Endometrial Cancer: Symptoms, Diagnosis, and Modern Care

The uterus, or womb, is a pear-shaped pelvic organ where a foetus develops during pregnancy. It consists of two principal layers: the myometrium, which is the outer muscular coat responsible for uterine contractions, and the endometrium, the specialised cellular lining on the inside. Under the influence of cyclical reproductive hormones—namely oestrogen and progesterone—the endometrium thickens each month to prepare for potential pregnancy and sheds during menstruation if conception does not occur. Endometrial cancer begins when the epithelial cells lining this inner surface acquire genetic alterations, causing them to multiply uncontrollably and form a tumour.

Endometrial cancer is medically distinct from uterine sarcoma. While uterine sarcomas develop within the connective tissues or smooth muscle of the myometrium and are relatively uncommon, carcinomas of the endometrium account for over 90% of all uterine malignancies. Historically, these tumours were broadly categorised by how they appeared under a microscope into Type I (low-grade endometrioid tumours, typically driven by oestrogen) and Type II (high-grade non-endometrioid tumours, such as serous or clear cell carcinomas, which behave more aggressively). While this histological assessment remains useful, oncology today classifies these tumours using their specific genetic and molecular characteristics.

Because the endometrium is naturally sensitive to bodily signals and easily sheds cellular debris, endometrial malignancies typically trigger noticeable symptoms early. When malignant cells disrupt the normal architecture of the lining, fragile microvessels break down, resulting in early-stage bleeding. This biological characteristic makes endometrial cancer one of the few internal malignancies that routinely presents with clear, visible warning signals long before spreading to neighbouring anatomical structures or distant organs.

If you or a family member has been diagnosed with endometrial cancer, the most reassuring fact to hold onto is that the vast majority of cases are diagnosed at an early, highly manageable stage. Hearing the word 'cancer' invariably brings anxiety, but early-stage endometrial cancer has one of the most favourable clinical outlooks among all solid tumours. In many instances, comprehensive minimally invasive surgery provides both definitive staging and complete removal of the disease.

Even in cases where the cancer has progressed deeper into the uterine wall, spread to adjacent lymph nodes, or recurred after initial care, the therapeutic landscape has evolved substantially. The introduction of immunotherapy, refined radiotherapy techniques that protect healthy bowel and bladder tissues, and biomarker-guided treatment regimens mean that options are far more precise and effective than they were even five years ago. You will work closely with a multidisciplinary team—including gynaecological oncologists, medical oncologists, radiation oncologists, and specialist clinical nurses—who will tailor each step of your care to your personal health needs and tumour biology.

The cardinal and most frequent symptom of endometrial cancer is abnormal vaginal bleeding, which occurs in approximately 90% of individuals diagnosed with the condition. For postmenopausal women—defined as having had no menstrual periods for twelve consecutive months—any vaginal bleeding, spotting, or pinkish-brown staining is abnormal. It is essential to understand that postmenopausal bleeding is never a natural consequence of ageing. While common benign issues such as vaginal atrophy, cervical polyps, or endometrial thinning cause the majority of postmenopausal bleeding episodes, ruling out endometrial cancer through urgent medical evaluation is mandatory.

For individuals who have not yet reached menopause or who are navigating the perimenopausal transition, identifying abnormal bleeding can be slightly more complex due to irregular baseline cycles. However, red flag symptoms include bleeding between scheduled periods, unusually heavy or prolonged menstrual flows (menorrhagia), or bleeding that occurs after sexual intercourse. Any persistent deviation from an individual's established menstrual rhythm warrants careful clinical assessment by a general practitioner or gynaecologist.

Less commonly, endometrial cancer may present with non-bloody symptoms, particularly in advanced stages or in elderly individuals whose cervical canal has become stenotic (narrowed or closed), preventing blood from escaping. In these situations, patients may notice a persistent, watery, or foul-smelling vaginal discharge. Others may experience vague pelvic discomfort, lower abdominal pressure, pain during intercourse, unexplained weight loss, or changes in urinary and bowel habits. If you experience persistent pelvic pain or an unusual watery discharge, do not wait for bleeding to occur before consulting a doctor.

