1. Comparison of 2009 and 2018 FIGO staging of cervical cancer.

Stage I (2018): carcinoma strictly confined to the cervix (extension to the uterine corpus should be disregarded)
2009 FIGO stage: description	2018 FIGO stage: description	Comment
IA: invasive carcinoma diagnosed only by microscopy, with maximum depth of invasion </= 5 mm and largest extension </= 7 mm	IA: invasive carcinoma diagnosed only by microscopy, with maximum depth of invasion < 5 mm	– Lateral extent of the carcinoma is no longer considered in distinguishing between FIGO Stage IA and IB carcinomas – If margins of loop are involved patient is allocated to Stage IB1
IA1: measured stromal invasion < 3 mm in depth and extension </= 7 mm	IA1: measured stromal invasion < 3 mm in depth
IA2: measured stromal invasion >/= 3 mm and < 5 mm in depth and extension </= 7 mm	IA2: measured stromal invasion >/= 3 mm and < 5 mm in depth
IB: clinically visible lesions limited to the cervix or preclinical cancers greater than Stage IA	IB: invasive carcinoma with measured deepest invasion >/= 5 mm (greater than Stage IA), lesion limited to the cervix uteri	– See above – LVSI must be commented upon, although does not affect FIGO stage
IB1: clinically visible lesion </= 4 cm in greatest dimension	IB1: invasive carcinoma >/= 5 mm depth of stromal invasion, and < 2 cm in greatest dimension	– New stage category
	IB2: invasive carcinoma >/= 2 cm and < 4 cm in greatest dimension	– New stage category
IB2: invasive carcinoma > 4 cm in greatest dimension	IB3: invasive carcinoma >/= 4 cm in greatest dimension	– New stage category

Adapted from Singh 2019.
LVSI: lymphovascular space invasion.