In a 50‑year‑old male with right buccal mucosa squamous cell carcinoma treated by wide local excision (WLE), marginal mandibulectomy, and radical neck dissection (RND) with negative margins and no nodal involvement, is adjuvant radiotherapy or chemotherapy indicated?

Adjuvant Therapy for Buccal Mucosa Carcinoma with Negative Margins and Nodes

No adjuvant radiotherapy or chemotherapy is routinely indicated for this patient with negative surgical margins and no nodal involvement following adequate surgical resection.

Rationale Based on Risk Stratification

Your patient has achieved optimal surgical outcomes with:

• Negative surgical margins (all margins free of tumor)
• No nodal involvement (pN0 disease)
• Adequate surgical procedure (wide local excision with marginal mandibulectomy and neck dissection)

These features place him in a favorable prognostic category that does not meet standard criteria for adjuvant therapy 1.

Evidence Against Routine Adjuvant Therapy

When Adjuvant Radiotherapy IS Indicated

The guidelines clearly define specific high-risk pathologic features that warrant postoperative radiotherapy 1:

• Positive or close surgical margins (< 5 mm) 1
• Nodal involvement (any positive lymph nodes) 1
• Extracapsular extension in lymph nodes 1
• Multiple involved nodes 1

Your patient has NONE of these features.

When Chemotherapy IS Indicated

Adjuvant chemotherapy (specifically concurrent chemoradiotherapy) is reserved for 1:

• Extracapsular extension in positive nodes 2
• Positive margins when re-excision is not feasible 2

The evidence shows that adjuvant chemotherapy alone has demonstrated no benefit in head and neck squamous cell carcinoma 1. Even concurrent chemoradiotherapy is only indicated when the specific high-risk features above are present 2.

Supporting Research Data

Outcomes with Surgery Alone for Early-Stage Disease

Research specifically examining buccal mucosa carcinoma demonstrates:

• Disease-free survival with surgery alone for appropriate cases ranges from 43-57% for T2-T3 lesions 3
• Negative surgical margins are the most critical prognostic factor 4
• When negative margins are achieved, T classification becomes the primary predictor of outcomes 4

Risk of Overtreatment

Studies show that:

• Only 39% of patients NOT receiving adjuvant therapy developed recurrence in one series, meaning 61% were cured by surgery alone 5
• The addition of postoperative radiotherapy is primarily beneficial for T3-T4 tumors or those with adverse pathologic features 3
• Adjuvant therapy should not be used routinely for intermediate-risk factors alone unless pathologic findings suggest particularly significant recurrence risk 2

Clinical Algorithm for Decision-Making

Step 1: Assess Margin Status

• ✓ All margins free → Proceed to Step 2
• ✗ Margins positive/close → Consider adjuvant RT 1

Step 2: Assess Nodal Status

• ✓ No nodal involvement (pN0) → Proceed to Step 3
• ✗ Nodes positive → Adjuvant RT indicated 1

Step 3: Assess for Extracapsular Extension

• ✓ No ECE (or N0 disease) → No adjuvant therapy indicated
• ✗ ECE present → Concurrent chemoradiotherapy 2

Step 4: Consider T-Stage and Tumor Thickness

• For T1-T2 lesions with negative margins and nodes: Surgery alone is adequate 3, 4
• Tumor thickness > 5.17 mm is a predictor for occult nodal disease, but your patient already had adequate neck dissection 4

Important Caveats

What About the Smoking History?

While smoking is a risk factor for developing buccal carcinoma, it does not independently mandate adjuvant therapy when surgical pathology shows favorable features 6, 5.

Surveillance is Critical

Even without adjuvant therapy, this patient requires:

• Close clinical follow-up with examination and endoscopy 1
• Most recurrences occur within 2 years 7, 6
• Annual chest X-ray given smoking history and risk of second primary 1
• Evaluation should be performed regularly to detect locoregional recurrence or second primaries early 1

When to Reconsider

If pathology review reveals any of the following that were initially missed:

• Margins actually < 5 mm 1
• Perineural invasion (substantial) 8, 2
• Lymphovascular invasion 2
• Occult nodal disease on final pathology 1

Then adjuvant radiotherapy should be reconsidered 1.

Common Pitfalls to Avoid

• Do not reflexively add adjuvant therapy for buccal mucosa location alone—treatment decisions must be based on pathologic risk factors 2
• Do not use adjuvant chemotherapy alone—it has no proven benefit in this setting 1
• Do not assume all oral cavity cancers need adjuvant therapy—negative margins and nodes represent favorable disease 1
• Do not neglect surveillance—40-50% of buccal carcinomas may recur, making close follow-up essential even without adjuvant therapy 6, 5