The best early stage is one where the disease is limited to the endometrium or does not extend to more than half the thickness of the wall of the womb (Stage 1a and 1b respectively). Where the disease extends to more than half the thickness of the wall of the womb (stage 1c) or to the cervix (Stage 2) then the risks of spreads are slightly increased and even moreso if the disease invades beyond the wall of the womb or into the vagina, or to local draining lymph nodes (Stage 3). The fourth stage (Stage4) is where the disease has infiltrated other pelvic organs such as the bladder or the rectum or has spread beyond the pelvis, both bad omens (prognostic factors in medical speak) for the future.
