Oral Cancer

Initial evaluation of oral cancer diagnosis begins with a thorough clinical examination.
A physician, dentist, or otolaryngologist (ear, nose & throat specialist) will inspect the entire oral cavity — including the lips, tongue, floor of the mouth, cheeks, gums, and palate — and palpate the neck for enlarged lymph nodes.

[Biopsy]

Tissue biopsy is the definitive method for confirming an oral cancer diagnosis. Suspicious lesions are sampled either by:

• Incisional biopsy: A small piece of tissue is surgically removed for histopathological analysis.
• Brush biopsy (exfoliative cytology): A small brush or spatula is used to collect surface cells from the lesion.

Pathological analysis determines not only whether cancer is present but also the cell type and degree of differentiation.

[Imaging studies]

Once a diagnosis is confirmed, imaging is required to determine the extent of disease:

• CT (Computed Tomography): Evaluates tumor size, depth of invasion, and regional lymph node involvement, particularly in bony structures.
• MRI (Magnetic Resonance Imaging): Provides superior soft tissue detail and is used to assess tongue involvement, floor-of-mouth tumors, and perineural invasion.
• PET-CT (Positron Emission Tomography – CT): Detects regional and distant metastases, and is especially useful for staging advanced disease.
• Chest X-ray or chest CT: Performed to rule out pulmonary metastasis.

Endoscopic evaluation: Laryngoscopy and pharyngoscopy may be performed to evaluate the extent of disease into adjacent structures such as the oropharynx and larynx, and to rule out synchronous second primary tumors.

Oral cancer is staged using the TNM system established by the American Joint Committee on Cancer (AJCC):

Stage I

• Tumor ≤ 2 cm in greatest dimension; no lymph node involvement; no distant metastasis
  
  

Stage II

• Tumor > 2 cm but ≤ 4 cm; no lymph node involvement; no distant metastasis
  
  

Stage III

• Tumor > 4 cm; OR tumor of any size with a single ipsilateral lymph node ≤ 3 cm; no distant metastasis
  
  

Stage IVA

• Moderately advanced local disease with invasion of adjacent structures; OR multiple or contralateral lymph node involvement (nodes ≤ 6 cm)
  
  

Stage IVB

• Very advanced local disease (tumor invades masticator space, pterygoid plates, skull base, or encases carotid artery); OR lymph node(s) > 6 cm
  
  

Stage IVC

• Distant metastasis present
  
  

The stage at diagnosis is one of the most important determinants of treatment planning and prognosis. Unfortunately, many patients are diagnosed at Stage III or IV, underscoring the importance of early detection.

Treatment is determined based on tumor stage, location, depth of invasion, and the patient's overall health and functional goals. Oral cancer treatment is most effective when delivered by a multidisciplinary team including head and neck surgeons, radiation oncologists, medical oncologists, reconstructive surgeons, speech therapists, and dietitians.

[Surgery]

Surgery is generally the primary treatment modality for resectable oral cavity cancers and takes priority over other treatment options in most cases.

Common surgical procedures include:

• Primary tumor resection: Surgical removal of the tumor with adequate margins, performed through the mouth (transoral) or via an external neck incision.
• Glossectomy: Partial or total removal of the tongue, performed for tongue cancer.
• Mandibulectomy: Partial resection of the mandible (jawbone) when the tumor invades bone.
• Maxillectomy: Removal of part or all of the hard palate when the tumor affects the upper jaw.
• Neck dissection: Removal of lymph nodes from the neck to address regional metastasis.
• Reconstructive surgery: When large areas of tissue are removed, reconstruction is necessary to restore form and function. Healthy tissue and bone — often from the forearm (radial forearm free flap), fibula, or thigh — are used to fill surgical defects. Reconstruction procedures typically last 6–7 hours, and flap survival rates are approximately 95%. 

[Radiation therapy]

Radiation therapy is one of the most widely used treatment approaches for oral cancer, either as a definitive treatment, in combination with chemotherapy, or as post-operative adjuvant therapy to eliminate residual microscopic disease.

• Treatment schedule: Typically 5 sessions per week over 6–7 weeks (total 30–40 sessions).
• Timing after surgery: Adjuvant radiation generally begins 4–6 weeks after surgery, once surgical wounds have healed.
• Advantage: High-energy X-rays target and destroy cancer cells while sparing surrounding oral structures.

[Chemotherapy]

Chemotherapy is typically used in combination with radiation therapy (concurrent chemoradiation) for advanced or unresectable tumors, or as adjuvant therapy after surgery in high-risk cases. It may also be used for recurrent or metastatic disease.