Primary Treatment for Endometrial Cancer

Surgical Staging

Staging is not merely a description of the tumor but a critical step in determining the risk of recurrence. For Stage I disease, surgical staging is essential to assess the lymph nodes (LN). This can be achieved through:

• Sentinel Lymph Node (SLN) mapping: A technique to identify and biopsy the first nodes to which the cancer is likely to spread.
• Complete Lymphadenectomy: The surgical removal of a full set of lymph nodes.

If a patient undergoes a simple TH/BSO without adequate staging but is found to have high-risk features (such as Stage IB or myometrial invasion with LVSI), they may require imaging or surgical restaging to ensure no extrauterine spread has occurred.

Ovarian Preservation

In specific, highly selected cases, patients may avoid a BSO. This is considered for premenopausal patients with Stage IA, Grade 1 (G1) endometrioid cancer where the ovaries appear normal. However, this option is contraindicated if there is a family history of Lynch syndrome or breast/ovarian cancer, or if molecular markers like p53 abnormalities or MMR deficiency are present.

Fertility-Sparing Therapy

For patients who prioritize preserving fertility, continuous progestin-based therapy serves as a primary alternative to hysterectomy. This is not a universal option and is reserved for a very narrow subset of patients.

Criteria for Eligibility

To qualify for fertility-sparing management, a patient must meet all of the following criteria:

1. Biopsy-proven Grade 1 (well-differentiated) endometrioid adenocarcinoma.
2. Stage IA disease (noninvasive).
3. Consultation with a fertility expert prior to starting therapy.

High-grade histologies (serous, clear cell, or carcinosarcoma) are absolute contraindications.

Treatment Regimens and Monitoring

The preferred method for fertility preservation is the levonorgestrel-containing IUD. Other options include oral megestrol acetate or medroxyprogesterone.

Once therapy begins, rigorous monitoring is required:

• Endometrial sampling: Performed every 3 to 6 months via hysteroscopy, D&C, or biopsy.
• Complete Response (CR): If a CR is achieved by 6 months, the patient may attempt conception with continued surveillance every 6 to 12 months.
• Transition to Surgery: If the disease progresses, therapy is ineffective, or the patient completes childbearing, a TH/BSO with surgical staging is recommended.

Adjuvant Therapy Options

Adjuvant therapy is used to reduce the risk of recurrence in patients with high-risk features or advanced stages.

Radiotherapy

For patients with Stage IB or any myometrial invasive carcinoma that shows lymphovascular space invasion (LVSI) on imaging, radiotherapy is recommended. This may include:

• External Beam Radiotherapy (EBRT).
• Vaginal Brachytherapy.

Systemic and Targeted Therapy

In more advanced or recurrent cases, systemic options become necessary. For Stage III–IV tumors with measurable disease, regimens such as Carboplatin/Paclitaxel + Bevacizumab may be used. Furthermore, the rise of molecular profiling has allowed for biomarker-directed therapies, such as using checkpoint inhibitors for MSI-H/dMMR tumors or targeted agents for HER2-positive or RET gene fusion-positive cancers.

Exam Tip: If a question asks about the "preferred" fertility-sparing agent for Stage IA G1 endometrioid cancer, the answer is the Levonorgestrel IUD, not oral progestins.