Parulekar SV
Ovarian cancer is
often asymptomatic until it is quite advanced. Thus it is more
dangerous than other gynecologic cancers because it is diagnosed at a
more advanced stage than others. There are no good and easy screening
methods for its early detection. If its prevention is at all
possible, it would be ideal from the women's point of view, the
lifetime risk of developing ovarian cancer being 1-2%. Recently there
has been quite a bit of interest in the role of salpingectomy in
reducing the risk of development of ovarian cancers. It has been
shown that both bilateral tubal ligation and bilateral salpingectomy
before the age of 35 years reduces the risk of development of ovarian
cancer by up to 50%. The benefit is greater with salpingectomy than
with tubal ligation. The cancers prevented are mainly the
endometrioid cancer. Significant benefit is also seen with serous
epithelial cancers. There is no protection from the development of
borderline cancers. The mechanism underlying this protection is not
understood very clearly.
The process of
ovulation causes surface injury to the ovary. If the process of
healing of that injury is not proper, there is a possibility of
mutations which could lead to the development of cancer.
Gonadotropins could be involved in the development of the malignant
change. Inflammatory agents and infection that reach the ovary by
ascending route from the lower genital tract through the uterus and
the fallopian tubes could also be causative agents. The process of
tubal interruption would prevent such agents and endometrial cells
reaching the ovary and protect it from development of cancer.
Interruption of the tube could be associated with reduced blood flow
from anastomosis between uterine and ovarian arteries to the ovary,
reducing the amount of gonadotropins reaching the ovary and thus
reduce the risk of development of ovarian cancer. It is also likely
that the cancer, especially the serous type, originates in the
adjacent fallopian tube and spreads to the ovary. Removal of the
fallopian tube would afford protection from ovarian cancer, but not
simple ligation. For women who desire permanent contraception,
salpingectomy rather than tubal ligation should be offered. But that
may be associated with higher morbidity and deterioration of ovarian
function due to reduced blood supply. If a woman has a high risk of
ovarian cancer, prophylactic removal of ovaries after completion of
the childbearing function should be combined with salpingectomy, if
the woman so desires.