| STAGE 0 |
Carcinoma in situ, intraepithelial carcinoma |
| I |
Carcinoma strictly confined to the cervix (extension to the corpus should be disregarded) |
| Ia |
Preclinical carcinomas of the cervix, that is, diagnosed only by microscopy |
| Ia1 |
Minimal microscopically evident stromal invasion |
| Ia2 |
Lesions detected microscopically that can be measured. The upper limit of the measurement should not show a depth on invasion of more than 5 mm taken from the base of the epithelium, either surface or glandular, from which it originates, and a second dimension, the horizontal spread, must not exceed 7 mm. Larger lesions should be staged as Ib |
| Ib |
Lesions of greater dimensions than stage Ia2, whether seen clinically or not. Performed space involvement should not alter the staging but should be specifically recorded so as to determine whether it should affect treatment decisions in the future. |
| Stage II |
Involvement of the vagina but not the lower third, or infiltration of the parametria but not out to the sidewalls |
| IIa |
Involvement of the vagina but no evidence of parametrial involvement |
| IIb |
Infiltration of the parametria but not out to the sidewalls |
| Stage III |
Involvement of the lower third of the vagina, or extension to the pelvic sidewalls. All cases with a hydronephrosis or nonfunctioning kidney should be included, unless they are known to be attributable to other cause. |
| IIIa |
Involvement of the lower third of the vagina but not out to the pelvic sidewalls if the parametria are involved |
| IIIb |
Extension onto the pelvic sidewalls and/or hydronephrosis or nonfunctional kidney |
| STAGE IV |
Extension outside the reproductive tract |
| IVa |
Involvement of the mucosa of the bladder or rectum |
| IVb |
Distant metastasis or disease outside the true pelvis |
