The Link Between Tobacco, Alcohol, and Oral Cancer

Oral cancer is a significant public health problem worldwide, ranking as the 6th most common cancer with a 5-year survival rate of 50% [1]. It accounts for roughly 3% of all cancers diagnosed annually in the United States. On average, 90% of these cases are oral squamous cell carcinoma (OSCC). The American Cancer Society’s most recent estimates for oral cavity and oropharyngeal cancers in the United States are for 2024 [2]:

• Approximately 58,450 new cases of oral cavity or oropharyngeal cancer

• About 12,230 deaths from oral cavity or oropharyngeal cancer

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Although some cases can be challenging to diagnose, oral cancer is usually associated with clinical phenotypes and risk factors that clinicians must recognize to avoid delays in diagnosis or misdiagnosis. Studies have shown that oral screening programs reduce delayed diagnosis and mortality by an average of 21-26% and increase the survival rate to 45% [3].

Common Locations of OSCC

• The most common intraoral locations (Figure 1) are the lateral borders and the base of the tongue. Less common sites include the lips, gingiva, dorsal tongue, palate, and salivary glands.
• Primary squamous cell carcinoma (SCC) of bone is rare; however, a tumor may develop from epithelial rests and epithelium of odontogenic lesions, including cysts and benign lesions.

Figure 1: Diagram of the intraoral locations 

Etiology and Risk Factors of OSCC

• Tobacco: Tobacco is the strongest risk factor for OSCC (80% of patients with OSCC have a history of smoking or other tobacco exposure) due to its potent carcinogens (a total of 83 carcinogens have been identified) [4, 5]. Smoking contains addictive drugs such as nicotine, making it challenging for patients to quit. However, it’s essential to note that quitting smoking can reduce the risk of cancer by about 35% within the first 4 years, with an 80% reduction by 20 years of cessation [6].
• Other forms of tobacco products (snuff, dip, spit, chew, dissolvable) are also linked to oral cancer and oral potential malignant disorders (OPMD)(Table 1). The most common sites for these forms are the buccal, gingiva, and labial mucosa. Early diagnosis and treatment of OPMD can prevent transformation to OSCC and increase the 5-year survival rate [10].

• Alcohol: All forms of alcohol, including hard liquor, wine, and beer, have been implicated in the etiology of oral cancer. Heavy drinkers are at higher risk than light drinkers. The synergistic effects of alcohol and tobacco may include the dehydrating effects of alcohol on the mucosa, increased mucosal permeability, and the effects of potential carcinogens in alcohol or tobacco [8,11,13].
• Smoking and drinking alcohol together multiply the risk of oral cancer. The risk of OSCC in people who heavily smoke and drink is about 30 times higher than in those who don’t smoke or drink. In the case of chewing tobacco and alcohol drinking, the risk of oral cancer increases by 24-fold [10,11].

Other risk factors of OSCC

These include but are not limited to, certain medical conditions or syndromes like Fanconi’s anemia, Li-Fraumeni syndrome, Dyskeratosis congenita, excess body weight, certain types of HPV (human papillomavirus, type 16, most associated with OSCC), age (average older than 55 years old, not linked to HPV, and younger than 55 with HPV positive), and poor nutrition (8).

Importantly, OSCC and OPMD can also occur in patients without any risk factors like smoking/alcohol or syndromes. The majority of healthy patients who get oral cancer still get it on the tongue, so screening is essential in any age adult to rule out oral cancer or catch precancerous lesions and early-stage disease [14].

Signs and Symptoms [6,7,12,15]

• Dysphagia, odynophagia, otalgia, limited movement, oral bleeding, neck masses, and weight loss may occur with advanced OSCC.
• Paresthesia, including unilateral numbness and dysesthesia, may indicate neural involvement and require ruling out cancer.
• Loss of tongue function can affect speech, swallowing, and diet.
• Non-homogeneous white, red, or mixed red and white lesions; changes in surface texture producing smooth, granular, rough, or crusted lesions; or the presence of a mass or ulceration for more than 10-14 days should be evaluated.
• It’s essential to rule out causes such as trauma, chronic irritation, and infection (fungal, viral, or bacterial).

The Importance of Oral Cancer and OPMD Screening

Cancer screening and preventive dental care are crucial in identifying and addressing potential issues before they escalate. Regular dental check-ups allow oral healthcare providers to monitor oral health status, perform screenings for oral cancers, and provide timely interventions when necessary. By attending routine appointments, individuals can stay proactive about their oral health and minimize the risk of overlooking OPMD and oral cancer.

Conclusion

In conclusion, recognizing tobacco and alcohol as key risk factors for oral cancer is essential in both clinical practice and public health initiatives. With oral cancer ranking as the 6th most common cancer worldwide and accounting for a significant portion of cancer-related deaths, understanding and addressing these risk factors are vital. Through early detection, timely intervention, and preventive measures such as smoking cessation and moderation of alcohol consumption, we can significantly reduce the burden of oral cancer. Moreover, the importance of regular oral cancer screenings cannot be overstated, as they play a crucial role in identifying and addressing potential issues before they progress to advanced stages. By prioritizing awareness, education, and proactive healthcare measures, we can work towards a future where oral cancer incidence and mortality rates are significantly reduced.

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References

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