TNM classification: rectal cancer and anal cancer. скачать в хорошем качестве

TNM classification: rectal cancer and anal cancer.

🎯 Rectal Cancer vs Anal Cancer: Are You Staging It Correctly? ❓ A tumor located 2 cm from the dentate line — rectum or anal canal? ❓ Inguinal lymph nodes — regional or distant metastasis? ❓ Is T3 about depth or size? These questions sound simple — but errors in TNM staging of anorectal tumors are surprisingly common. And they matter: incorrect staging can lead to incorrect treatment decisions. Let’s break down the key differences between rectal cancer and anal canal cancer, based on the latest TNM 8th edition (AJCC/UICC). ⸻ 🔹 T Category: Different Logic • In rectal adenocarcinoma, the T stage is based on the depth of invasion through the bowel wall and into surrounding structures. • In anal canal squamous cell carcinoma, the T stage depends solely on tumor size: → T1 – more than 2 cm → T2 – 2–5 cm → T3 – more than 5 cm → T4 – invasion of adjacent organs (e.g., vagina, bladder) 📌 Conclusion: T3 in the rectum ≠ T3 in the anal canal. They reflect different tumor behaviors. ⸻ 🔹 N Category: Different Nodes • For rectal cancer, regional nodes include mesorectal and pelvic lymph nodes. Inguinal nodes are not regional → their involvement is M1. • For anal cancer, inguinal and femoral nodes are regional → involvement is staged as N1b, not metastatic. 📌 Conclusion: The same CT or PET-CT findings can lead to different stages — depending on the tumor’s location. ⸻ 🔹 Treatment Approach: Opposite Strategies • Rectal cancer: usually neoadjuvant chemoradiotherapy → surgery (TME). • Anal canal cancer: non-surgical treatment is standard — combined chemoradiotherapy (Nigro protocol). 📌 Mistaking one for the other can lead to undertreatment or overtreatment — with serious consequences. ⸻ 📚 Reference: TNM Classification of Malignant Tumours, 8th Edition (AJCC/UICC) https://doi.org/10.1002/9781119263578 ⸻ ⚠️ Key takeaways: • T — is it depth or size? • N — which nodes are truly regional? • Treatment — surgery or not? 💬 Have you encountered staging dilemmas in lower GI cancers? Share your experience in the comments below.