4. STAGING AND CLASSIFICATION SYSTEMS
4.1. Pathological staging
For staging, the Tumour, Node, Metastasis (TNM) Classification (2017, 8th edition) is recommended [83]. Blood and lymphatic vessel invasion have an independent prognostic significance [84,85].
4.2. Tumour, node, metastasis classification
The TNM classification of malignant tumours is the method most widely used to classify the extent of cancer spread [83] (Table 4.1).
Table 4.1: TNM Classification of urinary bladder cancer [83]
T - Primary Tumour | ||
Tx | Primary tumour cannot be assessed | |
T0 | No evidence of primary tumour | |
Ta | Non-invasive papillary carcinoma | |
Tis | Carcinoma in situ: “flat tumour” | |
T1 | Tumour invades subepithelial connective tissue | |
T2 | Tumour invades muscle | |
T2a | Tumour invades superficial muscle (inner half) | |
T2b | Tumour invades deep muscle (outer half) | |
T3 | Tumour invades perivesical tissue: | |
T3a | microscopically | |
T3b | macroscopically (extravesical mass) | |
T4 | Tumour invades any of the following: prostate stroma, seminal vesicles, uterus, vagina, pelvic wall, abdominal wall | |
T4a | Tumour invades prostate stroma, seminal vesicles, uterus, or vagina | |
T4b | Tumour invades pelvic wall or abdominal wall | |
N - Regional Lymph Nodes | ||
Nx | Regional lymph nodes cannot be assessed | |
N0 | No regional lymph node metastasis | |
N1 | Metastasis in a single lymph node in the true pelvis (hypogastric, obturator, external iliac, or presacral) | |
N2 | Metastasis in multiple regional lymph nodes in the true pelvis (hypogastric, obturator, external iliac, or presacral) | |
N3 | Metastasis in a common iliac lymph node(s) | |
M - Distant Metastasis | ||
M0 | No distant metastasis | |
M1a | Non-regional lymph nodes | |
M1b | Other distant metastasis | |
Staging after neoadjuvant chemotherapy (NAC) and RC can be done, but must be mentioned as ypTNM (International Collaboration on Cancer Reporting) [86]. ypT0N0 after NAC and cystectomy is associated with better prognosis [71,87,88].