Tongue cancer epidemiology in Brazil: incidence, morbidity and mortality

Isolation and phenotypic characterization of cancer stem cells from metastatic oral cancer cells

OBJECTIVES

To isolate cancer stem cells (CSC) from a metastatic oral squamous cell carcinoma (OSCC) cell line and investigate their in vitro and in vivo phenotypic characteristics.

MATERIALS AND METHODS

Subpopulations with individual staining intensities for CD44 and CD326 were isolated from the OSCC cell line LN-1A by FACS: CD44Low/CD326- (CSC-M1), CD44Low/CD326High (CSC-E), and CD44High/CD326- (CSC-M2). Proliferation, clonogenic potential, adhesion, migration, epithelial-mesenchymal transition markers, and sensitivity to cisplatin and TVB-3166 were analyzed in vitro. Tumor formation and metastasis were assessed by subcutaneous and orthotopic inoculations into BALB/c mice.

RESULTS

E-cadherin levels were higher in CSC-E cells while vimentin and Slug more produced by CSC-M2 cells. CSC-M1 and CSC-M2 subpopulations showed higher proliferation, produced more colonies, and have stronger adhesion to the extracellular matrix. All cell lines established tumors; however, CSC-E and CSC-M2 formed larger masses and produced more metastases.

CONCLUSION

The CSC subpopulations here described show increased cancer capabilities in vitro, tumorigenic and metastatic potential in vivo, and may be exploited in the search for novel therapeutic targets for OSCC.

SOX9 promotes stemness in the CAL27 cell line of tongue squamous cell carcinoma

Tongue squamous cell carcinoma (TSCC) is a prevalent form of oral malignancy, with increasing incidence. Unfortunately, the 5-year survival rate for patients has not exceeded 50%. Studies have shown that sex-determining region Y box 9 (SOX9) correlates with malignancy and tumor stemness in a variety of tumors. To investigate the role of SOX9 in TSCC stemness, we analyzed its influence on various aspects of tumor biology, including cell proliferation, migration, invasion, sphere and clone formation, and drug resistance in TSCC. Our data suggest a close association between SOX9 expression and both the stemness phenotype and drug resistance in TSCC. Immunohistochemical experiments revealed a progressive increase of SOX9 expression in normal oral mucosa, paracancerous tissues, and tongue squamous carcinoma tissues. Furthermore, the expression of SOX9 was closely linked to the TNM stage, but not to lymph node metastasis or tumor diameter. SOX9 is a crucial gene in TSCC responsible for promoting the stemness function of cancer stem cells. Developing drugs that target SOX9 is extremely important in clinical settings.

Epidemiology of tongue squamous cell carcinoma: A retrospective cohort study

OBJECTIVE

To analyze the epidemiological profile and the specific survival of patients diagnosed with tongue squamous cell carcinoma at the National Cancer Institute (INCA).

MATERIALS AND METHODS

Hospital Cancer Registry System Data and Mortality Information from 2007 to 2009 were retrieved in a retrospective cohort study of patients diagnosed with tongue squamous cell carcinoma. Specific survival was estimated using the Kaplan-Meier method. The association between independent variables and the risk of death was explored in a Cox proportional hazards regression model.

RESULTS

A total of 346 patients were eligible, mostly male (77.5%), smokers (87.6%), with alcohol consumption (80.9%), with low education (65.6%), advanced staging at the time of diagnosis (71.1%), and presenting a high mortality rate (72.5%). In total, 44.5% of patients underwent a surgical approach alone or associated with another treatment modality, of which 85.1% of patients underwent neck dissection and 90.1% had free surgical margins. Specific survival was 40.6% in two years and 31.2% in five years.

CONCLUSION

The 5-year specific survival was considered worse in individuals over 60 years, and who did not undergo surgical treatment or had surgery associated with another treatment, compared to patients undergoing isolated surgery.

Diverging incidence trends of oral tongue cancer compared to other head and neck cancers in young adults in France

While head and neck cancer incidence decreased worldwide due to reduced tobacco and alcohol consumption, oral tongue cancer (OTC) incidence has been reported to be increasing in several countries. Our study examines the incidence trends of OTC in France from 1990 to 2018, globally and by age; and compares the incidence trends with the evolution of the incidence of other human papilloma virus-unrelated head and neck squamous cell carcinoma, that is, cancers of the remaining subsites of the oral cavity (RSOCC) and laryngeal cancers for the period 1990 to 2018. World age-standardized incidence rates of oral tongue cancers (C02), cancers of the remaining subsites of the oral cavity (RSOCC, C03-06) and laryngeal cancers (C32) were estimated using the French National Network of Cancer Registries for the period 1990 to 2018. Trends in national incidence rates were estimated from a mixed-effect Poisson model including age and year effects using penalized splines and a district-random effect. In women aged 30 and 40, a significant increase in OTC incidence was observed, while ROSCC showed a nonsignificant incidence decrease. In young men aged 25, a marginally significant increase of OTC incidence years was observed, while incidence rates of RSOCC significantly declined. The results suggest a tendency towards diverging incidence trends for OTC compared to RSOCC and laryngeal cancer in young adults. The observed trends may reflect changes in underlying exposures or emerging exposures not yet identified, and stress the need to further investigate the etiology of oral tongue cancers.

