Endometrial cancer is a disease in which malignant (cancer) cells form in the tissues of the endometrium. Cancer of the endometrium is different from cancer of the muscle of the uterus, which is called sarcoma of the uterus.
Taking tamoxifen for breast cancer or taking estrogen alone (without progesterone) can affect the risk of developing endometrial cancer. Possible signs of endometrial cancer include unusual vaginal discharge or pain in the pelvis.
The prognosis and treatment options depend on the stage of the cancer (whether it is in the endometrium only, involves the whole uterus, or has spread to other places in the body); how the cancer cells look under a microscope; and whether the cancer cells are affected by progesterone.
Patients with endometrial cancer are treated at our Gynecologic Cancer Unit. You can also review the tabs at top of this page for information on endometrial cancer symptoms and risks, diagnosis, and treatment.
The main cause of most endometrial cancer is an imbalance between the hormone estrogen compared to the body's progesterone level. Progesterone is responsible for the process of menstrual bleeding, which thins the lining of the uterus (endometrium) each month. When there is too much estrogen in the body, progesterone can't do its job and the the endometrium gets thicker. Over time, the endometrial cells can become cancerous.
Risk factors may include:
- Estrogen-only replacement therapy (taking estrogen in combination with the hormone progesterone does not appear to increase the risk of endometrial cancer)
- Taking tamoxifen to treat or prevent breast cancer. If you're taking or have taken tamoxifen, be sure to see your physician for an annual pelvic exam and report any unusual vaginal bleeding
- Infertility or never giving birth
- Starting menstruation early (usually before age 12) which exposes your endometrium to more estrogen over time
- Starting menopause after age 50
- A high-fat diet
- The presence of ovarian tumors such as granulosa-theca cell tumors that make estrogen, or polycystic ovarian disease
- The gene for hereditary non-polyposis colon cancer (HNPCC)
- Personal history of ovarian or breast cancer, which share some of the same risk factors with endometrial cancer
The most common symptom of endometrial cancer is unexpected vaginal bleeding after menopause. For this reason, many cases of endometrial cancer are found early because post-menopausal women will usually see their doctor if they have vaginal bleeding or other discharge. Be sure to let your physician know if this occurs.
These additional early symptoms might also be noticed:
- Pain when urinating or during sexual intercourse
- Pelvic area pain or a mass
- Unexplained weight loss
If endometrial cancer is suspected, your doctor will perform a pelvic exam and may perform a Pap test, although the latter, which obtains cells from the cervix, will generally not reveal endometrial cancer. To confirm a diagnosis of endometrial cancer, an endometrial biopsy will be performed, which will allow a pathologist to examine a small sample of your endometrium under a microscope. The sample tissue is obtained through a thin flexible tube inserted into the uterus through the cervix.
Your doctor may also recommend some of the following tests:
- Blood tests
- Chest X-ray
- Transvaginal ultrasound, in which the ultrasound wand is inserted into the vagina. The wand emits and receives sound waves that are translated into images that can be analyzed by a radiologist or your physician. Abnormal thickening of the endometrium may be an indication of endometrial cancer.
- Dilation & Curettage (D&C), an outpatient procedure where the cervix is enlarged (dilated) and tissue is scraped from inside the uterus. This procedure is sometimes used when not enough tissue to confirm a diagnosis was obtained through the biopsy.
- Intravenous pyelogram (IVP) may done when it appears the cancer may have spread around the ureters, the tubes that connect the kidneys to the bladder. This test uses X-rays with a contrasting dye to show the internal organs. However, a CT scan will often provide the same information.
- Imaging studies such as Magnetic Resonance Imaging (MRI), Computed Tomography (CT) scan, or Positron Emission Tomography (PET) scan.
Your doctors will determine the “grade” of your cancer, which is how it looks under the microscope. If 95% or more looks like glands of normal endometrial tissue, it is called grade 1. Grade 2 tumors have between 6% and 50% normal-looking gland formations. Cancers with fewer than 50% are grade 3.
