrospective database review.

SETTING

National Cancer Database.

METHODS

A retrospective review of 3262 OTSCC cases in young patients between 2005 and 2014 was performed by using data from the National Cancer Database. Factors affecting 2-year survival in patients with early- and late-stage disease were evaluated via univariate and multivariate analyses.

RESULTS

Overall, 1899 patients with early-stage OTSCC and 1363 with late-stage OTSCC were analyzed. In multivariate analysis of early-stage OTSCC, high tumor grade (hazard ratio, 2.08 [95% CI, 1.45-2.99]), local metastasis (2.85 [1.37-5.95]), and tumor size (1.04 [1.02-1.07]) were predictors of mortality. In late-stage OTSCC, African American race (2.79 [1.40-5.56]), positive surgical margins (1.77 [1.07-2.93]), local metastasis (2.20 [1.03-4.72]), distant metastasis (11.66 [2.10-64.73]), depth of invasion (1.03 [1.01-1.05]), and tumor size (1.01 [1.003-1.01]) were predictors of mortality. Subset analysis of clinical N0-stage tumors revealed that treatment with surgery alone was associated with improved survival (P < .001).

CONCLUSION

Positive lymph nodes, high tumor grade, and larger tumor size were associated with increased mortality risk in early- and late-stage young OTSCC. More aggressive up-front treatment, including extirpative surgery and elective neck dissection, may be associated with improved outcomes and should be considered in early-stage cases with high-risk features.

Early-onset oral cancer as a clinical entity: aetiology and pathogenesis

Oral squamous cell carcinoma (OSCC) is one of the most important medical and socio-economic problems in many of the developed countries worldwide, due to the high mortality. The incidence of OSCC among individuals under 45 years of age is growing every year; however, the aetiological factors and pathogenetic mechanisms are poorly understood. This review summarizes the available information regarding clinicopathological features, extrinsic and intrinsic aetiological factors, and the molecular and immune landscape of early-onset OSCC. This cancer shows high recurrence rates and is not associated with the aetiological factors specific to adult-onset OSCC. Young adults with OSCC are not infected with human papillomavirus and rarely consume alcohol or tobacco, but more frequently use smokeless tobacco. Data from single studies indicate the hereditary nature of early-onset OSCC: the KIR2DL1⁺-HLA-C2⁺ genotype and MMP-1 2 G allele are frequently detected in young patients. Early-onset OSCC shows specific genetic, epigenetic, transcriptomic, and proteomic changes. The tumour microenvironment in early-onset OSCC is tolerogenic rather than immunogenic. All of the data suggest that OSCC in young patients is a separate clinical entity with a specific aetiology and pathogenesis. Further studies are needed to reveal the causes and molecular targets of early-onset OSCC for the development of preventive and therapeutic strategies.

PRKCA Overexpression Is Frequent in Young Oral Tongue Squamous Cell Carcinoma Patients and Is Associated with Poor Prognosis

Oral tongue squamous cell carcinomas (OTSCCs) have an increasing incidence in young patients, and many have an aggressive course of disease. The objective of this study was to identify candidate prognostic protein markers associated with early-onset OTSCC. We performed an exploratory screening for differential protein expression in younger (≤45 years) versus older (>45 years) OTSCC patients in The Cancer Genome Atlas (TCGA) cohort (n = 97). Expression of candidate markers was then validated in an independent Austrian OTSCC patient group (n = 34) by immunohistochemistry. Kaplan-Meier survival estimates were computed, and genomic and mRNA enrichment in silico analyses were performed. Overexpression of protein kinase C alpha (PRKCA) was significantly more frequent among young patients of both the TCGA (p = 0.0001) and the Austrian cohort (p = 0.02), associated with a negative anamnesis for alcohol consumption (p = 0.009) and tobacco smoking (p = 0.02) and poorer overall survival (univariate p = 0.02, multivariate p< 0.01). Within the young subgroup, both overall and disease-free survival were significantly decreased in patients with PRKCA overexpression (both p < 0.001). TCGA mRNA enrichment analysis revealed 332 mRNAs with significant differential expression in PRKCA-upregulated versus PRKCA-downregulated OTSCC (all FDR ≤ 0.01). Our findings suggest that PRKCA overexpression may be a hallmark of a novel molecular subtype of early-onset alcohol- and tobacco-negative high-risk OTSCC. Further analysis of the molecular PRKCA interactome may decipher the underlying mechanisms of carcinogenesis and clinicopathological behavior of PRKCA-overexpressing OTSCC.

Genetic Mutations in Young Nonsmoking Patients With Oral Cavity Cancer: A Systematic Review

Objective

This investigation aims to review the known genetic mutations associated with oral cavity squamous cell carcinoma (OCSCC) in young adults with limited environmental risk factors (YLERs).

Data Sources

A comprehensive search strategy was designed to identify studies in MEDLINE (Ovid), Embase (Ovid), and Scopus from database inception to May 2017 that included adults ≤50 years of age with OCSCC and minimal tobacco use history (≤10 pack-years) who had their tumors genetically sequenced or mutational profiles analyzed.

Review Methods

Identified articles were screened by 2 reviewers. Quality of evidence was graded by the MINORS criteria for case-control studies; other studies were graded by assigning a level of evidence for gene mutation literature.

Results

Thirteen studies met our inclusion criteria, and 130 patients met our criteria for age and tobacco history. TP53 was the most commonly evaluated gene (10 of 13 studies) and the most frequently observed mutation. One study reported that nonsmokers had significantly fewer TP53 mutations, while 9 studies found no difference in the prevalence of TP53 mutations. No other mutations were found specific to this cohort.

Conclusions

TP53 mutations may occur at a similar rate in YLERs with OCSCC as compared with older patients or those with risk factors. However, few studies have aimed to characterize the genetic landscape of oral cavity tumors in this population, often with small sample sizes. Future studies are needed to explore unidentified genetic alterations leading to tumor susceptibility or alternative mechanisms of carcinogenesis.

Histological features and survival in young patients with HPV-negative oral squamous cell carcinoma

OBJECTIVES

The frequency of oral squamous cell carcinoma in young adults has increased in the last decades, and there are conflicting results in literature about its prognosis in young subjects. The aim of this study was to analyse the clinical and pathological features of oral squamous cell carcinoma in a cohort of young adults in order to investigate the presence of new independent prognostic markers.

