Oral Squamous Cell Carcinoma (OSCC) is the most common malignancy affecting the oral cavity and the throat, accounting for approximately 90% of all cancers found in this region. This disease arises from the cells lining the moist surfaces inside the mouth and the back of the throat. Early identification is a significant factor in successful treatment, making awareness of its symptoms and causes important.
Defining Oral Squamous Cell Carcinoma
OSCC originates in the squamous cells, which are the flat, thin cells that form the lining, or epithelium, of the oral cavity and oropharynx. This cancer is a type of head and neck squamous cell carcinoma (HNSCC) and is one of the most prevalent oral malignancies worldwide. The areas most frequently affected include the lateral border of the tongue, the floor of the mouth, and the lower lip. It can also develop on the gums, the inner lining of the cheeks (buccal mucosa), the hard palate, and the tonsils. Because the disease often begins without causing pain, detection is frequently delayed until it has reached later stages.
Recognizable Symptoms and Warning Signs
The initial presentation of OSCC can often be subtle, with early-stage lesions sometimes being asymptomatic. The most frequent warning sign is the presence of a mouth sore or ulcer that fails to heal. Any non-healing sore on the lips or inside the mouth that persists for more than two weeks warrants immediate professional evaluation.
Another common manifestation involves abnormal patches of tissue known as leukoplakia and erythroplakia. Leukoplakia appears as white, hyperkeratotic patches that cannot be scraped away. Erythroplakia presents as red, flat, or velvety eroded lesions. The red patches of erythroplakia are generally considered more concerning and are associated with a higher risk of turning cancerous than the white patches.
As the cancer progresses, it may present as a lump or a thickened area in the mouth, cheek, or neck. These masses are often firm to the touch and can sometimes have a rolled border. A person might also notice persistent pain, tenderness, or a feeling of numbness in the mouth, tongue, or face that does not resolve.
Functional difficulties are also indicators of a potential problem in the oral cavity or oropharynx. These can include pain or trouble when swallowing (dysphagia) or chewing food. Additionally, a persistent sore throat, chronic hoarseness, or a noticeable change in the voice may signal a tumor in the back of the mouth or throat. Other signs can involve jaw pain, swelling, or the loosening of teeth for no apparent dental reason.
Primary Risk Factors and Causes
The development of Oral Squamous Cell Carcinoma is often linked to exposure to various environmental factors. The two most significant modifiable risk factors are the use of tobacco products and heavy consumption of alcohol. The combination of both habits dramatically increases the danger, with the risk of developing oral cancer estimated to be substantially higher for those who heavily use both substances compared to those who use neither.
Tobacco use, in all its forms, introduces cancer-causing chemicals that damage the DNA of the squamous cells lining the mouth. This includes smoking cigarettes, cigars, and pipes, as well as using smokeless products like chewing tobacco and snuff. The risk is dose-dependent, meaning that the more a person smokes or chews, the greater the likelihood of cellular mutation and cancer development.
Heavy alcohol intake contributes to risk by damaging the cells and potentially enhancing the ability of tobacco carcinogens to penetrate the mouth lining. Consuming more than a certain amount of distilled liquor, wine, or beer daily is associated with a sharply increased chance of developing OSCC.
The Human Papillomavirus (HPV), particularly strain HPV-16, has emerged as a cause, especially for cancers located in the oropharynx, which includes the tonsils and the base of the tongue. While HPV is a major independent cause of oropharyngeal squamous cell carcinoma, its contribution to cancers specifically within the oral cavity itself is less significant.
Ultraviolet (UV) radiation exposure is a distinct risk factor primarily associated with cancer on the lips, especially the lower lip. Other contributing factors include a diet lacking in fruits and vegetables and chronic physical irritation from poorly fitting dentures or rough teeth causing long-term trauma to the mucosal lining. Genetic predisposition may also play a role in a small number of cases.