What is Cancer?

Cancer is a disease caused by an uncontrolled division of abnormal cells that can occur in different areas of the body. This division of such cells can result in a malignant growth, mass or tumor, however some cancers involving the blood and blood-forming organs do not form tumors. Instead, they circulate through other tissues where they grow.

A tumor may be benign (non-cancerous) or malignant (cancerous). Cells from cancerous tumors can spread throughout the body. This process, called metastasis, occurs when cancer cells break away from the original tumor and travel in the circulatory or lymphatic systems until they are lodged in a small capillary network in another area of the body. Common locations of metastasis are the bones, lungs, liver and the central nervous system.

Each type of cancer is characterized by the uncontrolled growth of cells, and the type of cancer refers to the organ or area of the body where the cancer first occurred. Cancer that has metastasized to other areas of the body is named for the part of the body where it originated. For example, if breast cancer has spread to the bones, it is called “metastatic breast cancer” not bone cancer.

How/Why Did I Get Cancer?

The reason why certain individuals develop cancer is still not well understood. Each individual case can have a number of variables. There are some known carcinogens (materials that can cause cancer), but many are still undiscovered. We do not know why some people who are exposed to carcinogens get cancer and others do not. However, the length and amount of exposure are believed to affect the chances of developing a disease. For example, as your exposure to the sun increases, the chance of you developing skin cancer also increases. As your exposure to cigarette smoking increases, the chance of you developing lung cancer also increases. Genetics also plays an important role in whether an individual develops cancer. For example, certain types of breast cancer have a genetic component, which put certain individuals who have a family history of breast cancer at a higher risk.

What is the difference between a diagnosis and a prognosis?

A diagnosis is an identification of a particular type of cancer. When making a diagnosis, the initial signs and symptoms are investigated through a variety of tests in order to identify whether cancer is causing them and, if so, what type of cancer it is. Diagnosis is not the same as detection. Cancer may be detected when symptoms or abnormalities, such as a lump or a growth, are recognized by a patient or doctor. After a cancer is detected, it still must be carefully diagnosed. For example, breast cancer may be detected when a patient notices a lump, but it must be carefully evaluated with a number of tests in order to determine an accurate diagnosis. The diagnosis describes what type of breast cancer it is and how advanced it is. Following a diagnosis of cancer, the most important step is to accurately determine the stage of cancer.

The probable course and/or outcome of cancer is referred to as the prognosis. Identifying factors that indicate a better or worse prognosis may help you and your doctor plan your treatment. There are many factors that help determine your prognosis. Your doctor will evaluate all possible factors to determine your prognosis. Some of these include:

• Your age
• Your level of physical fitness
• Size of your cancer
• Stage of your cancer
• Aggressiveness of your cancer (cancer cells that are growing and dividing rapidly are considered more aggressive).

Recently, the genetic make-up of cancer is being increasingly recognized as an important prognostic factor. For example, some genes have been associated with an aggressive course or tendency to recur. Identification of these in an early stage cancer may indicate a poor prognosis. Some research suggests that the genetic make-up of the cancer may be even more important for determining prognosis than the stage of the cancer.

How is cancer diagnosed?

Diagnosing cancer involves the use of a variety of tests that provide details about abnormal cells, which may have been detected through routine medical examinations, self-examination, or reported symptoms. More information about these cells must be gathered in order to identify them as malignant (cancerous) or non-malignant (non-cancerous), and if they are malignant, to determine how serious (aggressive) the particular cancer cells are. Aggressive cancers grow and spread more quickly than less-aggressive or “indolent” cancers. There are many types of tests specifically designed to evaluate cancer. Some of these include:

• A pathology report is based on observation of abnormal cells under a microscope.
• Diagnostic imaging involves visualization of abnormal masses using high tech machines that create images, such as x-rays, computed tomography (CT), positron emission test (PET), magnetic resonance imaging (MRI), and combined PET/CT.
• Blood tests measure substances in the blood that may indicate how advanced the cancer is or other problems related to the cancer.
• Tumor marker tests detect substances in blood, urine, or other tissues that occur in higher than normal levels with certain cancers.
• Special laboratory evaluation of DNA involves the identification of the genetic make-up—the DNA—of the abnormal cells.