MATERIALS AND METHODS

Only HPV-negative young patients (under 40-year-old) affected by oral squamous cell carcinoma were considered in this study. Clinical and pathological data were collected. Patients were re-staged according to the 8th edition of AJCC.

RESULTS

Overall, 66 patients were considered in this study. Perineural invasion significant correlated with both 7th and 8th edition of AJCC, and lymphovascular invasion (p-value < .05). The multivariate survival analysis showed that patients with perineural invasion had a significant worse prognosis (HR = 6.384 95% C.I. 1.304-31.252; p-value = .022).

CONCLUSIONS

Perineural invasion emerged as an independent prognostic factor for disease-specific survival in young patients with oral squamous cell carcinoma. Furthermore, the evaluation of this parameter is simple, inexpensive and can be used to augment the risk stratification of oral cancer based on the 8th edition of AJCC.

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.

John MA. The promise of immunotherapy in the treatment of young adults with oral tongue cancer

Historically considered a disease of the older male resulting from cumulative tobacco and alcohol use, more recently we have witnessed a rise in the global incidence of oral tongue squamous cell carcinoma in younger adults, particularly those without any identifiable risk factor exposure. These patients appear to be at higher overall risk for locoregional treatment failure and often experience a more heterogeneous clinical course, with some afflicted with particularly aggressive, rapidly progressive disease. Recent research efforts have supported the idea that although this disease may be genomically similar in these groups, and molecular differences in the tumor immune microenvironment may account for biological differences between young and older patients, as well as patients with and without exposure to alcohol or tobacco. In this review, we seek to summarize current knowledge regarding pathogenesis of oral tongue carcinoma in the young adult patient and examine the potential role of the immune response in disease progression and as a target for novel immunotherapies.

Comparison of Squamous Cell Carcinoma of the Tongue between Young and Old Patients

Background

The worldwide incidence of squamous cell carcinoma of the tongue (SCCOT) in young patients has been increasing. We investigated clinicopathologic features of this unique population and compared them with those of SCCOT in the elderly to delineate its pathogenesis.

Methods

We compared clinicopathological parameters between patients under and over 45 years old. Immunohistochemical assays of estrogen receptor, progesterone receptor, androgen receptor, p53, p16, mdm2, cyclin D1, and glutathione S-transferase P1 were also compared between them.

Results

Among 189 cases, 51 patients (27.0%) were under 45 years of age. A higher proportion of women was seen in the young group, but was not statistically significant. Smoking and drinking behaviors between age groups were similar. Histopathological and immunohistochemical analysis showed no significant difference by age and sex other than higher histologic grades observed in young patients.

Conclusions

SCCOT in young adults has similar clinicopathological features to that in the elderly, suggesting that both progress via similar pathogenetic pathways.

P53 Alteration in Oral Tongue Cancer is Not Significantly Associated with Age at Diagnosis or Tobacco Exposure

Aims and background

The tumor suppressor gene P53 is mutated in almost half of head and neck cancers. The current work assessed the prognostic significance of P53 alteration in patients with squamous cell carcinoma of the oral tongue treated with a curative intent, its association with age at diagnosis (using 45 years as a cut point), and risk exposure as defined by tobacco and/or alcohol consumption.

Methods

P53 alteration was determined immunohistochemically in 45 patients with tongue cancer treated with a curative intent.

Results

P53 alteration occurred in 20 of 45 tumors (44%) and was more common among younger patients (58% versus 36% for younger versus older patients, respectively) and those lacking tobacco/alcohol exposure (53% versus 40% for “no-risk” and “risk” groups, respectively), but the differences were not statistically significant. With a median follow-up of 56 months, 5-year progression-free survival rates were 48% and 66% in patients with and without P53 detection, respectively (P = 0.22).

Conclusions

Despite a trend of a younger age at diagnosis in P53-altered tumors, results did not reach statistically significant differences. A trend of a worse clinical outcome with P53 alteration was noted.

Tongue carcinoma in young adults: a review of the literature

SUMMARY

A recent reduction in the number of smoke-related tumours has been observed thanks to the diffusion of anti-tobacco campaigns carried out in the majority of developed countries. Nevertheless, as demonstrated by recent global epidemiologic studies, squamous cell carcinoma of the mobile tongue appears to be progressively increasing in incidence, particularly among young adults and especially in females. The driving mechanism responsible for such changes is still to be precisely defined. Several genetic studies have compared the mutational pattern of tongue squamous cell carcinoma in young adults to that of more elderly patients, without identifying significant differences that may help in better characterising this subgroup of subjects. Tongue squamous cell carcinomas in young adults have been historically considered as particularly aggressive clinical entities, with a high risk of loco-regional relapse, survival rates inferior to those of the general head and neck cancer group and need for a more aggressive therapy. However, considering the most recent studies, prognostic results in this patient group are heterogeneous and it is not possible to confirm this tendency. Thus, it is not justified to embrace different therapeutic approaches according to patient age. Eventually, an additional element to consider when examining young subjects affected by tongue cancer is the possibility of genetic predisposition. Alterations affecting pathways involved in DNA repair, surveillance of genetic stability or regulation of cellular growth may determine an increased likelihood of developing head and neck cancers.

Early onset oral tongue cancer in the United States: A literature review

The incidence of early onset oral tongue squamous cell carcinoma (OTC) has been increasing in the United States, and no clear etiology has been identified. Studies on this topic have generally been small and presented varied results. The goal of this review is to analyze and synthesize the literature regarding early onset OTC risk factors, outcomes, and molecular analyses within the US. To date, studies suggest that early onset OTC patients tend to have less heavy cigarette use than typical onset patients, but there may be an association between early onset OTC and smokeless tobacco (chewing tobacco and snuff) use. Early onset OTC is associated with similar or possibly improved survival compared to typical onset OTC. There has been no evidence to support a significant role for human papillomavirus in development of early onset OTC. Further research with larger cohorts of these patients is needed to better characterize this disease entity.

Oral tongue carcinoma among young patients: An analysis of risk factors and survival

INTRODUCTION

The incidence of oral tongue squamous cell carcinoma (OTSCC) in younger adults has rapidly increased over the past two decades. While tobacco and alcohol use may be less likely to cause these tumors, it remains controversial whether differences also exist in their prognosis. Our aim is to examine the risk factors for cancer among young (<45 years old) OTSCC patients at our institution, and to compare their recurrence and survival with older patients in a matched cohort.

