Rare gynaecological cancers: Uterine sarcomas
Uterine sarcomas are a group of rare cancers that originate in the muscle or connective tissue of the uterus. Unlike the more common cancers of the uterus, such as endometrial cancer, which starts in the lining of the uterus, uterine sarcomas develop in the supporting tissues of the uterus. Uterine sarcomas are rare and account for approximately 1 in 20 malignancies arising from the uterus.
The diagnosis of uterine sarcomas is very difficult. Some patients may have abnormal vaginal bleeding or an increase, clear vaginal discharge, which triggers a doctor’s visit and a D&C. In other patients, the only symptom is a growth on the uterus as detected on medical imaging. While a growth in the uterus is “normal” for premenopausal women, for women after the menopause such a growth should be regarded as suspicious.
There are several types of uterine sarcomas, and they are classified based on the specific types of cells or tissues they originate from.
The three main types include:
Origin: Arises from the smooth muscle cells of the uterus (myometrium). They can be faster growing and may be more likely to spread to other parts of the body.
Prevalence: Leiomyosarcoma is the most common type of uterine sarcoma.
Risk Factors: Mostly unknown. Risk factors are not well-defined, but prior radiation therapy to the pelvis, a history of breast cancer and certain genetic conditions may increase the risk.
Endometrial Stromal Sarcoma:
Origin: Develops from the connective tissue or stromal cells of the endometrium (lining of the uterus). They are typically low-grade, slow-growing tumours.
Prevalence: Less common than leiomyosarcoma.
Risk Factors: Mostly unknown. Certain genetic conditions may be associated with an increased risk.
Undifferentiated Uterine Sarcoma:
Origin: Arises from undifferentiated or poorly differentiated cells, making it more challenging to classify into specific tissue types. They can be faster growing and may be more likely to spread to other parts of the body, such as the lungs and the liver..
Risk Factors: Limited known risk factors, but prior pelvic radiation may be associated.
Symptoms: Symptoms of uterine sarcomas are unspecific. The symptoms of uterine sarcomas may include abnormal vaginal bleeding, pelvic pain or pressure, and a palpable mass in the pelvic area. These symptoms are not specific to uterine sarcomas and can occur with other benign and malignant gynaecological conditions.
Diagnosis: Diagnosis by medical Imaging (for e.g. CT, MRI), blood tests are unreliable. A biopsy through the skin (transdermal) is not recommended because it may cause tumour cell dissemination and the result is often inaccurate or false negative. A large number of uterine sarcomas are diagnosed incidentally following a hysterectomy or a myomectomy due to lack of any reliable screening options. In this case, my colleagues and I will review the histopathology and will recommend further action to the patient and the referring general gynaecologist.
Due to the unspecific symptoms and because medical imaging is unreliable, unfortunately, only half of all uterine sarcomas will be diagnosed prior to surgery.
Treatment: Uterine sarcomas do not respond well to any type of adjuvant treatment (chemotherapy or radiation). Patients will solely rely on surgery for treatment.
For that very reason, it is super important that gynaecologists perform hysterectomies for patients at the highest surgical standard. That includes that the uterus is removed intact, without any spillage and without any cross sectioning. If this is not adhered to, tumour dissemination and spillage can occur and the impact for the unfortunate patient will be detrimental.
It's important for individuals diagnosed with uterine sarcomas to work closely with their healthcare team to develop a personalised treatment plan and to discuss prognosis and potential side effects of treatment.
Being diagnosed with an aggressive, rare cancer can be a distressing process—speaking to a gynaecological oncologist will help you to be informed on how to effectively treat the disease.