The FIGO staging system for uterine corpus carcinoma and carcinosarcoma relies on a three-pronged classification approach covering tumor characteristics, lymph node involvement, and metastasis status. By considering these aspects, we can systematically determine the stage of cancer using the combinations below.

### Tumor Classification Options:
- Tx: Primary tumor cannot be assessed
- T0: No evidence of primary tumor
- T1a: Tumor limited to endometrium or invading less than one-half of the myometrium
- T1b: Tumor invading one-half or more of the myometrium
- T2: Tumor invading stromal connective tissue of cervix but not extending beyond uterus; excludes endocervical glandular involvement
- T3a: Tumor involving serosa and/or adnexa (either by direct extension or metastasis)
- T3b: Tumor involving the vaginal route (either by direct extension or metastasis) or parametrium
- T4: Tumor invading bladder mucosa and/or bowel mucosa

### Lymph Node Classification Options:
- Nx: Regional lymph nodes cannot be assessed
- N0: No regional lymph node metastasis
- N1mi: Metastasis in pelvic lymph nodes with a size greater than 0.2 mm but less than or equal to 2.0 mm
- N1a: Metastasis in pelvic lymph nodes with a size greater than 2 mm
- N2mi: Metastasis in para-aortic lymph nodes with a size greater than 0.2 mm but less than or equal to 2.0 mm, possibly alongside positive pelvic lymph nodes
- N2a: Metastasis in para-aortic lymph nodes with a size greater than 2 mm, possibly alongside positive pelvic lymph nodes

### Metastasis Classification Options:
- M0: No distant metastasis
- M1: Presence of distant metastasis

### Interpretation of Results:

By inputting the selections from these classifications, we can deduce the cancer stage:

- **Stage IA:** T1a classification with no lymph node involvement (N0) and no distant metastasis (M0).
- **Stage IB:** T1b classification with no lymph node involvement (N0) and no distant metastasis (M0).
- **Stage II:** T2 classification with no lymph node involvement (N0) and no distant metastasis (M0).
- **Stage IIIA:** T3a classification with no lymph node involvement (N0) and no distant metastasis (M0).
- **Stage IIIB:** T3b classification with no lymph node involvement (N0) and no distant metastasis (M0).
- **Stage IIIC1:** Tumors classified from T1a to T3b with pelvic lymph node metastasis (N1mi or N1a) and no distant metastasis (M0).
- **Stage IIIC2:** Tumors classified from T1a to T3b with para-aortic lymph node metastasis (N2mi or N2a) and no distant metastasis (M0).
- **Stage IVA:** T4 classification with any lymph node status and no distant metastasis (M0).
- **Stage IVB:** Any tumor classification from T1a upward, with any lymph node status and presence of distant metastasis (M1).

This structured approach helps in evaluating the extent of tumor spread, enabling an understanding of disease severity and informing treatment decisions.

The FIGO staging of uterine corpus carcinoma and carcinosarcoma is a clinical tool designed for the classification and staging of these specific types of gynecological cancers. The primary purpose of this staging system is to provide a standardized method for assessing the extent of disease, which in turn aids in treatment planning and prognostication.

The FIGO staging system is based on three primary components: tumor classification (T), lymph node classification (N), and metastasis classification (M). The tumor classification ranges from Tx (primary tumor cannot be assessed) to T4 (tumor invading bladder mucosa and/or bowel mucosa). The lymph node classification ranges from Nx (regional lymph nodes cannot be assessed) to N2a (metastasis in para-aortic lymph nodes > 2 mm in diameter, with or without positive pelvic lymph nodes). The metastasis classification is binary, with M0 indicating no distant metastasis and M1 indicating the presence of distant metastasis.

The final stage is determined by a combination of these classifications. For example, Stage IA is defined by a tumor limited to the endometrium or invading less than one-half of the myometrium (T1a), no regional lymph node metastasis (N0), and no distant metastasis (M0). Stage IVB, the most advanced stage, is defined by any tumor classification (T), any lymph node classification (N), and the presence of distant metastasis (M1).

The FIGO staging system for uterine corpus carcinoma and carcinosarcoma is a critical tool for clinicians in the assessment and management of these cancers. It provides a comprehensive and standardized method for evaluating the extent of disease, which is essential for determining appropriate treatment strategies and estimating prognosis.