Oral Cavity Cancer

Oral cavity cancer is a malignant tumor arising from structures within the oral cavity. The oral cavity includes:

• Upper and lower lips.

• Gingivobuccal sulcus.

• Buccal mucosa.

• Upper and lower gingiva.

• Retromolar trigone.

• Hard palate.

• Floor of the mouth.

• Anterior two-thirds of the tongue.

The majority of oral cavity cancers are epithelial malignancies, commonly squamous cell carcinomas. The disease may cause significant functional impairment affecting speech, swallowing, nutrition, and quality of life.

Early detection is important because localized disease can often be treated successfully with single-modality therapy.

Epidemiology

Oral cavity cancer is one of the common malignancies of the head and neck region. Its occurrence varies according to exposure to risk factors, lifestyle practices, and geographical location.

Many patients present late due to delayed recognition of early oral lesions, leading to advanced local disease and lymph node involvement.

Risk factors

Risk factors associated with oral cavity cancer include:

• Tobacco smoking.

• Excessive alcohol consumption.

• Poor oral hygiene.

• Prolonged focal irritation from dentures.

• Betel nut chewing.

• Syphilis.

• Human papillomavirus (HPV) infection.

• Increasing age.

The combination of tobacco and alcohol significantly increases the risk of oral cavity malignancy.

Pathophysiology

Oral cavity cancer develops through malignant transformation of epithelial cells lining the oral mucosa.

Chronic exposure to carcinogenic factors leads to:

• Cellular injury.

• Genetic mutations.

• Abnormal epithelial growth.

• Development of malignant lesions.

• Local invasion of adjacent structures.

• Spread to cervical lymph nodes.

• Distant metastasis in advanced disease.

The pattern of spread depends on the primary site and tumor characteristics.

Clinical presentation

Clinical features depend on:

• Site of origin.

• Tumor size.

• Depth of invasion.

• Presence of lymph node involvement.

Early lesions may be asymptomatic or present as persistent mucosal changes, while advanced disease causes functional symptoms.

Symptoms

Common symptoms include:

• Non-healing oral ulcer.

• Speech difficulty.

• Excessive salivation (hypersalivation).

• Neck mass.

• Dysphagia.

• Ear pain (otalgia).

• Persistent oral discomfort.

• Difficulty chewing.

• Altered sensation in the mouth.

Clinical signs

Clinical findings may include:

• Persistent oral ulcer.

• Oral mass or swelling.

• Abnormal mucosal changes.

• Restricted tongue movement.

• Cervical lymphadenopathy.

• Evidence of local tissue invasion.

• Poor dental and oral health.

Differential diagnosis

Conditions that may mimic oral cavity cancer include:

• Aphthous ulcers.

• Traumatic oral ulcers.

• Oral candidiasis.

• Leukoplakia.

• Erythroplakia.

• Benign oral tumors.

• Chronic inflammatory oral lesions.

• Syphilitic oral lesions.

• Tuberculosis of the oral cavity.

Diagnostic criteria

Oral cavity cancer should be suspected in patients presenting with:

• Non-healing oral ulcer.

• Persistent oral mass.

• Speech difficulty.

• Dysphagia.

• Neck mass.

• Persistent unexplained oral symptoms.

Definitive diagnosis requires histopathological confirmation by biopsy.

Investigations

Laboratory investigations

• Full blood count (FBC).

• Liver function tests (LFT).

• Renal function tests (RFT).

• HIV test.

Imaging investigations

• Chest X-ray (CXR).

• Computed tomography (CT) scan of the head and neck.

• Magnetic resonance imaging (MRI) of the head and neck.

Imaging assesses:

• Primary tumor extent.

• Depth of invasion.

• Bone involvement.

• Cervical lymph node involvement.

• Possible metastatic disease.

Endoscopic examination

• Mirror examination.

• Fibre-optic endoscopic examination.

Histopathological investigation

• Biopsy of the lesion for histological confirmation.

Histology confirms diagnosis and guides treatment planning.

Diagnostic staging

Oral cavity cancer is staged using:

• TNM staging system.

Management

Management depends on:

• Disease stage.

• Tumor site.

• Resectability.

• Presence of lymph node involvement.

• Patient general condition.

The main treatment modalities include:

• Surgery.

• Radiotherapy.

• Chemotherapy.

A multidisciplinary approach is recommended involving surgical, radiation, and medical oncology teams.

Non-pharmacological treatment

Surgery

Surgery is the mainstay treatment modality for oral cavity cancer.

The aim of surgery is:

• Complete removal of the primary tumor.

• Achievement of clear surgical margins.

• Management of regional lymph nodes when indicated.

Early-stage disease

For early-stage oral cavity cancer:

• Single modality treatment is preferred.

Options include:

• Surgery alone.

OR

• Radiotherapy alone.

Choice depends on tumor characteristics and clinical considerations.

Locally advanced unresectable disease

For unresectable locally advanced disease:

• Definitive radiotherapy with concurrent chemotherapy is the current standard treatment approach.

Radiotherapy

Radiotherapy may be used:

• As definitive treatment in selected patients.

• In combination with chemotherapy for unresectable disease.

• As palliative treatment for primary tumors or metastatic sites.

Pharmacological treatment

(No chemotherapy drugs or specific dosing schedules were provided in the source information; therefore, no additional drug regimens are added.)

Chemotherapy may be used:

• Concurrently with radiotherapy for unresectable locally advanced disease.

• As palliative treatment in very advanced disease.

Management according to disease stage

Early-stage oral cavity cancer

Management:

• Surgery alone.

OR

• Radiotherapy alone.

Single modality treatment is preferred.

Locally advanced resectable disease

Management:

• Surgical treatment as the primary modality.

Additional treatment may be considered depending on pathological findings.

Locally advanced unresectable disease

Management:

• Definitive radiotherapy with concurrent chemotherapy.

Advanced metastatic disease

Management:

• Palliative radiotherapy for symptomatic primary or metastatic sites.

AND/OR

• Palliative chemotherapy for very advanced disease.

Referral

All patients with suspected or confirmed oral cavity cancer should be referred to a specialized head and neck oncology center for:

• Histological confirmation.

• TNM staging.

• Surgical assessment.

• Multidisciplinary treatment planning.

Urgent referral is required for:

• Non-healing oral ulcers.

• Persistent oral masses.

• Neck masses.

• Progressive swallowing difficulty.

• Persistent unexplained oral symptoms.

Complications

Complications may include:

• Difficulty swallowing.

• Speech impairment.

• Malnutrition.

• Airway compromise.

• Cervical lymph node metastasis.

• Facial disfigurement.

• Local recurrence.

• Distant metastasis.

• Treatment-related complications.

Prognosis

Prognosis depends on:

• Stage at diagnosis.

• Tumor size.

• Depth of invasion.

• Cervical lymph node involvement.

• Completeness of surgical removal.

• Response to treatment.

Early-stage disease has better outcomes compared with advanced disease.

Prevention

Preventive measures include:

• Avoidance of tobacco use.

• Limiting alcohol consumption.

• Avoidance of betel nut chewing.

• Maintaining good oral hygiene.

• Regular dental examination.

• Early assessment of persistent oral lesions.

• Prompt treatment of suspicious oral abnormalities.

Follow-up

Patients require regular follow-up after treatment to monitor:

• Local recurrence.

• Cervical lymph node recurrence.

• Distant metastasis.

• Functional outcomes.

• Nutritional status.

Follow-up may include:

• Clinical oral examination.

• Neck examination.

• Endoscopic assessment when indicated.

• Imaging studies when clinically required.