Increasing incidence of oral cancer in Hong Kong—Who, where…and why?

Oral squamous cell carcinomas and oral potentially malignant disorders: A Latin American study

OBJECTIVE

To determine the frequency of oral squamous cell carcinoma (OSCC) associated or not with oral potentially malignant disorders (OPMD), and the epidemiological profile and traditional risk factors in Latin America.

METHODS

A retrospective observational study was conducted in 17 Latin American centres. There were included cases of OSCC, analysing age, gender, OSCC and their association with previous OPMD. Clinicopathological variables were retrieved. The condition of sequential-OSCC versus OSCC-de novo (OSCC-dn) was analysed concerning the aforementioned variables. Quantitative variables were analysed using Student's t-test, and qualitative variables with chi-square.

RESULTS

In total, 2705 OSCC were included with a mean age of 62.8 years old. 55.8% were men. 53.75% of the patients were smokers and 38% were common drinkers. The lateral tongue border was the most affected site (24.65%). There were regional variations in OPMD, being leukoplakia the most frequent. Of the overall 2705 OSCC cases, 81.4% corresponded to OSCC-dn, while s-OSCC were 18.6%. Regarding lip vermillion SCC, 35.7% corresponded to de novo lip SCC and 64.3% were associated with previous OPMD.

CONCLUSIONS

In Latin America, OSCC-dn seems to be more frequent with regional variations of some clinical and histopathological features. Further prospective studies are needed to analyse this phenomenon.

Predicting oral cancer survival-Development and validation of an Asia-Pacific nomogram

BACKGROUND

Nomograms are graphical calculating devices that predict response to treatment during cancer management. Oral squamous cell carcinoma (OSCC) is a lethal and deforming disease of rising incidence and global significance. The aim of this study was to develop a nomogram to predict individualized OSCC survival using a population-based dataset obtained from Queensland, Australia and externally validated using a cohort of OSCC patients treated in Hong Kong.

METHODS

Clinico-pathological data for newly diagnosed OSCC patients, including age, sex, tumour site and grading, were accessed retrospectively from the Queensland Cancer Registry (QCR) in Australia and the Clinical Data Analysis and Reporting System (CDARS) in Hong Kong. Multivariate Cox proportional hazard regression was used to construct overall survival (OS) and cancer-specific survival (CSS) prediction models. Nomograms were internally validated using 10-fold cross validation, and externally validated against the Hong Kong dataset.

RESULTS

Data from 9885 OSCC patients in Queensland and 465 patients from Hong Kong were analysed. All clinico-pathological variables significantly influenced survival outcomes. Nomogram calibration curves demonstrated excellent agreement between predicted and actual probability for Queensland patients. External validation in the Hong Kong population demonstrated slightly poorer nomogram performance, but predictive power remained strong.

CONCLUSION

Based upon readily available data documenting patient demographic and clinico-pathological variables, predictive nomograms offer pragmatic aid to clinicians in individualized treatment planning and prognosis assessment in contemporary OSCC management.

Oral Cancer Awareness and Individuals' Inclination to Its Screening and Risk Prediction in Hong Kong

Assessing the baseline knowledge status and expectations of the target population of any health promotion and secondary prevention program is essential to the success of such intervention. To obtain this information about the Hong Kong population a priori to implementing these preventive strategies for oral cancer in addition to determining the willingness of potential screening participants to take risk-profiling assessments, a cross-sectional survey was conducted between November 2019 and March 2020. A total of 964 residents between the ages 18 and 86 years were invited to participate in this study across the three geographical areas in Hong Kong. Most participants self-reported being aware of oral cancer (86.3%), although the proportion of those with substantial knowledge on salient risk factors and early identifiable signs were very low (2.9%). Age and level of education were the only demographic characteristics associated with the knowledge status. The proportion of participants willing to attend community screening and partake in risk profiling assessment was high (83.9% and 80.9% respectively). Willingness to attend community screening was directly associated with respondents' self-reported oral cancer awareness status (OR: 1.9, 95% CI: 1.22-2.96). Also, we observed that those participants who were willing to attend screening are more inclined to take risk prediction assessments that those not willing to attend. These findings have showcased the need to intensify health promotion via personal skills development to encourage early disease presentation and will assist in the planning of these programs accordingly in the Hong Kong population.

