What is the prognosis for stage 4 cancer of the buccal mucosa?

Stage 4 Buccal Mucosa Cancer: Prognosis

Stage IV buccal mucosa squamous cell carcinoma carries a poor prognosis, with 5-year disease-specific survival rates of approximately 47% and no survivors reported in some series of Stage IV disease, particularly in indigent populations. 1, 2

Overall Survival Data

The prognosis for Stage IV buccal mucosa cancer is significantly worse than earlier stages:

• 5-year disease-specific survival for Stage IV disease: 47% 1
• 5-year overall survival for all stages combined: 64-69%, but this drops substantially for Stage IV 1, 3
• One series reported 0% 5-year survival for Stage IV buccal mucosa cancer in an indigent population 2
• 5-year overall survival across all head and neck cancers in Europe: 42%, with marked variation by age (54% for ages 15-45 years vs 35% for ≥75 years) 4

Disease Control Rates

Local and regional control remains challenging in advanced disease:

• 5-year local control rate: 57.5% for all stages of buccal mucosa cancer 3
• 5-year regional control rate: 83.5% 3
• Recurrence-free survival at 5 years: 46% 3

Stage-Specific Outcomes by T-Stage

For T4 buccal mucosa tumors specifically:

• Disease-free survival at 18 months with surgery alone: 21% 5
• Disease-free survival with surgery plus postoperative radiotherapy: 35% 5
• Well-differentiated T4 tumors: 48% disease-free survival with surgery, 72% with surgery plus radiotherapy 5
• Moderately differentiated T4 tumors: 12% disease-free survival with surgery, 21% with surgery plus radiotherapy 5
• Poorly differentiated T4 tumors: 0% survivors 5

Critical Prognostic Factors

The most important independent predictors of poor survival are:

• Advanced pathologic stage (Stage IV: relative risk 4.64) 6
• Positive surgical margins (relative risk 2.02) 6
• Extracapsular spread of cervical lymph node metastasis (relative risk 6.89) - this is the single strongest predictor 6
• Positive nodal status and extranodal extension 3
• Histologic grade - poorly differentiated tumors have dramatically worse outcomes 5, 1

Recurrent/Metastatic Disease Prognosis

For patients with recurrent or metastatic head and neck squamous cell cancer (which includes Stage IVC):

• Median overall survival with platinum-based chemotherapy: 7.8 months 4
• Objective response rate to combination chemotherapy: <40% in most studies, with responses measured in months, not years 4
• A small percentage of patients experience long-term survival, but this is uncommon 4

Geographic and Risk Factor Considerations

Betel quid chewing is specifically linked to poor prognosis in buccal mucosa squamous cell carcinoma in regions where this exposure is common 4

Additional negative prognostic factors include:

• Weight loss >5% 4
• ECOG performance status ≥1 4
• Prior radiation therapy 4
• Oral cavity primary site (vs. other head and neck sites) 4

Treatment Implications

Stage IV disease is subdivided into IVa (moderately advanced), IVb (very advanced), and IVc (distant metastatic), and Stage IV designation does not necessarily mean incurable disease, particularly in the absence of distant metastases. 4

For Stage IVa/IVb without distant metastases, aggressive combined modality treatment with surgery plus postoperative chemoradiotherapy (cisplatin-based) for high-risk features offers the best chance for cure, though outcomes remain significantly worse than earlier stages. 4