At its most fundamental biological level, endometrial cancer is initiated when DNA mutations occur within the epithelial cells of the endometrium. These genetic errors disrupt the normal mechanisms that regulate cellular growth, replication, and natural cell death (apoptosis). As abnormal cells proliferate without restraint, they form a mass that can invade the underlying muscular layer of the uterus (the myometrium), infiltrate lymphatic vessels, and potentially spread to regional lymph nodes and distant anatomical sites.

A primary driving force behind the majority of endometrial cancers is an imbalance between the female sex hormones oestrogen and progesterone, a state often described as 'unopposed oestrogen'. Oestrogen acts as a powerful growth signal, stimulating the endometrial cells to divide and multiply. Progesterone, by contrast, acts as a biological counterweight, halting proliferation, maturing the tissue architecture, and preparing the lining to shed. If oestrogen levels remain persistently high relative to progesterone, the endometrial lining becomes chronically overstimulated, leading first to endometrial hyperplasia (an abnormal thickening of the lining) and eventually, in some individuals, to malignant transformation.

Several established clinical and demographic factors can increase an individual's lifetime risk of developing endometrial cancer, primarily through mechanisms involving prolonged oestrogen exposure. Obesity is the most significant modifiable risk factor; adipose tissue contains the enzyme aromatase, which converts circulating androgens into oestrogen, generating continuous hormonal stimulation. Other hormonal risk factors include early age at menarche (starting periods before age 12), late natural menopause (after age 55), never having given birth (nulliparity), and conditions associated with chronic anovulatory cycles, such as polycystic ovary syndrome (PCOS). The use of unopposed oestrogen hormone replacement therapy (HRT)—giving oestrogen without an accompanying progestogen to protect the uterine lining—carries a substantial risk, which is why combined HRT is universally prescribed for individuals with an intact uterus.

Non-hormonal risk factors include advancing age, with most diagnoses occurring between the ages of 60 and 75, as well as personal treatment history. Tamoxifen, a targeted anti-oestrogen medication widely used to treat and prevent recurrence of breast cancer, acts as an oestrogen antagonist in breast tissue but paradoxically behaves as a mild oestrogen agonist in the uterus, slightly raising the risk of endometrial changes. Additionally, roughly 3% to 5% of all endometrial cancers arise due to inherited genetic cancer syndromes, most notably Lynch syndrome. Individuals carrying germline mutations in DNA mismatch repair genes face a cumulative lifetime risk of endometrial cancer that can reach 40% to 60%, frequently developing the disease at an earlier age than the general population.

The diagnostic pathway for suspected endometrial cancer typically begins in a primary care setting, followed by rapid referral to a specialised gynaecology clinic under fast-track suspected cancer pathways. The initial objective assessment usually involves a transvaginal ultrasound scan (TVS). During this non-invasive examination, an ultrasound probe is gently inserted into the vagina, allowing the sonographer to capture high-resolution images of the pelvic organs. The primary metric evaluated is the endometrial thickness; in a postmenopausal woman without bleeding, the lining is typically paper-thin. An endometrial thickness measuring greater than 4 millimetres in a postmenopausal woman with bleeding indicates the need for formal tissue sampling.

Tissue diagnosis is the definitive cornerstone of an endometrial cancer evaluation. This is most frequently achieved through an outpatient endometrial biopsy, commonly performed using a slender, flexible plastic suction device known as a Pipelle. The clinician passes the Pipelle through the cervix into the uterine cavity to collect microscopic fragments of the lining. While this procedure can cause brief uterine cramping similar to a sharp menstrual cramp, it requires no general anaesthetic and is completed within minutes. However, if the tissue yield is insufficient, if the cervix is too narrow to enter, or if ultrasound findings suggest a focal abnormality such as a polyp, formal direct visualisation is required.

In such cases, a hysteroscopy combined with targeted biopsy or curettage is performed. A hysteroscope—a thin, illuminated telescope equipped with a camera—is introduced through the vagina and cervix into the womb, which is gently expanded with sterile fluid. This allows the gynaecologist to directly inspect the entire endometrial cavity, identify suspicious lesions, and excise precise tissue specimens under visual guidance. Hysteroscopy can be carried out in an outpatient setting with local anaesthesia or as a day-case surgical procedure under light general anaesthesia, ensuring comprehensive histological verification.

