Metastatic cancer is indiscriminate and can develop from almost any form of cancer. Cancer cells can continue to multiply and spread beyond their original point of origin, forming tumors and invading other healthy tissues.
When various types of cancer, regardless of where they are located, travels from the original site of its origin and goes on to invade other parts of the body, it has metastasized. This is defined as metastatic cancer. The tumors that spread to other areas are referred to as metastasis or metastatic tumors. When cancer has metastasized to another area of the body, it maintains the original name it is given based on its point of origin.
For example, if an individual is diagnosed as having stomach cancer and the tumors spread and metastasize to the liver, the cancer cells in the liver are referred to as metastatic stomach cancer, not liver cancer.
There is not one particular type of metastatic cancer. Metastatic cancer is not a type of cancer, but is simply the spread of cancer from one area of the body to another. The formation of metastatic cancer is a complicated one. Many things need to occur before the cancer has the ability to spread beyond the original site of origin. The development of metastatic cancer can happen in a few different ways:
- The cancer can attack the cells and tissue that are located within close proximity to the original site.
- The cancer cells can infiltrate the bloodstream and the blood can carry the cancer to other areas in the body, even if they are far away from the original site.
- The cancer cells can occupy lymph vessels and move through freely through the body, attacking the lymph nodes or additional organs of the body.
Most cancers have the capacity to invade many different parts of the body. However, the origin of the cancer is often times an indication of where in the body the cancer may eventually spread to. When cancer cells separate from their original site of origin and begin to travel through the body via the blood or lymph system, the cancerous cells will often inhabit the next available part of the body, organ or lymph nodes.
For instance, a cancer that originally starts out in the intestines may become metastatic in the liver because the blood flows from the original source into the liver. The most common places for cancer to spread, for all types of cancer, are the liver, lungs, bones and brain.
Symptoms of metastatic cancer vary amongst individuals and according to their original site of origin. In some cases, there will be no outward symptoms. For other individuals, the symptoms will largely depend upon where the metastasis has formed and how large the cancer cells have become.
For patients suffering from metastasis to the brain, possible symptoms they experience may include headaches or dizziness. Likewise, patients with metastasis occurring in the bones may experience bone aches and pain, or even broken bones. Overall symptoms of metastatic cancer can include:
- General weakness or exhaustion
- Experiencing weight loss, without dieting
- Localized pain
- Feeling short of breath
Causes And Risk Factors
There are no known causes or risk factors associated with metastatic cancer. Researchers have yet to uncover why cancer remains in one area for some individuals and metastasizes to other parts of the body in others. There is a correlation between late diagnosis and metastatic tumors. Cancer that has been left undiagnosed and untreated in the body has more opportunity to spread to other areas than cancer that is diagnosed and treated during the early stages.
In some cases, a simple blood test can identify advanced stages of cancer after proper diagnosis has been made for the original cancer. Certain types of cancer emit substances in the blood. These substances, known as tumor markers, can indicate metastasis. In other cases, imaging tests are used to spot tumors or abnormalities in the patient. Imaging tests include:
- Chest X-ray
- CT scan
- PET scans
- Bone scans
Both the type of cancer that is present and its location will determine which diagnostic tests your doctor will order. For instance, chest x-rays may be able to find small tumors in the lungs while an MRI is better suited for viewing tumors in the spinal cord and brain.
Once a diagnostic test has found an abnormality or a suspected tumor, a biopsy may be the next step in diagnosing metastatic cancer. To be sure that what has been found is indeed cancer, your doctor is likely to perform a biopsy. A biopsy involves the removal and testing of a portion of the cells within the mass or tumor. Depending on the location of the mass, a biopsy can be performed with a needle or surgically.
Treatment options for metastatic cancer will vary greatly depending upon the type of cancer, the size or quantity of the tumors, and where in the body the cancer has spread. In many instances, metastatic cancer cannot be cured, but the use of treatment can slow the growth of cancer cells, relieve symptoms and improve the patients overall quality of life.
Treatment options may include one method or a combination of approaches. Treatment options include: radiation, chemotherapy, surgery or drug therapy. When a patient has been diagnosed with metastatic cancer, the same course of treatment that is used to treat the original cancer is commonly used because the cancer cells that are spreading are of the same origin as the original cancer. In certain cases, treatment will be changed or added to in order to better treat certain metastasis that occur, typically in the brain, lungs or liver.