Staging
Of Uterine Cancer As with other cancers, it is very important to complete
all the above mentioned tests before embarking on any cancer treatment. Sometimes a woman may be irate with the specialist
as the diagnosis may already be known from the histology of the dilatation and
curretage (uterine cancer), but the cancer stage has yet to be determined. The
specialist needs to explain to the woman that depending on what stage is found
the treatment can be radically different and this is the reason why there is no
room for short-cuts. In the past, particularly with uterine cancer the
work-up was not that thorough often neglecting to look for possible pelvic metastases.
As a result a simple hysterectomy was done leaving pelvic or paraaortic lymph
glands untreated. Of course, this led to very disappointing survival data. With
proper investigation this would never have happened. Cancer is very unforgiving
and there is no room for errors. The revised FIGO staging (1988, slightly
modified in 2000) is what is used in the major Cancer Clinics throughout the U.S.:
| Staging of uterine
cancer (FIGO classification) | | Stage: | Description
of extent of uterine cancer: | | IA | tumor
limited to lining of uterus | | IB | invasion
to ‹ 1/2 thickness of lining | | IC | invasion
to › 1/2 thickness of lining | | IIA | invasion
into cervical lymph glands | | IIB | invasion
of cervical tissue | | IIIA | invasion
of ovaries, positive peritoneal cytology |
| IIIB | vaginal
metastases | | IIIC | pelvic
or paraaortic LN * |
| IVA | invasion
of bladder or bowel | | IVB | distant
or abdominal metastases, also inguinal LN |
| * stands for "lymph
node metastases" | Apart
from the stage of the tumor, which is determined by the depth of invasion and
the spread into neighboring structures, the patient's survival also depends on
what histological type the tumor is. This is called the "grade" of the
tumor. It determines how aggressive the growth pattern will be.
Histological grading and tumor behavior of
uterine cancer
| Histological grading
of uterine cancer | | Grade: | Description: |
| 1 | well-differentiated |
| 2 | moderately
differentiated | | 3 | poorly
differentiated | Many different investigators
from the U.S. and elsewhere have found that groups of women with uterine cancer
divide usually into about 40% with grade 1, 40% with grade 2 and 20% with grade
3 disease. This has practical implications as particularly grade 3 tumors, which
consist of rapidly dividing immature cancer cells, tend to metastasize early into
lymph glands of the pelvis or into the paraaortic lymph nodes. The physician will
therefore take particular care to look for hidden metastases in order to develop
a treatment plan that is appropriate for this patient (Ref.1, page 1197). Radiotherapy
will be included in these cases to cover for pelvic and paraaortic lymph gland
metastases.
Tumor
growth behavior The lining of the uterus (called "endometrium"
by doctors) goes through similar cell changes in the development of cancer as
is the case in cervical cancer, where I described this process in detail. The
equivalent for "dysplasia" in cancer of the cervix would be called "atypical
adenomatous hyperplasia" in uterine cancer. I would not want you to remember
that, but understand the principal that there are warning signs that tell the
gynecologist, when an endometrial biopsy is done, that this type of change will
go on to develop into uterine cancer. Since the early 1990's endometrial biopsies
have become a more common procedure and this can significantly determine the risk
for uterine cancer development down the road (see below).
Once
cancer of the uterus is established, it has the tendency to grow along the uterine
cavity down into the cervix and also towards the fallopian tubes. The cancer cells
produce lytic enzymes, which enable the cancer also to eat its way slowly through
the uterine wall. Frequently the cancer invades the ovaries, the uterine support
ligaments (called "broad ligament"), the vagina and the pelvic lymp
nodes. Next the cancer cells spread further through the lymphatic passages into
the paraaortic lymph nodes and into the blood stream. From here any organ
can be metastasized. Inside the abdomen the cancer cells shed into the peritoneal
cavity from either the fallopian tube, an invasion through the uterus or through
an ovarian metastasis. The cells can also migrate through lymphatic migration
channels (described in more detail in the ovarian cancer chapter) into the liver,
the right lung or into retroperitoneal lymph glands. There is another channel
for metastases to migrate through and this is along the round
ligaments (a uterine ligamentous support to the front of the lower
abdominal wall) and through lymphatic connnections to the thigh lymph nodes (called"
femoral nodes"). If there are lumps under the skin of the upper front thigh
region in a woman with uterine cancer, this is not a good sign: it is associated
with a very poor survival rate. It can be difficult to establish the
stage of uterine cancer. Sometimes it appears that only 10% of the pelvic lymph
glands would be affected. However, autopsy studies showed later that much more
invasive disease was present with 65% of pelvic metastases (Ref. 1, p. 1196).
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