Staging describes the physical extent of the cancer within the body, providing the critical foundation for determining prognosis and tailoring the subsequent treatment strategy. Endometrial cancer is staged surgically, which means the definitive stage can only be confirmed after the uterus, fallopian tubes, ovaries, and relevant lymph nodes have been removed and examined in detail by a specialist pathologist. Staging follows the unified framework established by the International Federation of Gynaecology and Obstetrics (FIGO), which was substantially updated in 2023 to integrate modern molecular and biological criteria alongside anatomical extent.

Anatomically, the disease is divided into four main stages. In Stage I, the malignancy is entirely confined to the body of the uterus. Stage I is subdivided into IA, where the tumour is restricted to the endometrium or invades less than half of the underlying muscular myometrium, and IB, where invasion extends through half or more of the myometrial depth. In Stage II, the cancer has spread directly into the supporting connective tissue (stroma) of the cervix, but remains within the uterus. In Stage III, regional spread has occurred: the tumour may have reached the outer surface of the uterus (serosa), the fallopian tubes, or the ovaries (Stage IIIA); the vagina or tissues directly surrounding the uterus (parametria) (Stage IIIB); or the regional pelvic or para-aortic lymph nodes (Stage IIIC).

Stage IV represents advanced or metastatic disease. In Stage IVA, the tumour has directly invaded the inner mucosal lining of the adjacent bladder or bowel. In Stage IVB, malignant cells have travelled through the bloodstream or distant lymphatic channels to distant anatomical sites, such as the liver, lungs, bones, or distant abdominal lymph nodes within the omentum. Importantly, the revised FIGO 2023 staging guidelines formally incorporate tumour histological type and molecular subgroups directly into stage allocations, ensuring that biologically indolent or aggressive characteristics modify the final stage classification appropriately.

Biomarker and molecular testing has revolutionised the management of endometrial cancer, moving clinical practice firmly into the era of precision medicine. Every newly diagnosed endometrial cancer specimen should now undergo molecular profiling, which categorises the tumour into one of four distinct genomic groups originally defined by The Cancer Genome Atlas (TCGA). The first group is POLE-ultramutated, characterised by pathogenic mutations in the exonuclease domain of the POLE gene; although these tumours often appear highly abnormal under a microscope, they evoke an intense immune response and have an exceptionally favourable prognosis with minimal risk of recurrence. The second group is Mismatch Repair Deficient (dMMR) or Microsatellite Instability-High (MSI-H), where tumours have lost functional DNA repair proteins; these represent roughly 25% to 30% of cases and exhibit remarkable sensitivity to modern immunotherapies.

The third group is the p53-abnormal (p53abn) or copy-number high group, which accounts for roughly 15% of cases and includes most serous carcinomas; these tumours display aberrant p53 protein expression on immunohistochemistry, behave aggressively, and typically require intensive multi-modality treatment. The fourth group is termed No Specific Molecular Profile (NSMP) or copy-number low, comprising roughly 50% of patients; these are predominantly low-to-intermediate grade endometrioid cancers that often express high levels of oestrogen and progesterone receptors and possess an intermediate clinical prognosis.

In addition to guiding therapeutic choices, testing for mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2) serves as a universal screening mechanism for Lynch syndrome. If an endometrial tumour displays loss of MLH1, reflex testing for MLH1 promoter hypermethylation is performed to distinguish sporadic epigenetic changes from hereditary mutations. If MSH2, MSH6, or PMS2 proteins are absent, or if MLH1 loss is unmethylated, the patient is promptly referred for formal germline genetic counselling and testing. Identifying Lynch syndrome provides actionable insights, enabling tailored cancer surveillance and risk-reducing interventions for the patient and their biological relatives.

Endometrial carcinomas are histologically diverse, and accurate subtyping under the microscope remains an essential partner to molecular classification. The most prevalent histological subtype is endometrioid adenocarcinoma, which accounts for approximately 75% to 80% of all diagnoses. Endometrioid tumours typically exhibit gland-like structures resembling the normal endometrium, are frequently associated with excess oestrogen exposure, and are graded on a scale from 1 to 3 based on their architectural complexity and solid cellular growth patterns. Grade 1 and 2 tumours are considered low-grade and generally carry an excellent prognosis, whereas Grade 3 tumours behave more aggressively.

