In the United States, they are more common in white women, particularly those with a history of endometrial hyperplasia. Type I endometrial cancers are often low-grade, minimally invasive into the underlying uterine wall (myometrium), estrogen-dependent, and have a good outcome with treatment. Type I carcinomas represent 75–90% of endometrial cancer.Type II endometrial carcinomas usually occur in older, post-menopausal people, in the United States are more common in black women, and are not associated with increased exposure to estrogen or a history of endometrial hyperplasia. Type II endometrial cancers are often high-grade, with deep invasion into the underlying uterine wall (myometrium), are of the serous or clear cell type, and carry a poorer prognosis. They can appear to be epithelial ovarian cancer on evaluation of symptoms. They tend to present later than Type I tumors and are more aggressive, with a greater risk of relapse and/or metastasis. Endometrioid adenocarcinoma
In endometrioid adenocarcinoma, the cancer cells grow in patterns reminiscent of normal endometrium, with many new glands formed from columnar epithelium with some abnormal nuclei. Low-grade endometrioid adenocarcinomas have well differentiated cells, have not invaded the myometrium, and are seen alongside endometrial hyperplasia. The tumors glands form very close together, without the stromal tissue that normally separates them. Higher-grade endometrioid adenocarcinomas have less well-differentiated cells, have more solid sheets of tumor cells no longer organized into glands, and are associated with an atrophied endometrium. There are several subtypes of endometrioid adenocarcinoma with similar prognoses, including villoglandular, secretory, and ciliated cell variants.
VBT is used to treat any remaining cancer solely in the vagina, whereas EBRT can be used to treat remaining cancer elsewhere in the pelvis following surgery. However, the benefits of adjuvant radiotherapy are controversial. Though EBRT significantly reduces the rate of relapse in the pelvis, overall survival and metastasis rates are not improved. VBT provides a better quality of life than EBRT.Radiotherapy can also be used before surgery in certain cases. When pre-operative imaging or clinical evaluation shows tumor invading the cervix, radiation can be given before a total hysterectomy is performed. Brachytherapy and EBRT can also be used, singly or in combination, when there is a contraindication for hysterectomy. Both delivery methods of radiotherapy are associated with side effects, particularly in the gastrointestinal tract. Hormonal therapy
Hormonal therapy is only beneficial in certain types of endometrial cancer. It was once thought to be beneficial in most cases. If a tumor is well-differentiated and known to have progesterone and estrogen receptors, progestins may be used in treatment. There is no evidence to support the use of progestagen in addition to surgery for newly diagnosed endometrial cancer. About 25% of metastatic endometrioid cancers show a response to progestins. Also, endometrial stromal sarcomas can be treated with hormonal agents, including tamoxifen, hydroxyprogesterone caproate, letrozole, megestrol acetate, and medroxyprogesterone. This treatment is effective in endometrial stromal sarcomas because they typically have estrogen and/or progestin receptors. Progestin receptors function as tumor suppressors in endometrial cancer cells.