Researchers are looking at using circulating tumour cells to diagnose cancer instead of a tissue sample biopsy. And at whether they can test circulating cancer cells to predict which treatments will work better. The circulating blood sweeps the cancer cells along until they get stuck somewhere. Often they get stuck in a very small blood vessel such as a capillary.
Then the cancer cell must move through the wall of the capillary and into the tissue of the organ close by. The cell can multiply to form a new tumour if:. This is quite a complicated process and most cancer cells don't survive it. Of the many thousands of cancer cells that reach the bloodstream, only a few survive to form a secondary cancer. The white blood cells in our immune system find and kill some cancer cells. Others cancer cells might die because they get battered around by the fast flowing blood.
Cancer cells in the circulation may try to stick to platelets to form clumps to give themselves some protection. Platelets are blood cells that help the blood to clot. This could also help the cancer cells to move into the surrounding tissues. The lymphatic system is a network of tubes and glands in the body that filters body fluid and fights infection. It also traps damaged or harmful cells such as cancer cells.
Cancer cells can go into the small lymph vessels close to the primary tumour and travel into nearby lymph glands.
In the lymph glands, the cancer cells might die. But some may survive and grow to form tumours in one or more lymph nodes. This is called lymph node spread. The lymphatic drainage system! Content not working due to cookie settings. Read a transcript of the video. No matter where else in the body it spreads, a cancer is still named for the place it originated.
For instance, prostate cancer that has spread to the liver is still prostate cancer, not liver cancer, and treatment will reflect that. Cancer can spread through:. Cancer cells that have more genetic damage poorly differentiated usually grow faster than cancer cells with less genetic damage well differentiated. Based on how abnormal they appear under a microscope, tumors are graded as follows:. Some may never require treatment. Many of these cancers can be effectively treated. Cancers are staged according to tumor size and how far it has spread at the time of diagnosis.
Stages help doctors decide which treatments are most likely to work and give a general outlook. There are different types of staging systems and some are specific to certain types of cancer.
The following are the basic stages of cancer:. Your pathology report may use the TNM staging system, which provides more detailed information as follows:. Benign tumors are noncancerous. Benign tumors can cause a few problems if they:. Cancerous tumors are called malignant. Cancer cells form when DNA abnormalities cause a gene to behave differently than it should. They can grow into nearby tissue, spread through the bloodstream or lymph system, and spread through the body.
Malignant tumors tend to grow faster than benign tumors. Treatment depends on the specific type of cancer as well as the stage. In many cases, treatment will consist of more than one therapy. Depending on the type of cancer you have, surgery may be the first-line treatment. When surgery is used to remove a tumor, the surgeon also removes a small margin of tissue around the tumor to lower the chances of leaving cancer cells behind. Surgery can also help stage the cancer.
For example, checking the lymph nodes near the primary tumor can determine if cancer has spread locally. You may also need chemotherapy or radiation therapy following surgery. This may be an added precaution in case any cancer cells were left behind or have reached the blood or lymph system. This can be helpful if the tumor was causing pressure on an organ or causing pain.
Radiation uses high-energy rays to kill cancer cells or slow their growth. The rays target a specific area of the body where cancer has been found. Even if one cancer cell is left behind, it can grow and divide to become a new tumour. A new tumour can start to grow in the same area of the body where the cancer first started, or the cancer may have spread through the blood or lymphatic system to another part of the body, where it grows into a new tumour. This is why doctors sometimes use another treatment right after the first treatment, such as giving chemotherapy after surgery.
This is called adjuvant therapy. The goal of adjuvant therapy is to help prevent the cancer from coming back in case some cancer cells are left behind in the body. In some cases, treatment may stop working become resistant so cancer cells are no longer being destroyed. So cancer that was shrinking or had disappeared may start to grow again and get bigger. This can happen when the genes inside cancer cells mutate.
Some gene mutations make cancer cells resistant to chemotherapy and other drug treatments. If you become resistant to a treatment, your doctor may suggest that you try another one. Many cancers can be cured with treatment. But cancer that is thought to be cured can still come back even years later. This is why some doctors prefer to say that the cancer is in remission.
Remission means there are fewer signs and symptoms of a disease such as cancer or that they have completely gone away. Home Cancer information What is cancer? How cancer starts, grows and spreads. See topics What is cancer? Types of cancer Human body Immune system Lymphatic system Blood and bone marrow Endocrine system and hormones Female sex organs and reproductive system Male sex organs and reproductive system How cancer starts, grows and spreads Types of tumours Genes and cancer Stage and grade Prognosis and survival What causes cancer?
What is cancer? Diagram of cell division.
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