High-grade endometrial stromal sarcoma (HGESS) is a rare and aggressive form of uterine cancer. It originates from the connective tissue cells within the inner lining of the uterus, known as the endometrium.
Understanding High Grade Endometrial Stromal Sarcoma
High-grade endometrial stromal sarcoma (HGESS) develops from the supportive connective tissue (stroma) of the endometrium. It is classified as “high grade” because its cells appear significantly different from normal cells under a microscope, indicating a more aggressive and faster-growing disease compared to low-grade variants. HGESS is a subtype of uterine sarcoma, accounting for approximately 0.2% to 1% of all uterine cancers.
This malignancy is considerably rarer than the more common endometrial cancers, such as adenocarcinoma. While the exact cause remains unknown, some research suggests a connection to hormone therapies, pelvic radiotherapy, and polycystic ovary syndrome (PCOS). HGESS most commonly affects individuals with a uterus, typically between the ages of 40 and 60, with a median age of diagnosis around 55 years. Common, non-specific symptoms may include abnormal uterine bleeding, such as bleeding between periods, heavier than usual menstrual bleeding, or post-menopausal bleeding. Pelvic pain or the presence of a palpable pelvic mass can also occur.
Diagnosing High Grade Endometrial Stromal Sarcoma
Identifying high-grade endometrial stromal sarcoma typically begins with a thorough medical history and a physical examination. Imaging techniques play a role in detecting abnormalities within the uterus and assessing the potential extent of the tumor. A transvaginal ultrasound can provide initial images, while magnetic resonance imaging (MRI) and computed tomography (CT) scans offer more detailed views of the uterus and surrounding areas, helping to identify irregular margins, nodular lesions, or tumor extension.
While imaging can provide diagnostic clues, a definitive diagnosis of HGESS relies on a tissue biopsy. This can be obtained through procedures like a dilation and curettage (D&C), hysteroscopy with biopsy, or from a hysterectomy specimen if surgery is performed initially. The tissue sample is then examined by a pathologist, who can distinguish HGESS from other uterine conditions based on the appearance of the cells, including high mitotic activity and necrosis. Accurate staging of the tumor is performed once the diagnosis is confirmed to guide subsequent treatment decisions.
Treatment for High Grade Endometrial Stromal Sarcoma
Treatment for high-grade endometrial stromal sarcoma primarily involves surgery. A total hysterectomy is typically performed. Often, bilateral salpingo-oophorectomy is also recommended to prevent recurrence, given that HGESS often lacks hormone receptor expression. In cases of early-stage HGESS, particularly for premenopausal women, ovarian preservation may be considered if there is no visible adnexal tumor or gross extra-uterine disease, as the likelihood of ovarian metastasis is low.
Following surgery, adjuvant therapies may be considered based on the tumor’s characteristics and stage. Radiation therapy can be used, sometimes in combination with chemotherapy, especially for advanced or recurrent cases. Chemotherapy regimens, which may include agents like doxorubicin combined with ifosfamide or dacarbazine, or gemcitabine with dacarbazine, are employed for advanced or metastatic disease. However, HGESS is less responsive to hormonal therapies compared to low-grade variants, as it often does not express hormone receptors.
For advanced or recurrent cases, targeted therapies or participation in clinical trials may be explored. Treatment plans for HGESS are individualized, taking into account the specific stage and characteristics of the disease, and are often developed by a multidisciplinary team of specialists.
Outlook and Ongoing Monitoring
The outlook for high-grade endometrial stromal sarcoma varies, influenced by the stage of the disease at diagnosis, the specific characteristics of the tumor, and how well it responds to treatment. Patients diagnosed at an advanced stage typically face a less favorable prognosis, with recurrences often occurring within a year of diagnosis. The five-year survival rates for stage I-II disease can exceed 90%, but this percentage drops to around 50% for those with stage III-IV disease.
Given the potential for recurrence, including late recurrence, long-term surveillance is an important part of post-treatment care. Regular follow-up appointments are scheduled to monitor for any signs of the disease returning. These appointments typically include physical examinations and imaging studies to detect any new or recurring abnormalities. While most recurrences are observed in the pelvis and abdomen, distant sites such as the lungs and vagina can also be involved. Continued adherence to follow-up schedules is important for early detection and management of any potential recurrence.