Uterine sarcoma (womb sarcoma): types, symptoms, diagnosis and treatment

The womb (uterus) has an inner lining, the endometrium, and a thick muscle wall. Cancer Research UK explains that most womb cancers start in the lining and are called endometrial cancers. Sarcoma of the womb is different: it develops from cells in the muscle layer of the womb, rather than the lining, and is a type of soft tissue sarcoma. Soft tissue sarcomas are cancers of the supporting tissues of the body.

Cancer Research UK says sarcomas of the womb tend to spread in the bloodstream to other parts of the body, especially the lungs, and that the treatment you need is not the same as for other types of womb cancer.

A related term, carcinosarcoma, can be confusing. Cancer Research UK says carcinosarcoma has features of both carcinoma and sarcoma under the microscope, is different from sarcoma of the womb and is treated as a carcinoma rather than a sarcoma.

Two types are described in the UK sources used for this page.

Symptoms vary with the size and location of the tumour, and you may have all, some or none of them before diagnosis, according to Sarcoma UK. For endometrial stromal sarcoma it lists the following, and says that if you have any of them you should visit your GP.

• Abnormal vaginal bleeding: between periods, heavier than usual during a period, or after the menopause.

• Abnormal vaginal discharge.

• Pain in the pelvic or stomach region.

• A lump you can feel in the pelvic or stomach region.

• Changes in how you pee, such as peeing more often.

• Constipation.

Sarcoma UK says a specialist sarcoma doctor or gynaecologist diagnoses endometrial stromal sarcoma through tests that may include a physical examination, scans such as ultrasound, CT, MRI or PET (often a transvaginal ultrasound for ESS), a hysteroscopy, in which a thin tube is passed through the vagina and cervix into the uterus so the doctor can look and take a biopsy, and a biopsy. For uterine leiomyosarcoma it describes a hysteroscopy, a pelvic ultrasound and an endometrial biopsy.

Cancer Research UK says the type of womb cancer is shown by laboratory tests on cells from a biopsy and on tissue removed at surgery. Grading describes how much cells look like normal cells, which gives an idea of how quickly the cancer might grow and spread.

Because sarcoma can resemble a fibroid, Sarcoma UK advises that fibroids that continue to grow in size after the menopause should be seen for further examination.

Surgery is the main treatment. Sarcoma UK says that for uterine leiomyosarcoma a hysterectomy, removal of the uterus, is often recommended if the cancer is limited to the uterus and has not spread. For endometrial stromal sarcoma, it says the type of surgery depends on how far the cancer has spread, from removal of a small tumour with a margin, to total hysterectomy, to radical hysterectomy or hysterectomy with removal of the fallopian tubes and ovaries (bilateral salpingo-oophorectomy).

It notes that if the ovaries are removed you will go through the menopause if you have not already, which is called a surgical menopause, and that after any hysterectomy you can no longer become pregnant; if you want children in the future you can talk to your doctor about possible fertility treatments.

Radiotherapy may be given before or after surgery for ESS. For uterine leiomyosarcoma, Sarcoma UK says studies have shown radiotherapy is not effective following surgery but may be useful for inoperable tumours to help with symptoms such as pain or bleeding. Chemotherapy may be used if there is a high risk of the cancer returning or it has spread, though it says there is limited data on its role in leiomyosarcoma. For some ESS tumours that are driven by hormones, hormone therapy can sometimes help slow growth. Targeted therapies and immunotherapies are being studied in clinical trials.

After treatment you will have regular follow-up appointments for several years, and Sarcoma UK says you should receive a schedule from your sarcoma clinical nurse specialist. Follow-up usually includes a chance to discuss symptoms, an examination, scans such as CT, MRI or ultrasound, and a chest X-ray to rule out secondary cancers in the lungs.

The cancer can come back in the same place (local recurrence) or elsewhere. Sarcoma UK says that if it reappears you should have treatment as quickly as possible, which may involve more surgery or radiotherapy, and that you should contact your doctor or nurse if you are worried about it returning.

Outlook varies with type, grade and stage, and the sources used here do not give survival figures for uterine sarcoma specifically, so individual outlook is best discussed with the sarcoma team.

Rare sarcomas are managed in the NHS by specialist sarcoma and gynaecological cancer multidisciplinary teams. Because uterine sarcoma can be mistaken for a fibroid, a growing fibroid or unusual bleeding is a reason to ask for further assessment, and a suspected or confirmed sarcoma is the point at which referral to a specialist team is sensible.

Private gynaecology can give quick access to scans and consultations, and some people use it for a second opinion. For a confirmed or suspected sarcoma, access to the multidisciplinary expertise of a sarcoma service is the important factor.