A 45-year-old man from Bangalore presents with dysphagia and weight loss for 4 months. Upper endoscopy reveals a 5 cm ulcerated tumour in the mid-oesophagus. Biopsy confirms squamous cell carcinoma. CT chest and abdomen shows invasion into the adventitia, involvement of 3 regional lymph nodes, and no distant metastases. Endoscopic ultrasound confirms T3 disease. According to the TNM classification, what is the stage of this oesophageal cancer?

## TNM Staging of Oesophageal Squamous Cell Carcinoma **Key Point:** Oesophageal cancer staging depends on T stage, N stage, and M stage: **T Classification:** - T1: Invasion into submucosa - T2: Invasion into muscularis propria - T3: Invasion into adventitia (as in this case) - T4: Invasion into adjacent structures **N Classification (Regional Lymph Nodes):** - N0: No regional lymph node metastasis - N1: 1–2 regional lymph nodes involved - N2: 3–6 regional lymph nodes involved - N3: ≥7 regional lymph nodes involved **Stage Grouping for Squamous Cell Carcinoma:** | Stage | T | N | M | |-------|---|---|---| | IIA | T3 | N0 | M0 | | IIB | T3 | N1 | M0 | | IIIA | T3 | N1–2 | M0 | | IIIB | T3 | N2–3 | M0 | | IV | Any T | Any N | M1 | **In this case:** - T3 (invasion into adventitia) - N1 (3 regional lymph nodes) → Actually N2 (3–6 nodes) - M0 (no distant metastases) - **Correct stage: IIIA (T3N2M0)** (Note: 3 nodes = N2, not N1) **Clinical Pearl:** Stage IIIA oesophageal cancer is locally advanced and typically requires multimodal therapy (neoadjuvant chemotherapy + surgery or chemoradiation).