Table 1. Definitions of FIGO Stage Ia

StageDescriptionIllustration
IThe carcinoma is strictly confined to the cervix (extension to the uterine corpus should be disregarded).
IAInvasive cancer identified only microscopically. (All gross lesions even with superficial invasion are Stage IB cancers.) Invasion is limited to measured stromal invasion with a maximum depth of 5 mmb and no wider than 7 mm.
IA1Measured invasion of stroma ≤3.0 mm in depth and ≤7.0 mm width.
Stage IA1 and IA2 cervical cancer; drawing shows a cross-section of the cervix and vagina. An inset shows cancer in the cervix that is up to 5 mm deep, but not more than 7 mm wide.
IA2Measured invasion of stroma >3.0 mm and < 5.0 mm in depth and ≤ 7 mm width.
IBClinical lesions confined to the cervix or preclinical lesions greater than stage IA.
IB1Clinical lesions no greater than 4 cm in size.
Stage IB1 and IB2 cervical cancer shown in three cross-section drawings of the cervix and vagina. An inset on the left shows stage IB1 cancer that is 7 mm wide and more than 5 mm deep. Drawing in the middle shows stage IB1 cancer that is smaller than 4 cm. Drawing on the right shows stage IB2 cancer that is larger than 4 cm.
IB2Clinical lesions >4 cm in size.

FIGO = Féderation Internationale de Gynécologie et d’Obstétrique.

aAdapted from FIGO committee on gynecologic oncology.[3]

bThe depth of invasion should not be more than 5 mm taken from the base of the epithelium, either surface or glandular, from which it originates. Vascular space invasion should not alter the staging.

From: Cervical Cancer Treatment (PDQ®)

Cover of PDQ Cancer Information Summaries
PDQ Cancer Information Summaries [Internet].
Bethesda (MD): National Cancer Institute (US); 2002-.
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