Age-Related Cancer-Associated Microbiota Potentially Promotes Oral Squamous Cell Cancer Tumorigenesis by Distinct Mechanisms

Roles of intralesional bacteria in the initiation and progression of oral squamous cell carcinoma

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the predominant form of head and neck cancer, often diagnosed at late stages, resulting in a poor prognosis. Recent studies indicate a potential association between OSCC and microbial presence. Microorganisms have been identified in various tumors and lesions, including OSCC and oral potentially malignant disorders (OPMDs). Intralesional microbiota are considered important components of the tumor microenvironment (TME) and may contribute to carcinogenesis.

METHODS

Sources were collected through thorough searches of databases PubMed and Embase. The review focused on microbial characteristics, potential origins, and their impact on cancer progression.

RESULTS

Bacteria display varying abundance and diversity throughout the stages of OSCC and OPMDs. Intraleisional bacteria may have diverse sources, including not only oral plaque and saliva but also potentially the gut. Intralesional bacteria have both pro-carcinogenic and anti-carcinogenic effects, affecting processes like cell proliferation, invasion, and immune response.

CONCLUSIONS

Intralesional microbiota are crucial in OSCC and OPMDs, influencing both disease progression and treatments. Despite their significance, challenges like inconsistent sampling and microbial identification remain. Future research is required to fully understand their role and improve clinical applications.

Trends in Oral Tongue Cancer Incidence in the US

Importance

Oral tongue cancer (OTC) incidence has increased rapidly among young (<50 years) non-Hispanic White individuals in the US during the past 2 decades; however, it is unknown if age-associated trajectories have persisted.

Objective

To examine US trends in OTC incidence and project future case burden.

Design, Setting, and Participants

This cross-sectional analysis of OTC incidence trends used the US Cancer Statistics Public Use Database, which covers approximately 98% of the US population, and included individuals with an OTC diagnosis reported to US cancer registries between January 1, 2001, and December 31, 2019.

Exposures

Sex, race and ethnicity, and age.

Main Outcomes and Measures

Estimated average annual percentage change in OTC incidence from 2001 to 2019. Given the substantial incidence rate increases among non-Hispanic White individuals compared with those of racial and ethnic minority groups, subsequent analyses were restricted to non-Hispanic White individuals. Forecasted OTC incidence trends and case burden among non-Hispanic White individuals to 2034.

Results

There were 58 661 new cases of OTC identified between 2001 and 2019. Male individuals (57.6%), non-Hispanic White individuals (83.7%), those aged 60 years or older (58.0%), and individuals with localized stage disease at diagnosis (62.7%) comprised most cases. OTC incidence increased across all age, sex, and racial and ethnic groups, with marked increases observed among non-Hispanic White individuals (2.9% per year; 95% CI, 2.2%-3.7%). Increases among female individuals aged 50 to 59 years were most notable and significantly outpaced increases among younger non-Hispanic White female individuals (4.8% per year [95% CI, 4.1%-5.4%] vs 3.3% per year [95% CI, 2.7%-3.8%]). While all non-Hispanic White birth cohorts from 1925 to 1980 saw sustained increases, rates stabilized among female individuals born after 1980. Should trends continue, the burden of new OTC cases among non-Hispanic White individuals in the US is projected to shift more toward older individuals (from 33.1% to 49.3% among individuals aged 70 years or older) and female individuals (86% case increase vs 62% among male individuals).

Conclusions and Relevance

The results of this cross-sectional study suggest that the period of rapidly increasing OTC incidence among younger non-Hispanic White female individuals in the US is tempering and giving way to greater increases among older female individuals, suggesting a birth cohort effect may have been associated with previously observed trends. Recent increases among non-Hispanic White individuals 50 years or older of both sexes have matched or outpaced younger age groups. Continuing increases among older individuals, particularly female individuals, may be associated with a shift in the OTC patient profile over time.

