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Staging is the process of finding out how widespread a cancer
is. The stage of a liver cancer is one of the most important factors in
considering treatment options.
A staging system is a standardized way for the cancer care
team to summarize information about how far a cancer has spread.
Doctors use staging systems to get an idea about a patient's prognosis
(outlook) and to try to determine the most appropriate treatment.
There are several staging systems for liver cancer, and not
all doctors use the same system.
The American Joint Committee on Cancer
(AJCC) TNM system
The American Joint Committee on Cancer (AJCC) TNM system is a
major system used to describe the stages of liver cancer. It is based
on the results of the physical exam, imaging tests (ultrasound, CT or
MRI scan, etc.) and other tests, which are described in the section "How
is liver cancer diagnosed?"
The TNM system for staging contains 3 key pieces of
information:
- T
describes the number and size of the primary tumor(s), measured
in centimeters (cm), and whether the cancer has spread to organs next
to the tumor.
- N
describes the extent of spread to nearby (regional) lymph nodes.
- M
indicates whether the cancer has metastasized
(spread) to other organs of the body. (The most common sites of liver
cancer spread are the lungs and bones.)
Numbers or letters appear after T, N, and M to provide more
details about each of these factors:
- The numbers 0 through 4 indicate increasing severity.
- The letter X means "cannot be assessed" because the
information is not available.
T groups
- TX: Primary
tumor cannot be assessed
- T0: No
evidence of primary tumor
- T1: Single
tumor (any size) without invasion into blood vessels
- T2: Single
tumor (any size) with invasion into blood vessels, OR multiple tumors
where none are greater than 5 cm (about 2 inches) across
- T3: Multiple
tumors that are greater than 5 cm (about 2 inches) across, OR a tumor
involving a major branch of the portal or hepatic vein(s)
- T4: The
tumor is invading a nearby organ (other than the gallbladder), OR the
tumor is invading the visceral peritoneum (covering surrounding the
liver)
N groups
- NX:
Regional lymph nodes cannot be assessed.
- N0: The
cancer has not spread to the regional lymph nodes.
- N1: The
cancer has spread to the regional lymph nodes.
M groups
- MX: Distant
spread cannot be assessed.
- M0: The
cancer has not spread to distant lymph nodes or other organs.
- M1:
The cancer has spread to distant lymph nodes or other organs.
Stage grouping
The T, N, and M groups are then combined to give an overall
stage:
Stage I:
T1, N0, M0: There is a single tumor (any size) that does not invade
blood vessels.
Stage II:
T2, N0, M0: There is a single tumor (any size) that does invade blood
vessels; OR there are several tumors, and all are less than 5 cm (2
inches) in diameter.
Stage IIIA:
T3, N0, M0: There are several tumors, and at least one is larger than 5
cm (2 inches) in diameter; OR a tumor invades a branch of the major
liver blood vessels (portal vein or hepatic vein).
Stage IIIB: T4,
N0, M0: A tumor invades a nearby organ (other than the gallbladder); OR
a tumor has penetrated the outer covering of the liver.
Stage IIIC: Any
T, N1, M0: The cancer has invaded nearby lymph nodes. (Tumors can be
any size or number.)
Stage IV: Any
T, Any N, M1: The cancer has spread to other parts of the body. (Tumors
can be any size or number, and nearby lymph nodes may or may not be
involved.)
Other liver cancer staging systems
The staging systems for most types of cancer depend solely on
the extent of the cancer, but liver cancer is complicated by the fact
that most patients have liver damage along with their cancer. This also
has an effect on treatment options and prognosis.
Although the TNM system defines the extent of liver cancer in
some detail, it does not take into account liver function. Several
other staging systems have been developed that include both of these
factors:
- the Barcelona-Clinic Liver Cancer (BCLC) system
- the Cancer of the Liver Italian Program (CLIP) system
- the Okuda system
These staging systems have not been compared against each
other, and at this time there is no single staging system that all
doctors use. If you have questions about the stage of your cancer or
which system you doctor uses, be sure to ask.
Child-Pugh score (cirrhosis staging system)
The Child-Pugh score is a measure of liver function,
especially in people with cirrhosis. Because people with liver cancer
often have 2 diseases, their cancer and cirrhosis, doctors treating
liver cancer need to know the extent of liver function. This system
looks at 5 factors, the first 3 of which are blood tests:
- blood levels of bilirubin (the substance that can cause
yellowing of the skin and eyes)
- blood levels of albumin (a major protein normally made by
the liver)
- the prothrombin time (measures how well the liver is making
blood clotting factors)
- whether there is fluid in the abdomen
- whether the liver disease is affecting brain function
Based on the score, liver function is divided into 3 classes.
If all these factors are normal, then liver function is called class A.
Mild abnormalities are class B, and severe abnormalities are class C.
People with liver cancer and class C cirrhosis are generally too sick
for any treatment.
The Child-Pugh score is actually part of the BCLC and CLIP
staging systems mentioned previously.
Localized resectable, localized
unresectable, and advanced liver cancer
For treatment purposes, doctors often classify liver cancers
by whether or not they can be entirely cut out (resected). Resectable
is the medical term meaning "able to be removed by surgery."
Localized
resectable cancers: Only a small number of patients with
liver cancer have tumors that can be completely removed by surgery.
This would include most stage I and some stage II cancers in the TNM
system, in patients who do not have cirrhosis.
Localized
unresectable cancers: Cancers that have not spread to the
lymph nodes or distant organs but cannot be completely removed by
surgery are classified as localized unresectable. This would include
some early stage cancers, as well as stage IIIA and IIIB cancers in the
TNM system. There are several reasons that it might not be possible to
safely remove a localized liver cancer. If the non-cancerous part of
your liver is not healthy (due to cirrhosis, for example), surgery
might not leave enough liver tissue behind for it to function properly.
Also, curative surgery may not be possible if your cancer is spread
throughout the liver or is close to the area where the liver meets the
main arteries, veins, and bile ducts.
Advanced
cancers: Cancers that have spread to lymph nodes or other
organs are classified as advanced. These would include stage IIIC and
stage IV cancers in the TNM system. Most advanced liver cancers cannot
be treated with surgery.
Survival rates for liver cancer
Only a small number of liver cancers are found in the early
stages and can be removed with surgery. The 5-year survival rate for
patients with resectable early stage cancer is in the range of 30% to
60%. This percentage drops for more advanced cancers or with more
severe liver disease.
The 5-year survival rate for people with cancer that has
spread widely throughout the liver or to distant sites is less than 5%,
and the average survival time is often measured in months.
The overall 5-year survival rate from liver cancer is less
than 10%. Part of the reason for this low survival rate is that most
patients with liver cancer also have other liver problems such as
cirrhosis, which itself can be fatal.
The 5-year survival rate refers to the percentage of patients
who live at least 5 years after their cancer is diagnosed. Five-year
rates are used to produce a standard way of discussing prognosis. Of
course, some people live much longer than 5 years.
Last Medical Review: 12/07/2008 Last Revised: 05/12/2009
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