To begin with, ovarian cancer is relatively uncommon compared to other cancers such as breast cancer. According to the American Cancer Society, the average woman has about a 1% (1 in 108) lifetime probability of dying from ovarian cancer, and a 1 in 79 lifetime probability of being diagnosed with ovarian cancer.

The American College of Obstetricians and Gynecologists recommends salpingectomy at the time of tubal ligation. Recent research suggests the tubes are the origin of the majority of ovarian cancers and that removal of the tubes reduces ovarian cancer risk. (However, given that some ovarian cancers originate in the ovaries themselves and not in the tubes, removing the tubes won’t eliminate the risk of ovarian cancer.)

Here is a summary of the current research via the National Cancer Institute (US): Many Ovarian Cancers May Start in Fallopian Tubes

Here is another summary via Harvard Medical School: Will removing your fallopian tubes reduce your risk of ovarian cancer? | Harvard Women’s Health Watch

A 2015 study found that “Salpingectomy […] is associated with reduced risk of ovarian cancer. […] a substantial fraction of ovarian cancer arises in the fallopian tube. Our results suggest that removal of the fallopian tubes […] is an effective measure to reduce ovarian cancer risk in the general population.”

A 2016 study found a “significant decrease in the risk of [ovarian cancer] occurrence in the patients who underwent [bilateral salpingectomy] relative to the controls”.

Tubal ligation alone (without tube removal as in bilateral salpingectomy) also reduces risk of ovarian cancer, but the current understanding is that salpingectomy reduces it more because it removes the fimbriated part of the tube where ovarian cancers are thought to originate.