Because of the rarity of this cancer, there are no guidelines for how it should be treated, nor any typical treatment. The common genetic causes remain uncharacterized. Primary transitional cell carcinomas of the endometrium are even more rare; 16 cases had been reported as of 2008. Its pathophysiology and treatments have not been characterized. Histologically, TCCE resembles endometrioid carcinoma and is distinct from other transitional cell carcinomas. Sarcoma
In contrast to endometrial carcinomas, the uncommon endometrial stromal sarcomas are cancers that originate in the non-glandular connective tissue of the endometrium. They are generally non-aggressive and, if they recur, can take decades. Metastases to the lungs and pelvic or peritoneal cavities are the most frequent. They typically have estrogen and/or progesterone receptors. The prognosis for low-grade endometrial stromal sarcoma is good, with 60–90% five-year survival. High-grade undifferentiated endometrial sarcoma (HGUS) has a worse prognosis, with high rates of recurrence and 25% five-year survival. HGUS prognosis is dictated by whether or not the cancer has invaded the arteries and veins. Without vascular invasion, the five-year survival is 83%; it drops to 17% when vascular invasion is observed. Stage I ESS has the best prognosis, with five-year survival of 98% and ten-year survival of 89%. ESS makes up 0.2% of uterine cancers. Metastasis
Endometrial cancer frequently metastasizes to the ovaries and Fallopian tubes when the cancer is located in the upper part of the uterus, and the cervix when the cancer is in the lower part of the uterus.
The 2009 FIGO staging system is as follows:
Myometrial invasion and involvement of the pelvic and para-aortic lymph nodes are the most commonly seen patterns of spread. A Stage 0 is sometimes included, in this case it is referred to as "carcinoma in situ". In 26% of presumably early-stage cancers, intraoperative staging revealed pelvic and distant metastases, making comprehensive surgical staging necessary. Management
Surgery
The initial treatment for endometrial cancer is surgery; 90% of women with endometrial cancer are treated with some form of surgery. Surgical treatment typically consists of hysterectomy including a bilateral salpingo-oophorectomy, which is the removal of the uterus, and both ovaries and Fallopian tubes. Lymphadenectomy, or removal of pelvic and para-aortic lymph nodes, is performed for tumors of histologic grade II or above. Lymphadenectomy is routinely performed for all stages of endometrial cancer in the United States, but in the United Kingdom, the lymph nodes are typically only removed with disease of stage II or greater. The topic of lymphadenectomy and what survival benefit it offers in stage I disease is still being debated. In women with presumed stage I disease, a 2017 systematic review found no evidence that lymphadenectomy reduces the risk of death or relapse of cancer when compared with no lymphadenectomy. Women who undergo lymphadenectomy are more likely to experience systemic morbidity related to surgery or lymphoedema/lymphocyst formation. In stage III and IV cancers, cytoreductive surgery is the norm, and a biopsy of the omentum may also be included.