A team of Canada scientists has provided more evidence that fallopian tube removal can slash the risks of ovarian cancer risk, finding women who underwent opportunistic bilateral salpingectomy (OBS) with hysterectomy had almost an 80% lower risk of developing serous ovarian cancer versus hysterectomy alone.
MedPage Today reports that the study of more than 80 000 patients yielded a hazard ratio of 0.22 in favour of OBS. Secondarily, investigators solicited de-identified data from pathologists around the world regarding serous ovarian cancers that occurred in women without fallopian tubes.
Only six of 26 (23.1%) cases were high-grade serous cancers (HGSCs) as compared with 642 of 942 (68.1%) cancers in a historical cohort of women with intact fallopian tubes.
Many of the surgical procedures involved women younger than age at peak risk for HGSC, resulting in a small number of ovarian cancers in the OBS group.
“Despite that limitation, these findings provide robust support for the effectiveness of OBS as a preventive intervention and underscore that broader implementation of OBS has the potential to significantly reduce the incidence and mortality of serous ovarian carcinoma,” concluded Gillian Hanley, PhD, of Vancouver General Hospital in British Columbia, and co-authors in JAMA Network Open.
The study added to a large existing volume of evidence that has consistently shown a risk-reducing effect of OBS on ovarian cancer, said Karen Lu, MD, of Moffitt Cancer Centre in Tampa, Florida and current President of the Society of Gynaecologic Oncology.
Ironically, the word has yet to get around.
“We’ve got good data to support it, and it’s surprisingly not well known,” Lu, who was not involved in the study, told MedPage Today. “The average age of a patient with ovarian cancer is 61, so this was a younger age group. Even so, it is kind of continuous information highlighting that we have sufficient data to recommend opportunistic bilateral salpingectomy for women undergoing gynaecological procedures and even for women undergoing other abdominal or pelvic surgeries that are non-gynaecologic.
“Ovarian cancer is a devastating disease, and early detection has been a real challenge,” she added. “Now we have a lot of continuous compelling data that we can prevent this devastating disease. I think we have to embrace the fact that we have a strategy, but we really need to educate the public and physicians as well.”
Large volume of evidence
In a statement published simultaneously with the Vancouver study, a European Society of Gynaecological Oncology (ESGO) consensus panel referenced 129 published articles supporting the risk-reducing benefits of OBS.
“Existing evidence demonstrates that opportunistic salpingectomy is significantly associated with a lower risk of developing tubo-ovarian carcinoma,” members of the writing group concluded in JAMA.
“Clinicians should include this prevention intervention in preoperative counselling of eligible women.”
A study reported last year highlighted the need for education. Data for 1 877 women with HGSC showed that a quarter of them did not have OBS at the time they underwent surgery for permanent contraception or other abdomino-pelvic procedures before ovarian cancer diagnosis.
For the most part, the benefits of OBS have surfaced only within the past 10 years, as research showed that most HGSCs, the most common and aggressive form of ovarian cancer, arise in the fallopian tubes, not the ovaries.
Since then, dozens of studies have shown risk-reducing benefits of OBS, as reflected in the ESGO statement.
Hanley and colleagues wanted to enhance the evidence base in two ways: estimating the magnitude of ovarian cancer risk reduction afforded by OBS, and examining whether ovarian cancers that occur in women without fallopian tubes are histologically different from normal histotype distribution.
Investigators identified all patients who underwent hysterectomy or tubal permanent contraception in British Columbia from 2008-2020. They compared the incidence of serous ovarian cancer after OBS with that of a comparison group that underwent hysterectomy alone or tubal ligation. They combined low- and high-grade serous carcinomas.
Data analysis included 40 527 patients who underwent OBS and 45 296 who underwent a comparator procedure. The OBS cohort had a median follow-up of 4.72 years versus 8.45 years for the comparison group. The OBS group had a mean age of 40.7 years versus 42.4 for the control arm.
Only 26 cases of serous ovarian cancer were identified, five in the OBS group and 21 in the control group. Nonetheless, the differences represented a statistically significant 78% reduction in the hazard in favour of OBS (95% CI 0.05-0.95).
For their second objective, the investigators asked pathologists to enter anonymised data into a REDCap database for any ovarian cancers diagnosed in patients who had undergone bilateral salpingectomy.
Consistent with the risk-reducing impact of OBS, significantly fewer HGSCs occurred in patients who had undergone the procedure versus the control group (P<0.001).
Getting general surgeons Involved
The ESGO consensus statement noted that OBS is not limited to gynaecologic oncologists. Available evidence shows that ‘salpingectomy is feasible during gynaecological and non-gynaecological procedures and should be considered in women undergoing gynaecological surgery and, where possible, in women undergoing selected non-gynaecological pelvic or abdominal surgeries”.
A recent study examined the potential impact of OBS at the same time as cholecystectomy (CCK) on incident ovarian cancer. Using statistical modelling methods, they estimated the number of CCKs performed annually in the US and expected number of ovarian cancers, and assumed that OBS reduces the risk of ovarian cancer by 65% (based on a nationwide Swedish study).
The results showed that incorporating OBS into 40% of CCKs performed in women aged 40-44 would prevent six cases of ovarian cancer within five years, 41 cases within 20 years, and 139 cases after 50 years of follow-up.
Increasing OBS to 80% of CCKs would prevent 12, 81, and 279 ovarian cancers at the same follow-up intervals. Investigators found that performing OBS in 40% of CCKs in all women over 40 would prevent 111 cases of ovarian cancer after five years, 349 cases after 15 years, 660 after 30 years, and 850 lifetime cases.
At its annual meeting last November, the American College of Surgeons devoted an entire session to incorporating OBS into general surgery practice. Evidence cited during the session included a systematic review (co-authored by Lu) showing that OBS could reduce ovarian cancer risk by 80% and ovarian cancer mortality by 15%.
Providing a gynaecologic oncologist’s perspective, Lu said general surgeons should be able to perform a straightforward salpingectomy, meaning no major complicating factors, such as pelvic adhesions. A couple of ongoing studies should add some clarity to the discussion.
One of the studies includes questionnaires that assess surgeons’ knowledge about and attitudes toward OBS. The other is evaluating certain outcomes, such as the additional time OBS adds to a procedure, said Lu.
See more from MedicalBrief archives:
Fallopian tube removal in sterilisation is safe – Swedish experts
Prevent ovarian cancer by removing fallopian tubes, urge experts
Most UK women mistakenly believe pap smear will detect ovarian cancer