MATERIALS AND METHODS

All OTSCC patients seen at our institution between 2000 and 2015 were reviewed. Patients under 45 who with sufficient treatment information were matched 1:1 on race, T-stage, and N-stage with patients 45 and older. Three-year recurrence and survival were determined in stratified and adjusted Cox regression models.

RESULTS

Of 397 OTSCC patients were seen at our institution, 117 (29%) were less than 45 years old. Younger patients were significantly more likely to be female, (50% vs. 39%; p = 0.04) and to abstain from tobacco (51% vs. 39%; p < 0.01). Young patients in the matched cohort were significantly more likely to have a recurrence (HR 3.9 95% CI 1.4-10.5). There was no difference in overall survival.

CONCLUSION

Younger OTSCC patients in a matched cohort were more likely to recur within 3 years, although there was no difference in overall mortality. Differences in risk factors and recurrence between older and younger patients suggest that some cancer among younger patients may be distinct from traditional OTSCC.

Low level laser therapy induces increased viability and proliferation in isolated cancer cells

OBJECTIVES

Low level laser therapy (LLLT), which stimulates natural biological processes in the application region, is frequently used in dental treatments. The aim of our study was to evaluate the effects of LLLT which could activate precancerous cells or increase existing cancerous tissue in case of clinically undetectable situations.

MATERIALS AND METHODS

Saos-2 osteoblast-like osteosarcoma cells and A549 human lung carcinoma cells were used. Twenty-four hours after preparation of cell culture plates, laser irradiation was performed 1, 2 and 3 times according to the test groups using Nd:YAG laser with the power output 0.5, 1, 2 and 3 W. Cell proliferation analysis was performed by MTT assay at the 24th hour following the last laser applications.

RESULTS

Generally, it was observed that the proliferation rates increased as the number of applications increased, when compared to the controls, especially in those cases in which the irradiation was performed 2 or 3 times more.

CONCLUSION

The findings of this study have led to the conclusion that LLLT increases cancer cell proliferation, depending on the power output level of the laser and the number of applications. In addition to the proliferation and mitotic activity of the cancer tissue cells, we concluded that LLLT, which is frequently used in dental practice, could activate precancerous cells or increase existing cancerous tissue.

A Comparison of Clinicopathological Differences in Oral Squamous Cell Carcinoma in Patients Below and Above 40 Years of Age

Introduction

Recent times have revealed an increase in incidence of Oral Squamous Cell Carcinoma (OSCC) in young adults including those who lack association with typical risk factors such as tobacco. There are reported variations in clinical behaviour of tumours in young and older individuals.

Aim

Present study evaluated differences in clinicopathological characteristics between two groups of OSCC, below and above 40 years of age.

Materials and Methods

An analytical study was performed on two groups of OSCC patients, below and above 40 years of age. Clinicopathological parameters of site distribution, type of habit, histological grade, nodal metastasis, margin status, mitotic index and Argyrophilic Nucleolar Organizing Regions (AgNOR) count were compared. Chi-square test and Students t- test were applied for statistical analysis.

Results

Present study revealed that mean AgNOR count was significantly higher in older group (6.38) than younger group (4.27). However, no significant differences were noted in site distribution, tobacco habit, histological grade, mitotic index, nodal metastasis and status of resected surgical margins between the two age groups. A trend for increased metastasis and poor histological differentiation was also observed in the older and younger age group respectively. Most common site was buccal mucosa followed by tongue in both groups.

Conclusion

Reasons for documented variability in tumour characteristics between young and older patients are currently unclear. Difference in AgNOR count found in present study is suggestive of variability in proliferative and ploidy characteristics between different age groups and supports the hypothesis of genetic and epigenetic influences in development of oral cancer.

P53 nuclear stabilization is associated with FHIT loss and younger age of onset in squamous cell carcinoma of oral tongue

BACKGROUND

Squamous cell carcinoma of tongue (SCCT) is expected to harbor unique clinico-pathological and molecular genetic features since a significant proportion of patients are young and exhibit no association with tobacco or alcohol.

METHODS

We determined P53, epidermal growth factor receptor, microsatellite instability, human papilloma virus infection and loss of heterozygosity status at several tumor suppressor loci in one hundred and twenty one oral SCCT (SSCOT) samples and analyzed their association with clinico-pathological features and patient survival.

RESULTS

Our results revealed a significantly higher incidence of p53 nuclear stabilization in early (as against late) onset SCCOT. FHIT loss was significantly associated with p53 nuclear stabilization and the association was stronger in patients with no history of tobacco use. Samples harboring mutation in p53 DNA binding domain or exhibiting p53 nuclear stabilization, were significantly associated with poor survival.

CONCLUSION

Our study has therefore identified distinct features in SCCOT tumorigenesis with respect to age and tobacco exposure and revealed possible prognostic utility of p53.

Impact of young age on the prognosis for oral cancer: a population-based study in Taiwan

Background

Oral cancer leads to a considerable use of health care resources. Wide resection of the tumor and reconstruction with a pedicle flap/ free flap is widely used. This study was conducted to investigate if young age at the time of diagnosis of oral cancer requiring this treatment confers a worse prognosis.

Methods

A total of 2339 patients who underwent resections for oral cancer from 2004 to 2005 were identified from The Taiwan National Health Insurance Research Database. Survival analysis, Cox proportional regression model, propensity scores, and sensitivity test were used to evaluate the association between 5-year survival rates and age.

Results

In the Cox proportional regression model, the older age group (>65 years) had the worst survival rate (hazard ratio [HR], 1.80; 95% confidence interval [CI], 1.45-2.22; P<0.001). When analyzed using the propensity scores, the adjusted 5-year survival rates were also poorer for oral cancer patients with older age (>65 years), compared to those with younger age (<45 years) (P<0.001). In sensitivity test, the adjusted hazard ratio remained no statistically elevated in the younger age group (<45 years).

Conclusions

For those oral cancer patients who underwent wide excision and reconstruction, young age did not confer a worse prognosis using a Cox proportional regression model, propensity scores or sensitivity test. Young oral cancer patients may be treated using general guidelines and do not require more aggressive treatment.

