Oral cancer screening: Insights into epidemiology, risk factors, and screening programs for improved early detection

Cancer is a complex disease characterized by uncontrolled cell growth, significantly impacting global health. Head and neck cancers rank as the sixth most prevalent cancers worldwide, with a higher incidence in South-central Asia. Oral squamous cell carcinoma (OSCC) is the predominant malignancy in this category, posing a significant health concern due to its high mortality and often late-stage diagnosis. The significance of early detection and appropriate screening measures cannot be overstated, as they play a pivotal role in improving survival rates and reducing the disease burden.

Overview of Oral Cancer

Oral cancer involves the malignant growth of cells in the mouth’s tissues, including the lips, tongue, gums, cheeks, and throat. The five-year survival rate is discouragingly low, between 50% and 60%, largely due to late diagnosis. Early detection is crucial for improving prognosis and survival rates. However, diagnostic delays are common, often attributed to patient-related issues like lack of awareness and delayed consultation, as well as healthcare provider factors such as misdiagnosis or inadequate suspicion of malignancy.

Epidemiology

The global burden of oral cancer is substantial, with approximately 377,713 new cases and 177,757 deaths in 2020, predominantly in Asia. India faces a particularly high incidence due to cultural and behavioral factors like tobacco use. Oral cancer is the most diagnosed cancer among men and the third among women in India, with significant regional variations in incidence and mortality rates. The high prevalence in South-central Asia can be linked to specific risk behaviors and socioeconomic factors that necessitate targeted public health interventions.

Characteristics

Over 90% of oral cancers are OSCCs, often located in the tongue and floor of the mouth. Early-stage carcinomas typically go unnoticed due to the absence of symptoms, leading to late-stage diagnoses characterized by pain, bleeding, and other severe symptoms. The prognosis is poor once the disease progresses to advanced stages. Early detection relies heavily on clinical examination and biopsy. Recognizing the subtle clinical signs in the early stages can significantly alter the treatment outcomes and improve survival rates.

Risk Factors

Major risk factors for oral cancer include tobacco use, alcohol consumption, betel quid chewing, and HPV infection. These factors contribute to the majority of oral cancer cases, with synergistic effects observed when multiple risk factors are present. Other factors include the oral microbiome, chronic mucosal inflammation, and trauma from dental prosthetics. Ultraviolet radiation is a significant risk for lip cancer, while genetic conditions like Xeroderma pigmentosum increase susceptibility. Public health efforts aimed at reducing these risk factors can lead to a significant decrease in oral cancer incidence.

Prevention and Detection

Prevention strategies focus on reducing risk factors such as tobacco and alcohol use. Public health campaigns and policy measures targeting these behaviors are crucial for primary prevention. Secondary prevention involves screening high-risk populations to detect oral cancer early. Clinical trials in India have shown that reducing tobacco and betel quid use can lower the risk of malignancy. Nutritional interventions with vitamins C, A, and E may also reduce cancer risk. Regular clinical examinations and biopsies are crucial for early detection, particularly in high-risk areas like the floor of the mouth and the tongue. Implementing community-based screening programs can facilitate early diagnosis and treatment, improving patient outcomes.

Screening Techniques

Conventional screening methods include visual and tactile examinations, but these have limitations such as sampling bias. Visual inspection alone may miss early or subtle lesions. Advanced techniques like imaging and artificial intelligence (AI) are being explored to improve accuracy. Imaging technologies such as autofluorescence, narrow-band imaging, and optical coherence tomography enhance the visualization of suspicious lesions. AI, in particular, shows promise in integrating with conventional methods to enhance early detection and intervention strategies. AI algorithms can analyze large datasets, identify patterns, and assist clinicians in making more accurate diagnoses.

Conclusions

Early detection of oral cancer is critical for improving patient outcomes and reducing mortality. By integrating advanced technologies like imaging and AI with traditional screening methods, the accuracy and effectiveness of early detection can be significantly improved. This approach is particularly vital for underdeveloped and developing nations, where the burden of oral cancer is highest. Effective screening and prevention strategies can lead to earlier detection, more successful interventions, and ultimately, better prognosis for patients. Public health policies focusing on education, risk factor modification, and accessible screening programs are essential for combating the high incidence of oral cancer and improving global health outcomes.

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The study was recently published in the Cancer Screening and Prevention.

Cancer Screening and Prevention (CSP) publishes high-quality research and review articles related to cancer screening and prevention. It aims to provide a platform for studies that develop innovative and creative strategies and precise models for screening, early detection, and prevention of various cancers. Studies on the integration of precision cancer prevention multiomics where cancer screening, early detection and prevention regimens can precisely reflect the risk of cancer from dissected genomic and environmental parameters are particularly welcome.

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