Staging
Of Ovarian Cancer Cancer staging is important for any cancer before treatment
is instituted, but for ovarian cancer it is doubly important. It is important, because nobody can predict what
stage the woman with ovarian cancer is actually in until after the exploratory
surgery has been completed and all the histology is in. Another complication with
ovarian cancer is that there is a phenomenon called "transperitoneal dissemination." Even
in a stage I or stage II ovarian cancer there can be leakage of cancer cells through
the intact ovarian capsule, which is shed into the peritoneal fluid. Unfortunately
there is an intraperitoneal flow of peritoneal fluid from the pelvic area going
up through the right abdominal gutter to the right hemidiaphragm. The right hemidiaphragm,
which is the border between the right upper abdominal cavity and the right chest
cavity, functions like a sieve through which 80% of the peritoneal fluid gets
drained into the mediastinal lymph glands and lymphatic vessels and then into
the blood stream. With these physiological facts it is now understandable how
cancer from an ovarian tumor, which to the eye still appears intact (stage I or
II) can shed cancer cells through transperitoneal dissemination. The cancer cells
migrate through the peritoneal flow described above to the right upper abdomen,
the liver, the base of the right lung and into the mediastinum. These facts are
only known since the late 1980's and following this the staging laparotomy
was developed. This elaborate surgery is performed by cancer surgeons in the major
Cancer Centers throughout the world. Taking into consideration the peritoneal
fluid flow, there are standard points that are checked within the abdominal cavity
and tissue biopsies are taken even when there is no apparent cancer. This way
the microscopic spread would become apparent as the pathologist analyzes all the
samples. The surgeon will remove any ovarian cancer metastases that are
obvious in a procedure called "cytoreductive surgery", where not only
the visible cancer is removed, but also the affected lymph glands are removed
and sent for pathology. This removes much of the tumor load. Lateron the patient
is treated with the appropriate therapy (chemotherapy and/or radiotherapy).
The conventional staging for ovarian cancer uses the FIGO stage grouping. There
are four stages I to IV and each has three subclasses A, B and C. The higher the
group or the subclass denomination, the worse the outcome(prognosis). The following
brief outline explains the staging:
| Staging
of Ovarian Cancer (Figo stage) |
| Stage (Figo): | Description
of extent of disease: |
| I A | Local
tumor in one ovary | |
I B | Local tumor in both ovaries |
| I
C | Tumor on surface, capsule ruptured or
positive peritoneal washings | | II
A | Involves 1 or 2 ovaries, pelvic extension |
| II
B | Extension to uterus and/or tubes |
| II
C | Like IIA or IIB, but capsule ruptured,
cells on surface of tubes or positive peritoneal washings |
| III A | Appears
grossly limited to pelvic cavity, but positive for abdominal peritoneal surfaces |
| III B |
Like IIIA, but also abdominal implants not exceeding 2cm(=3/4") in diameter
| | III
C | Abdominal implants greater than 2cm(=3/4"),
lymph glands in groin (inguinal) or behind abdominal wall(retroperitoneal) |
| IV | Extensive
local disease, also distant metastases in lungs, liver or pleural fluid |
In addition to this staging system there is also a histological
staging system (Broder classification) depending on the maturity of the cells.
The higher the number, the worse the prognosis. Broder grade I has a good prognosis,
but the worst would be Broder grade IV. The staging procedure takes these factors
into account as well.
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