Bronchoalveolar Lavage Fluid Microbiota is Associated with the Diagnosis and Prognosis Evaluation of Lung Cancer

The gut microbiota and cancer have been demonstrated to be closely related. However, few studies have explored the bronchoalveolar lavage fluid (BALF) microbiota in patients with lung cancer (LC), specifically the microbiota related to progression-free survival (PFS) in LC. A total of 216 BALF samples were collected including 166 LC and 50 benign pulmonary disease (N-LC) samples, and further sequenced using 16S rRNA amplicon sequencing. Enrolled LC patients were followed up, the therapeutic efficacy was assessed, and PFS was calculated. The associated clinical and microbiota sequencing data were deeply analysed. Distinct differences in the microbial profiles were evident in the lower airways of patients with LC and N-LC, which was also found between non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). A combined random forest model was built to distinguish NSCLC from SCLC and reached area under curves (AUCs) of 0.919 (95% CI 86.69-97.1%) and 0.893 (95% CI 79.39-99.29%) in the training and test groups, respectively. The lower alpha diversity of the BALF microbiota in NSCLC patients was significantly associated with reduced PFS, although this link was not observed in SCLC. Specifically, NSCLC with a higher abundance of f_Lachnospiraceae, s_Prevotella nigrescens and f_[Mogibacteriaceae] achieved longer PFS. The enrichment of o_Streptophyta and g_Prevotella was observed in SCLC with worse PFS. This study provided a detailed description of the characteristics of BALF microbiota in patients with NSCLC and SCLC simultaneously and provided insights into the role of the diagnosis and prognosis evaluation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43657-023-00135-9.

Identification of consensus head and neck cancer-associated microbiota signatures: a systematic review and meta-analysis of 16S rRNA and The Cancer Microbiome Atlas datasets

Introduction. Multiple reports have attempted to describe the tumour microbiota in head and neck cancer (HNSC).Gap statement. However, these have failed to produce a consistent microbiota signature, which may undermine understanding the importance of bacterial-mediated effects in HNSC.Aim. The aim of this study is to consolidate these datasets and identify a consensus microbiota signature in HNSC.Methodology. We analysed 12 published HNSC 16S rRNA microbial datasets collected from cancer, cancer-adjacent and non-cancer tissues to generate a consensus microbiota signature. These signatures were then validated using The Cancer Microbiome Atlas (TCMA) database and correlated with the tumour microenvironment phenotypes and patient's clinical outcome.Results. We identified a consensus microbial signature at the genus level to differentiate between HNSC sample types, with cancer and cancer-adjacent tissues sharing more similarity than non-cancer tissues. Univariate analysis on 16S rRNA datasets identified significant differences in the abundance of 34 bacterial genera among the tissue types. Paired cancer and cancer-adjacent tissue analyses in 16S rRNA and TCMA datasets identified increased abundance in Fusobacterium in cancer tissues and decreased abundance of Atopobium, Rothia and Actinomyces in cancer-adjacent tissues. Furthermore, these bacteria were associated with different tumour microenvironment phenotypes. Notably, high Fusobacterium signature was associated with high neutrophil (r=0.37, P<0.0001), angiogenesis (r=0.38, P<0.0001) and granulocyte signatures (r=0.38, P<0.0001) and better overall patient survival [continuous: HR 0.8482, 95 % confidence interval (CI) 0.7758-0.9273, P=0.0003].Conclusion. Our meta-analysis demonstrates a consensus microbiota signature for HNSC, highlighting its potential importance in this disease.

Recent and Projected Trends in Oral Tongue Cancer in the United States: A Demographic Shift in Case Burden as Early Onset Increases Among Females Subside

Background

Oral tongue cancer (OTC) incidence has increased rapidly among young (< 50 years) non-Hispanic White (NHW) individuals in the United States (U.S.) over the last two decades; however, it is unknown if age-associated trajectories have persisted. Furthermore, incidence trends for all 50 U.S. states and the District of Columbia have never been investigated.

Materials and methods

Using U.S. Cancer Statistics data, we investigated incidence trends from 2001-2019, overall and according to age, sex, race/ethnicity, and state of residence. We used age-period-cohort analysis to explore temporal patterns among birth cohorts and to project future trends and case counts.

Results

OTC incidence increased across all age, sex, and racial/ethnic groups, with marked increases observed among the NHWs (2.9%/year; 95%CI, 2.2%-3.7%). Incidence among NHWs increased in most U.S. states, particularly in the Southeast. Increases were significantly greater among NHW females compared to males (3.6%/year vs 2.6%/year; P = 0.022). Increases among females aged 50-59 years were most notable and significantly outpaced increases among younger females (4.8%/year [95% CI, 4.1%-5.4%] vs. 3.3%/year [95% CI, 2.7%-3.8%]; P < .001). While both NHW male and female birth cohorts from 1925 to 1980 saw sustained increases, rates stabilized among females born after 1980. Should trends continue, the burden of new OTC cases among NHWs in the U.S. is projected to shift to older individuals (33.1% versus 49.3% aged ≥ 70) and females (86% case increase versus 62% among males).

