• Breast Cancer



Cancer occurs when cells grow out of control and crowd out normal cells in the body. Cancer can begin in any place in the body, including in your blood, your bones, your organs, and even in your hair follicles. Cancer is the 2nd leading cause of death in the United States (~600,000) after heart disease (~650,000). The number of people who die from cancer is 35% of all people who are diagnosed with cancer. Although cancer is in the top 10 global causes of death and is one of the leading causes of death in many countries, mortality from cancer in low- and low-middle income countries can be as high as 80%. Different types of cancer occur at different rates but lung cancer is a major global killer.

There are many different types of cancer with the more common being lung, breast, prostate, colon, and skin cancer. In fact, each cancer is as unique as a fingerprint. This is why laboratory testing is so important, because it allows your healthcare practitioners to understand the uniqueness of your individual cancer and tailor a treatment and/or management plan specific to your cancer.


The definitive diagnosis of cancer occurs in the laboratory through a variety of different tests and testing methods. Pathologists and laboratory professions perform tests and provide results that guide a medical team to make the right decisions in treatment and follow up care. Every cancer diagnosis is unique to a patient. Our Patient Champions who have received a cancer diagnosis used the laboratory as a resource in managing their diagnosis, using information from their lab results and medical team to empower themselves in making decisions that work best for them. The laboratory plays a critical role throughout a patient’s cancer journey.


The stage of cancer determines how far the cancer has spread and to what parts of the body. The progression of stage is based on the size of lesions and its location. Your treatment plan and prognosis will depend on the staging portion of your diagnosis. Below is a short description of each stage for a typical cancer:

Stage 0: There are some abnormal cells in a part of your body and those cells may develop into cancer. The number of abnormal cells is too small to form a tumor and they may never form a malignant tumor (cancer). Term for this stage are “carcinoma in situ” or may be referred to as “pre-cancer” or a “pre-cancerous lesion”.

Stage I: The cancer cells are contained within the organ or body part in which it started. The cancer is relatively small.

Stage II: The cancer is larger than in Stage 1 but still contained within the initial location it started.

Stage III: The cancer is larger and it may have spread to surrounding tissues, possibly including some nearby lymph nodes.

Stage IV: The cancer has spread to other parts of the body or metastasized.

Note that, just like each patient’s tumor is unique, each type of staging for a given cancer is different and specific so your staging process may use slightly different language and terms.

Breast Cancer Progression

Here is a diagram showing the progression of breast cancer from Stage I through Stage IV. Please note that Stage II may represent a larger tumor with no nodes or a small tumor with positive nodes.



Cancers also come in grades. There is a progression of grades that feeds into staging, however grading is a prognostic factor that is representative of how aggressive a tumor is. Broadly defined, “low grade” cancers are often less aggressive and generally indicate a better prognosis (which is an estimate of the likely outcome or course of a disease) and “high grade” cancers may grow and spread more quickly, and may require immediate or more aggressive treatment. The grade of a cancer depends on what the cells look like under a microscope, which pathology and laboratory professionals determine, allowing physicians to use that information to help guide treatment options for patients. The grading system that is usually used is mentioned here along with histology images that were provided by Jane Brock, MBBS, PhD, Chief of Breast Pathology at Brigham and Women’s Hospital:

Grade I

Cancer cells that resemble normal cells and aren’t growing rapidly.

Breast Cancer Progression

Here is a Grade I histology image of invasive ductal breast carcinoma that is well differentiated, meaning that the tumor tubules recapitulate normal breast glands and rarely divide.

Grade II

Cancer cells that don’t look like normal cells and are growing faster than normal cells.

Breast Cancer Progression

Here is a Grade 2 histology image of invasive ductal breast carcinoma that is moderately differentiated.

Grade III

Cancer cells that look abnormal and may grow or spread more aggressively.

Breast Cancer Progression

Here is a Grade 3 histology image of invasive ductal breast carcinoma that is poorly differentiated, meaning that there are often solid sheets of large, rapidly dividing tumor cells.