Pelvic organ prolapse is not a sign of cancer in the vast majority of cases. It is a common, benign condition most often caused by weakened pelvic floor muscles after vaginal childbirth, aging, or heavy lifting. That said, there are rare situations where a prolapse can be connected to an underlying malignancy, either because a tumor is creating pressure that pushes organs out of place, or because cancer happens to develop within tissue that has already prolapsed.
Why Prolapse Is Usually Not Cancer
Prolapse happens when the muscles and connective tissue supporting your pelvic organs (bladder, uterus, rectum) weaken enough that one or more of those organs drops downward. The American College of Obstetricians and Gynecologists classifies pelvic organ prolapse as a common, benign condition. According to MD Anderson Cancer Center, pelvic organ prolapse “is not related to the development of any particular type of cancer.”
When surgeons remove a uterus to treat prolapse, they occasionally find unexpected cancer in the tissue. But this is uncommon. In a study of over 5,300 prolapse surgeries performed over a decade, the rate of incidental endometrial cancer discovered afterward was 0.56%. Broader estimates across multiple studies range from 0.3% to 2.6%. These are cancers that happened to coexist with prolapse, not cancers caused by it.
When a Tumor Can Cause Prolapse
In rare cases, a large mass in the abdomen or pelvis can create enough downward pressure to push organs out of position, mimicking or worsening a prolapse. A sizable ovarian tumor, for example, can press on the bladder or displace it. Similarly, a large uterine or cervical tumor can add bulk and weight that overwhelms weakened pelvic support structures.
Prolapse can also develop after cancer surgery. When the bladder, rectum, or cervix is removed, some of the surrounding tissue that supports the vaginal wall goes with it. This can destabilize the vaginal walls and lead to what’s called a secondary prolapse months or years later. This doesn’t mean the cancer has returned. It’s a mechanical consequence of the surgery itself.
Cervical Cancer Found in Prolapsed Tissue
One of the more striking scenarios involves cervical cancer developing on a uterus that has already prolapsed completely outside the body, a condition called procidentia. A systematic review identified 15 reported cases of cervical cancer in this setting, almost all squamous cell carcinoma. The average age at diagnosis was 74, with cases ranging from 54 to 89 years old. All patients had advanced prolapse (stage III or IV).
In a typical case, an older woman with a longstanding prolapse noticed a new fungating lesion on the protruding tissue along with vaginal bleeding and a foul smell. A biopsy confirmed invasive cancer. These cases are rare, but they illustrate why any new growth, ulceration, or bleeding on prolapsed tissue deserves prompt evaluation rather than being dismissed as normal wear and tear.
Rectal Prolapse and Colorectal Cancer
Rectal prolapse, where part of the rectum slides out through the anus, shares several symptoms with colorectal cancer: rectal bleeding (present in 75% to 100% of rectal prolapse cases), constipation (25% to 50%), and fecal incontinence (50% to 75%). Because these symptoms overlap so heavily, a single symptom on its own has low accuracy for distinguishing between a benign prolapse and something more serious.
A systematic review in BMC Cancer found that colorectal cancer can, in rare instances, first show up as what looks like rectal prolapse. About 19% of the reported cases involved a bowel intussusception, where a section of intestine telescopes into itself and pushes out through the anus, closely resembling a simple prolapse. If this is misdiagnosed as benign rectal prolapse, the consequences can be life-threatening. For this reason, a colonoscopy is recommended for patients with rectal prolapse who don’t have the usual predisposing factors (like a history of chronic straining, multiple childbirths, or connective tissue disorders).
Symptoms That Warrant Closer Investigation
Most prolapse develops gradually over years and has a clear explanation, such as aging, vaginal childbirth, chronic constipation, or obesity. Certain patterns, however, should prompt a more thorough workup:
- Postmenopausal bleeding. Any vaginal bleeding after menopause can signal endometrial or cervical cancer and should be evaluated with ultrasound and possibly a tissue sample, regardless of whether prolapse is also present.
- Rapid onset. A prolapse that appears suddenly or worsens quickly, especially without an obvious cause, raises the possibility that a growing mass is creating downward pressure.
- New lesions or growths. Any ulcer, lump, or fungating mass on prolapsed tissue needs a biopsy.
- Rectal bleeding with a change in bowel habits. This combination, particularly in adults over 40, is a recognized referral criterion for suspected colorectal cancer.
- A palpable mass in the rectum or anal canal. This should be distinguished from simple mucosal prolapse through further examination.
- Unexplained pelvic pressure or pain. Persistent pelvic pressure is a recognized symptom of both ovarian and uterine cancers, and can overlap with the heaviness or dragging sensation of prolapse.
How Cancer Is Ruled Out
Before prolapse surgery, standard preoperative evaluation typically includes cervical cancer screening (a Pap test or HPV test done within the prior year) and basic blood work. If you have abnormal bleeding, such as heavy periods or any bleeding after menopause, you’ll likely also get a transvaginal ultrasound and an endometrial biopsy to check the uterine lining. Women without abnormal bleeding are not routinely given these additional tests, since the odds of finding hidden cancer are low.
For rectal prolapse, a colonoscopy is the key tool for ruling out a colorectal tumor, especially if the prolapse appeared without typical risk factors or if you’re experiencing bleeding alongside changes in bowel habits. The goal is to confirm that what looks like a simple prolapse on the outside isn’t being driven by something more concerning on the inside.