Rare mesodermal tumours called uterine sarcomas make up 3-7% of uterine malignancies. Uterine sarcomas have been classified historically into carcinosarcomas which accounts for 40% of cases followed by leiomyosarcomas (ULMS) (40%), endometrial stromal sarcomas (high grade and low grade) (10– 15%), undifferentiated sarcomas (5–10%), and others such as PEComas, adenosarcoma, rhabdomyosarcoma (RMS) and Smooth muscle tumour of uncertain malignant potential. Recently, carcinosarcomas have been reclassified as a metaplastic form of endometrial carcinoma. The majority of subgroups exhibit aggressive behaviour and have a poor prognosis due to high rates of distant metastases and local recurrence. Women over 50 have a higher incidence rate than younger patients. Studies and analysis have revealed that 52.4% of patients had no suspicion of cancer at the time of surgery.
Risk factors
Studies have shown that factors that increase the risk of developing uterine sarcomas include the use of combined HRT and tamoxifen in postmenopausal women for five years or more, pelvic radiation exposure, obesity, diabetes, and exposure to elevated unopposed estrogen levels. Hereditary leiomyomatosis and
renal cell cancer (HLRCC), rare family cancer syndromes, have been related to an increased risk of uterine sarcomas. Women who have had congenital (heritable) retinoblastoma as a child have an increased risk of uterine sarcomas.
Signs & symptoms
The signs and symptoms of uterine sarcomas are frequently mistaken for uterine myomas. Sarcomas frequently results in pelvic or abdominal pain, abdominal distension, and abnormal uterine bleeding. An enlarged uterus can cause pressure or obstruction symptoms like urinary retention, constipation, obstipation, and tenesmus. Certain clinical characteristics should raise red flags, such as a fibroid that grows quickly over a three-month period in a postmenopausal or perimenopausal woman who does not use hormone replacement treatment. Rarely, uterine sarcomas are symptomless, and the first symptoms of the disease are respiratory system problems brought on by metastasis in the lungs.
The diagnosis is typically made after surgery after reviewing the histology. Although progress is being made, common imaging techniques like ultrasound and magnetic resonance imaging (MRI) are still unable to reliably and accurately identify between benign leiomyoma and malignant disease. To characterise uterine tumours and identify the safest therapy approach, preoperative diagnosis is crucial. For the treatment of uterine leiomyoma, minimally invasive procedures such as laparoscopic intervention, morcellation, myomectomy, and uterine artery embolisation have been developed.
Contrary to ovarian cancer, there are no blood tests or tumour markers that can raise suspicion. Serum lactate dehydrogenase and conventional and dynamic MRI scans, when used together, do help to distinguish between degenerated leiomyoma and LMS, with an increase in positive predictive and negative values from 93.3% and 83.3%, respectively. The management and surveillance of these patients should be undertaken in the gynaecological oncology centre management of early-stage tumours. The standard of care for treating early-stage uterine sarcomas is total abdominal hysterectomy and bilateral salpingo-oophorectomy. Ovarian conservation may be taken into account on a case-by-case basis because the probability of ovarian metastases has been estimated to be 4%.
The single most significant prognostic factor is the tumour stage. The staging for uterine sarcomas used by the International Federation of Gynaecology and Obstetrics (FIGO) was modified in 2009 to take into account particular histological subtypes.
Advanced disease & recurrent disease
Due to the uterine sarcomas’ aggressive disease biology, patients may frequently present with metastatic disease at the time of diagnosis. The chance of distant metastatic relapse is substantial, even in individuals with early-stage illness that has been surgically removed, hence these patients should be subjected to
routine monitoring.
Systemic therapy is an option in patients with locally advanced, recurrent, or metastatic uterine sarcoma. Unfortunately, response rates have not greatly increased over time. The choice of treatment is histology-guided, and the uterine sarcoma histologic subtypes exhibit a range of responses to systemic therapy. Other treatment options for advanced and metastatic uterine sarcoma include surgery, radiotherapy, radiofrequency ablation, immunotherapy, and targeted therapy. Hormonal therapy has shown promising results in recent years due to the high death rate and poor clinical benefit of surgery and adjuvant chemoradiotherapy.
(The author is an associate consultant in gynaecologic oncology at a leading Bengaluru-based hospital.)