What are the treatment options for oral cavity cancer?

Treatment of Oral Cavity Cancer

For oral cavity cancer, surgery is the primary treatment modality, followed by risk-adapted adjuvant radiotherapy or chemoradiotherapy based on pathologic features, with early-stage disease (T1-2N0) treated with single-modality therapy and locally advanced disease requiring multimodal approaches. 1

Early-Stage Disease (T1-2N0, Stage I-II)

Single-modality treatment is the standard approach for early-stage oral cavity cancer. 1

Primary Treatment Options:

• Conservative surgery provides similar locoregional control to radiotherapy and is generally preferred for oral cavity tumors 1
• Radiotherapy alone (EBRT or brachytherapy) is an alternative for selected subsites, though this is based on retrospective data only 1
• The choice between surgery and radiotherapy should prioritize functional outcome and treatment morbidity for each individual patient 1

Neck Management for Early Disease:

• If depth of invasion (DOI) <5 mm and cT1N0: active surveillance of the neck is acceptable 1
• If DOI <10 mm: sentinel lymph node biopsy is a valid option 1
• If DOI ≥10 mm: elective neck dissection is recommended 1

Locally Advanced Disease (T3-4a or N+, Stage III-IVA)

Primary surgical resection followed by risk-adapted adjuvant therapy is the standard treatment for resectable locally advanced oral cavity cancer. 1

Surgical Approach:

• Wide surgical excision with appropriate reconstruction is mandatory for T3/T4 oral cavity cancers 1
• Free vascularized soft tissue flaps (radial forearm, anterolateral thigh) are preferred when mandibular continuity is intact 1
• Bony flaps (fibula) are required if mandibular continuity is disrupted 1
• Neck dissection should be performed for all node-positive disease 1

Adjuvant Therapy Decision-Making:

Adjuvant chemoradiotherapy (CRT) reduces the risk of death by 16% compared to radiotherapy alone and is indicated for high-risk pathologic features. 2

High-Risk Features Requiring Adjuvant CRT:

• Positive surgical margins 1, 3
• Extracapsular extension in lymph nodes 1, 3
• These patients should receive 60-66 Gy at 2 Gy/fraction with concurrent cisplatin 4

Intermediate-Risk Features Requiring Adjuvant RT Alone:

• Multiple positive lymph nodes without extracapsular extension 1
• Perineural invasion 1
• Lymphovascular invasion 1
• Close margins 4
• These patients should receive 56-60 Gy in standard fractionation 4

Chemotherapy Regimen for Adjuvant CRT:

• Cisplatin 100 mg/m² every 3 weeks is the standard regimen (total dose 200 mg/m²) 1
• Weekly cisplatin 30 mg/m² is inferior and should not be used 1
• Platinum plus 5-fluorouracil is an alternative for patients who cannot tolerate high-dose cisplatin 1

Critical Timing:

• Treatment must begin within 6-7 weeks of surgery 4
• The entire treatment sequence must be completed within 11 weeks 4
• Any delays should be avoided as they negatively impact local control 1

Unresectable Disease (T4b or Fixed Nodes, Stage IVB)

For unresectable oral cavity cancer, concurrent chemoradiotherapy is the standard treatment, reducing the risk of death by more than 20% compared to radiotherapy alone. 1, 2

Primary CRT Approach:

• Concurrent cisplatin-based CRT is the standard 1
• Gross disease receives 70 Gy in 2.0 Gy fractions 4
• Elective nodal regions receive 44-64 Gy (1.6-2.0 Gy/fraction) 4
• Cisplatin 100 mg/m² every 3 weeks remains the preferred chemotherapy regimen 1

Alternative Options:

• Induction chemotherapy (cisplatin plus 5-FU) followed by RT or CRT for responders is an option, though evidence for survival benefit is insufficient 1, 2
• Cetuximab with radiotherapy is inferior to cisplatin-based CRT and should not be used as a substitute 1

Special Considerations

Adenoid Cystic Carcinoma:

• Surgery and radiotherapy are the standards of care 3
• Postoperative CRT should be considered for adverse pathologic features 3
• PET-CT may be useful for identifying additional disease sites in suspected advanced disease 3

Pre-Treatment Optimization:

• Nutritional assessment is mandatory - patients with >10% weight loss in 6 months require enteral feeding before treatment 1
• Dental evaluation and rehabilitation are essential before radiotherapy 1, 4
• Percutaneous gastrostomy is preferred over nasogastric tube for long-term support 1

Pathologic Assessment Requirements:

• Depth of invasion (DOI) must be measured 1
• Number of invaded lymph nodes must be documented 1
• Extracapsular extension must be assessed 1
• Surgical margin status must be clearly reported 1

Common Pitfalls to Avoid

• Do not use weekly cisplatin 30 mg/m² in the curative setting - it is inferior to 3-weekly dosing 1
• Do not substitute cetuximab for cisplatin in concurrent CRT for oral cavity cancer - it is less effective 1
• Do not delay adjuvant treatment beyond 6-7 weeks post-surgery - delays compromise outcomes 4
• Do not use primary radiotherapy or CRT for resectable oral cavity cancer - surgery is the preferred primary modality 1, 5
• Do not omit dental evaluation before radiotherapy - this leads to severe complications including osteoradionecrosis 4, 6

Recurrent/Metastatic Disease

• PD-L1 expression should be evaluated for treatment planning 1
• Palliative systemic therapy (chemotherapy/immunotherapy) and/or palliative RT are options 1
• Best supportive care should be considered based on performance status 1