Non-endometrioid carcinomas are less frequent but clinically significant due to their higher intrinsic propensity for rapid local invasion and distant spread. Serous endometrial carcinoma represents roughly 10% of cases, often arises in older individuals with atrophic endometrial tissue, and is characterised by widespread cellular abnormalities, deep myometrial invasion, and frequent p53 mutations. Clear cell carcinoma is another uncommon, high-grade variant comprising roughly 2% to 3% of cases. Carcinosarcoma, previously categorised as a mixed mullerian tumour, is now recognized as a highly aggressive, dedifferentiated form of endometrial carcinoma containing both epithelial and mesenchymal malignant components. Understanding these histological and molecular distinctions ensures the oncological team can anticipate disease behaviour and design appropriate therapeutic regimens.

The primary management of endometrial cancer is surgical, which serves as both the definitive diagnostic staging procedure and the principal curative treatment. For the vast majority of patients with apparent early-stage disease, the standard operation is a total laparoscopic or robotic-assisted hysterectomy (removal of the uterus and cervix) alongside a bilateral salpingo-oophorectomy (removal of both fallopian tubes and ovaries). Minimally invasive keyhole approaches are preferred because they offer significantly reduced blood loss, lower infection rates, less postoperative pain, and much faster return to normal daily activities compared to traditional open abdominal surgery. Surgical staging also typically incorporates sentinel lymph node (SLN) mapping using an indocyanine green (ICG) fluorescent dye technique, which identifies and evaluates the primary drainage lymph nodes while sparing patients the significant risk of lower-limb lymphoedema associated with full pelvic lymph node dissection.

Following surgery, the multidisciplinary team reviews the final pathology—including tumor grade, myometrial invasion depth, lymphovascular space invasion (LVSI), and molecular classification—to determine whether adjuvant therapy is warranted. For patients with low-risk Stage I disease, observation alone is standard. For intermediate-risk disease, adjuvant radiotherapy is frequently recommended to sterilise any microscopic residual cells. This may involve vaginal brachytherapy, where a specialised radioactive source is temporarily placed directly into the upper vagina to treat the vaginal cuff with minimal radiation exposure to surrounding organs, or external beam radiotherapy (EBRT), which directs focused radiation beams to the broader pelvic basin when there is deeper invasion or nodal involvement.

For high-risk early-stage disease, Stage III, or Stage IV cancer, systemic therapy forms an essential part of treatment. The international standard chemotherapy regimen consists of carboplatin and paclitaxel administered intravenously every three weeks for approximately six cycles. In recent breakthrough developments, landmark global clinical trials have fundamentally rewritten standard care: adding immune checkpoint inhibitor immunotherapy (such as dostarlimab or pembrolizumab) to carboplatin and paclitaxel, followed by single-agent immunotherapy maintenance, significantly prolongs progression-free and overall survival in patients with advanced or recurrent endometrial cancer, with the most dramatic, sustained benefits observed in mismatch repair-deficient (dMMR) tumours.

Clinical trials represent an invaluable treatment consideration at multiple stages of the endometrial cancer care pathway. Far from being a last resort, clinical trials evaluate innovative therapeutic concepts, such as combining novel antibody-drug conjugates (ADCs) with immunotherapy, testing de-escalated therapy for POLE-mutated tumours to spare patients radiation, or evaluating endocrine-based combinations for hormone-sensitive disease. Participating in a well-designed clinical trial grants access to emerging cutting-edge agents under meticulous clinical supervision while advancing the scientific standards of care for future generations.

When considering survival statistics for endometrial cancer, it is essential to remember that published data reflect population-wide historical averages, whereas every individual patient's prognosis is shaped by their unique physical health, tumour grade, and molecular characteristics. Overall, endometrial cancer carries one of the most encouraging prognostic outlooks in gynaecological oncology because the vast majority of diagnoses occur when the tumour is entirely confined to the uterus. For individuals diagnosed with localized, Stage I disease, the five-year relative survival rate is approximately 90% to 95%, with many patients requiring no further interventions following initial surgical resection.

For regional disease that has extended into adjacent tissues or regional lymph nodes (Stage III), five-year survival rates typically range between 60% and 70%, reflecting the need for combined surgical, radiation, and systemic approaches. Advanced, metastatic disease (Stage IV) presents greater clinical challenges, with historical five-year survival figures roughly between 15% and 25%. However, these older baseline figures do not fully reflect the profound impact of recent treatment advances. The integration of modern molecular stratification and the widespread introduction of immune checkpoint inhibitors are actively transforming outcomes for patients with advanced and recurrent disease, extending life expectancies and improving long-term disease stability.