Bleeding indicates cancer only in a small percentage of cases, even though endometrial cancers are on the rise in American women.
You've gone through menopause and you thought your periods were a thing of the past — but suddenly, you're bleeding again, more than a year after your last period.
Should you be concerned?
The good news according to an analysis published in JAMA Internal Medicine, is that most likely your bleeding is caused by a noncancerous condition, such as vaginal atrophy, uterine fibroids, or polyps. But the study also reinforces the idea that postmenopausal bleeding should always be checked out by your doctor to rule out endometrial cancer, a cancer of the uterine lining, says Dr. Ross Berkowitz, William H. Baker Professor of Gynecology at Harvard Medical School.
Although most postmenopausal bleeding is not caused by cancer, more than 90% of women with endometrial cancer have bleeding. By investigating bleeding, doctors have a way to catch endometrial cancer early, when it's most treatable. "Any unusual bleeding or postmenopausal bleeding should always be investigated," says Dr. Berkowitz.
Rising rates of endometrial cancer
The researchers who conducted this study were looking for clues about postmenopausal bleeding and how it relates to endometrial cancer.
Endometrial cancer, which affects 2% to 3% of American women, is the most common type of gynecological cancer. It most often affects postmenopausal women — 60 is the average age at diagnosis — according to the American Cancer Society. Identifying it early has become a pressing issue, because the incidence of this cancer has risen gradually but steadily over the past 10 years, according to the National Cancer Institute.
"Endometrial cancer is a fairly common disease, and it's unfortunately becoming more common due to the growing rates of obesity," says Dr. Berkowitz. A woman's risk of endometrial cancer can increase substantially if she is obese. Generally, risk rises among women who are 50 pounds or more above their ideal body weight, he says.
This is the case because of the role estrogen plays in endometrial cancer. The most common type of endometrial cancer, known as type 1 cancer, is fueled by estrogen. Estrogen is produced by body fat, so women with a larger amount of fatty tissue generally have higher levels of estrogen. They also typically have more free estrogen, an active form that produces stronger effects. This may lead to cancerous changes in the uterine lining.
Are you at high risk for endometrial cancer?
A number of factors put you at higher risk for endometrial cancer, including
- your age (endometrial cancers are most commonly diagnosed between ages 60 and 70)
- early start of menstruation (before age 12)
- late menopause (beginning after age 55)
- never having given birth
- obesity — in particular, being 50 or more pounds overweight
- a history of irregular menstruation
- a history of endometrial hyperplasia (overgrowth of the uterine lining)
- a family history of Lynch syndrome or family members with colon, ovarian, or uterine cancer
- taking estrogen therapy without a progestin
- receiving radiation directed to the pelvis
- taking the drug tamoxifen.
Because endometrial cancer is becoming more common, researchers were looking for clues that could help doctors spot the condition early. They wanted to answer these questions:
- How common is it for women with endometrial cancer to experience postmenopausal bleeding?
- How often are women with postmenopausal bleeding diagnosed with endometrial cancer?
The researchers looked at 129 different studies involving more than 34,000 women who experienced postmenopausal bleeding and 6,358 additional women who were diagnosed with endometrial cancer. They found that 91% of the women with endometrial cancer had experienced postmenopausal bleeding. However, among the women who experienced bleeding after menopause, only 9% had endometrial cancer.
The results don't really differ from what doctors have historically thought about the incidence of endometrial cancer and bleeding, says Dr. Berkowitz. But they do finally put solid data behind those figures, which was something that was missing in the past, he says.
Study authors said that their findings show that checking for endometrial cancer in women who experience postmenopausal bleeding could potentially find as many as 90% of these cancers. But the only way to find those cases is to properly evaluate all women with bleeding, most of whom will not have cancer.
What to do if you experience postmenopausal bleeding
So, if you do experience unusual or postmenopausal bleeding, make an appointment with your doctor to have the problem investigated, says Dr. Berkowitz. Your doctor will likely recommend an ultrasound, a biopsy, or both.
Ultrasound. This painless test uses sound waves to measure the thickness of the lining inside the uterus. It is performed either using an external ultrasound device or a wand placed in the vagina. In some women with endometrial cancer, this lining becomes thicker than usual, which alerts doctors to the possibility that it is cancerous. Not all thickened linings are cancer, though.
Biopsy. The ultrasound should be followed by a biopsy, even if the ultrasound doesn't show any thickening of the uterine lining, says Dr. Berkowitz. A biopsy can often be done as an in-office procedure, in which the doctor uses a thin tube with a collection device on the end to gather some uterine cells. You may feel some cramping during the procedure and experience bleeding afterward. The sample is then examined under a microscope to check for cancer or precancerous changes.
Dr. Berkowitz stressed the importance of doing both tests because not all endometrial cancers thicken the uterine lining. Some cases are caused by type 2 endometrial cancer, which may not produce the thickening typically seen in the more common type 1. If only ultrasound is used for screening, up to 20% of endometrial cancer cases may be missed. Many of these are type 2, which tend to be the more aggressive, invasive, and deadly.
"Assuming the patient does not have any health issues, such as serious heart disease, and is otherwise healthy, doing a biopsy would be the safest, most assured way to rule out endometrial cancer," says Dr. Berkowitz.
Won't my Pap test detect endometrial cancer?
Some women mistakenly believe that a Pap test can spot endometrial cancer. This is not the case. A Pap is designed to detect only cervical cancer or its precursors. So, even if your Pap comes back negative, if you have abnormal bleeding or postmenopausal bleeding, it's still important to pay a visit to your doctor to get it checked.
Following up on the results
If your doctor investigates your bleeding and doesn't believe you have endometrial cancer, but the bleeding comes back or continues, it's reasonable to have it re-evaluated, says Dr. Berkowitz. If you do have bleeding again after your first evaluation and normal biopsy, most likely it's not because cancer was missed. However, it's worth getting checked again. "I don't recommend waiting much more than six months," he says.
Investigate unusual bleeding early, because endometrial cancer is highly curable. "The vast majority of patients with endometrial cancer can be cured with surgery alone," says Dr. Berkowitz. In most cases, this means a hysterectomy, a procedure to remove the uterus and cervix. Often your doctor will also remove the ovaries and fallopian tubes and take a sample from your lymph nodes or other tissue. The surgery is often done using a minimally invasive technique without large incisions, and women who undergo the procedure very often go home the same day.