Today’s blog is about metastasis in cancer.
We learned in C is for Cancer Cells that one of the reasons that cancer is such a deadly disease is its ability to metastasize, or spread from one part of the body to another. Depending on what kind of cancer the patient has, this, most serious form of cancer is known as “metastatic,” or “stage IV.”
How Cancer Metastasizes
The place where cancer first develops is called the primary tumor site.
From there, cancer spreads locally, invading nearby healthy tissue.
If too much time passes between the emergence of the primary tumor and treatment or treatment is unsuccessful, cancer cells will break away from the primary tumor site.
They then move through the walls of nearby lymph nodes or blood vessels.
Cancer cells proceed to travel through the patient’s bloodstream or lymphatic system.
They can get lodged in small blood vessels in distant locations, lymph nodes, or other organs. Like when they initially began growing, the cells invade the blood vessel walls and surrounding tissue. New blood vessels to form, providing an abundant blood supply to nourish the tumor as it grows.
After that, they can continue to spread to more distant parts of the body. Most of these cancer cells die along the way, but some continue the invasion and form more new tumors in different parts of the body.
The Same Cancer
Even though they’re in a new location, these metastatic tumors are the same type of cancer as the primary
tumor. Doctors can see what kind of cancer the cells are through a microscope when they do a biopsy.
This is important because the treatment options that are most likely to be successful, are dependent on the type of cancer rather than the location of the cancer.
My husband, Dan, has stage IV, metastatic lung cancer. The primary tumor in his lung was very small. Yet, in a short amount of time, it spread to his spine and his lymph nodes. Eventually, it spread to his brain. This is called a brain “met.” The cancer cells in his brain were lung cancer cells, not brain cancer cells.
Sometimes, a patient gets cancer again, months or years after they were treated cancer. Usually, this cancer is the same type of cancer the patient had before. Occasionally, the cancer is a different kind of cancer. This is known as a second primary cancer. Thankfully, second primary cancers are rare, but they do happen.
Where does a metastasis travel?
Most forms of cancer can spread nearly anywhere in the body, but some cancers are more likely to spread to certain locations than others. The following is a table of the most common sites of metastasis (not including the lymph nodes) of various cancers. (1)
Common Sites of Metastasis
|Cancer Type||Main Sites of Metastasis|
|Bladder||Bone, liver, lung|
|Breast||Bone, brain, liver, lung|
|Colon||Liver, lung, peritoneum|
|Kidney||Adrenal gland, bone, brain, liver, lung|
|Lung||Adrenal gland, bone, brain, liver, other lung|
|Melanoma||Bone, brain, liver, lung, skin, muscle|
|Ovary||Liver, lung, peritoneum|
|Pancreas||Liver, lung, peritoneum|
|Prostate||Adrenal gland, bone, liver, lung|
|Rectal||Liver, lung, peritoneum|
|Stomach||Liver, lung, peritoneum|
|Thyroid||Bone, liver, lung|
|Uterus||Bone, liver, lung, peritoneum, vagina|
What are the symptoms of a metastasis?
Even Metastatic Cancer can be Asymptomatic. Your doctor will be keeping a close eye on you, if you have already been diagnosed with cancer. They will see you in clinic on a regular basis, and order scans at regular intervals.
There are some symptoms to be aware of. Headaches, lack of balance and seizures, are a symptom of a brain met. Shortness of breath is a symptom of metastasis to the lung. Bone metastasis is suspected when there is bone pain. Sometimes they aren’t discovered until there is a fracture. If cancer has metastasized to the liver, the patient’s skin will often become jaundice (yellow) and there may be abdominal swelling.
A Word About Brain Mets…
One of the reasons brain metastasis are common, even when treatment is working for cancer in the rest of the body, is the blood-brain barrier. A semi-permeable membrane that selectively allows nutrients in while protecting the brain from toxins. As far as your brain is concerned, cancer treatments are toxic. Because of that tumors often retreat to the safety of the brain.
Thankfully, doctors have gotten very good at zapping those nasty mets with precision radiation. By keeping a close eye on your cancer and following your treatment plan, you have the best chance of being able to get a metastasis under control.
- National Cancer institute, Metastatic Cancer: Where Cancer Spreads; Common Sites of Metastasis. February 6, 2017.
I am an author, writer, and speaker and homeschooling mom of 3. Since my husband, Dan was diagnosed with stage IV lung cancer in 2012, I’ve focused my writing and speaking on helping cancer patients and their families advocate for themselves and live life to the fullest, despite their illness.
My goal is to help people face cancer with grace.
My book Facing Cancer as a Friend: How to Support Someone Who Has Cancer, is available on Amazon.com.