TP53 mutation and human papilloma virus status of oral squamous cell carcinomas in young adult patients

OBJECTIVE

Little is known about the molecular carcinogenesis of oral squamous cell carcinoma (OSCC) in young adult patients. The aim of this study was to investigate the detailed TP53 mutation and human papilloma virus (HPV) status of OSCC in patients, younger than 45 years.

METHODS

TP53 mutations were determined with direct sequencing on paraffin-embedded carcinoma tissue from 31 young patients and compared with two older age OSCC reference groups: one from the same institute (N = 87) and an independent one (N = 675). Biologically active tumour HPV was detected by p16-immunohistochemistry followed by a HPV-DNA GP5 + /6 + -PCR.

RESULTS

HPV16 was present in one OSCC (3%). TP53 mutations were found in 14 (45%) OSCC: five were missense and nine resulted in a truncated protein. Six of these latter were insertions or deletions of one or more nucleotides leading to frameshift, one was at a splice site and two resulted in a stop codon. The percentage of truncating mutations (64% of all mutations) was higher than that observed in the institute's reference group (44%, P = 0.23) and in the independent reference group (24%, P = 0.002).

CONCLUSIONS

This study shows that TP53 mutations are common in OSCC of young adult patients; infection with biologically active HPV is rare.

Protein expression and promoter methylation of the candidate biomarker TCF21 in head and neck squamous cell carcinoma

PURPOSE

Epigenetic alterations of the transcription factor 21 (TCF21) gene have been associated with head and neck squamous cell carcinoma (HNSCC) and other tumor entities. So far, however, no reports have appeared in the literature on TCF21 protein expression in HNSCC and its relevance as a putative biomarker.

METHODS

TCF21 protein expression was assessed in 74 HNSCCs and 31 benign tonsils by immunohistochemistry. Methylation analyses of the corresponding gene promoter were performed in 45 HNSCCs and 31 benign tonsils. The TCF21 expression levels in the tumors and controls were compared with each other and within each group and, in addition, with the TCF21 promoter methylation status and various clinicopathological characteristics.

RESULTS

Overall, both the expression levels and methylation frequencies of TCF21 were significantly higher in the HNSCCs than in the benign controls (p < 0.001 each). Specifically, TCF21 promoter hypermethylation resulted in a reduced protein expression in a subgroup of the HNSCCs (p = 0.038), but not in the tonsils. In the tonsils, TCF21 protein expression positively correlated with that of CD31 (p = 0.039), a marker for blood vessels. Also, in the tonsils the TCF21 protein methylation frequency showed a positive correlation with age (p = 0.008). The HNSCCs of patients with a positive history for alcohol and nicotine abuse showed higher TCF21 protein expression levels than their respective counterparts (p = 0.028 and p = 0.062, respectively). The same was observed in human papilloma virus (HPV)-negative tumors (p = 0.042), tumors located in the oral cavity (p = 0.016) and early-stage tumors (p = 0.025). Interestingly, expression rates in tumors of the oropharynx, where HPV-positive tumors were most frequently found, tended to be lower (p = 0.065). The methylation frequencies of TCF21 were found to be significantly higher in tumors of patients without nicotine abuse (p = 0.030), in HPV-positive tumors (p = 0.014) and in tumors exhibiting over-expression of p16, a protein induced by HPV (p = 0.006).

CONCLUSIONS

Both over-expression and increased promoter methylation of TCF21 were frequently observed in HNSCCs. TCF21 promoter hypermethylation was found to lead to gene silencing in the HNSCCs, but not in the benign tonsils. These epigenetic, and possibly also genetic, alterations of the TCF21 gene in HNSCCs may be driven by HPV infection, nicotine and alcohol abuse, or both. These findings, together with its stage- and primary site-dependent expression, turn TCF21 into a promising candidate biomarker in HNSCC.

Cyclin A1 shows age-related expression in benign tonsils, HPV16-dependent overexpression in HNSCC and predicts lower recurrence rate in HNSCC independently of HPV16

Background

Promoter methylation of the tumor suppressor gene Cyclin A1 could be associated with Human Papillomavirus 16 (HPV16) induced Head and Neck Squamous Cell Carcinoma (HNSCC) and Cervical Carcinoma. There is disagreement about the impact of this epigenetic event on protein expression of Cyclin A1 in malignant and non-malignant tissue and there hardly exists any information about possible relationships between Cyclin A1 expression and clinicopathological characteristics in HNSCC.

Methods

We analyzed protein expression of Cyclin A1 in 81 HNSCC and 74 benign tonsils by immunohistochemistry and correlated it to Cyclin A1 methylation status, presence of HPV16 infection and other clinicopathological characteristics.

Results

Overexpression of Cyclin A1 was more present in HNSCC than in tonsils (p < 0.001). In both entities, HNSCC and benign tonsils, expression of Cyclin A1 significantly correlated with the expression of Cyclin-dependent kinase-inhibitor p16 (p = 0.000672 and 0.00495). In tonsils, expression of Cyclin A1 was inversely proportional to age (p = 0.00000396), and further correlated with expression of tumor suppressor gene p53 (p = 0.000228). In HNSCC Cyclin A1 expression was associated with the presence of HPV16 DNA (p = 0.0014) and a lower recurrence rate in univariate and multivariate analysis (p = 0.002 and 0.013). Neither in HNSCC nor in tonsils Cyclin A1 expression correlated with promoter methylation.

Conclusions

Cyclin A1 is an important cell cycle regulator with age-related increased expression in tonsils of children. HPV16 induces overexpression of Cyclin A1 in HNSCC despite promoter methylation. Overexpression of Cyclin A1 predicts a lower recurrence rate in HNSCC independently of HPV16.

LOH-profiling by SNP-mapping in a case of multifocal head and neck cancer

AIM: To introduce an approach for the detection of putative genetic host factors that predispose patients to develop head and neck squamous cell carcinomas (HNSCC).

METHODS: HNSCC most often result from the accumulation of somatic gene alterations found in tumor cells. A cancer-predisposing genetic background must be expected in individuals who develop multiple cancers, starting at an unexpectedly young age or with little carcinogen exposure. Genome-wide loss of heterozygosity (LOH) profiling by single nucleotide polymorphism microarray mapping was performed in a patient with a remarkable history of multifocal HNSCC.

