Stage I. Carcinoma confined to the cervix
Ia. Preclinical carcinoma, that is, diagnosed only by microscopy
Ia1. Stromal invasion no greater than 3 mm and no wider than 7 mm (so-called microinvasive carcinoma)
Ia2. Maximum depth of invasion of stroma greater than 3 mm and no greater than 5 mm taken from base of epithelium, either surface or glandular, from which it originates;horizontal invasion not more than 7 mm
Ib. Histologically invasive carcinoma confined to the cervix and greater than stage Ia2
Stage II. Carcinoma extends beyond the cervix but not onto the pelvic wall. Carcinoma involves the vagina but not the lower third.