NCCN Guidelines for Patients
Breast Cancer – Metastatic (STAGE IV), Version 2.2017
Cancer lab tests
A biopsy is a procedure that removes tissue or fluid
samples for testing. The methods used to remove
samples will depend on where the cancer has
spread. A biopsy is advised to confirm if the distant
site has cancer. If your doctor does not suggest a
biopsy, ask why.
If you were treated for earlier stages of breast
cancer, tissue from the breast tumor was likely
tested. Expect a biopsy of the distant site. In a small
number of cases, the biology of the tumor changes.
Such changes can greatly impact how the cancer
responds to treatments and your treatment options.
Cancer lab tests
Tissue samples from the biopsy will be sent to a
pathologist. A pathologist is a doctor who’s an expert
in testing cells to find disease. He or she will examine
the samples using a microscope.
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.
If cancer is present, the pathologist will study the
parts of the cancer cells to classify the disease. This
is called histologic typing. The pathology report will
state if the cancer started in the breast or elsewhere.
If breast cancer is found, the subtype will be noted
in the report. The most common subtype is ductal
breast cancer. Out of every 100 breast cancers,
about 85 to 90 are ductal cancers. These cancers
started in the breast ducts. Breast cancer can also
start in the lobules. These cancers are called lobular
Not all breast cancer cells are alike. They can differ
by the type of receptors they have. A receptor is a
protein found in the membrane of cells or inside of
cells. Substances bind to the receptors and cause
changes within the cell.
Hormone receptor test
. Estrogen and progesterone
are hormones that are present in all women. Among
some women with breast cancer, the cancer cells
have receptors to which these hormones attach. After
hormones attach, the receptors enter the nucleus
and cause cells to grow in number.
See Figure 6.
However, the growth of cancer cells with hormone
receptors is usually slower than cancer cells without
Testing for hormone receptors is important. There
are drugs that can be used to stop hormones from
causing cancer growth. IHC (
is the lab test used by pathologists for hormone
IHC involves applying a stain to cells then looking
at them with a microscope. The stain shows how
many cells have hormone receptors and the amount
of hormone receptors in the cells. If at least 1 out of
every 100 cancer cells stains positive, the cancer is
called hormone receptor–positive. If fewer cancer
cells stain positive for hormone receptors, the cancer
is called hormone receptor–negative.