Here is a summary table of your lecture on Oral Squamous Cell Carcinoma (OSCC).
📋 OSCC Lecture Summary
| Category | Key Points |
|---|---|
| 🧬 Aetiology & Pathogenesis | - Main Risk Factors: Tobacco (smoked & smokeless), alcohol, and betel nut/areca quid are the primary drivers. - Specific Risks: Sunlight (UV radiation) is the main cause for lip cancer. HPV plays a minor role in the oral cavity proper. - Mechanism: Arises from a multi-step accumulation of 6-8 genetic mutations that provide a growth advantage to cells. |
| 🌍 Epidemiology | - Prevalence: Accounts for over 95% of all oral cancers. - Demographics: Primarily affects older adults (median age >60) and historically more men, though the gap is narrowing. - Geography: A major burden in South Asia (~40% of all cancers) due to betel quid use. - Most Common Site: The posterolateral tongue is the most frequent intraoral location. |
| 🩺 Clinical Features | - Early Signs: Often starts as a painless, long-standing white patch (leukoplakia) or red patch (erythroplakia). - Suspicious ‘Red Flag’ Signs: Induration (hardness), ulceration (especially if lasting >2 weeks), fixation to underlying structures, and bone destruction. - Symptoms: Pain and paraesthesia (numbness) can occur, especially in later stages. |
| 🔬 Histopathology | - Definition: Invasive dysplastic stratified squamous epithelium that has breached the basement membrane. - Grading: Classified as well-differentiated (shows features like keratin pearls), moderately-differentiated, or poorly-differentiated (high atypia, difficult to identify origin). - Prognostic Features: Perineural invasion (spread along nerves, causes pain) and lymphovascular invasion are signs of aggressive disease. |
| 📝 Diagnosis & Staging | - Diagnosis: Definitive diagnosis is made via an incisional biopsy. - Staging System: The TNM system is used to classify the extent of the cancer: - T (Tumor): Size and invasion of the primary tumor (T1-T4). - N (Node): Spread to regional lymph nodes (N0-N3). - M (Metastasis): Spread to distant sites (M0-M1). |
| ⚕️ Management & Prognosis | - Treatment: A combination of surgery, radiation, and/or chemotherapy, depending on the stage and location. - Neck Management: May involve neck dissection (therapeutic or elective) or a less invasive sentinel node biopsy to check for spread. - Prognosis: Highly dependent on the stage at diagnosis. The 5-year survival rate drops from >80% for Stage I to <15% for Stage IV. - Prevention: Smoking/alcohol cessation and early detection are crucial for improving survival rates. |