Cervical Cancer is
cancer of the cervix, the lower part of the uterus
that opens into the birth canal.
It is one of the most common types of cancer in women in worldwide,
but also one of the most preventable.
Thanks to early detection with Pap tests.
Cervix has two major cell types:
flat squamous cells lining the outer part
and column shaped glandular cells covering the inside of the cervical canal.
Both types can become cancerous.
But squamous cell carcinomas are much more common.
Cancer usually starts in the zone where the two cell types meet
known as the transformation zone.
Virtually all Cervical Cancers are
caused by Human Papilloma Viruses or HPVs.
There are over a hundred different types of HPV.
Some of which pose higher risks than others.
About 70 percent of all cases are caused by just two types:
HPV-16 and HPV-18.
Two proteins produced by HPV,
known as E6 and E7,
interfere with cell functions that normally prevent
excessive cell division.
This causes the cells to grow in an uncontrolled manner.
HPV is sexually transmitted and is very common.
But in most women HPV infections resolved on their own,
and do not cause cancers.
Factors that may increase the risk of persistent HPV infections
include weakened immune system,
other sexually transmitted diseases and smoking.
Chances of developing Cervical Cancer also increase
with having many children
and long term use of birth control pills.
Early stage Cervical Cancer generally produces no symptoms;
advanced stage disease may cause
abnormal or irregular vaginal bleeding,
pelvic pain or unusual vaginal discharge.
Early detection is the key to prevent Cervical Cancer.
Cervical Cancer Screening may include Pap tests alone
or in combination with HPV DNA tests.
In a Pap test, cells are scraped from the cervix
and examined for precancerous changes,
known as Cervical Intraepithelial Neoplasia,
or Cervical Dysplasia.
These morphological changes can range from mild to severe
if the results are abnormal
the test is repeated again after six months or a year
to monitor the condition.
Additional diagnostic tests may also be performed.
In most cases, mild dysplasia resolves on its own
and a follow-up Pap test is all that is required to confirm.
In a small number of cases,
these abnormal cells may develop into cancer
but they usually take years to do so
which allows plenty of time for treatment when detected early.
in the u.s., a Pap test is
recommended every three years from the age of 21
or every five years if combined with an HPV test.
Treatment options for Cervical Cancer include
手术 放射 化疗
surgery, radiation, chemotherapy,
or a combination of these.
Early stage cervical cancer is typically treated
with surgical removal of the uterus.
This option is the most effective in
preventing cancer from coming back and
is usually preferred when patients do not need to maintain fertility.