Breast Cancer Basics
Invasive Breast Cancer Staging
To assess prognosis and to guide treatment decisions, as well as research, breast
cancer is generally assessed using a system
called staging. Invasive breast cancer tumor
stages range from Stage I to
Stage IV, with Stage I having the best prognosis and Stage IV
having the poorest. The breast cancer staging system takes into account three
major features of a woman's breast cancer:
- Breast cancer tumor size
- Lymph node status
- Metastasis status
Non-Invasive Breast Cancer & DCIS
DCIS is an early or pre-invasive form of breast cancer, sometimes referred to as
Stage 0 breast cancer. Unlike invasive breast cancer, the tumor cells in DCIS are
confined to the milk ducts within the breast.
Breast Cancer Tumor Size
Breast Cancer tumor size can be an important indicator of how quickly a tumor is
growing. However, a small tumor may be small because it is growing very slowly,
or because it was growing quickly but was found early. Tumor size is only one of
many factors used to indicate whether a woman's breast cancer is more or less aggressive.
Lymph Node Status
Lymph node status indicates whether any breast cancer cells have moved from the
original tumor into the lymph nodes. Lymph nodes are found throughout the body,
and make up part of the lymphatic system, which is part of the body's immune system.
If breast cancer does spread, it usually spreads first to the lymph nodes under
the arm on the side of the breast cancer.
If lymph node status is positive, meaning the lymph nodes contain breast cancer
cells, the cancer may be more likely to return or recur.
If the lymph node status is negative, meaning that the lymph nodes appear free of
breast cancer cells, the breast cancer is less likely to recur.
Breast Cancer Tumor Histologic Grade
Pathologists are doctors who are experts in diagnosing disease and who study both
the overall and microscopic appearance of the tumors of women with breast cancer.
In addition to the stage, pathologists classify tumors into one of three
grades based on how similar in appearance the breast cancer cells are to
normal cells, and on how many of those tumor cells are dividing. The greater the
number of cells dividing, the higher the breast cancer tumor grade. Tumor grade
is one of many factors that, when used in combination, can indicate how aggressive
someone's breast cancer is.
Grade 1: Breast cancer tumor cells are more similar to normal cells
and grow slowly (also called well-differentiated).
Grade 2: Breast cancer tumor cells are somewhat abnormal and growing
at moderate speed (also called moderately differentiated).
Grade 3: Breast cancer tumor cells are abnormal and growing quickly
(also called poorly differentiated).
Hormones are naturally occurring chemicals in the body that stimulate the growth
of hormone-sensitive tissues, such as those in the breast. In some cases of breast
cancer, the hormones estrogen and progesterone may stimulate tumor growth. To find
out if your cancer is hormone-dependent, your doctor will likely have your tumor
tissue tested for the presence of hormone
receptors, which are proteins on the surfaces of cells to which hormones
bind, thus activating tumor growth.
If your breast cancer is estrogen receptor-positive (ER+)
or progesterone receptor-positive (PR+),
meaning it has receptors for those respective hormones, you may be a candidate for
Human epidermal growth factor receptor 2 (HER2/neu) is a protein that appears in
the cancer cells of some women with breast cancer. Approximately 20%-40% of women
with breast cancer show HER2 overexpression (gene amplification), which correlates
with poor prognosis and is predictive of response to trastuzumab.1
A woman whose tumor has greater-than-normal levels of HER2/neu is considered HER2-positive.
A woman whose tumor has normal levels of HER2/neu is considered HER2-negative.
Genomic Testing - Oncotype DX®
Genomic tests look at groups of genes and how active they are within a tumor. This
activity can influence how breast cancer is likely to grow and respond to treatment.
For example, the Oncotype DX® test looks at a group
of genes and their activity in breast tumor tissue. Validation studies have already
been performed on the Oncotype DX Breast Cancer Assay for patients with pre-invasive
or DCIS, node-negative and node-positive, estrogen-receptor-positive (ER+) breast
cancer; for single gene reporting quantitative of ER (estrogen receptor), PR (progesterone
receptor negative) and HER2 (human epidermal growth factor receptor 2) genes, and
for patients treated with Tamoxifen or an Aromatase Inhibitor. The Oncotype
DX breast cancer tests are currently commercially available. For detailed information
please call: (866) ONCOTYPE or visit
Breast Cancer Recurrence And Metastasis
Recurrence is the return of the same cancer
after initial breast cancer treatment. Therapy for
early-stage breast cancer aims to reduce the chance that cancer will return,
or recur. It is valuable to know the chance that your particular breast cancer will
return, because that can help you and your doctor determine whether additional treatment
beyond surgery is appropriate.
There are two main types of recurrence:
Local recurrence is the return of cancer to
the area where a woman originally had cancer and subsequent surgery. Signs of local
recurrence of breast cancer usually become apparent during mammograms, physical
examinations by a health professional or self-examinations. Local recurrence is
often treated similarly to the way the original cancer was treated: with surgery,
followed by radiation therapy (if it was not done initially),
In distant recurrence, the
cancer metastasizes, or spreads to parts of the body other than the
original location (breast or lymph nodes located near the breast). Symptoms such
as bone pain, weight loss, and shortness of breath may be signs of distant recurrence.
If cancer does metastasize, it commonly spreads to the lungs, bones, liver or brain.
For more information on a breast cancer diagnosis and treatment options, please visit My Breast Cancer Coach.
Back to Top
Source For This Page:
Bonadonna, Gianni, Gabriel N. Hortobagyi, and A. Massimo Gianni, eds. Textbook of
Breast Cancer: A Clinical Guide to Therapy. 2nd ed. London: Martin Dunitz,
1. HER2 information appears on p. 56 of the above-referenced work. Trastuzumab (HERCEPTIN®),
as part of a treatment regimen containing doxorubicin, cyclophosphamide, and paclitaxel,
is indicated for the adjuvant treatment of HER2-overexpressing breast cancer. HERCEPTIN
as a single agent is indicated for the adjuvant treatment of HER2-overexpressing
node-negative (ER/PR-negative or with one high-risk feature) or node-positive breast
cancer, following multi-modality anthracycline-based therapy. Lapatinib (TYKERB®)
is indicated in combination with capecitabine (XELODA®) for the treatment of patients
with advanced or metastatic breast cancer whose tumors overexpress HER2 and who
have received prior therapy including an anthracycline, a taxane, and trastuzumab
HERCEPTIN is a registered trademark of Genentech, Inc.
TYKERB is a registered trademark of GlaxoSmithKline.
XELODA is a registered trademark of Roche Laboratories Inc.
i Hughes et al, J Clin Oncol. 2009; 27:39