By the time someone has symptoms of ovarian cancer, it is usually in an advanced stage. The treatment is extremely difficult and unfortunately most people will die. A in 78 women ovarian cancer will develop, and more than 230,000 women in the US are currently being affected. Of this approximately 80 percent have no family history of ovarian cancer and no indication that they were at risk of developing it.
In addition to the lack of early symptoms, diagnosis occurs at a late stage because there is no effective way to screen for or diagnose ovarian cancer in its earliest forms. This was shown by a recent survey of hundreds of thousands of women screening with ultrasound and blood tests has not saved as many lives as hoped. Ineffective screening leading to false reassurance (via a false negative result) is a serious problem even in high-risk patients.
Despite the name “ovarian cancer,” scientific discoveries over the past 20 years point to the oviducts (two thin tubes that allow eggs to travel from the ovaries to the uterus) as the site of origin for the most common and most deadly form of ovarian cancer, high-grade serous carcinoma. Researchers found that cells lining the fallopian tubes are particularly susceptible to mutations in a cancer-suppressing gene called p53. These mutations cause cancer cells to multiply uncontrollably and spread throughout the body. When studying p53 mutations in ovarian cancer, scientists have traced them to small precancers in the fallopian tubes.
Because most ovarian cancers originate in the fallopian tube, researchers decided to investigate whether people who have had their fallopian tubes removed, what is done to remove an ectopic pregnancy, treat inflammatory processes in the fallopian tube, and sometimes as a form of birth control, should have a reduced risk of developing ovarian cancer. Large epidemiological studies show that this is the case, and it was eye-opening for doctors like us. Given the seemingly insurmountable challenge of developing a screening test, clinicians are beginning to offer people who are pregnant and already undergoing scheduled surgeries the option of having their fallopian tubes removed to prevent ovarian cancer. This strategy, called ‘opportunistic salpingectomy’, is safe – and early data suggest it can reduce the risk of ovarian cancer by at least 65 per cent. And as part of another gynecological operation, the preventive removal of the fallopian tubes is supported by the American College of Obstetricians and Gynecologists and many professional associations worldwide.
Removing someone’s fallopian tubes may sound like a radical idea, especially since elective procedures carry risks, but in the U.S. alone, more than a million women undergo hysterectomies or tubal ligations each year, which are often also considered electives. A simple change in surgical technique — removing the fallopian tubes with the uterus during hysterectomy, and removing the fallopian tubes instead of “tying” the tubes for those opting for surgical contraception — would add ovarian cancer prevention to two of the most common gynecological procedures without the need for separate medical intervention. This is a step that we, as surgeons, believe is in the best interest of our patients.
For now, surgery is simply the best possible option to reduce the risk of ovarian cancer. While ultrasound and other pelvic imaging techniques are useful for visualizing the uterus and ovaries, they cannot reliably show us the fallopian tubes. In addition, cancer cells from the fallopian tubes are likely to spread while they are still microscopic. Technology that can both “see” the tube and identify microscopic precancers would be needed for effective screening.
It’s been equally difficult to find a biomarker for early disease. Known biomarkers are usually detectable in the bloodstream only after the cancer has progressed far beyond the fallopian tubes and adjacent ovaries. Since early disease progression occurs through direct spread of microscopic cells from the fallopian tubes and onto the surfaces of organs and tissues in the abdominal cavity rather than through the blood, testing for blood biomarkers may never prove useful.
Unlike removal of the ovaries, which causes menopause, removal of the fallopian tubes has no known negative health consequences after the pregnancy is complete, and it nominally adds risk and time to performance and recovery of the original surgical procedure. Salpingectomy during hysterectomy and instead of tubal ligation for surgical contraception became routine practice in British Columbia more than 10 years ago. researchers recently published preliminary data show this practice results in a reduced incidence of ovarian cancer in the general population. The possibility that we can reduce the number of people affected by this deadly cancer through a change in surgical practice that has no lasting consequences beyond the completion of pregnancy is a breakthrough. Extending this option to non-gynecological surgery would exponentially increase the number of people with access to surgical prevention of ovarian cancer, and forms the capstone of ongoing implementation research.
It’s important that people have more control over their health, especially when it comes to preventing cancers for which we don’t have adequate screening or a reliable cure. Work is underway to ensure that all patients desiring surgical contraception or undergoing hysterectomy are offered an opportunistic salpingectomy. In addition, efforts to scale this up from gynecologic procedures to surgeries such as gallbladder surgery, hernia repair, and others are increasing. Saving lives from ovarian cancer can become a reality in our lives if we provide the option of fallopian tube removal to the hundreds of thousands of patients who undergo abdominal surgery each year in the US.
This is an opinion and analysis article and the views of the author or authors are not necessarily those of Scientific American.