RESULTS: Regions of genomic deletions in germline DNA were identified on several chromosomes with a remarkable size between 1.6 Mb and 8.1 Mb (mega base-pair). No LOH was detected at the genomic location of the tumor suppressor gene P53.

CONCLUSION: Specific patterns of germline DNA deletions may be responsible for susceptibility to HNSCC and should be further analyzed.

Oral cancer in young non-habituè females: a report of four cases and review of the literature

BACKGROUND

The aim of this study is to highlight the growing incidence of oral cancer in young females without apparent traditional risk factors.

METHODS

We present a case series of young female patients with histopathologically diagnosed squamous cell carcinoma of the tongue and no known exposure to major risk factors, reporting to our institution over one year. A review of the literature was carried out to find documented studies on oral cancer in young females.

RESULTS

We found an increase in the number of young female patients presenting with squamous cell carcinomas on the lateral border of the tongue who did not have any of the traditional risk factors associated with the disease, which is in contrast with the number of male patients presenting with the same disease.

CONCLUSIONS

Our study highlights the increasing incidence of oral cancer in young females without apparent traditional risk factors, an area of growing concern. Published studies in this particular group are limited. Nevertheless, the situation is alarming owing to the seriousness this problem poses for the community. More research is required to determine the aetiological and risk factors associated with this outcome.

Impact of smoking status on clinical outcome in oral cavity cancer patients

The association between smoking status and survival in oral cavity squamous cell carcinoma (OSCC) patients remains unclear. Therefore, we evaluated the association between smoking status before treatment and clinical outcome in OSCC patients. We conducted a retrospective cohort study of 222 OSCC patients who were treated at Aichi Cancer Center in Japan. Of these, 82 patients (36.9%) were non-smokers, 65 (29.3%) were light smokers (pack-years smoking (PY) <30), 54 (24.3%) were moderate smokers (30≤PY<60), and 21 (9.5%) were heavy smokers (60≤PY). The survival impact of pre-treatment smoking status was evaluated using multivariate proportional hazard models. Five-year overall survival for non-, light, moderate, and heavy smokers was 72.9% (95% confidence interval CI): (61.4-81.5), 85.5% (74.0-92.2), 59.9% (44.3-72.4) and 69.0% (42.8-85.0). Adjusted hazard ratios (HRs) for moderate and heavy smokers in comparison with light smokers were 2.44 (1.07-5.57, P=0.034) and 2.66 (0.97-7.33, P=0.058) and the dose-response relationship among smokers was statistically significance (P(trend)=0.024). In addition, adjusted HR for non-smokers relative to light smokers was 2.27 (0.84-6.15, P=0.108). We observed a suggestive heterogeneity in the impact of smoking status by treatment method (P for heterogeneity=0.069). Effect of smoking was evident only among the chemoradiotherapy or radiotherapy group. In this study, we found the significant positive dose-response relationship among smokers on clinical outcome in OSCC patients and that non-smokers were worse prognosis than light smokers. In addition, this effect might differ by treatment method.

Head and neck cancer in young adults and nonsmokers: study of cancer susceptibility by genome-wide high-density SNP microarray mapping

CONCLUSION

Our results raise the question as to whether specific patterns of 'germline loss of heterozygosity (LOH)' could contribute to the genetic susceptibility for head and neck squamous cell carcinoma (HNSCC).

OBJECTIVES

HNSCC usually occurs in older individuals with a history of smoking. However, about 5% of HNSCC patients have never used tobacco or develop this disease at an exceptionally young age. Therefore, genetic susceptibility must contribute significantly to HNSCC risk. The objective was to introduce a novel approach that might help to unveil candidate genes contributing to cancer predisposition and to identify individuals at risk for HNSCC, and to present our observations with this method in a specific group of patients.

METHODS

High-resolution SNP (single-nucleotide polymorphism) microarray mapping for homozygous stretches in germline DNA was performed in 12 patients who appeared particularly susceptible to develop HNSCC, because they were exceptionally young or never users of tobacco.

RESULTS

We could identify strings of consecutive homozygous SNPs that were much longer than would be expected to appear by chance alone, indicating regions of DNA deletions that we named germline LOH.

Promoter methylation of cyclin A1 is associated with human papillomavirus 16 induced head and neck squamous cell carcinoma independently of p53 mutation

Aberrant promoter methylation of specific genes and infection with human papillomavirus 16 (HPV16) are known risk factors for the development of Head and Neck Squamous Cell Carcinoma (HNSCC). Little knowledge exists on the interaction of HPV16 infection and promoter methylation in HNSCC. The promoter methylation status of 12 genes (TIMP3, CDH1, CDKN2A, DAPK1, transcription factor 21 (TCF21), CD44, MLH1, MGMT, RASSF1, cyclin A1 (CCNA1), LARS2, and CEBPA) was evaluated by methylation-specific polymerase chain reaction in 55 primary HNSCC and 31 controls. The results were correlated with HPV16 status and clinicopathological characteristics. CCNA1 and p53 protein expression were additionally determined by immunohistochemistry and compared with p53 mutation status. Methylation of DAPK1 (P = 0.043), CCNA1 (P = 0.016) and TCF21 (P = 0.0005) was significantly more present in HNSCC than in controls. The genes TIMP3 (P = 0.018) and CCNA1 (P = 0.015) showed higher methylation frequency in HPV16 positive HNSCC compared to HPV16 negative tumors. CCNA1 methylation did not correlate with CCNA1 protein expression and p53 mutation, respectively. Methylation of TCF21 was associated with higher age (P = 0.044) and nicotine abuse (P = 0.035). Methylation of CCNA1 was significantly more present in females (P = 0.003). Methylation of TCF21 and CCNA1 are important risk factors for HNSCC development. CCNA1 methylation may play a crucial role in HPV16-induced carcinogenesis of HNSCC independently of p53.

Contemporary concepts in the diagnosis of oral cancer and precancer

This article addresses several issues in the approach to diagnosis of oral cancer. The term oral cancer is clarified. Key aspects of the biologic basis of development of oral cancer and the known risk factors associated with the disease are summarized. The clinical presentation of oral cancers and precancerous lesions and their histopathologic correlates is discussed. The importance of conventional tissue biopsy as the prevailing gold standard for diagnosis is emphasized. Other current technologies available for detecting and diagnosing oral cancer and premalignant lesions are acknowledged, and their respective strengths and weaknesses are discussed.