Conclusion

The period of rapidly increasing OTC incidence among younger NHW females in the U.S. is tempering and giving way to greater increases among older females, suggesting that a birth cohort effect may have influenced previously observed trends. Recent increases among NHWs aged ≥ 50 of both sexes have matched or outpaced younger age groups. Continuing increases among older individuals, particularly females, will lead to a shift in the OTC patient profile over time.

A bibliometric study of the top 100 most cited papers on aging and cancer

Cancer has been the major and increasing cause of premature death and years of life lost. Various studies suggested the correlation between the aging process and cancer genesis. To evaluate the performance of the articles and to identify and compare the top-cited articles on aging and cancer, a cross-sectional bibliometric analysis was performed. Top-cited articles that were indexed in the Core databases in Web of Science were utilized to identify articles published from inception to September 3, 2022. The top 100 most-cited articles on aging and cancer were evaluated for their specific characteristics. Both Microsoft Office Excel and Visual Basic for Applications were used to analyze the number of publications and scientific cooperations among authors over time. The query identified the top 100 most-cited articles from the 368,504 articles. The top cited articles accumulated 308,106 citations. The citations per article ranged from 39,141 to 1040. Thirty journals published these 100 articles, with the Ca-A Cancer Journal for Clinicians publishing the largest number. Most articles have focused on the trend analysis of incidence, survival outcomes, and prognosis of cancer from different origins. Co-authorship analysis revealed intense collaborative activity between United States authoritative academic institutions and scholars. The present study is the first to analyze most cited papers in "aging and cancer." The historical trends, current status, and future direction in the field of older patients with cancer are systematically summarized. The occurrence and development of cancer is correlated with aging.

Microbial Communities in Gynecological Cancers and Their Association with Tumor Somatic Variation

There are strong correlations between the microbiome and human disease, including cancer. However, very little is known about potential mechanisms associated with malignant transformation in microbiome-associated gynecological cancer, except for HPV-induced cervical cancer. Our hypothesis is that differences in bacterial communities in upper genital tract epithelium may lead to selection of specific genomic variation at the cellular level of these tissues that may predispose to their malignant transformation. We first assessed differences in the taxonomic composition of microbial communities and genomic variation between gynecologic cancers and normal samples. Then, we performed a correlation analysis to assess whether differences in microbial communities selected for specific single nucleotide variation (SNV) between normal and gynecological cancers. We validated these results in independent datasets. This is a retrospective nested case-control study that used clinical and genomic information to perform all analyses. Our present study confirms a changing landscape in microbial communities as we progress into the upper genital tract, with more diversity in lower levels of the tract. Some of the different genomic variations between cancer and controls strongly correlated with the changing microbial communities. Pathway analyses including these correlated genes may help understand the basis for how changing bacterial landscapes may lead to these cancers. However, one of the most important implications of our findings is the possibility of cancer prevention in women at risk by detecting altered bacterial communities in the upper genital tract epithelium.

Role of oral microbiome in oral oncogenesis, tumor progression, and metastasis

Squamous cell carcinoma is the most common malignant tumor of the oral cavity and its adjacent sites, which endangers the physical and mental health of patients and has a complex etiology. Chronic infection is considered to be a risk factor in cancer development. Evidence suggests that periodontal pathogens, such as Porphyromonas gingivalis, Fusobacterium nucleatum, and Treponema denticola, are associated with oral squamous cell carcinoma (OSCC). They can stimulate tumorigenesis by promoting epithelial cells proliferation while inhibiting apoptosis and regulating the inflammatory microenvironment. Candida albicans promotes OSCC progression and metastasis through multiple mechanisms. Moreover, oral human papillomavirus (HPV) can induce oropharyngeal squamous cell carcinoma (OPSCC). There is evidence that HPV16 can integrate with host cells' DNA and activate oncogenes. Additionally, oral dysbiosis and synergistic effects in the oral microbial communities can promote cancer development. In this review, we will discuss the biological characteristics of oral microbiome associated with OSCC and OPSCC and then highlight the mechanisms by which oral microbiome is involved in oral oncogenesis, tumor progression, and metastasis. These findings may have positive implications for early diagnosis and treatment of oral cancer.