The impact of tobacco smoking on survival of patients with oral squamous cell carcinoma: a population-based retrospective study

Genomic alterations in the stepwise progression from normal mucosa to metastasizing oral squamous cell carcinoma

Introduction

The aim of this study was to investigate the genomic changes that occur in the development from dysplasia, cancer and to regional metastases in patients with oral cavity squamous cell carcinoma (OSCC).

Material and methods

We included OSCC patients with lymph node metastases at diagnosis, treated with primary surgery at Rigshospitalet, University of Copenhagen in the period 2007-2014. The resected tumor specimens were evaluated by a pathologist, who marked areas of morphologically normal tissue and dysplasia surrounding the cancer, two areas from the cancer tissue, and one area within the lymph node metastases. From these areas a punch biopsy was taken, and DNA from each sample was extracted and sequenced using Illumina's TSO500 HT cancer panel.

Results

From 51 OSCC patients, 255 samples were included, comprising a wide variety of genomic alterations. Substantial intratumor heterogeneity was found. The most commonly mutated gene was TP53, mutated in 65% of all samples. Only two patients had no TP53 mutation in any samples. We found that morphologically normal appearing mucosa as well as surrounding dysplasia also contained malignant mutations, supporting the theory of field cancerization. There was a significant lower average tumor mutational burden (TMB) in the lymph node metastases compared to the primary tumors, supporting the theory of clonal selection.

Conclusion

Substantial inter- and intratumor genomic heterogeneity was found. Mutation of TP53 was the most common and was present in all but two patients. Our data strongly supports the theory of clonal selection and the theory of field cancerization.

Association of Site and Recurrence in Oral Squamous Cell Carcinoma Patients Visiting Private Hospital in Chennai: A Retrospective Study

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the most common malignant neoplasms of the oral cavity. Tongue, buccal mucosa, and gingivobuccal sulcus are the most commonly involved sites for the local recurrence of OSCC. The site of the tumor can be a critical parameter in relation to the recurrence of OSCC because of the varied action of tumor cells in different tumor macro and microenvironments. Hence, the current study aims to evaluate the correlation between the site and recurrence of OSCC among patients visiting private oral cancer hospitals.

MATERIALS AND METHODS

Details of n=300 OSCC cases reported during 2019-2023, which included primary and recurrent OSCC, were collected. The sample population selected includes 261 primary and 39 recurrent oral squamous cell carcinoma cases. The demographic and clinicopathological data were retracted from the institution's common clinical database and transported to IBM-SPSS 23 software for statistical analysis. Chi-square was done to evaluate the association between site and recurrence status, and p<0.05 was considered statistically significant.

RESULTS

Males have a high predilection for OSCC, and the recurrent cases account for 13% of the sample population. The buccal mucosa was the most commonly affected site in primary and recurrent OSCC cases. However, the association between the site of the lesion and the status of recurrence was found to be statistically significant, with a p-value of 0.001.

CONCLUSION

Even though buccal mucosa was the most common site for recurrent OSCC(p value-0.001), the present study carries a small sample size and a location-specific sampling. Hence, further studies must be conducted with a large sample size to test the significant correlation between the site and recurrence rate among patients diagnosed with OSCC.

Oral cavity cancer in young, non-smoking, and non-drinking patients: A contemporary review

Oral squamous cell carcinoma (OSCC) in non-smoking and non-drinking (NSND) individuals appears to be distinct from the traditional head and neck squamous cell carcinoma (HNSCC). The incidence of this subset is increasing, as are the number of studies examining its characteristics. NSND OSCC individuals tend to be younger (<45 years) compared to traditional HNSCC patients. The proportion of females in the NSND OSCC cohort is also higher. The tongue is the predominantly affected subsite. Studies have revealed several gene mutations and unique epigenomic profiles but no definitive genetic etiology. Transcriptomic analysis has not found any causative viral agents. Other proposed etiologies include chronic dental trauma, microbiome abnormalities, marijuana consumption, and genetic disorders. There are international efforts to determine the relative prognostic outcome of this unique cohort, but no consensus has been reached. Here, we review the incidence, demographics, subsite, possible etiologies, prognosis, and therapy implications of the NSND OSCC cohort.

Prevalence of locoregional recurrence and survival post-treatment of head and neck cancers in Africa: a systematic review and meta-analysis

Background

Recurrent cancers of the head and neck are associated with poor survival outcome. Yet, their burden in Africa is not reliably known. We therefore aimed to estimate the prevalence of recurrence and the 5-year overall survival among patients treated for head and neck cancers (HNC) in Africa.

Method

In this systematic review and meta-analysis, we searched four electronic databases (Pubmed, CINAHL, MEDLINE, and Web of Science) and the grey literature for studies reporting the prevalence of HNC recurrence and 5-year overall survival post treatment, published between January 1, 2002, and December 31, 2022. We contacted corresponding authors of relevant studies. Searches were extended to reference lists of review articles and other relevant sources for potentially eligible studies. Each record was assessed for inclusion or exclusion by two independent reviewers. Records with individual-level data on recurrence and survival conducted in Africa were included while exclusion was based on the study design and availability of relevant data. Data were independently extracted by three reviewers from eligible studies, and summary estimates were sought. Our primary outcomes were recurrence and 5-year overall survival of patients who have been treated for HNC, and our secondary outcomes included risk factors, tumor site, squamous cell histology, clinical stage of tumor, and treatment options received. Only records selected for primary outcomes were assessed for secondary outcome data extraction. Random-effects meta-analysis was conducted for each outcome. Meta-regression models were used in addressing sample heterogeneity among the studies. Protocol for this study was registered with PROSPERO, CRD42022372307.