Clinical outcome of squamous cell carcinoma of the tongue in young patients: a stage-matched comparative analysis

Objectives

The reported incidence of tongue cancer in young patients has recently increased. The aim of this study was to analyze the clinical characteristics of tongue cancer in a young group of patients, and to compare them with those of an older group of tongue cancer patients.

Methods

We retrospectively reviewed the records of 85 patients who were diagnosed with squamous cell carcinoma of the tongue. They were divided into two age groups: over 45 years of age and under 45 years. To compare the prognosis of similarly staged patients in the group, each age group was divided into the early (stage I, II) and advanced stage groups (stage III, IV), and then they were compared. The young group consisted of 23 patients and the older group had 62 patients.

Results

At the early stage, the clinical prognosis of the patients in both age groups was good, and no significant difference was observed. However, at the advanced stage, the overall and regional recurrence rates were significantly higher in the younger age group as compared to that in the old age group (P=0.007, P=0.001, respectively). The disease-specific survival rate of the patients in the young group was significantly lower than that in the old age group (P=0.025).

Conclusion

Tongue cancer in young subjects has significantly different clinical outcomes according to the stage. The clinical outcome of the advanced-stage tongue cancer in young subjects was poorer than that in the older subjects. Regional recurrence seemed to be the main cause of the poor prognosis.

Proteomic profiling of differential display analysis for human oral squamous cell carcinoma: 14-3-3 σ Protein is upregulated in human oral squamous cell carcinoma and dependent on the differentiation level

Oral squamous cell carcinoma (OSCC) has an absolute majority of all oral cancer. We used proteomic technology to analyze the protein expression profile in OSCC tissues and accompanying surrounding normal tissues in four oral locations (buccal mucosa, gingival mucosa, oral floor, and tongue). Ten protein spots were overexpressed more strongly in cancer tissues than normal ones, and were identified as proliferating cell nuclear antigen, 14-3-3 ε, 14-3-3 σ, proteasome subunit α type 5, translationally controlled tumor protein, eukaryotic translation initiation factor 3 subunit, macrophage capping protein, and mitochondrial isocitrate dehydrogenase subunit α. Macrophage capping protein and mitochondrial isocitrate dehydrogenase subunit α had two spots. Especially, we focused on 14-3-3 σ protein, one of the eight identified proteins, and assessed its expression level in four oral locations of OSCC by using differential display methods. The expression level of 14-3-3 σ protein was upregulated in four locations of oral cavity. Eight proteins which we identified in this study may play an important role in OSCC carcinogenesis and progression and could be used as diagnostic biomarkers of OSCC.

Etiology of oral cancer in the young patient: is tongue cancer becoming the other cancer in women?

The recently reported increase in the incidence of oral cancer in a younger population, especially in young women, in the absence of the traditional risk factors has raised concern. Of particular interest is the increased incidence of carcinoma of the tongue, which has been suggested to be a distinct entity. Although there are conflicting data on incidence and sex distribution, studies suggest that the physiologic response to risk factors by men and women and the clinical behavior of these cancers in the younger population may be different than the normal variant. Effort is currently being made to elucidate the etiology and pathogenesis of oral cancer in the younger population.

Changing trends in oral squamous cell carcinoma with particular reference to young patients: 1971-2006. The Emory University experience

BACKGROUND

Several recent reports suggest an increasing incidence of oral squamous cell carcinoma (OSCC) among young persons in many regions of the world--a trend which is particularly concerning given the overall stabilization or even decline in incidence rates for head and neck cancer in general. The aim of this study is to determine whether there has been an increase in the number of cases of OSCC diagnosed in patients < 40 years old by our biopsy service from 1971 to 2006.

METHODS

A retrospective review of all OSCC cases diagnosed from 1971 to 2006 by the Emory University Hospital Oral Pathology biopsy service was performed. A comparison of demographic information, frequency, location and histologic grade was made between these cases as a whole and those occurring in a subset of patients < 40 years old. Statistical procedures included chi-square analyses.

RESULTS

From 1971-2006, 1,919 cases of OSCC were diagnosed, and 95 (5.0%) occurred in patients < 40 years old. A total of 8 cases were diagnosed from 1971 to 1980, compared to 36 cases during the period 1981-1990, 31 during the period 1991-2000 and 21 cases from 2001 to 2006. The increase in OSCC incidence from the 1970s when compared to 1981-2000 was statistically significant (P < 0.002). A 1.7:1 male:female ratio was seen in all decades. The mobile (oral) tongue was the most common location in all decades (62.1%) in young patients. In contrast, tongue cancers accounted for 27.4% in patients > or = 40. This difference between the two groups was statistically significant (P < 0.0001). Of great surprise, however, was the significant increase in tongue cancer during the study period in patients > or = 40 which accounted for 37.1% of all OSCC diagnoses from 2001 to 2006, compared to 20.5% of OSCC cases from 1971 to 1980 (P < 0.0001).

CONCLUSIONS

We demonstrated a greater than fourfold increase in the incidence of oral squamous cell carcinoma (OSCC) in young patients < 40 years old beginning in 1974 and peaking in the late 1980s, then remaining stable. The mobile tongue is the most common location for cancer in this age group accounting for 62.1% of cancers. However, the mobile tongue increasingly appears to be the most common site for oral cancer in all age groups.

EGFR, p16, HPV Titer, Bcl-xL and p53, sex, and smoking as indicators of response to therapy and survival in oropharyngeal cancer

PURPOSE

To prospectively identify markers of response to therapy and outcome in an organ-sparing trial for advanced oropharyngeal cancer.

PATIENTS AND METHODS

Pretreatment biopsies were examined for expression of epidermal growth factor receptor (EGFR), p16, Bcl-xL, and p53 as well as for p53 mutation. These markers were assessed for association with high-risk human papillomavirus (HPV), response to therapy, and survival. Patient variables included smoking history, sex, age, primary site, tumor stage, and nodal status.

