Ovarian Cancer: What do the tubes have to do with it?

It may come as a surprise to most people that many ovarian cancers do not start in the ovary. A growing body of evidence is pointing to the Fallopian tubes as the origin of many (and perhaps even most) ovarian cancers. If the tubes are a source of cancer, will taking them out help reduce ovarian cancer risk? In this blog post I’ll review the latest on what we know about Fallopian tubes and cancer.

How common is ovarian cancer? About 1 in 7 women in the United States will develop ovarian cancer during her lifetime. Each year, 22,000 women in the US are diagnosed with ovarian cancer. Women with certain genetic disorders have an increased risk of ovarian cancer, such as the BRCA gene mutation, which also carries an increased risk of breast cancer. Despite the fact that women with a genetic predisposition for ovarian cancer are more likely than the general population to develop it, the vast majority (85%-90%) of ovarian high-grade serious carcinomas occur in women with no currently identified genetic predisposition.

What do the tubes have to do with ovarian cancer? In women with no genetic predisposition for ovarian cancer, 70% of high-grade serous ovarian carcinoma originates in the Fallopian tubes. In women at high risk of ovarian cancer, the Fallopian tubes are the most common sites of hidden cancers. Geneticists have studied the genetic make-up of ovarian cancer cells and it is more similar to the cells in the tubes than the ovaries.

What is salpingectomy? The fancy surgical term for removing the Fallopian tubes. Salpingo-oophorectomy means removing the tubes and ovaries.

Does taking out the tubes decrease cancer risk? In short, probably yes. Some prior research indicates that women with a history of tubal ligation (tying the tubes for permanent sterilization) have a lower risk of ovarian cancer. Women with a genetic predisposition for ovarian cancer have the option of "risk reducing" surgery- removal of the tubes and ovaries (risk reducing salpingo-oophorectomy or RRSO), which has been shown to lower cancer risk. When pathologists examine the tubes and ovaries after these RRSO surgeries, they find hidden, undiagnosed cancers in the Fallopian tubes more often than the ovaries. We do not yet have studies to know whether it is worthwhile to perform a risk-reducing salpingectomy as a stand-alone procedure for the general population (without genetic predisposition).

If you are already having another surgery, should the surgeon remove the tubes? The official word is that salpingectomy at the time of another surgery should be "considered" and the potential benefits should be discussed with the patient. The American College of Obstetricians and Gynecologists, the Society of Gynecologic Oncology, and others have reported that there is not yet enough evidence to know for certain if there is a benefit. But, if a surgeon is performing a hysterectomy for another reason such as fibroids, it is reasonable to also remove the tubes, if the patient desires. There are about 600,000 hysterectomies performed in the US each year and 90% are performed for benign disease. Salpingectomy can also be considered as an option for permanent sterilization instead of tying the tubes. But we are still waiting for a big clinical trial to see if salpingectomy or tubal ligation reduces cancer risk more.

Should surgeons also take out the ovaries during operations? No! Prior research has shown that removing ovaries during a hysterectomy for benign (not cancer) disease is actually worse in the long term. It increases the risk of heart disease and death from any cause. Of course, the case is different for women with a genetic predisposition for ovarian cancer.

Does taking out the tubes affect ovarian function? Two studies have demonstrated normal ovarian function after removing the tubes at the same time as a hysterectomy. We are still waiting for studies on the long term effects, but so far, salpingectomy does not appear to harm ovarian function.

The take home? Removing the Fallopian tubes- salpingectomy- has a lot of potential to reduce ovarian cancer risk. Research over the next few years will reveal if this is true and who will benefit most. 

We want to hear from you! Would you request a salpingectomy if you were getting a hysterectomy or tubal ligation? Please comment below!