What is a Cancer Stage?

Staging describes the severity of a person’s cancer based on the extent of the original (primary) tumor and whether or not cancer has spread in the body. Staging is based on knowledge of the way cancer progresses and is important for several reasons:

• The stage can be used to estimate the person’s prognosis.
• Staging helps the doctor plan the appropriate treatment and identify clinical trials that may be suitable for a particular patient.
• Staging helps health care providers and researchers exchange information about patients; it also gives them a common terminology for evaluating the results of clinical trials and comparing the results of different trials.

What are the Common Elements of Staging?

Staging systems for cancer have evolved over time and continue to change as scientists learn more about cancer. Some staging systems cover many types of cancer while others focus on a particular type. The common elements considered in most staging systems are as follows:

• Site of the primary tumor.
• Tumor size and number of tumors.
• Lymph node involvement (spread of cancer into lymph nodes).
• Cell type and tumor grade (how closely the cancer cells resemble normal tissue cells).
• The presence or absence of metastasis.

How are Stages Determined?

The TNM system is one of the most widely used staging systems. This system has been accepted by the International Union Against Cancer (UICC) and the American Joint Committee on Cancer (AJCC). Most medical facilities use the TNM system as their main method for cancer reporting.

The TNM system is based on the extent of the tumor (T), the extent of spread to the lymph nodes (N), and the presence of distant metastasis (M). A number is added to each letter to indicate the size or extent of the primary tumor and the extent of cancer spread. For many cancers, TNM combinations correspond to one of five stages. Criteria for stages differ for different types of cancer.

Most types of cancer have TNM designations, but some do not. For example, cancers of the brain and spinal cord are staged according to their cell type and grade. Different staging systems are also used for many cancers of the blood or bone marrow, such as lymphomas

What are the different staging levels?

• Stage 0 –Precancer
• Stage I –Small cancer found only in the organ where it started
• Stage II –Larger cancer that may or may not have spread to the lymph nodes
• Stage III –Larger cancer that has spread to the lymph nodes
• Stage IV –The cancer has spread to another organ(s) other than where it started>
• Recurrent

What types of tests are used to determine the stage of cancer?

Following a diagnosis of cancer, the most important step is to accurately determine the stage of cancer. Some cancers, such as leukemia, may not be staged. Each stage of cancer may be treated differently. The types of tests used for staging depend on the type of cancer. Tests include the following:

• Physical Exams are used to gather information about the cancer. The doctor examines the body by looking, feeling, and listening for anything unusual. The physical exam may show the location and size of the tumor(s) and the spread of the cancer to the lymph nodes and/or to other organs.
• Imaging Studies produce pictures of areas inside the body. These studies are important tools in determining stage. Procedures such as x-rays, computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, and positron emission tomography (PET) scans can show the location of the cancer, the size of the tumor, and whether the cancer has spread.
• Laboratory Tests are studies of blood, urine, other fluids, and tissues taken from the body. For example, tests for liver function and tumor markers (substances sometimes found in increased amounts if cancer is present) can provide information about the cancer.
• Pathology Reports may include information about the size of the tumor, the growth of the tumor into other tissues and organs, the type of cancer cells, and the grade of the tumor. A biopsy may be performed to provide information for the pathology report. Cytology reports also describe findings from the examination of cells in body fluids.

I have cancer. Now what?

Once you’re diagnosed with cancer, it is now time to decide how you want to treat your cancer. Your choice of cancer treatment is influenced by several factors, including the specific characteristics of your cancer, your overall condition and whether the goal of treatment is to cure your cancer, keep your cancer from spreading or to relieve the symptoms caused by cancer. Depending on these factors, you may receive one or more of the following treatments:

• Surgery
• Chemotherapy
• Radiation Therapy
• Hormonal Therapy
• Targeted Therapy
• Biological Therapy
• Clinical Trials

One or more treatment methods (modalities) may be used to provide you with the most effective treatment for your specific type of cancer. It is even becoming more common to use several treatment modalities together concurrently or in sequence with the goal of preventing recurrence. This is referred to as multi-modality treatment of the cancer.