Endometrial cancer is a type of cancer that begins in the uterus. The uterus is the hollow, pear-shaped pelvic organ in women where fetal development occurs. Endometrial cancer begins in the layer of cells that form the lining (endometrium) of the uterus. Endometrial cancer is sometimes called uterine cancer. Other types of cancer can form in the uterus, including uterine sarcoma, but they are much less common than endometrial cancer. Uterine sarcoma forms in the muscle and tissue that support the uterus.

The most common sign of endometrial cancer is unusual vaginal bleeding. Endometrial cancer can usually be cured. Endometrial cancer is often detected at an early stage because it frequently produces abnormal vaginal bleeding, which prompts women to see their doctors. If endometrial cancer is discovered early, removing the uterus surgically often cures endometrial cancer.

Endometrial Cancer Statistics 

In the United States, cancer of the endometrium is the most common cancer of the female reproductive organs. The American Cancer Society estimates for cancer of the uterus in the United States for 2015 are: About 54,870 new cases of cancer of the body of the uterus (uterine body or corpus) will be diagnosed. About 10,170 women will die from cancers of the uterine body. These estimates include both endometrial cancers and uterine sarcomas. Up to 8% of uterine body cancers are sarcomas, so the actual numbers for endometrial cancer cases and deaths are slightly lower than these estimates. 

Endometrial cancer is rare in women under the age of 45. Most (about 3 out of 4) cases are found in women aged 55 and over. The average chance of a woman being diagnosed with this cancer during her lifetime is about 1 in 37. There are over 600,000 women who are survivors of this cancer. This cancer is slightly more common in white women, but black women are more likely to die from it.

What causes Endometrial Cancer? 

We don't really know what causes endometrial cancer. What's known is that something occurs to create a genetic mutation within cells in the endometrium — the lining of the uterus. The genetic mutation turns normal, healthy cells into abnormal cells. Healthy cells grow and multiply at a set rate, eventually dying at a set time. Abnormal cells grow and multiply out of control, and they don't die at a set time. Cancer cells invade nearby tissues and can separate from an initial tumor to spread elsewhere in the body (metastasize).
Factors that increase the risk of endometrial cancer include:

• Obesity, certain inherited conditions, and taking estrogen alone (without progesterone) can increase the risk of endometrial cancer.
• Taking tamoxifen for breast cancer can increase the risk of endometrial cancer.
• Changes in the balance of female hormones in the body. Your ovaries make two main female hormones — estrogen and progesterone. Fluctuations in the balance of these hormones cause changes in your endometrium.
• A disease or condition that increases the amount of estrogen, but not the level of progesterone, in your body can increase your risk of endometrial cancer. Examples include irregular ovulation patterns, such as can occur in women with polycystic ovary syndrome, obesity and diabetes. Taking hormones after menopause that contain estrogen but not progesterone increases the risk of endometrial cancer.
• Never having been pregnant. Women who have never been pregnant have a higher risk of endometrial cancer than do women who have had at least one pregnancy.
• Older age. As you get older, your risk of endometrial cancer increases. The majority of endometrial cancer occurs in older women who have undergone menopause.
• Obesity. Being obese increases your risk of endometrial cancer. This may occur because excess body fat alters your body's balance of hormones.
• An inherited colon cancer syndrome. Hereditary nonpolyposis colorectal cancer (HNPCC) is a syndrome that increases the risk of colon cancer and other cancers, including endometrial cancer. HNPCC occurs because of a gene mutation passed from parents to children. If a family member has been diagnosed with HNPCC, discuss your risk of the genetic syndrome with your doctor. If you've been diagnosed with HNPCC, ask your doctor what cancer screening tests you should undergo.

What are Early Symptoms of Endometrial Cancer? 

Signs and symptoms of endometrial cancer may include:

How does my doctor know I have Endometrial Cancer? 