A process called staging is used to determine how much your cancer has spread and what treatment options will be considered. According to the National Cancer Institute, the following stages are used for endometrial cancer.
- Stage I: The cancer is limited to the body of the uterus and has not spread to lymph nodes or distant sites. Staging of Endometrial Cancer
- Stage IA: The cancer is in the earliest form and limited to the endometrium (inner lining)
- Stage IB: The cancer has spread into the inner half of the myometrium (muscular wall of the uterus)
- Stage IC: The cancer has spread into the outer half of the myometrium.
- Stage II: The cancer has spread from the body of the uterus to the cervix, but not to lymph nodes or distant sites.
- Stage IIA: The cancer has spread to the endocervical glands.
- Stage IIB: The cancer has spread to the connective tissue of the cervix.
- Stage III: The cancer has spread beyond the uterus and cervix, but has not spread outside the pelvic area.
- Stage IIIA: The cancer has spread to outermost layer of uterus, tissue just beyond the uterus and/or the peritoneum (membrane lining the abdominal cavity)
- Stage IIIB: The cancer has spread to the vagina.
- Stage IIIC: The cancer has spread to lymph nodes near the uterus.
- Stage IV: The cancer has spread beyond the pelvic area.
- Stage IVA: The cancer has spread to the bladder and/or bowel wall.
- Stage IVB: The cancer has spread to organs beyond the pelvic area, including lymph nodes in the abdomen and/or groin.
You and your doctor will decide your treatment options based upon the type, grade, and state of your cancer; the results of tests; your overall health; whether you wish to try to preserve your fertility; and other personal considerations. Surgery is the primary treatment for endometrial cancer. Additional treatment may include hormone therapy, radiation therapy and chemotherapy.
You may want to also consider a clinical trial of new therapies offered through the UC San Diego Health.
Surgery is the most common treatment for endometrial cancer. Our gynecologic oncologists are specialists in both traditional surgical procedures and those that are minimally invasive, including robotic-assisted surgical techniques.
The following surgical procedures may be used:
- Total hysterectomy: A surgical procedure to remove the uterus, including the cervix.
- Bilateral salpingo-oophorectomy: A surgical procedure to remove both ovaries and both fallopian tubes.
- Radical hysterectomy: A surgical procedure to remove the uterus, cervix, and part of the vagina. The ovaries, fallopian tubes, or nearby lymph nodes may also be removed. Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given radiation therapy or hormone treatment after surgery to kill any cancer cells that are left.
Hormone therapy may be an alternative to surgery in women who wish to preserve their fertility or who are poor candidates for surgery due to other health issues. Hormone therapy is a form of cancer treatment that removes hormones or blocks their action and stops cancer cells from growing.
Radiation therapy is used in the treatment of a wide variety of gynecologic cancers. It may be used alone in early stage tumors or combined with chemotherapy in locally advanced disease. In addition, it may be used before or after surgery.
- High-Dose Brachytherapy is a form of internal radiation therapy where radioactive sources are placed inside the body, close to the tumor. Methods used at UCSD include cylinder, interstitial, tandem and ovoid, and tandem and ring.
- Image Guided Radiation Therapy (IGRT) is a form of external-beam radiation that uses sophisticated technologies to locate the tumor and improve treatment accuracy so that healthy tissue is not harmed.
- Intensity Modulated Radiation Therapy (IMRT) is another state-of-the-art external beam radiation therapy that improves delivery precision, thereby minimizing dosage to surrounding normal tissue. UC San Diego’s Dr. Arno Mundt pioneered the use of IMRT in gynecologic cancers.
Chemotherapy is the administration of drugs by mouth, injection or IV to kill cancer cells. One of the unique aspects of gynecologic oncology is that specialists in this field are specially trained in chemotherapy for cancers of women’s reproductive organs. With their advanced knowledge, gynecologic oncologists can select the best drug combinations for each patient, manage complications and minimize side effects.