Management of cT1N0 Tongue Carcinoma
For cT1N0 tongue carcinoma, primary surgical resection with wide local excision (achieving ≥5 mm margins) is the recommended initial treatment, with the decision for elective neck dissection based on depth of invasion (DOI) and other adverse features. 1
Primary Treatment Approach
Surgery is the preferred single-modality treatment for early-stage tongue cancer. 1 The surgical approach should include:
- Wide local excision (partial glossectomy) with margins of ≥5 mm when possible 1, 2
- For cT1N0 tumors, conservative surgery or radiotherapy provides similar locoregional control, but surgery is preferred 1
- Single-modality treatment (surgery alone) should be pursued whenever possible for early disease 1
Neck Management Strategy
The management of the clinically negative neck (cN0) requires careful risk stratification based on tumor characteristics:
When Observation is Appropriate:
- DOI <5 mm and cT1N0: Active surveillance of the neck is a valid option 1
- These low-risk tumors have minimal risk of occult nodal metastasis 1
When Sentinel Lymph Node Biopsy is Appropriate:
- DOI <10 mm: Sentinel lymph node biopsy is a valid option 1
- This provides staging information while avoiding the morbidity of formal neck dissection 1
When Elective Neck Dissection is Recommended:
- DOI ≥3-4 mm: Elective neck dissection should be strongly considered 3
- A 3-mm cutoff provides 92.9% sensitivity and 43.1% specificity for detecting occult metastases 3
- Ipsilateral selective neck dissection (levels I-IV) is appropriate for well-lateralized tongue lesions 1, 2
- Occult cervical metastasis occurs in approximately 20% of clinically N0 necks 4
Additional High-Risk Features Warranting Neck Dissection:
- Histologic grade ≥2 (moderately or poorly differentiated) 5
- Ventral tongue location 3
- Presence of erythroleukoplakia 3
- Perineural invasion on biopsy 2
Preoperative Assessment
Accurate determination of tumor depth is critical for treatment planning:
- Biopsy depth combined with palpation is accurate in determining tumor depth preoperatively in 87.7% of cases 3
- MRI can help assess DOI when clinical examination is uncertain 1
- The specific features to assess include: tumor thickness on palpation, surface characteristics (erythroleukoplakia vs leukoplakia), and exact anatomic subsite 3
Adjuvant Therapy Considerations
Most cT1N0 tongue cancers treated with adequate surgery do not require adjuvant therapy. However, adjuvant treatment should be considered based on final pathology:
Indications for Adjuvant Radiotherapy:
- Perineural invasion: 56-60 Gy to tumor bed and ipsilateral neck 2
- Close margins (<5 mm): 56-60 Gy using standard fractionation 6
- Positive margins: 60-66 Gy 6, 7
- Lymphovascular invasion 2
- Unexpected nodal disease (pN1): 56-60 Gy to tumor bed and involved nodal regions 6
Radiation Parameters When Indicated:
- Standard fractionation: 2 Gy per fraction, once daily 6, 2
- For well-lateralized tumors with pN0-N1 disease, unilateral radiotherapy may be considered 6, 2
- Treatment must begin within 6 weeks of surgery 6, 7
Critical Pitfalls to Avoid
- Underestimating depth of invasion: Failure to assess DOI preoperatively leads to inadequate neck management 3
- Inadequate surgical margins: Margins <5 mm significantly increase local recurrence risk 1
- Ignoring histologic grade: Grade ≥2 tumors have significantly higher neck recurrence rates even in cT1N0 disease 5
- Delaying adjuvant therapy: When indicated, radiation must start within 6 weeks postoperatively 6, 7
- Overlooking occult metastases: Approximately 20-25% of cN0 necks harbor occult disease, particularly with DOI ≥3 mm 4, 3
Expected Outcomes
- Five-year survival for cT1N0 tongue cancer treated surgically: 86% 8
- Local recurrence occurs in approximately 17% of cases 8
- Regional recurrence (neck metastases) develops in 24% of patients, typically within the first 2 years 8, 4
- Patients with histologic grade ≥2 have significantly worse cancer-specific survival and higher neck recurrence rates 5