Oral cancer (OC) is a public health problem in Brazil, with high morbidity and mortality, mainly associated with late diagnosis, which implies high-cost treatments and great social impact, with aesthetic and functional sequelae. Smokers and alcoholics are at increased risk for the disease, being early detection the most effective way to increase survival. In Brazil, cancer plan recommends early diagnosis of OC through opportunistic examination, which is carried out during regular visits to the dentist. However, this strategy has not yet been able to reverse the late diagnosis, which may be due to the low access to dental appointments by the most vulnerable groups. Studies point to the effectiveness of the preventive physical examination of the mouth for early detection when directed to the high-risk population. The aim of the present study is to compare different strategies aimed at expanding the access of the high-risk population to preventive physical examination of the mouth. A cluster-randomized trial (control group and experimental groups I and II) will be carried out in Primary Health Care units in Programmatic Area 5.2 of the city of Rio de Janeiro (eight neighborhoods in the West Zone).

In the control group, there will be no change in current care. In both experimental groups, Community Agents and health professionals will be trained in OC prevention and instructed to call the users with high-risk for OC to the preventive examination of the mouth at the health unit. After 6 months, in experimental group I, an active search will be carried out for users who did not show up for the preventive examination, while in experimental group II, a campaign on OC will be carried out for a month, inviting the population to the preventive examination. After one year, the number of people at increased risk for OC examined in each group will be compared and correlated with sociodemographic and clinicopathological variables.

Oral cancer (OC) is a significant public health concern in Brazil, with the country having the highest incidence of the disease in Latin America. It ranks as the fourth most common cancer among men in the southeast region. This condition carries substantial morbidity and mortality, largely due to the majority of patients being diagnosed at advanced stages, leading to elevated treatment costs, prolonged rehabilitation, and profound social impacts such as loss of labor capacity and exclusion from social environments.

Squamous cell carcinoma, constituting 90 to 95% of OC cases, primarily affects men over 50 years old, with an emerging incidence in individuals under 40. In Brazil, the lateral border of the tongue is the primary site, characterized by invasive growth, significant recurrence rates, and metastasis to regional lymph nodes.

The main etiological factors for OC include tobacco and alcohol for intraoral lesions, prolonged exposure to ultraviolet (UV) radiation for lip cancer, and, for oropharyngeal cancer, human papillomavirus (HPV) infection. Cultural characteristics, socioeconomic level, and access to public health services also contribute to the variation in oral cancer incidence.

Primary prevention is paramount and involves educating individuals on behavioral risk factors, limiting tobacco and alcohol use, sun protection for the lips, HPV vaccination for oropharyngeal cancer prevention, and maintaining a healthy diet. Secondary prevention focuses on early disease through detection for pre-clinical signs and early diagnosis for individuals exhibiting suspected symptoms.

The justification for implementing a population screening program as a public health policy is based on established criteria. While OC meets ten out of the 19 criteria presented at the Global Oral Cancer Forum in 2016, its cost-effectiveness remains unproven, unlike breast and cervical cancer, which have well-defined population screening protocols.

Although a clinical trial in Kerala, India, did not demonstrate reduced OC mortality through population monitoring, a reanalysis in 2021 highlighted the effectiveness of targeted preventive mouth examinations by trained health professionals for at-risk populations.

In many countries, including Brazil, opportunistic examinations of the mouth's soft tissues are recommended for early diagnosis of lesions, but the majority of oral cancer cases are still diagnosed at advanced stages. The National Oral Health Policy, established in 2004, aims to promote, prevent, recover, and maintain oral health through primary care and specialized dental centers.

Recognizing structural and social determinants is crucial for effective prevention, detection, and management of OC. The "inverse screening law" highlights challenges in opportunistic examinations, and barriers to accessibility and diagnostic delays persist, especially among the elderly.

Despite the current strategy in Brazil relying on opportunistic testing, the majority of OC cases are diagnosed late. Weaknesses in the city of Rio de Janeiro, including low population coverage in Oral Health in Primary Care and limited access for at-risk populations, underscore the likely ineffectiveness of the current preventive strategy.

The present study is justified by the imperative to expand access to preventive oral examinations for individuals at increased risk for OC, aiming for early diagnosis and subsequently reducing mortality and morbidity.

Inclusion Criteria:

• Individuals who are regular smokers and/or chronic alcohol users
• Individuals registered as patients at Family Clinics within Programmatic Area 5.2 in the city of Rio de Janeiro
• Individuals aged 35 years or older

Exclusion Criteria:

• Individuals who have had a regular dental visit within the last 12 months