Why does cancer metastasize?

The metastasis of cancer cells may be caused by awakening dormant embryonic development-related transcription factors in the body.

Generally speaking, cancer cell metastasis is divided into several stages: the first stage is called invasion. In this stage, cancer epithelial cells will loosen the connections between cancer cells, causing the cancer cells to " Be free" and be able to move to other places. The second stage is called intravasation, in which cancer cells cross the endothelium of blood or lymphatic vessels and enter the circulation. The third stage is called extravasation, in which survivors of the circulatory journey pass through the endothelial cells of the capillaries and reach other tissues. The final stage is the immigration of these cancer cells to new lands, multiplying and thriving in other tissues to form metastatic malignant tumors.

The reason why cancer cells can metastasize may be because they awaken long-dormant genes in the body that are responsible for early embryonic development, thereby activating related programs and thus gaining the terrifying ability to metastasize.

In the future, drugs may be developed clinically to inhibit the expression of genes such as Twist and avoid tumor metastasis; or by screening these genes, the future direction of tumors can be detected early and appropriate treatment can be given . Maybe in the future, cancer will no longer be such a terrifying scourge, but it may become another chronic disease.

How cancer metastasizes:

Cancer cells are very "greedy" and will run wherever they can, and there are three main paths:

1. Lymphatic metastasis

Lymphatic metastasis is usually the earliest, so when performing tumor resection, lymph node dissection is required; radiotherapy not only irradiates the primary tumor lesion, but also irradiates surrounding lymph nodes. The lymphatic system is spread throughout the body and is the ideal and preferred channel for cancer cell metastasis. Lymphatic metastasis often occurs from near to far. For example, breast cancer first metastasizes to the ipsilateral axillary lymph node, and then to the supraclavicular and subclavian lymph nodes, and even the contralateral axillary lymph node.

2. Hematogenous metastasis

Cancer cells that invade blood vessels directly or enter blood vessels through lymphatic vessels will follow the blood flow to other parts such as the lungs, brain, liver and bones. This is Hematogenous transfer. Gastrointestinal cancer often metastasizes to the liver and lungs, breast cancer, kidney cancer, osteosarcoma, etc. often metastasize to the lungs, lung cancer easily metastasizes to the brain, and prostate cancer easily metastasizes to the bones. Chemotherapy is used to prevent cancer cells from metastasizing through the bloodstream and to use drugs to destroy cancer cells "along the way."

3. Planting

There is another type of transfer that is relatively rare, which is planting transfer. If cancer cells fall off the surface of the tumor and "fall" into the chest, abdominal cavity, cerebrospinal cavity, etc., they will "take root and sprout." It usually occurs in the lower part of these cavities, such as the costophrenic angle, rectovesical fossa, skull base, etc.

People always like to say that things cause cancer. In fact, we cannot say that you will not get cancer as long as you don’t eat anything, or that you will get cancer if you come into contact with anything. No factor has been found to be an inevitable factor in inducing cancer. The most important thing to defeat cancer is early detection. Most early-stage cancers can be cured. For this reason, we first need to have regular physical examinations, and secondly, if we feel uncomfortable, we should look for some symptoms that may be related to cancer. We should not go to the doctor only when we feel pain.