Tests and procedures used to diagnose endometrial cancer include:

• Pelvic examination.
• Using ultrasound waves to create a picture of the uterus. We may recommend a transvaginal ultrasound to look at the thickness and texture of the endometrium and help rule out other conditions. 
• Using a scope to examine your endometrium. During a hysteroscopy, the doctor inserts a thin, flexible, lighted tube (hysteroscope) through your vagina and cervix into your uterus. A lens on the hysteroscope allows your doctor to examine the inside of your uterus and the endometrium.
• Removing a sample of tissue for testing. To get a sample of cells from inside your uterus, you'll likely undergo an endometrial biopsy. This involves removing tissue from your uterine lining for laboratory analysis. Endometrial biopsy may be done in your doctor's office and usually doesn't require anesthesia.
• Performing surgery to remove tissue for testing. If enough tissue can't be obtained during a biopsy or if the biopsy results are unclear, you'll likely need to undergo a procedure called dilation and curettage (D&C). During D&C, tissue is scraped from the lining of your uterus and examined under a microscope for cancer cells.

If endometrial cancer is found, you'll be referred to a doctor who specializes in treating cancers involving the female reproductive system (gynecologic oncologist).

What does Classification and Staging of my Endometrial Cancer mean? 

The 2 main types of cancer of the uterus are: 1.) Endometrial carcinomas, which start in the cells of the inner lining of the uterus (the endometrium). Nearly all cancers of the uterus are this type. These cancers are the focus of the remainder of this information. 2.) Uterine sarcomas, which start in the muscle layer (myometrium) or supporting connective tissue of the uterus. 
Endometrial carcinomas can be divided into two main different types based on how the cells look under the microscope (histologic types). These include:

Type 1 endometrial cancers are made up of cells in glands that look much like the normal uterine lining (endometrium). Some of these cancers contain squamous cells (squamous cells are flat, thin cells that can be found on the outer surface of the cervix), as well as glandular cells. A cancer with both types of cells is called an adenocarcinoma with squamous differentiation. If both the squamous cells and the glandular cells look malignant (cancerous), these tumors can be called adenosquamous (or mixed cell) carcinomas. The grade of an endometrial cancer is based on how much the cancer forms glands that look similar to those found in normal, healthy endometrium. In lower-grade cancers, more of the cancerous tissue forms glands. In higher-grade cancers, more of the cancer cells are arranged in a haphazard or disorganized way and do not form glands. Grade 1 tumors have 95% or more of the cancerous tissue forming glands. Grade 2 tumors have between 50% and 94% of the cancerous tissue forming glands. Grade 3 tumors have less than half of the cancerous tissue forming glands. Grade 3 cancers are called "high-grade." They tend to be aggressive and have a poorer outlook than lower grade cancers (grades 1 and 2). Type 1 endometrial cancers are thought to be caused by excess estrogen. They sometimes develop from atypical hyperplasia, an abnormal overgrowth of cells in the endometrium (see the risk factors section). Type 1 cancers are usually not very aggressive and are slow to spread to other tissues. Grades 1 and 2 endometrioid cancers are “type 1” endometrial cancers.

Type 2 endometrial cancer make up a smaller number of endometrial cancers. Experts aren’t sure what causes type 2 cancers, but they don’t seem to be caused by too much estrogen. Type 2 cancers include all endometrial carcinomas that aren’t type 1, such as papillary serous carcinoma, clear-cell carcinoma. These cancers don’t look at all like normal endometrium and so are called “poorly differentiated” or “high-grade.” Because type 2 cancers are more likely to grow and spread outside the uterus, they have a poorer outlook (than type 1 cancers). Doctors tend to treat these cancers more aggressively. 

Uterine carcinosarcoma (CS) starts in the endometrium and has features of both endometrial carcinoma and sarcoma. In the past, CS was considered a type of uterine sarcoma, but doctors now believe that CS is a carcinoma that is abnormal and so no longer looks much like the cells it came from (poorly differentiated). Uterine CS is considered a type 2 endometrial carcinoma. CS tumors are also known as malignant mixed mesodermal tumors or malignant mixed mullerian tumors (MMMTs).

