Cancers cells proliferate rapidly. Cancerous (malignant) tumors are masses of tissue growths compose of cancer cells. Cancerous tumors usually first develop in one place: the primary tumor.
However, in order to expand, tumors must develop a blood supply to obtain oxygen and nutrients for new and dividing cells. In fact, if the tumor has no blood supply, its growth will not exceed the size of the needle.
The chemicals produced by cancer cells stimulate the growth of surrounding tiny blood vessels. Which are separate from existing blood vessels.
This ability of cancer cells to stimulate the growth of blood vessels is called angiogenesis. Cancer cells also have the ability to pass through or pass through normal cells. Then, as they divide and multiply, cancer cells invade and destroy local surrounding tissues.
Spread to lymph channels
Some cancer cells can enter local lymphatic vessels. (The body contains a network of lymphatic vessels that drain fluid called lymphatic fluid, which bathes and surrounds the body’s cells.) Lymphatic channels drain lymph into the lymph nodes.
There are many lymph nodes throughout the body. Cancer cells can transport to the lymph nodes and trappe there. However, it can multiply and become a tumor. This is why the lymph nodes close to the tumor become larger and contain cancer cells.
Move to other areas of the body
Some cancer cells can enter a small local blood vessel (capillary). They can then transport through the blood to other parts of the body. The cells can then multiply, forming a secondary tumor (metastasis) in one or more parts of the body.
These secondary tumors can then grow, invade and destroy nearby tissues and spread again. Why do non-cancerous (benign) tumors not spread to other areas? The cells that make up benign tumors are different from cancerous (malignant) tumors.
Cells in benign tumors are often very similar to normal cells. They do not invade local tissues. Benign tumors usually grow slowly in normal cells in the capsule or around the tumor.
Benign tumors often look and feel smooth and regular, and have well-defined boundaries. This is different from malignant tumors, which may appear irregular and steep, whose edges tend to fuse with nearby normal cells and tissues.
What is cancer staging?
The staging of cancer is a measure of the extent to which cancer has grown and spread. Some cancers can also be staged by observing the characteristics of the cancer cells, using a microscope or other tests.
The stage and grade of cancer help determine how advanced it is and how well it responds to treatment. As a general rule of thumb, the earlier the cancer is stage and the lower the grade, the better the outlook (prognosis). A common cancer staging metho is called the TNM classification:
- T stands for tumor: the degree of local growth of the primary tumor.
- N stands for node: if cancer has spread to the local lymph nodes (nodes).
- M stands for metastasis: if cancer has spread to other parts of the body. When the cancer is staged, a number is provided for each of these three characteristics. For example, in gastric cancer: •
- T-1 means that the primary tumor is still in the stomach wall. T-3 means the primary tumor grows on the stomach wall, and T-4 means that it is invading nearby structures, such as the pancreas.
- N-0 means no spread to lymph nodes. N-1 means that some lymph nodes are affectedtumers. N-2 means more extensive spread to local lymph nodes
- M-0 means no metastasis. M-1 means that some other areas of the body have metastases, such as the liver or brain.
Therefore,
for some gastric cancers, the doctor may say: “The staging is T-3, N-1, M-0.” This means that cancer has spread to the stomach wall, some spread to the local lymph nodes, but there is no metastasis elsewhere in the body.
There are other staging classifications that are sometimes used for various cancers. For example, digital systems are used in certain cancers.
In other words, you can simply say that the cancer is in stages 1, 2, 3, or 4 (or stage I, II, III, or IV). Similarly, staging reflects the size of the primary tumor and whether cancer has spread to the lymph nodes or other parts of the body.
It can become complicated because each number can be subdivide into a, b, c, etc. For example, you may have stage 3b cancer. Grade 4 is usually called advance cancer.
Why are cancers stage?
By determining the stage of cancer, you can:
- Help the doctor make recommendations on the best treatment.
- Give a reasonable indication of the prospect (forecast).
- Use standard language (a shortened language) to describe cancer, which is helpful when doctors talk about patients and their participation in clinical trials.
For example, if you have bowel cancer and are diagnose at an early stage, surgical removal of the tumor may be curative. (
That is if the cancer is confine to the lining of the intestine and has not sprea to the lymph nodes (lymph nodes) or other parts of the body.)
However, if the cancer is at an advance stage, the primary tumor may or may not be remove and treatment may be possible Including chemotherapy, the chance of cure will be reduce.
How are cancers stage?
After the cancer is diagnose for the first time, you may need to have multiple tests in order to get an accurate stage. Tests may vary depending on cancer but may include blood tests and scans, such as computed tomography (CT) scans, magnetic resonance imaging (MRI), bone scans, ultrasounds, etc.
You may even need surgery. Look at one or more parts of your body. Sometimes, cancer cannot be accurately stage before surgery to remove the primary tumor.
Examine the tissue removed with the tumor under a microscope to see how much cancer cells have grown in normal tissue and whether nearby lymph nodes (nodes) contain cancer cells.
A separate booklet provides detailed information on the various scans and tests that may be recommende for cancer staging.
What is cancer grading?
Some cancers are also stage. Observe the cancer sample under a microscope or by other means (biopsy). By looking at certain characteristics of cells, cancer can be classified as low, medium, or high.
- Low grade means that cancer cells tend to grow slowly, look a lot like normal cells (well differentiated), tend to be less aggressive, and are unlikely to spread quickly.
- Intermediate is intermediate.
- High grade means that cancer cells tend to grow quickly, look very abnormal (poorly differentiated), tend to be more aggressive, and are more likely to spread quickly.
Some cancers have slightly different staging systems. For example, breast cancer is classified as 1, 2, or 3, which is very similar to low, medium, and high grades.
Another example is prostate cancer that uses the Gleason score for staging. This is similar to other scoring systems.
A low Gleason score means roughly the same as a low score, while a high Gleason score means roughly the same as a high score.
For some cancers, doctors will use information about the grade and stage of cancer when providing recommendations for treatment options and commenting on the outlook (prognosis).
