Uterine Cancer Stages
Uterine cancer stages provide a uniform way for physicians to describe the location of the cancer and the extent to which it has spread to other areas of the body. One tool that is used to classify the stages of uterine, or endometrial, cancer is the tumor, node and metastasis (TNM) system. T represents the size and location of the primary tumor, N specifies whether the cancer has spread to the lymph nodes and M indicates whether the cancer has metastasized to distant areas of the body.
The T, N and M classifications can be determined through tests such as physical exams, imaging, biopsies and surgical procedures. Once confirmed, this information is viewed collectively to establish the various uterine cancer stages.
How is endometrial cancer staged?
Most commonly, however, people refer to the standard numerical system when discussing stages. These stages are usually number zero through four, as follows:
- Stage 0 (carcinoma in situ) – Pre-invasive cancer is found in the surface layer of uterine cells and has not spread.
- Stage 1 – The cancer is confined to the uterus. If the cancer is found only in the endometrium or in less than one-half of the middle layer of the uterine wall (myometrium) then it is referred to as stage IA, and if it has spread beyond that, stage IB.
- Stage 2 – The cancer has spread beyond the uterus to the cervix.
- Stage 3 – The cancer has spread beyond the uterus to the pelvic area. The cancer may have spread to the outer layer of the uterus and/or the fallopian tubes and ovaries (stage IIIA), the vagina or other tissues surrounding the uterus (stage IIIB) or to lymph nodes (stage IIIC.)
- Stage 4 – The cancer has spread to the rectum and/or bladder (stage IVA) or beyond to lymph nodes (stage IVB).
Additionally, uterine cancer stages include a grade (G) that describes the degree to which the cancer cells resemble healthy cells when viewed under a microscope. This information can be helpful to a physician in determining how quickly the cancer can be expected to spread.