NCCN Guidelines for Patients
Rectal Cancer, Version 1.2017
The only way to know if you have cancer is to test
tissue. A biopsy is a procedure that removes samples
of fluid or tissue for testing. A biopsy is advised
before receiving treatment.
First, your doctor will perform a digital rectal exam.
Your doctor will put a glove on his or her hand.
Lubricant will be applied to his or her index finger.
Next, your doctor will insert this finger into your
rectum. He or she will be able to feel your rectum
and nearby tissue.
Before the biopsy, your rectum may be numbed
to prevent pain. For samples near your anus, an
anoscope will be used. This is a round, hollow tool
that has a light. It will be inserted a few inches into
your rectum. For distant samples, a sigmoidoscope
will be used. This tool is shaped like a tube. It has a
light, camera, and cutting device.
Samples of tissue or fluid can sometimes be
removed from the body with a needle. This procedure
is called a needle biopsy. The methods of obtaining
samples with a needle differ based on the body
site. If your doctor suspects metastases, a needle
biopsy may be done. The samples will be sent to a
pathologist for cancer testing.
Cancer cell tests
Tissue removed from your body will be sent to a
pathologist. This may be tissue from a biopsy or
surgery. The pathologist will examine the samples
using a microscope.
The pathologist will study the parts of the cells to
classify any disease. This is called histologic typing.
When cancer is found, he or she will do other tests to
learn more about the cancer.
One important test result is the cancer grade. The
cancer grade is a score assigned by the pathologist.
He or she will rate the cancer based on how the
cancer cells look. The score is a sign of how fast the
cancer will likely grow and spread. Higher scores
mean that the cancer will likely grow and spread fast.
All lab results are recorded in a pathology report.
A report will be written each time tissue is removed
from your body and tested for cancer. These reports
are vital to planning treatment.
Review your pathology report(s) with your doctor. Ask
questions if you don’t understand. This information
can be complex. It’s also a good idea to get a copy of
your pathology report(s) and take notes.
Not all rectal cancer cells are alike. Cancer cells can
differ by which genes have mutations. Some gene
mutations are known to have an effect on cancer
treatment. Molecular testing includes tests of genes
or their products (proteins). Molecular testing that is
advised for rectal cancer is described next.
RAS is a family of proteins found in cells. Some
rectal cancers have abnormal genes that control
the RAS proteins. As a result, the RAS proteins are
overactive and promote cancer cell growth. Some
Cancer cell tests