TNM/FIGO Staging and Prognostic Factors
Overview
This domain covers the FIGO and TNM staging systems for gynecologic cancers. Key concepts: Cervical cancer stages I-IV based on tumor size, extension to parametrium, pelvic wall, lower vagina, bladder/rectum, and distant metastasis. Endometrial cancer stages I-IV based on myometrial invasion, cervical stroma involvement, adnexa, lymph nodes, and distant spread. Ovarian cancer stages I-IV based on extent of disease, ascites, peritoneal implants, lymph nodes, and distant metastasis. Vulvar cancer stages I-IV based on tumor size, invasion, lymph node involvement, and metastasis. Vaginal cancer stages I-IV. Prognostic factors include stage, grade, histology, lymphovascular space invasion (LVSI), depth of invasion, tumor size, and molecular markers (e.g., p53, MSI in endometrial).
Traps
Questions often test the specific criteria for each stage. A common trap is confusing cervical cancer stage IIB (parametrial involvement) with IIIB (pelvic wall extension). Another trap is the distinction between endometrial cancer stage IA (invasion <50% myometrium) and IB (≥50%). For ovarian cancer, stage IC includes positive washings or capsule rupture. Also, note that FIGO staging is updated periodically (e.g., 2018 for cervical, 2023 for endometrial). Always use the most recent FIGO staging.
Worked Example
A patient with endometrial cancer has tumor invading 60% of the myometrium and no other spread. What is the FIGO stage? Stage IB (≥50% myometrial invasion). Rule of thumb: Depth of invasion is a key prognostic factor; stage I is confined to uterus, stage II involves cervix, stage III spreads locally, stage IV distant.