Uterine and Endometrial Cancer: Symptoms, Diagnosis, and Treatment

Uterine cancer is the most common gynecologic malignancy in the United States, with the American Cancer Society estimating approximately 67,880 new cases and 13,250 deaths in 2024 (American Cancer Society, Cancer Facts & Figures 2024). The vast majority of uterine cancers — roughly 90% — originate in the endometrium, the inner lining of the uterus, and are classified as endometrial carcinomas. This page covers the biological basis of the disease, its recognized subtypes, the clinical pathway from symptom recognition through staging, and the primary treatment modalities used in evidence-based oncology practice. Understanding this cancer is especially relevant alongside broader discussions of hereditary cancer risk in women and other gynecologic conditions.

Definition and Scope

Uterine cancer refers to malignant tumors arising from the uterus. The two principal categories are:

• Endometrial carcinoma — arising from the glandular epithelium of the endometrial lining
• Uterine sarcoma — arising from the muscular wall (myometrium) or connective tissue; far less common, accounting for fewer than 10% of uterine malignancies

Endometrial carcinomas are further divided into two biologically distinct groups, designated by the Gynecologic Oncology Group and reflected in staging guidelines published by the International Federation of Gynecology and Obstetrics (FIGO):

• Type I (endometrioid adenocarcinoma): Estrogen-driven, low-grade tumors typically diagnosed at early stage; associated with obesity, nulliparity, late menopause, and polycystic ovary syndrome
• Type II (non-endometrioid carcinomas): Includes uterine papillary serous carcinoma and clear-cell carcinoma; not estrogen-dependent; more aggressive behavior and worse prognosis regardless of stage

FIGO publishes the globally recognized staging system for endometrial cancer, updated most recently in 2023, classifying the disease across Stages I through IV based on depth of myometrial invasion, cervical involvement, regional lymph node spread, and distant metastasis (FIGO Staging of Endometrial Cancer 2023).

The National Cancer Institute (NCI) classifies uterine cancer under gynecologic cancers and supports surveillance through the Surveillance, Epidemiology, and End Results (SEER) program, which reports a 5-year relative survival rate of approximately 81% for all stages combined (NCI SEER Program).

How It Works

Endometrial carcinogenesis in Type I tumors proceeds through a well-characterized hormonal pathway. Prolonged exposure to unopposed estrogen — estrogen without adequate progesterone counterbalance — stimulates endometrial cell proliferation. Over time, this produces endometrial hyperplasia, which exists on a spectrum:

1. Hyperplasia without atypia — Excess glandular proliferation; low malignant potential
2. Atypical hyperplasia / Endometrial intraepithelial neoplasia (EIN) — Cytological atypia present; the World Health Organization (WHO) classification recognizes EIN as a direct precursor lesion with approximately 25–30% risk of concurrent or subsequent endometrial carcinoma

In Type II tumors, the pathway is distinct. Mutations in TP53 and HER2 amplification are characteristic of uterine papillary serous carcinoma. These tumors arise from atrophic rather than hyperplastic endometrium, explaining why they occur in older, often thin, postmenopausal women without classical estrogen-excess risk factors.

Molecular classification, formalized through The Cancer Genome Atlas (TCGA) research program, divides endometrial cancers into four prognostic groups: POLE ultramutated, microsatellite instability hypermutated (MSI-H), copy-number low, and copy-number high (serous-like). MSI-H status is directly relevant to eligibility for FDA-approved immunotherapy agents such as pembrolizumab (FDA drug approval records).

The connection between Lynch syndrome — a hereditary mismatch repair deficiency — and endometrial cancer risk is clinically significant. Women with Lynch syndrome carry a lifetime endometrial cancer risk of 40–60%, compared with approximately 3% in the general population (National Comprehensive Cancer Network, NCCN Guidelines: Uterine Neoplasms).

Common Scenarios

Endometrial cancer most frequently presents in postmenopausal women, with median age at diagnosis around 63 years per SEER data. The clinical presentations that prompt evaluation include:

1. Abnormal uterine bleeding — Present in approximately 90% of diagnosed cases; in postmenopausal women, any vaginal bleeding warrants evaluation
2. Pelvic pain or pressure — More common with advanced-stage disease or uterine sarcoma
3. Abnormal discharge — May precede frank bleeding in some cases
4. Incidental finding — Endometrial thickening detected on pelvic ultrasound performed for another indication

For premenopausal women, the scenario is more diagnostically complex. Irregular or heavy menstrual bleeding in women with obesity, polycystic ovary syndrome, or tamoxifen use — a selective estrogen receptor modulator associated with increased endometrial proliferation — justifies endometrial sampling. The U.S. Food and Drug Administration (FDA) has maintained a black-box warning on tamoxifen packaging regarding the increased risk of endometrial cancer.

The standard diagnostic pathway follows a defined sequence:

1. Transvaginal ultrasound (TVUS): An endometrial stripe thickness greater than 4–5 mm in a postmenopausal woman is the established threshold for further sampling (Society of Radiologists in Ultrasound consensus guidelines)
2. Endometrial biopsy (EMB): Office-based sampling with sensitivity of approximately 90% for endometrial carcinoma when the sample is adequate
3. Hysteroscopy with dilation and curettage (D&C): Performed when office biopsy is inconclusive or when clinical suspicion remains high despite a negative biopsy
4. MRI pelvis: Primary imaging modality for preoperative assessment of myometrial invasion depth and cervical involvement
5. CT chest/abdomen/pelvis or PET-CT: Used for staging when metastatic disease is suspected

The broader landscape of gynecologic screening — including cervical cancer screening and HPV management — is covered at Cervical Cancer Screening and HPV. For context on how federal agencies frame cancer screening guidance within women's health policy, the regulatory context for women's health page provides relevant background on agency roles and oversight structures.

Decision Boundaries

Treatment decisions in endometrial cancer follow a risk-stratification model based on FIGO stage, histologic grade, molecular subtype, and patient comorbidities. The National Comprehensive Cancer Network (NCCN) publishes the primary clinical treatment guidelines used across U.S. oncology practices.

Surgical management is the cornerstone of treatment for stages I through III:

• Total hysterectomy with bilateral salpingo-oophorectomy (TH/BSO): Standard for virtually all operable endometrial cancers; minimally invasive (laparoscopic or robotic) approaches are preferred when feasible and are associated with shorter hospital stays and equivalent oncologic outcomes
• Sentinel lymph node (SLN) mapping: Adopted broadly to assess nodal spread while reducing lymphedema risk compared with systematic lymphadenectomy; supported by Society of Gynecologic Oncology (SGO) guidance

Adjuvant therapy is stratified by risk category:

The FDA approved pembrolizumab in combination with lenvatinib for advanced endometrial carcinoma that is not MSI-H or mismatch repair deficient (dMMR), based on the KEYNOTE-775 trial results, marking a significant expansion of systemic options (FDA approval, 2021).

For women with Stage IA, Grade 1 disease who wish to preserve fertility, progestin-based hormonal therapy — most commonly levonorgestrel intrauterine device or oral medroxyprogesterone acetate — may be considered under strict surveillance protocols. This approach is not standard care and requires shared decision-making with a gynecologic oncologist; complete response rates in carefully selected patients range from 48–75% according to

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