Oral Cavity Cancer

Oral Cavity Cancer - Mouth's Malignant Mayhem

• Malignancy of oral cavity structures: lips, tongue, buccal mucosa, floor of mouth, gingiva, palate, retromolar trigone.
• High incidence in India, primarily due to widespread tobacco and areca nut use.
• Key Risk Factors:
  • Tobacco (smoking, smokeless e.g., khaini, gutka).
  • Alcohol (synergistic with tobacco).
  • Betel quid (areca nut).
  • HPV (esp. HPV-16).
  • Chronic irritation, poor oral hygiene.
• Predominant Histology: >90% Squamous Cell Carcinoma (SCC).

⭐ Buccal mucosa & tongue are commonest Indian sites (betel quid link).

Oral Cavity Cancer - Mouth Map & Nodes

• Key Subsites: Lip, anterior 2/3 tongue (oral tongue), floor of mouth (FOM), buccal mucosa, gingiva (upper/lower), retromolar trigone, hard palate.
• Lymphatic Drainage (Primarily Levels I-III):
  • Level I (Submental/Submandibular): FOM, anterior tongue, lip, buccal mucosa.
  • Level II (Upper Jugular): All subsites, esp. posterior oral cavity.
  • Level III (Mid Jugular): Tongue, FOM.
  • Midline lesions → bilateral nodal risk.

⭐ Retromolar trigone cancers often invade mandible early due to close proximity and direct spread through the pterygomandibular raphe and surrounding spaces, impacting staging and resectability assessment significantly. This area is a common site for occult nodal metastases, even in clinically N0 necks, often necessitating elective neck dissection (END).

Oral Cavity Cancer - Clinical Red Flags

• Persistent Symptoms (Suspect if > 3 weeks):
  • Non-healing ulcer or sore
  • Pain: oral, odynophagia, referred otalgia
  • Unexplained bleeding, numbness, or loose teeth
  • Trismus (difficulty opening mouth)
  • Neck mass/swelling (lymphadenopathy)
  • Dysphagia, weight loss (late signs)
• High-Risk Oral Lesions & Signs:
  • Leukoplakia (white patch, cannot be wiped off)
  • Erythroplakia (velvety red patch) ⚠️
  • Erythroleukoplakia (speckled, mixed red/white)
  • Palpable induration, fixation, or exophytic growth
  • Restricted tongue mobility
• Crucial Diagnostic Step:
  • Biopsy (incisional) of any suspicious lesion is mandatory.

⭐ Erythroplakia carries the highest malignant transformation potential among premalignant oral lesions.

Oral Cavity Cancer - Staging the Spread

Staging (AJCC 8th Ed.) considers: Tumor size, Depth of Invasion (DOI), Nodal status (incl. Extranodal Extension - ENE), Metastasis.

• T (Tumor): Assessed by size & critical DOI (Depth of Invasion) thresholds (e.g., 5mm, 10mm).
• N (Nodes): Evaluates site, size, number. 📌 ENE (Extranodal Extension) is a key prognostic factor.
• M (Metastasis): M0 (no distant metastasis) vs M1 (distant metastasis present).

⭐ Depth of Invasion (DOI) significantly impacts T-staging and prognosis, even for small tumors. DOI >5mm can upstage a T1 tumor.

Oral Cavity Cancer - Treatment Blueprints

• Primary Goal: Curative intent with surgery as cornerstone for resectable disease.
• Early Stage (T1-T2, N0):
  • Wide local excision.
  • Consider Elective Neck Dissection (END) if Depth of Invasion (DOI) > 3-4 mm.
• Locally Advanced (T3-T4, or N+):
  • Comprehensive surgery (primary tumor resection + neck dissection).
• Adjuvant Therapy (Post-Sx):
  • Radiotherapy (RT): For most pN+ (pathologically positive nodes), close/positive margins, Perineural Invasion (PNI), Lymphovascular Invasion (LVI).
  • Concurrent Chemoradiotherapy (CCRT): For Extranodal Extension (ENE) or positive margins.
• Unresectable/Metastatic Disease:
  • Palliative chemotherapy and/or radiotherapy; targeted therapy; immunotherapy.
• Reconstruction: Essential for function (speech, swallowing) and quality of life post-resection.

⭐ Extranodal Extension (ENE) in cervical lymph nodes is a powerful adverse prognostic factor and a key indication for adjuvant concurrent chemoradiotherapy (CCRT) rather than RT alone.

High‑Yield Points - ⚡ Biggest Takeaways

• Squamous Cell Carcinoma (SCC) is the dominant histology (>90%).
• Key risk factors: tobacco (smoked/smokeless), alcohol, betel quid (India).
• Tongue (lateral border) is the most common site, followed by floor of mouth.
• Watch for premalignant lesions: leukoplakia, erythroplakia (high malignant potential).
• Cervical lymph node status is a critical prognostic factor.
• Surgery is the primary treatment for early stages; radiotherapy/chemotherapy for advanced.
• Persistent non-healing ulcers or oral pain are common presentations.