The uterus is the female reproductive organ where the unborn baby grows and develops until birth. This muscular organ is connected to the vagina by the cervix and contains entrances for the two fallopian tubes, which transfer eggs from the ovaries. The uterus is a highly hormone sensitive organ with monthly bleeding and shedding cycles (menstruation) in the absence of pregnancy. The growth of the most common uterine cancer, adenocarcinoma, is also sensitive to female hormones. Uterine cancer usually arises from the surface of the uterus or endometrium and less frequently from glands in the uterus. For most women, uterine cancer is brought to medical attention because of unanticipated or problematic bleeding from the uterus, usually occurring after menopause. Fortunately, 80% of women diagnosed after developing abnormal bleeding will have cancer limited to the uterus (stage I and II) and a high proportion are cured.
Uterine (endometrial) cancer is one of the most common gynecologic cancers in women, with 36,100 new cases each year. The incidence of uterine cancer would be even higher if it weren’t for the relatively large number of hysterectomies performed for non-cancerous reasons. It is estimated that approximately 6,500 women will die of uterine cancer in the U.S. in 2001. There has been an increase in the incidence of uterine cancer since the mid 1970s, which has been attributed to the use of hormone replacement therapy. Surgery is the primary treatment for uterine cancer and approximately 82% of women survive 5 years after diagnosis.
Currently, a dilation and curettage (D&C) is the most reliable method for diagnosing uterine cancer. During a D&C, a sample of the cells lining the uterus is removed for examination under a microscope to determine if cancer is present. Following a diagnosis of uterine cancer, additional tests are performed on the cancer cells to determine the stage of the cancer in order to provide optimal treatment.
There are several types of uterine cancer, which vary based on their appearance under the microscope. The most common type of uterine cancer is adenocarcinoma. Other variants of uterine cancer that behave more aggressively include serous carcinoma, uterine clear cell carcinoma and mixed type. These cancers, stage for stage, have a worse outcome than adenocarcinoma.
Outcomes following treatment of adenocarcinoma can also be affected by the appearance of cancer when examined under the microscope. Doctors grade adenocarcinomas, as poorly, moderately or well differentiated. These terms describe how closely the cancer resembles normal cells of the uterus. In general, the less differentiated the cells, the more aggressive the cancer. More poorly differentiated cancers have a higher rate of recurrence. The reason doctors are interested in this is that more or better treatments may be indicated for patients with more aggressive cancers.
Cancer cells also differ from one another based on what genes have mutations. Molecular diagnostic testing, including DNA sequencing can be used to identify cancer-driving abnormalities in a cancer’s genome. This “genomic testing” is performed on a biopsy sample of the cancer and increasingly in the blood using a “liquid biopsy.” When a genomic abnormality is defined a precision cancer medicine can be used to treat the cancer. Precision cancer medicine uses targeted drugs and immunotherapies engineered to directly attack cancer cells with specific genetic abnormalities, leaving normal cells largely unharmed. For example, 20% of uterine cancers are MSI-high and can be treated with precision immunotherapy instead of chemotherapy.
All newly diagnosed individuals with uterine cancer should make sure genomic-biomarker testing is performed on their cancer tissue. Once established these genomic markers can be followed in the blood using a "liquid biopsy" to evaluate response to treatment and the development of new mutations.
In addition to the type and grade of the cancer, the stage or extent of spread of cancer is the most useful predictor of survival and is relevant for treatment planning. Currently, surgery to remove the uterus, ovaries and lymph nodes is relied upon to determine the stage of the cancer.
Other tests that may be utilized to help stage the cancer include magnetic resonance imaging (MRI) scans and ultrasound. The most common method for examining the uterus is with transvaginal sonography. During transvaginal sonography, an ultrasound apparatus is passed through the vagina in order to examine the uterus. Another test, sonohysterography, improves the accuracy of sonography by first infusing a salt solution into the uterus through the cervix. MRI scans can also be useful in determining whether the lymph nodes are involved with cancer and may prevent the need for lymph node dissection.
In order to learn more about the most recent information available concerning the treatment of uterine cancer, click on the appropriate stage.
Stage I: Cancer does not spread outside the body of the uterus.
Stage II: Cancer involves the body of the uterus and the cervix.
Stage III: Cancer extends outside the uterus, but is confined to the pelvis.
Stage IV: Cancer involves the bladder or bowel or distant sites.
Recurrent: Cancer has returned after initial treatment.