## TNM Staging and Prognostic Factors in Laryngeal Carcinoma ### The FALSE Statement — Option B **Key Point:** Involvement of the anterior commissure or subglottic extension does **NOT** automatically upgrade a laryngeal tumor to T4a. This is the false statement. **High-Yield (AJCC 8th Edition TNM for Glottic Larynx):** - **T1**: Tumor limited to vocal cord(s), normal mobility - **T2**: Tumor extends to supraglottis or subglottis, OR impaired vocal cord mobility - **T3**: Tumor limited to larynx with vocal cord fixation, and/or invasion of paraglottic space, and/or inner cortex of thyroid cartilage - **T4a**: Tumor invades through the outer cortex of thyroid cartilage and/or invades tissues beyond the larynx (trachea, soft tissues of neck including deep extrinsic muscles of tongue, strap muscles, thyroid, or esophagus) - **T4b**: Tumor invades prevertebral space, encases carotid artery, or invades mediastinal structures Anterior commissure involvement and subglottic extension are **aggressive features** but they do **not** by themselves constitute T4a. T4a requires **cartilage destruction (outer cortex)** or **extralaryngeal spread**. Subglottic extension may upgrade from T1 to T2 (glottic), but does not jump to T4a. This is a classic distractor in NEET PG/INI-CET examinations. ### Option A — TRUE Vocal cord fixation is the hallmark of **T3 disease** (limited to larynx with fixation). If there is additional extralaryngeal spread or cartilage destruction, it becomes T4a/T4b. Vocal cord mobility is indeed the cornerstone of laryngeal staging. *(Harrison's Principles of Internal Medicine, 21st ed.)* ### Option C — TRUE (with nuance) HPV-positive laryngeal cancers do show a trend toward improved survival compared to HPV-negative tumors, though the magnitude is far less dramatic than in oropharyngeal carcinoma. The statement as written is broadly supported in the literature and is not the "false" option in this context. ### Option D — TRUE Lymph node involvement (N stage) is a significant independent prognostic factor in head and neck cancers broadly. While T stage is critically important in laryngeal carcinoma, N stage also independently affects prognosis and is not categorically "less significant than T stage" in all analyses. The statement in Option D is debatable but is not as clearly false as Option B. ### Summary Table | T Stage | Key Feature | |---------|-------------| | T1 | Vocal cord(s) only, normal mobility | | T2 | Supraglottic/subglottic extension OR impaired mobility | | T3 | Vocal cord fixation, paraglottic space, inner thyroid cartilage | | T4a | Outer thyroid cartilage destruction OR extralaryngeal spread | | T4b | Prevertebral, carotid encasement, mediastinum | **Clinical Pearl:** The key distinction tested here is that **anterior commissure involvement and subglottic extension ≠ T4a**. T4a requires cartilage destruction through the outer cortex or spread beyond the larynx. *(AJCC Cancer Staging Manual, 8th Edition; Cummings Otolaryngology, 7th ed.)*
Sign up free to access AI-powered MCQ practice with detailed explanations and adaptive learning.