Encyclopedia of Health and Medicine

surgery for cancer 393
case with traditional staging, criteria vary somewhat
among the different types of cancer.
Stage
Tumor (T)
T0
Tis
T1
T2
T3
T4
GENERAL CANCER STAGING: TNM METHOD
Extent of Cancer
no evidence of cancer
in situ; tumor confined to cells of origin
localized tumor less than 3 centimeters (cm) in
size
tumor is larger than 3 cm or has invaded
adjacent tissues
tumor is larger than 3 cm and has invaded
adjacent tissues
large tumor has invaded adjacent tissues or is
inoperable
Lymph Nodes (N)
N0 no cancer in regional lymph nodes
N1 cancer in local lymph nodes
N2 cancer in regional lymph nodes
N3 cancer in lymph nodes beyond the region of the
primary tumor
Metastasis (M)
M0 cancer remains local or regional (no METASTASIS)
M1 cancer has spread to distant sites (metastasis)
Cancer Grading
The grade of a cancer identifies the characteristics
of its cells and their growth patterns. Grade is relevant
only for cancers that can have varying
aggressiveness, such as sarcomas and some types
of brain cancer. The pathologist determines the
tumor’s grade from tissue samples and assigns a
numeric value that indicates the tumor’s aggressiveness
and likelihood for metastasis. As with
cancer staging, the criteria differ among the types
of cancer, though in general a higher grade value
indicates a more extensive or serious cancer. Some
tumors have a mix of different cancer cells, in
which case the pathologist usually assigns the
higher grade to the tumor overall.
Stage, Grade, and Outlook
Oncologists use cancer staging and grading as the
general framework for making treatment decisions
and assessing prognosis (expected outcome).
Though many types of cancer are treatable, controllable,
or curable with today’s range of treatment
options, the individual variation in cancer
diagnosis is significant. Each person who has cancer
has a unique response based on numerous and
sometimes intangible factors. Staging, grading, and
other diagnostic parameters represent only a best
attempt to characterize a cancer so as to structure
an optimal treatment approach; they do not
define the outcome.
See also CANCER TREATMENT OPTIONS AND DECISIONS;
DIAGNOSING CANCER; LYMPH NODE; TUMOR MARKERS.
surgery for cancer An OPERATION to remove a
cancerous tumor. Surgery is the first line of treatment
for cancer that a surgeon can readily reach
without endangering the person, and when there
is a single defined tumor. Multiple tumors may
also be appropriate for surgery, depending on the
type of cancer, the location of the tumors, and
how clearly contained the tumors are. Surgery is
typically the primary therapy for treating cancer,
with adjuvant (accompanying or follow-up) treatment
with RADIATION THERAPY, CHEMOTHERAPY,
IMMUNOTHERAPY, or HORMONE THERAPY for a comprehensive
approach. A person might undergo
chemotherapy or radiation therapy before surgery
to shrink the tumor, and also may undergo such
treatment after surgery to eradicate any remaining
cancer cells.
How Surgery Works to Treat Cancer
Surgery may be therapeutic (attempt to remove the
cancer) or palliative (remove enough of the tumor
to relieve PAIN or other symptoms). As oncologic
surgeons have learned more about how cancer
grows and spreads in the body, surgery methods
GENERAL TUMOR GRADING
Grade Cancer Cell Characteristics Cancer Aggressiveness
G1 good differentiation, nearly normal cells low
G2 moderate differentiation, somewhat abnormal cells intermediate
G3 poor differentiation, abnormal cells high
G4 no differentiation, unstructured cells very high