How can removal of fallopian tubes decrease risk of cancer?

Last year a paper was published suggesting that the majority of ovarian cancers originate from the fallopian tube and that removal of the tube has a major impact on cancer frequency. As a result of that study, the Canadian government recently issued an official recommendation that tubal removal should be performed instead of tubal ligation.

Recent studies suggest that ovarian cancer predominantly arises within the Fallopian tubes or the uterus. A group of Swedish researchers hypothesized that surgical removal of the Fallopian tubes (salpingectomy) is associated with a reduced risk for ovarian cancer.

Researchers compared hundreds of thousands of women who had had their Fallopian tubes removed with women who had not, and found that there was a statistically significant risk reduction for ovarian cancer among women with previous salpingectomy when compared with those who hadn’t had their Fallopian tubes removed. In addition, statistically significant risk reductions were observed among women with previous hysterectomy, sterilization and hysterectomy with bilateral salpingo-oophorectomy (the removal of both ovaries and both Fallopian tubes, or BSO). Bilateral salpingectomy was associated with a 50% decrease in risk for ovarian cancer compared with the unilateral procedure.