Uterine sarcoma is a malignant tumour which develops within the muscle wall of the uterus (womb). It is a very rare type, with most uterine cancers affecting the lining of the uterus (endometrium) rather than the myometrium. 

Uterine sarcomas are usually more aggressive than other types and can grow quickly depending on the exact type. 

Diagnosis can be difficult due to the location of the tumour and are often not diagnosed until an advanced stage. A variety of tests may be performed including pelvic examination, imaging and biopsy. Full body imaging may also be done to allow staging of the disease. 

After a diagnosis has been made treatment options may include surgery, radiotherapy, chemotherapy or hormonal treatments - or a combination of therapies. The prognosis is variable and depends on multiple factors. The earlier the tumour is diagnosed the better the long-term prognosis.¹

Symptoms

Signs commonly seen with uterine sarcoma may also be present with non-cancerous lesions such as fibroids, therefore it is important to consult a healthcare professional if you have any of the following clinical signs. 

• Abnormal vaginal bleeding (not your normal menstrual cycle bleeding)
• Bleeding after menopause
• Vaginal mass
• Pain in the abdomen
• Frequent urination²

Diagnosis

Uterine sarcoma is more common in older women around the age of 60 however, it is still possible for younger women to develop uterine sarcoma. 

Certain risk factors may also increase the likelihood of developing the disease, such as radiation to the pelvic region (usually for treatment of another type of cancer) and prolonged hormonal treatment such as tamoxifen (used to treat certain types of breast cancer) and genetic disorders.¹  

Even if you do not fall into these higher risk categories it is important to get any abnormal signs checked out by a healthcare professional. 

Physical examination 

To start with, a full history will be taken including establishing if there are any family members with a cancer diagnosis, as this may help determine if there is a genetic link. The patient's fitness will also be assessed. After this a routine physical examination will usually follow focusing on general health and if any lumps/bumps are present.² 

Pelvic examination 

Usually, a pelvic examination will be performed by a healthcare professional to check for anything abnormal.

• A speculum will be inserted into the vagina to allow the doctor/nurse to visually examine the vagina and cervix. 
• A smear test (pap test) may also be done at this point by taking a swab of the cells lining the cervix/vagina so the laboratory can assess the sample for any abnormal cells. 

By inserting a lubricated gloved finger, it may also be possible to feel for any abnormal masses within the uterus by simultaneously pressing on the lower abdomen with the other hand. A rectal exam to assess for any lumps which may have spread from the uterus may also be performed.² 

Transvaginal ultrasound

Transvaginal ultrasound involves the insertion of a probe into the vagina to assess the vagina, uterus, fallopian tubes and bladder. 

Ultrasound uses high-energy sound waves being projected into tissue and an image is created depending on how the waves echo back. This allows for the assessment of any masses within the tissues or organs which may not be visible to the naked eye.²

Dilatation and curettage 

This involves the uterus being expanded to allow for an instrument to be inserted which collects cells from the lining of the uterus. This sample is then sent to a laboratory to be analysed for any abnormal cells.²

Endometrial biopsy 

To obtain a sample of the cells of the lining of the uterus a tube inserted into the uterus is used to scrape the lining to gather a small amount of tissue which can be analysed at the lab.² 

Types of uterine sarcoma

There are 3 main types of uterine sarcoma which are usually diagnosed either on biopsy or after surgery. 

• Leiomyosarcoma - this is the most common type and develops within the muscular wall of the uterus
• Endometrial stromal sarcoma - this type develops in the tissue that joins the lining to the muscle wall
• Undifferentiated sarcomas of the uterus - this is extremely rare and often grows very quickly and is usually an aggressive sarcoma³

Staging

The most commonly used method of staging in the UK is the FIGO (International Federation of Gynecology and Obstetrics) staging. This takes into account the size of the tumour, if the tumour extends beyond the uterus and if there is spread elsewhere in the body (metastasis).⁴ 

Further imaging often involving CT, MRI or x-ray will be needed to assess the extent of the disease and allow accurate staging.² The higher the stage, the more advanced the disease and the worse the prognosis. 

Treatment 

Surgery

If possible surgery to remove the cancer and uterus may be performed. Sometimes a full diagnosis has not been made and surgery is used to diagnose, treat and stage the disease. This is partly due to the inaccessibility of the uterus and difficulty in obtaining biopsies of the muscular wall. There are many types of surgical procedures which may be used depending on the extent of the cancer/suspected cancer and the general health of the patient.² 

Total hysterectomy 

Surgical removal of the uterus and cervix usually via an abdominal incision. 

Total hysterectomy with salpingo-oophorectomy

Surgical removal of the uterus and cervix with the fallopian tube and ovary which may involve one or both sides. 

Radical hysterectomy

Surgical removal of the uterus, cervix, surrounding tissue, both fallopian tubes and both ovaries. 

Lymphadenectomy

During the same surgery lymph nodes may be removed to allow microscopic analysis of the cells to determine the extent of spread.² 

Chemotherapy 

In some cases when the tumour has been found early on with no spread elsewhere surgery may be curative. 

However, many cases are often only diagnosed beyond this point. This is when adjuvant treatment may be needed. This may also be the case if you are unable to have surgery. 

Chemotherapy involves giving cytotoxic drugs to kill cancer cells. Many types of chemotherapy agents are used (including carboplatin, paclitaxel, docetaxel and cisplatin) and they are often given in combination with other agents and sometimes with radiotherapy (chemoradiotherapy).⁵ 

Radiotherapy

This may be used if you cannot have surgery or the mass is large. It is commonly used with chemotherapy after surgery to help prevent recurrence. 

Radiotherapy can be given in a variety of ways some externally and some internally using brachytherapy via specialist implants to allow direct treatment.⁶ 

Hormonal therapy

Some types of uterine cancer may be treated with hormonal therapy, to reduce the levels of the hormones (usually oestrogen or progesterone) which may stimulate womb cancer cells to grow. The most common therapy used is medroxyprogesterone acetate which is a type of progesterone.⁷ Other types of hormonal therapy may be used depending on the sensitivity of that particular tumour.⁸ 

Immunotherapy and targeted therapy

Newer drugs including immunotherapy and targeted therapies may be indicated depending on the features of the tumour. 

Immunotherapy uses the body's immune system to find and kill any remaining cancer cells. 

Targeted therapy involves drugs which specifically target the cancer cells. Testing performed on the tumour cells at the lab may indicate if immunotherapy or targeted therapy is suitable for that specific patient. 

The main genes the lab is looking for mutations in include the mismatch repair gene (MMRd), p53abn, POLE mutations and no specific molecular profile (NSMP). Sometimes these drugs may be used in combination.⁹ 

Summary

Uterine sarcomas are rare, malignant, often aggressive cancers developing within the wall of the womb. Early detection results in a better prognosis however, diagnosis often occurs later in the disease process once the tumour has spread to other parts of the uterus or body. 

Diagnosis involves examination, imaging and biopsy or is confirmed after surgical removal of the womb. 

Treatment depends on the type of tumour, extent of spread and health of the patient. Usually, a combination of surgery, chemotherapy and radiotherapy will be used to treat uterine sarcoma and possibly hormonal, immunotherapy or targeted therapies if they are suitable.