Tests used to determine the endometrial cancer's stage may include a computerized tomography (CT), magnetic resonance imaging (MRI) or positron emission tomography (PET) scan and blood tests. The final determination of the cancer's stage may not be made until after surgery.

Stages of endometrial cancer include:

• Stage I cancer is found only in your uterus.
• Stage II cancer is present in both the uterus and cervix.
• Stage III cancer has spread beyond the uterus, but hasn't reached the rectum and bladder. The pelvic area lymph nodes may be involved.
• Stage IV cancer has spread past the pelvic region and can affect the bladder, rectum and more-distant parts of your body.

What are treatments for Endometrial Cancer? 

Options for treating primary endometrial cancer will depend on the characteristics of the cancer, such as the stage, the grade and histology but also on the general health and the patients preferences and are outlined below. Treatment of recurrent endometrial cancer may include radiation therapy as palliative therapy to relieve symptoms and improve the patient’s quality of life, hormone therapy, and chemotherapy with or without biologic therapy.

Surgery
Most women with endometrial cancer undergo a surgical procedure to remove the uterus (hysterectomy), as well as to remove the fallopian tubes and ovaries (salpingo-oophorectomy). The following surgical procedures may be used: 

• Total hysterectomy: Surgery to remove the uterus, including the cervix. If the uterus and cervix are taken out through the vagina, the operation is called a vaginal hysterectomy. If the uterus and cervix are taken out through a large incision (cut) in the abdomen, the operation is called a total abdominal hysterectomy. If the uterus and cervix are taken out through a small incision (cut) in the abdomen using a laparoscope, the operation is called a total laparoscopic hysterectomy.
• Bilateral salpingo-oophorectomy: Surgery to remove both ovaries and both fallopian tubes.
• Radical hysterectomy: Surgery to remove the uterus, cervix, and part of the vagina. The ovaries, fallopian tubes, or nearby lymph nodes may also be removed.

Even if all the cancer that can be seen at the time of the surgery has been removed, some patients may be given radiation therapy or hormone treatment after surgery to kill any cancer cells that are left. Treatment given after the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.

Radiation
Radiation therapy uses powerful energy beams, such as X-rays, to kill cancer cells. In some instances, radiation is recommended to reduce the risk of a cancer recurrence after surgery. In certain situations, radiation therapy may also be recommended before surgery, to shrink a tumor and make it easier to remove.

• Radiation from a machine outside your body. Called external beam radiation, during this procedure you lie on a table while a machine directs radiation to specific points on your body.
• Radiation placed inside your body. Internal radiation (brachytherapy) involves placing a radiation-filled device, such as small seeds, wires or a cylinder, inside your vagina for a short period of time.

Hormone therapy
Hormone therapy involves taking medications that affect hormone levels in the body. Hormone therapy may be an option if advanced endometrial cancer has been diagnosed that has spread beyond the uterus. Options include:

• Medications to increase the amount of progesterone in your body. Synthetic progestin, a form of the hormone progesterone, may help stop endometrial cancer cells from growing.
• Medications to reduce the amount of estrogen in your body. Hormone therapy drugs can help lower the levels of estrogen in your body or make it difficult for your body to use the available estrogen. Endometrial cancer cells that rely on estrogen to help them grow may die in response to these medications.

Chemotherapy
Chemotherapy uses chemicals to kill cancer cells. Patients may receive one chemotherapy drug, or two or more drugs can be used in combination. Chemotherapy may be recommended for women with advanced or recurrent endometrial cancer that has spread beyond the uterus. These drugs enter the bloodstream and then travel through the body, killing cancer cells.

Targeted therapy
Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells without harming normal cells. Monoclonal antibodies and tyrosine kinase inhibitors are two types of targeted therapy being studied in the treatment of endometrial cancer. Monoclonal antibody therapy is a cancer treatment that uses antibodies made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. Tyrosine kinase inhibitors are targeted therapy drugs that block signals needed for tumors to grow. Tyrosine kinase inhibitors may be used with other anticancer drugs as adjuvant therapy.