From the Guidelines
Squamous cell carcinoma of the oral cavity, particularly those affecting the tongue, is predominantly linked to alcohol and tobacco abuse, with a significant proportion being attributed to human papillomavirus (HPV) infection, especially in the oropharynx. The epidemiology of squamous cell carcinoma, including its variants, shows that it accounts for more than 90% of oral cavity and pharyngeal cancers 1. Key risk factors include:
- Alcohol abuse
- Tobacco abuse, which is a common etiologic factor in cancers of the oral cavity, oropharynx, and hypopharynx
- Human papillomavirus (HPV) infection, now well accepted as a risk factor for the development of squamous cancers of the oropharynx The overall incidence of HPV-positive head and neck (H&N) cancer is increasing in the United States, as noted in studies focusing on head and neck cancers 1.
Regarding the epidemiology and recurrent incidence, patients with head and neck cancer are at risk for developing second primary neoplasms of the H&N, lung, esophagus, and other sites that share these risk factors due to the exposure of the entire aerodigestive tract epithelium to carcinogens like alcohol and tobacco 1. The estimated new cases and deaths from oral cavity and pharyngeal cancers provide insight into the burden of these diseases, with an estimated 36,500 new cases and 7,900 deaths occurring in 2010 in the United States 1.
The epidemiology of squamous cell carcinoma, including its recurrence, highlights the importance of addressing modifiable risk factors such as tobacco and alcohol use, and the role of HPV infection in the development of these cancers, particularly in the oropharynx 1. The management and follow-up of patients with squamous cell carcinoma of the oral cavity, including those affecting the tongue, should prioritize smoking cessation, reduction of alcohol consumption, and consideration of HPV vaccination to prevent secondary cases, based on the most recent understanding of the disease's epidemiology and risk factors 1.
From the Research
Epidemiology of Squamous Cell Carcinoma of the Tongue
- The incidence of oral tongue squamous cell carcinoma is rising among those under age 50 years, with unknown etiology 2.
- A study of 395 cases of oral tongue squamous cell carcinoma found that 28.6% were early onset (age < 50 years) 2.
- Women comprised 25 percent of the patients with tumors of the base of the tongue and 45 percent of those with mobile tongue lesions 3.
Recurrent Incidence and Epidemiology
- The majority of patients with squamous cell carcinoma of the tongue base (77 percent) presented with advanced (stage III or IV) lesions at time of initial clinical and diagnostic staging 3.
- A systematic review of 13 articles found that the reported 5-year rates of disease-free survival ranged from 30% to 72% for the younger cohorts and 42% to 81% for the older cohorts 4.
- Three studies reported a statistically significant increased risk of recurrence in younger patients, while seven studies reported a similar risk in younger patients based on the time-to-event analyses 4.
- Early onset patients had better overall survival, with an adjusted hazard ratio of 0.6 2.
- The recognition of SCC subtypes is crucial for proper treatment, as some subtypes have distinct pathological features and biological behaviors 5.
Risk Factors and Patient Outcomes
- Patients with early onset oral tongue squamous cell carcinoma were more likely to receive multimodality treatment and report a history of snuff use 2.
- A history of cigarette use was less likely to be reported by early onset patients 2.
- The pattern of invasion, budding, desmoplastic reaction, lymphovascular invasion, and perineural invasion are morphological factors that could be predictive of prognosis 5.