11/28/04njm

Q. Does tubal ligation reduce the risk of ovarian cancer?

A. Yes, tubal ligation has reduced the risk of ovarian cancer in several
case control studies.

The findings below support the theory that contaminants from the vagina,
such as talc, and from the uterus, such as endometrium, gain access to
the peritoneal cavity through patent fallopian tubes and may enhance the
malignant transformation of ovarian surface epithelium. Surgical tubal
occlusion may reduce the risk of ovarian cancer by preventing the access
of such agents.

Numerous other studies are available at PubMed

<http://www.ncbi.nlm.nih.gov/entrez/query.fcgi>

Green A, et al Tubal sterilisation, hysterectomy and decreased risk of
ovarian cancer. Survey of Women\'s Health Study Group.  Int J Cancer.
1997 Jun 11;71(6):948-51.

<http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Display&dopt=pubmed_pubmed&from_uid=9185694>

We have examined the effect of tubal sterilisation and hysterectomy on
risk of ovarian cancer in a large case-control study in eastern
Australia involving 824 women aged 18-79 years, diagnosed with
epithelial ovarian cancer between 1990 and 1993, and 855 controls
randomly selected from the electoral roll. Relative risks for ovarian
cancer were estimated using multiple categorical regression to adjust
for age, parity, oral contraceptive use and other risk factors. Tubal
sterilisation was associated with a 39% reduction in risk of ovarian
cancer (RR 0.61, 95% CI 0.46-0.85) and hysterectomy with a 36% reduction
(RR 0.64, 95% CI 0.48-0.85). Risk remained low 25 years after surgery
and was reduced irrespective of sterilisation technique, and estimates
were similar among various types of epithelial ovarian cancer. The
greatest reduction (74%) was observed among women with primary
peritoneal tumours. Pelvic infection and use of vaginal sprays or
contraceptive foams were not related to ovarian cancer, while use of
talc in the perineal region slightly but significantly increased risk
among women with patent fallopian tubes. Reportedly heavy or painful
menses, perhaps associated with retrograde flow, were associated with
ovarian cancer, and reduction in risk of disease after hysterectomy was
greatest among women who had heavy periods. Our findings support the
theory that contaminants from the vagina, such as talc, and from the
uterus, such as endometrium, gain access to the peritoneal cavity
through patent fallopian tubes and may enhance the malignant
transformation of ovarian surface epithelium. Surgical tubal occlusion
may reduce the risk of ovarian cancer by preventing the access of such
agents

Modugno F, et al Oral contraceptive use, reproductive history, and risk
of epithelial ovarian cancer in women with and without endometriosis. Am
J Obstet Gynecol. 2004 Sep;191(3):733-40.

<http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15467532>

Using oral contraceptives, bearing children, and having a tubal ligation
or hysterectomy were associated with a similar reduction in the odds
ratios for ovarian cancer among women with and without endometriosis. In
particular, the use of oral contraceptives for \>10 years was associated
with a substantial reduction in risk among women with endometriosis
(odds ratio, 0.21; 95% CI, 0.08-0.58). CONCLUSION: Women with
endometriosis are at an increased risk of epithelial ovarian cancer.
Long-term oral contraceptive use may provide substantial protection
against the disease in this high-risk population.

Rosenblatt KA, Thomas DB. Reduced risk of ovarian cancer in women with a
tubal ligation or hysterectomy. The World Health Organization
Collaborative Study of Neoplasia and Steroid Contraceptives. Cancer
Epidemiol Biomarkers Prev. 1996 Nov;5(11):933-5.\
<http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8922304>

Possible relationships between tubal ligation and hysterectomy and
epithelial ovarian cancer were assessed in data that were collected for
a multinational hospital-based case-control study conducted between 1979
and 1988. Histologically confirmed incident cases (n = 393) were
compared with controls (n = 2563) matched on age, hospital, and year of
interview. A nonsignificant reduction in risk was observed for tubal
ligation \[odds ratio (OR), 0.72; 95% confidence interval (CI),
0.48-1.08\] and hysterectomy (OR, 0.58; 95% CI, 0.26-1.27). There was no
trend in risk with time since tubal ligation. The possible protective
effect of tubal ligation was greatest in women of parity less than four.
The apparent protective effect of tubal ligation was seen only for clear
cell (OR, 0.32; 95% CI, 0.006-2.50) and endometrioid (OR, 0.20; 95% CI,
0.046-1.46) tumors, suggesting a hormonal mechanism for the observed
associations.