Mitochondrial DHODH regulates hypoxia-inducible factor 1 expression in OTSCC

Oral tongue squamous cell carcinoma (OTSCC) was one of the most hypoxic tumors with unfavorable outcomes. Hypoxia-inducible factor-1 (HIF-1) signaling was associated with cancer proliferation, lymph node metastasis, angiogenesis and poor prognosis of OTSCC. Dihydroorotate dehydrogenase (DHODH) catalyzed the rate-limiting step in the de novo pyrimidine biosynthesis. The aim of the study was to explore the biological function of DHODH and investigate whether DHODH regulated HIF-1 signaling in OTSCC. Proliferation, migration and anoikis resistance were used to determine the function of DHODH. Western blot and luciferase activity assays were used to determine the regulatory role of DHODH on HIF-1. We found that increased DHODH expression was associated with advanced tumor stage and poorly differentiated tumor in head and neck cancer patients in The Cancer Genome Atlas (TCGA). DHODH enhanced the proliferation and aggressiveness of OTSCC. Moreover, DHODH prompted tumor growth and metastasis in vivo. DHODH promoted transcription, protein stability, and transactivation activity of HIF1A. DHODH-induced HIF1A upregulation in OTSCC can be reversed by reactive oxygen species (ROS) scavenger, indicating that DHODH enhanced HIF1A expression via ROS production. DHODH inhibitor suppressed DHODH-mediated ROS generation and HIF1A upregulation. Targeting DHODH using clinically available inhibitor, atovaquone, might provide a new strategy to treat OTSCC.

Prognostic value of non-smoking, non-alcohol drinking status in oral cavity cancer

OBJECTIVES

To compare the treatment response and prognosis of oral cavity cancer between non-smoking and non-alcohol-drinking (NSND) patients and smoking and alcohol-drinking (SD) patients.

METHODS

A total of 313 consecutively treated patients from 2000 to 2019 were included. Demographic, clinicopathologic, treatment, and prognosis information were obtained. Relapse-free survival (RFS), disease-specific survival (DSS), and overall survival (OS) were compared between NSND and SD groups using Kaplan-Meier plots, log-rank test, and multivariate Cox regression analysis.

RESULTS

Sample prevalence of NSND patients was 54.6%. These patients were predominantly females in their eighth decade with lower prevalence of floor of the mouth cancers compared to SD patients (1.8% vs 14.8%). No difference in the RFS and DSS between both groups was found following multivariable analysis; however, NSND patients had better OS (HR (95% CI) - 0.47 (0.29-0.75); p = 0.002). Extracapsular extension was associated with significantly poorer OS, DSS, and RFS in this oral cavity cancer cohort.

CONCLUSION

Treatment response and disease-specific prognosis are comparable between NSND and SD patients with oral cavity cancer. However, NSND patients have better OS.

CLINICAL RELEVANCE

This study shows that oral cavity cancer in NSND is not less or more aggressive compared to SD patients. Although better survival is expected for NSND than SD patients, this is likely due to the reduced incidence of other chronic diseases in the NSND group.

Multiple tumour recurrence in oral, head and neck cancer: Characterising the patient journey

BACKGROUND

Oral squamous cell carcinoma (OSCC) is the 15th most common cause of cancer-related mortality worldwide and approximately one oral cancer-related death occurs for every two new diagnoses. Death-due-to-disease is usually ascribed to inoperable primary tumours, treatment complications, second primary tumours arising due to field cancerization, or locoregional recurrence and distant metastases.