RESULTS

EGFR expression was inversely associated with response to induction chemotherapy (IC) (P = .01), chemotherapy/radiotherapy (CRT; P = .055), overall survival (OS; P = .001), and disease-specific survival (DSS; P = .002) and was directly associated with current smoking (P = .04), female sex (P = .053), and lower HPV titer (P = .03). HPV titer was significantly associated with p16 expression (P < .0001); p16 was significantly associated with response to IC (P = .008), CRT (P = .009), OS (P = .001), and DSS (P = .003). As combined markers, lower HPV titer and high EGFR expression were associated with worse OS (rho(EGFR) = 0.008; rho(HPV) = 0.03) and DSS (rho(EGFR) = 0.01; rho(HPV) = 0.016). In 36 of 42 biopsies, p53 was wild-type, and only one HPV-positive tumor had mutant p53. The combination of low p53 and high Bcl-xL expression was associated with poor OS (P = .005) and DSS (P = .002).

CONCLUSION

Low EGFR and high p16 (or higher HPV titer) expression are markers of good response to organ-sparing therapy and outcome, whereas high EGFR expression, combined low p53/high Bcl-xL expression, female sex, and smoking are associated with a poor outcome. Smoking cessation and strategies to target EGFR and Bcl-xL are important adjuncts to the treatment of oropharyngeal cancer.

Poor prognosis in patients with stage I and II oral tongue squamous cell carcinoma

BACKGROUND

The objective of this study was to compare survival in patients with squamous cell carcinoma (SCC) of the oral tongue with that in patients with SCC in other oral cavity subsites.

METHODS

Patients with stage I and II (T1-T2N0M0) SCC of the oral cavity diagnosed between 1988 and 2004 were queried by using the Surveillance, Epidemiology, and End Results (SEER) database. The log-rank test was used to compare the overall survival (OS) and cause-specific survival (CSS) of patients who had oral tongue SCC with those of patients who had SCC of other oral cavity subsites. A Cox proportional hazards multivariate analysis was performed to evaluate the influence of covariates on the risk of CSS and OS.

RESULTS

Between 1988 and 2004, 6791 patients with stage I and II SCC of the oral cavity were identified. Among them, 40% had oral tongue SCC, and 60% had SCC of other oral cavity subsites. The median patient age was 64 years. The 5-year OS and CSS rates were 60.9% and 83.5%, respectively, for patients with oral tongue SCC versus 64.7% and 94.1%, respectively, for patients with SCC of other oral cavity subsites (OS: hazard ratio, 1.24; P< .0001; CSS: hazard ratio, 3.04; P< .0001). On multivariate analysis, OS and CSS were influenced significantly by T classification, age, sex, and oral tongue subsite. The CSS for patients who had stage I and II oral tongue SCC also was unfavorable compared with the CSS for stage-matched patients who had SCC of other head and neck sites.

CONCLUSIONS

Oral tongue SCC was associated with poor survival compared with other oral cavity and head and neck sites. These data suggested a potential benefit for multimodality therapy in this cohort of patients.

Squamous cell carcinoma of the oral tongue in young patients: a matched-pair analysis

CONCLUSIONS

Young patients with squamous cell carcinoma (SCC) of the oral tongue developed fewer locoregional recurrences. The overall survival and disease-specific survival rates were better in the young patient population.

OBJECTIVES

To compare the survival rates of patients under 45 years of age and diagnosed with SCC of the oral tongue with those of patients older than 45 years.

PATIENTS AND METHODS

A retrospective review of 20 patients under 45 years of age with SCC of the oral tongue was performed. These patients were matched to an older population by sex and clinical stage. Overall survival, disease-free survival, disease-specific survival, and rates of local, regional and distant metastases were determined for both populations.

RESULTS

Stage and treatment modality were similar in the two age groups. There were significant differences in overall survival (p=0.013) and disease-specific survival (p=0.046) favoring young patients. Rates of locoregional recurrence and distant metastasis were higher in the older patients.

Squamous cell carcinoma of the oral cavity in young patients: a matched-pair analysis

There is an increased incidence of oral squamous cell carcinoma (SCC) in young patients. However, the literature concerning prognosis for young patients with oral SCC is conflicting. The aim of this study was to compare the survival rates of patients under 45 years of age and diagnosed with SCC of the oral cavity with those of patients older than 45 years. A retrospective review of 28 patients under 45 years of age with SCC of the oral cavity was performed. We matched each of these patients by sex, tumor site, and overall stage with two patients older than 45 years. Overall survival, disease-free survival, disease-specific survival, rates of local, regional and distant metastasis were determined for both populations. Survival analysis was performed using Cox proportional hazard models. Stage and treatment modality were similar in the two groups. There were significant differences in overall survival (P=0.024) and disease-specific survival (P=0.03) favoring young patients. Locoregional recurrence and distant metastasis were higher in the older patients. Furthermore, matched survival analysis demonstrated a difference in overall survival rate [risk ratio (RR) 2.457; P=0.033] and disease-specific survival [RR 2.475; P=0.048]. Young patients with SCC of the oral cavity developed fewer locoregional recurrences and distant metastasis. The overall survival and disease-specific survival rates were better in the young patient population.

The role of genetic factor in etiopathogenesis of squamous cell carcinoma of the head and neck in young adults

Patients with squamous cell carcinoma of the head and neck (HNSCC) aged less than 45 years are categorized as young adults (YA) and in opinion of many authors in comparison to older (typical) patients (OP) are characterized with more serious form of the disease and often lack the classical risk factors associated with the illness. Hence, there is a need of an exact clinical analysis and a search for additional causative factors. The purpose of this study was to estimate the role of genetic factors in the etiology of HNSCC in YA. Studies carried out on 60 patients of the study group (YA) and 72 older control patients were directed to: (1) a degree of spontaneous and induced chromosome breaks estimated by bleomycin test, (2) a degree of spontaneous and induced DNA damage and a potential of DNA repair determined by comet assay and (3) polymorphism of genes of glutathione transferases M1 and T1, responsible for detoxification of metabolites of carcinogens of tobacco smoke, studied by PCR-based genotyping. The level of chromosome breaks (spontaneous and induced), the level of DNA damage (spontaneous and induced), DNA repair potential and the distribution of polymorphic variants of GSTT1 gene are not significantly different in YA and in OP, which suggests that these factors do not appear the causative factors for HNSCC in young age. The significant risk factor of HNSCC in YA may be GSTM1 null genotype, which may cause the defective detoxification of metabolites of polycyclic aromatic hydrocarbons of tobacco smoke.

