What is the management protocol for oral cavity cancer (Ca Oral Cavity) according to the latest National Comprehensive Cancer Network (NCCN) guidelines?

Management Protocol for Oral Cavity Cancer According to Latest NCCN Guidelines

Surgery is the preferred primary treatment for resectable oral cavity cancers, followed by risk-adapted adjuvant therapy based on pathological features. 1

Diagnosis and Staging

• Complete physical examination including neck palpation and flexible head and neck endoscopy with pathological confirmation through biopsy is mandatory
• Imaging studies required:
  • Contrast-enhanced CT scan and/or MRI to assess primary tumor and regional lymph nodes
  • Chest imaging (minimum chest CT) to assess for distant metastases
  • FDG-PET/CT recommended for high-risk tumors or suspected recurrence
  • Dental evaluation (including Panorex) particularly important for staging and treatment planning 1, 2

Treatment by Stage

Early Stage Disease (T1-2, N0)

1. Primary Treatment Options:

   • Surgery (preferred approach) 1, 2

     • Conservative surgical approaches including transoral techniques when appropriate
     • Selective neck dissection guided by tumor thickness
     • For tumors with depth of invasion <5mm and cT1N0: active surveillance of neck is an option
     • For tumors with depth of invasion <10mm: sentinel lymph node biopsy is valid

   • Radiotherapy (alternative option) 1, 2

     • External beam RT or brachytherapy for selected cases
     • Dose of 44-64 Gy to the neck for T1-2, N0 disease

Advanced Stage Disease (T3-4a, N0-3)

1. Primary Treatment:

   • Surgery followed by adjuvant therapy (preferred approach) 1, 2
   • For T3/T4 oral cavity cancers, primary surgical treatment is strongly recommended 1

2. Adjuvant Therapy Based on Risk Factors:

   • Postoperative RT (58-63 Gy) for high-risk features: 1

     • pT3-4 tumors
     • Close margins (between 1-5mm)
     • Perineural infiltration
     • Lymphovascular spread
     • Multiple positive lymph nodes

   • Postoperative CRT (66 Gy with cisplatin) for: 1

     • Positive margins (R1 resection)
     • Extracapsular nodal spread
     • Standard chemotherapy: cisplatin 100 mg/m² on days 1,22, and 43 of RT

Very Advanced Stage Disease (T4b, unresectable)

1. Treatment Options: 1
   • Concomitant chemoradiotherapy
   • Induction chemotherapy followed by RT or CRT for responders
   • Palliative treatment: systemic chemotherapy/immunotherapy and/or palliative RT

Management of Recurrent/Metastatic Disease

Treatment based on PD-L1 status and previous treatment: 1, 3

1. PD-L1 positive tumors:

   • Pembrolizumab monotherapy (for CPS ≥1)
   • Pembrolizumab plus platinum/5-FU

2. PD-L1 negative tumors:

   • Platinum/5-FU/cetuximab (EXTREME regimen)

3. After progression on platinum-based therapy:

   • Nivolumab or pembrolizumab for immunotherapy-naïve patients

Important Treatment Considerations

• Postoperative RT or CRT should start within 6-7 weeks after surgery 1
• Nutritional assessment is essential; significant malnutrition (>10% weight loss in 6 months) requires nutritional support before treatment 1
• Dental evaluation and rehabilitation before radiotherapy is necessary to prevent complications 2
• Thyroid function should be monitored after neck irradiation (TSH every 6-12 months) 1, 2

Follow-up and Surveillance

• Regular clinical examinations to monitor for recurrence and second primaries
• Most recurrences occur within the first 2 years after treatment
• Imaging studies as clinically indicated
• Assessment of treatment-related complications and functional outcomes 2

Common Pitfalls and Caveats

1. Surgical Margins: Interpretation of margins varies by site - oral cavity requires wider margins than other head and neck sites 1

2. Timing of Adjuvant Therapy: Delays in starting adjuvant therapy beyond 6-7 weeks post-surgery can negatively impact outcomes 1

3. Depth of Invasion: This is a critical factor in determining the need for neck management in early oral cavity cancers 1, 2

4. HPV Testing: Unlike oropharyngeal cancers, HPV status does not currently guide treatment decisions for oral cavity cancers 1

5. Functional Considerations: Treatment decisions should consider critical physiologic functions of mastication, deglutition, and speech articulation 1, 2