METHODS

A retrospective review of OSCC patients treated over a 19-year period, betweenOctober 1^st , 2000 and October 1^st , 2019. Patient demographic records were collected from consecutively treated adult patients with clinical subtypes corresponding to ICD-10 C00-C06, C09 and C10 were retrieved from the database. Patients who had suffered three or more recurrences after diagnosis of the primary tumour are defined as multiple-recurrent patients.

RESULTS

A total of 467 OSCC patients were treated during the study period. One hundred and fifty-five patients developed recurrent OSCC, amongst which 22 were designated as multiple cases. The time between initial OSCC diagnosis and first tumour recurrence varied from 3 to 276 months. Nine of the 22 multiple patients (41%) were diagnosed with buccal mucosal SCC as the primary tumour, which is significantly higher than the average prevalence (or 4.4, 95% CI (1.8, 10.8), p < 0.001) for buccal tumours within the cohort. All patients were treated initially by surgical tumour excision. There were no demonstrable differences in adjuvant chemo-radiotherapy regimes in any of the study groups.

CONCLUSION

Multiple OSCC development may occur either synchronously or metachronously during the course of oral cancer disease and poses an important management problem in contemporary oncology practice.

Two-year follow-up of a randomized phase III clinical trial of nivolumab vs. the investigator's choice of therapy in the Asian population for recurrent or metastatic squamous cell carcinoma of the head and neck (CheckMate 141)

Background

The present study evaluated the 2‐year survival of the Asian population in the CheckMate 141 trial.

Methods

The CheckMate 141 trial included patients with recurrent or metastatic (R/M) squamous cell carcinoma of the head and neck (SCCHN). In the present study, 34 Asian patients (nivolumab group: 23 patients; investigator's choice of therapy [IC] group: 11 patients) were analyzed.

Results

The median overall survival (OS) was 12.1 and 6.2 months for the nivolumab and IC groups, respectively. The estimated 2‐year OS rates were 22.7% and 0% for the nivolumab and IC groups, respectively. In the nivolumab group, the patients with any treatment‐related adverse events (TRAEs), including skin‐related disorders, showed better OS than the patients without any TRAEs.

Conclusions

Nivolumab demonstrated prolonged OS benefits in the Asian population with platinum‐refractory R/M SCCHN and a favorable safety profile. TRAEs, including skin‐related disorders, may be favorable prognostic factors for nivolumab efficacy.

Clinical trial registration

NCT02105636.

Bayesian disease mapping and the 'High-Risk' oral cancer population in Hong Kong

BACKGROUND

Preventive and early diagnostic methods such as health promotion and disease screening are increasingly advocated to improve detection and survival rates for oral cancer. These strategies are most effective when targeted at "high-risk" individuals and populations. Bayesian disease-mapping modelling is a statistical method to quantify and explain spatial and temporal patterns for risk and covariate factor influence, thereby identifying "high-risk" sub-regions or "case clustering" for targeted intervention. Rarely applied to oral cancer epidemiology, this paper highlights the efficacy of disease mapping for the Hong Kong population.

METHODS

Following ethical approval, anonymized individual-level data for oral cancer diagnoses were obtained retrospectively from the Clinical Data Analysis and Reporting System (CDARS) of the Hong Kong Hospital Authority (HA) database for a 7-year period (January 2013 to December 2019). Data facilitated disease mapping and estimation of relative risks of oral cancer incidence and mortality.

RESULTS

A total of 3,341 new oral cancer cases and 1,506 oral cancer-related deaths were recorded during the 7-year study period. Five districts, located in Hong Kong Island and Kowloon, exhibited considerably higher relative incidence risks with 1 significant "case cluster" hotspot. Six districts displayed higher mortality risks than expected from territory-wide values, with highest risk identified for two districts of Hong Kong Island.

CONCLUSION

Bayesian disease mapping is successful in identifying and characterizing "high-risk" areas for oral cancer incidence and mortality within a community. This should facilitate targeted preventive and interventional strategies. Further work is encouraged to enhance global-level data and comprehensive mapping of oral cancer incidence, mortality and survival.