You might be aware that cancer is the uncontrollable and abnormal growth of cells in our body. Metastasis is a term associated with cancer. You might have heard about metastasis but have only a rough idea about it. It usually occurs in the advanced stages of cancer. Keep reading to learn more about metastasis.

What is metastasis?

Metastasis occurs when cancer spreads from the part where it started (or its primary site) to other body parts. It happens when the tumour cells break away from the tumour and travel to other body parts via the bloodstream or the lymphatic system. When cancer cells travel using the lymph system, they may settle in a lymph node or can travel to other organs. But usually, cancer cells spread using the bloodstream in our body. Most tumour cells die in this process, but some of these can survive and thrive in the newly found site.

Before cancer cells might start to spread, they have to go through some steps. It is not easy for them to break free from the original tumour and enter the bloodstream or the lymph. To do so, they need to find a way. After this, they need to find a way to cling to the wall of the blood vessel or the lymph vessel. Then they enter an organ. Even if they have successfully entered any organ, they have to figure out how to grow here. Above all, they need to hide from the immune system's attack.

When cancer has metastasised to a new location, it is still named after the primary site of cancer. For example, metastatic breast to the lungs means that breast cancer has spread to the lungs. The same goes for the treatment as well. If someone is diagnosed with breast cancer and it has metastasised to the lungs, the treatment will be for metastatic breast cancer. Also, it is still breast cancer, not lung cancer.

Cancer may not be metastatic when first diagnosed, but later it may spread to other parts. Sometimes, cancer has already spread when diagnosed. In such cases, it will be difficult to identify where it might have started.

Why do cancer cells spread to other body parts?

There is a connection between the place of origin of cancer cells and the place where they might spread. The cancer cells use the bloodstream or the lymph system as a mode of transportation to other body parts. They are trapped in the bloodstream or lymph system until they settle in their new place. Let's understand this with an example. In the case of breast cancer, cancer often spreads to the underarm lymph nodes, not to any other lymph nodes. Similarly, often cancer spreads to the lungs because the lungs receive blood from the rest of the body parts for oxygenation.

Symptoms of metastatic cancer

There can be several symptoms of metastatic cancer. We will discuss some of the most common symptoms here:

• Fatigue and low energy levels: You may find it hard to carry out your daily tasks. Your energy level might be low all the time, and you always feel exhausted.
• You may lose weight even without trying
• Unexplainable pain
• You may have breathing difficulties and shortness of breath
• Your bones may fracture easily
• Nasty headaches, seizures, or dizziness
• Swelling in the stomach or jaundice

You may have symptoms based on the area where the cancer has metastasised. You can talk to your doctor to clarify your doubts.

Types of cancer that usually metastasise

Any type of cancer has the potential to metastasise. But some cancers commonly seen to metastasise are breast cancer, lung cancer, kidney cancer, prostate cancer, liver cancer, pancreatic cancer, bone cancer, thyroid cancer, and colon cancer.

There are some sites where a type of cancer usually spreads. We tried to cover it in previous sections. For example, bladder cancer usually metastasizes to the liver, bone, and lungs. The most common sites for metastasis for all cancer types are the lungs, liver, brain, and bones.

How can metastatic cancer be tested or diagnosed?

There is no standard method or test to diagnose metastasis. But doctors will ask you for some tests based on the type of cancer and the symptoms.

Blood test: A blood test can reveal a lot about your current health condition. It can tell if your liver functioning is up to mark or not. but getting a normal report doesn't guarantee the absence of cancer.

Tumour markers: Tumour markers are present in some cancers. If the marker increases, it can be a sign of advancing cancer and possibly hint at the spreading too.

Imaging: Several imaging techniques can help generate images of the internal organs. Such techniques are ultrasound, CT scan, bone scan, MRI scan, and PET scan. These imaging techniques provide answers to many questions. And hence are vital diagnostic techniques.

Biopsy: Your doctor might ask for a biopsy of the tumour or the suspected tumour.

Treatments available

There are treatments for most types of metastatic cancer. Usually, the goal of treatment for metastatic cancer is to control it by stopping or slowing its growth. Some people can live for many years with well-controlled metastatic cancer. Other treatments can improve the quality of life by relieving symptoms. This type of care is called palliative care. It can be given at any time during cancer treatment.

The treatment you may receive depends on your main type of cancer, where it has spread, any treatments you've had in the past, and your general health.

If you have been told that your cancer is out of control, you and your loved ones may want to discuss hospice care. Whether you choose to continue with treatment to shrink or control its growth, you can still get palliative care to control your cancer symptoms and treatment side effects.