Neoadjuvant chemotherapy for squamous cell carcinoma of the oral tongue in young adults: a case series

BACKGROUND

Squamous cell carcinoma of the oral tongue (SCCOT) in the young population has emerged as a growing worldwide health problem. Standard therapies, consisting primarily of surgery with possible adjuvant radiotherapy, have resulted in only modest improvements in survival in recent decades, whereas the treatments for SCCOT continue to impair oral function. With the increased use and improved functional results of neoadjuvant chemotherapy in the treatment of squamous cell carcinoma of other upper aerodigestive tract sites, we have reviewed our experience with neoadjuvant chemotherapy in young patients with SCCOT.

METHODS

A retrospective review was conducted of all patients younger than 45 years (N = 49) with previously untreated SCCOT evaluated at a comprehensive cancer center from July 1995 to August 2001. Charts were reviewed to obtain demographic data, comorbidities, nutritional status, tumor status, treatment and response information, and follow-up data.

RESULTS

Fifteen patients were identified who received neoadjuvant chemotherapy with taxane-based regimens before undergoing glossectomy and neck dissection. Thirteen of these patients (87%) exhibited stage III or IV disease at presentation, and all exhibited at least a partial response at the primary site. Pathologically positive nodes were identified in only six patients (40%), although 13 (87%) had clinically or radiographically suspicious nodes at presentation. Adjuvant radiation therapy was administered to seven patients (47%). With a median follow-up of 39 months, no patient has had local or regional recurrence, although three patients (20%) have had distant metastases develop; one patient with an isolated distant metastasis was successfully salvaged with radiation. By comparison during the same period, 34 young adult patients with SCCOT were treated with surgery with or without postoperative radiotherapy but without the use of chemotherapy. Although these patients had lower T classifications (18% vs 67% T3/T4; p = .0007), incidence of nodal metastases (15% vs 87% N+; p < .0001), and overall disease stage (24% vs 87% stage III/IV; p < .0001) than the neoadjuvant chemotherapy group, the overall survival (82%), disease-specific survival (88%), and recurrence-free survival (82%) of the surgery-first group was similar to that of the neoadjuvant chemotherapy group (87%, 87%, and 80%, respectively).

CONCLUSIONS

This retrospective investigation demonstrates that neoadjuvant chemotherapy with taxane-based regimens may play a role in the successful treatment of SCCOT in young adult patients. Ultimately, this treatment plan may lead to improved functional outcomes in young patients with SCCOT by allowing function-sparing surgery and avoiding postoperative radiotherapy, without sacrificing disease control and survival, but a prospective trial is needed. We have initiated a prospective clinical trial to further investigate the impact of neoadjuvant chemotherapy in patients younger than 50 with SCCOT.

The relationship of the histologic grade at the deep invasive front and the expression of Ki-67 antigen and p53 protein in oral squamous cell carcinoma

BACKGROUND

Although many histopathologic characteristics of oral squamous cell carcinoma (O-SCC) have been identified as prognostic factors, accurate, and unequivocal factors have not been clearly identified. The purpose of this study was to evaluate a potential association between the histologic grade of malignancy at the deep invasive front and the expression of Ki-67 antigen and p53 protein in O-SCC.

METHODS

The expression of Ki-67 antigen and p53 at the invasive tumor front area of O-SCC was examined by immunohistochemistry of archived tissue from 62 cases. The mean age of patients was 60.7 years (range: 37-89) and the male-female ratio was 1.6:1 (38 men, 24 women). There were 20, 17, 14, and 11 cases classified as stage I to stage IV, respectively. The correlation between the intensity of immunostaining for Ki-67 antigen and p53 and the histologic grade of malignancy at the deep invasive front (invasive front grade, IFG) was analyzed. The expression of Ki-67 antigen and p53 in normal oral epithelia (10 cases) was also investigated.

RESULTS

The mean Ki-67 labeling index (LI) in the O-SCC samples was 32.8 +/- 12.0% (n = 62). The mean total score of IFG (IFG score) was 9.1 +/- 2.7 points (n = 62). There was a significant linear correlation between the IFG score and the Ki-67 antigen (gamma = 0.651, R2 = 0.596, P < 0.0001). Of 50 tumors examined, 27 (54.0%) exhibited p53-positive nuclear immunostaining. The staining patterns for Ki-67 antigen and p53 were similar. Both Ki-67-LI and p53-positive status were significantly correlated with the IFG scores.

CONCLUSION

The findings of this study demonstrate that overexpression of Ki-67 antigen and p53 at the deep tumor invasive front of O-SCC is associated with histologic grade of malignancy.

Laser-Assisted Low-Dose Retinoic Acid in Oral Cancer Chemoprevention

OBJECTIVES

Systemic retinoic acid (RA) treatment for chemoprevention of squamous cell carcinoma of the head and neck (HNSCC) is limited by RA's toxic side effects at therapeutic doses. The pulsed-dye laser (PDL), through a mechanism of selective vascular targeting, may allow reduction of the RA dose to one that is better tolerated when these treatments are used in combination. This study tests our hypothesis that combination therapy of PDL irradiation and low-dose systemic RA is as effective as high-dose RA therapy alone in the chemoprevention of HNSCC.

STUDY DESIGN

Randomized, prospective study in a hamster model.

METHODS

Dysplastic lesions were induced in the cheek pouches of 48 hamsters by painting with topical 9,10-dimethl-1,2-benzanthrancene (DMBA). The hamsters were randomly divided into four treatment groups: 1) control (no treatment); 2) PDL irradiation only; 3) 5.0 mg RA (all-trans retinoid, 5.0 mg/kg per day, intraperitoneally [IP]); and (4) PDL + 0.5 mg RA (0.5 mg/kg per day, IP). The PDL irradiation was conducted at day 0 and 15, whereas the RA treatment was continued for 27 days. Tumor burden was measured over time.

RESULTS

The lesions in all of three treatment groups grow more slowly than the untreated controls. The combination treatment of PDL and RA had the greatest inhibitory effect on tumors.

CONCLUSION

This study suggests that combination treatment of PDL and low-dose RA is more effective than high-dose RA alone in the chemoprevention of HNSCC in a hamster cheek-pouch model, so that it should allow greatly improved tolerance of this regimen.