Findings

This systematic review and meta-analysis returned 3998 records, yielding 28 included studies after exclusion. Eighteen studies reported on the prevalence of HNC recurrence while 24 articles reported on the 5-year overall survival. Of the pooled total study population, 7199 (70.5%) of 10,218 patients were males while 2603 (25.5%) were females. We found that the prevalence of HNC recurrence was 15.4% (I² = 96.2%; 95% CI: 9.5-22.3; n = 3214; k = 18), and the 5-year overall survival was 54.4% (I² = 99.5%; 95% CI: 40.1-68.4; n = 9798; k = 24). We also found that the prevalence of smoking and alcohol consumption as risk factors for HNC were 42.6% (I² = 98.8%; 95% CI: 25.2-61.0; n = 4374; k = 15) and 35.8% (I² = 98.9%; 95% CI: 21.7-51.4; n = 4110; k = 11) respectively. The pooled current prevalence for advanced HNC (clinical stages III-IV) was 80.0% (I² = 99.2%; 95% CI: 68.6-89.5; n = 7624; k = 18) compared to 12.2% (I² = 96.4%; 95% CI: 6.2-19.8; n = 7624; k = 18) in early disease (clinical stages I-II).

Interpretation

The results showed significantly high prevalence of cancer recurrence, poor 5-year overall survival and very high prevalence of advanced cancers at time of diagnosis. This study provides robust evidence for strategies towards prompt diagnosis and appropriate management of HNC to improve patients' outcome in the African continent.

Funding

This study was not supported by any funding.

Subgroup Analysis of Overall Survival among Smoking and Non-Smoking Elderly Patients with HNSCC

Smoking is a leading cause of head and neck squamous cell carcinoma (HNSCC). However, non-smokers are also affected by HNSCC, and the prognostic factors applicable to older non-smokers with HNSCC are largely unknown. The aim of this study was to determine predictors of overall survival (OS) in patients both with and without a smoking history aged 70 and over at initial diagnosis. Retrospective data of patients aged ≥70 (initial diagnoses 2004–2018) were examined. Evaluated predictors included tumour stage, biological age, health and therapy. A total of 688 patients (520 smokers, 168 non-smokers) were included with a median age of 74. The 5-year OS was 39.6%. Non-smokers had significantly improved OS compared to smokers (52.0% versus 36.0%, p < 0.001). Disease-free survival (DFS) differed significantly between both groups (hazard ratio = 1.3; 95%CI 1.04–1.626). TNM stage and the recommended therapies (curative versus palliative) were comparable. The proportion of p16-positive oropharyngeal carcinomas was significantly higher in non-smokers (76.7% versus 43.8%, p < 0.001). Smokers were significantly more likely to be men (p < 0.001), drinkers (p < 0.001), and have poorer health status (Karnofsky performance status, KPS, p = 0.023). They were also more likely to have additional tumours (p = 0.012) and lower treatment adherence (p = 0.038). Important predictors of OS identified in both groups, were, among others, alcohol abuse, KPS, Charlson comorbidity index, site of primary tumour, UICC stage and treatment received. Elderly non-smokers are also affected by HNSCC, however, both OS and DFS are increased compared to smokers.

TAB2 Promotes the Biological Functions of Head and Neck Squamous Cell Carcinoma Cells via EMT and PI3K Pathway

Background

Transforming growth factor β₁-activated kinase 1 binding protein 2 (TAB2) mediates a variety of biological processes through activated nuclear factor κ-light-chain-enhancer of activated B cell (NF-κB) signaling pathways. TAB2 has been reported to be upregulated in a variety of tumors. However, little is known about its potential role in oral squamous cell carcinoma (OSCC). Material and Methods. Patients' clinicopathological and transcription data were obtained from The Cancer Genome Atlas (TCGA) database. Immunohistochemistry staining was used to determine TAB2 expression in OSCC tissues (IHC). The expression of TAB2 in OSCC cell lines was detected by western blotting. The CCK-8 test and flow cytometry assay were utilized to evaluate cell proliferation, apoptosis, and cell cycle in OSCC cell lines. Enrichment analysis and identification of predicted signaling pathways were performed by Gene Ontology and KEGG analysis. Finally, the expression of downstream signal molecules was performed using western blotting to validate the mechanism investigations.

Results

TAB2 expression level was aberrantly upregulated in OSCC patients. TAB2 expression was shown to be inversely associated to prognosis. The phenotypic of OSCC cells was considerably impacted by TAB2. OSCC cells with deleted TAB2 exhibit decreased proliferation and increased apoptosis. Additionally, OSCC progression is aided by TAB2 overexpression. Further mechanism studies showed that TAB2 could regulate the progression of OSCC by mediating the upregulation of EMT and PI3K-AKT signaling pathways.

Conclusion

This study sheds light on the carcinogenic role of TAB2 in OSCC and provides a potential therapeutic strategy.