High Levels of Low-Density Lipoproteins Correlate with Improved Survival in Patients with Squamous Cell Carcinoma of the Head and Neck

Circulating lipoproteins as risk factors or prognostic indicators for various cancers have been investigated previously; however, no clear consensus has been reached. In this study, we aimed at evaluating the impact of serum lipoproteins on the prognosis of patients with squamous cell carcinoma of the head and neck (SCCHN). Levels of total cholesterol, low-density lipoproteins (LDL), high-density lipoproteins (HDL), triglycerides and lipoprotein(a) were measured in serum samples from 106 patients and 28 healthy controls. We found that HDL was the only lipoprotein exhibiting a significant difference in concentration between healthy controls and patients (p = 0.012). Kaplan–Meier survival curves indicated that patients with high levels of total cholesterol or LDL had better overall survival than patients with normal levels (p = 0.028 and p = 0.007, respectively). Looking at patients without lipid medication (n = 89) and adjusting for the effects of TNM stage and weight change, multivariate Cox regression models indicated that LDL was an independent prognostic factor for both overall (p = 0.005) and disease-free survival (p = 0.013). In summary, our study revealed that high LDL level is beneficial for survival outcome in patients with SCCHN. Use of cholesterol-lowering medicines for prevention or management of SCCHN needs to be evaluated carefully.

A systematic review and meta-analysis of the prognostic role of age in oral tongue cancer

While evidence suggests an increasing incidence of tongue cancer in young adults, published findings regarding the prognostic role of age at diagnosis are inconsistent. We performed a meta-analysis of the literature to highlight key points that might help in understanding the association between age of oral tongue cancer patients at diagnosis and their prognosis. According to age at diagnosis, a systematic literature review of all published cohort studies assessing the recurrence risks and mortality associated with tongue cancer was conducted. We compared the risk estimates between patients aged >45 years and those aged <45 years at diagnosis. Random-effects models were used to calculate summary relative risk estimates (SRRs) according to different clinical outcomes and sources of between-study heterogeneity (I2 ) and bias. We included 31 independent cohort studies published between 1989 and 2019; these studies included a total of 28,288 patients. When risk estimations were not adjusted for confounders, no significant association was found between age at diagnosis and overall survival (OS). Conversely, after adjustment for confounders, older age at diagnosis was associated with a significantly increased risk of mortality. The difference between SRRs for adjusted and unadjusted estimates was significant (p < 0.01). Younger patients had a significantly higher risk of local recurrence. Younger patients with oral tongue cancer have better OS but a greater risk of recurrence than older patients. These findings should be validated in a large prospective cohort study which considers all confounders and prognostic factors.

Analysis of the Filipinos' Interest in Searching Online for Oral Cancer

Objective:

This study analyzed the health-seeking behavior of Filipinos through relative search volume in Google Trends using oral cancer, mouth cancer, tongue cancer, gum cancer, and lip cancer as predetermined search terms.

Methods:

Comma-separated values files containing relative search volumes of search trends pertaining to oral cancer from 2009 to 2019 were assessed. Brown-Forsythe one-way ANOVA was used to measure differences of oral cancer between years and among months. Repeated measures two-way ANOVA measured differences among the searches for mouth cancer, tongue cancer, gum cancer, and lip cancer through the years. Time series models were fitted and used to forecast search interests.

Results:

The results revealed that interests in oral cancer were significantly higher in 2019 (43.75±5.5, p<0.05) compared to 2009 (29.0 ± 6.7). In terms of months, searches were higher in February (45.0 ± 6.6) compared to May (24.8 ± 3.4, p=0.015), June (25.3 ± 4.4, p=0.020), and December (26.5 ± 4.0, p=0.038). Search interests for gum cancer and lip cancer remained significantly lower from 2011 to 2019, and tongue cancer from 2016 to 2018 but approximated mouth cancer in 2019. The forecast shows mouth cancer (31.67%), tongue cancer (23.75%), and lip cancer (3.83%) fluctuating through the year, while gum cancer (8%) will remain steady in 2020.

Conclusion:

Health-seeking behavior through search trends show an increased interest in oral cancer in 2019 and during February. Search interests will fluctuate in 2020, but at the end of the year will decrease for mouth cancer and tongue cancer, will increase for lip cancer, and will remain steady for gum cancer.