|Cancer cells. Photo by Pixabay|
We’ve been aware of the dangers of cancer for thousands of years now. As scientific developments progress, we’ve been more aware of the possibilities of people getting and developing cancer, as well as minimizing their risks of getting it in the near future.
What baffles most scientists, however, is the capability of cancers to spread around the body so fast, that at the time when scientific medication is needed, it will no longer be effective. However, according to a recent study, they believe that they’ve found one of the main reasons why, and it has something to do with how our blood flows through our body every single day.
One of the most important terms in cancer research is metastasis, yet so little is known about it. Medically, metastasis is the way cancer grows to a different part of the body where it was first started, according to Cancer.net. We know this type of cancer whenever we hear the terms “metastatic cancer” or even “stage four cancer.”
Scientists have long studied how metastasis starts in a cancer patient’s body. It commonly develops whenever when the cancer cells break away from the tumor and enter the bloodstream and the lymphatic system, which means that these tumors can go far from the original site where they grew, making these grow in different parts of the body. A tumor can grow anywhere, meaning that if you have lung cancer, several metastases can develop in your colon, esophagus, or even breasts.
The scientific community has always known how cancers spread. As outlined by the National Cancer Institute, the metastasis involve few steps, known as the metastatic escapade. First, it will grow into, or invade a nearby normal tissue, which would, later on, move through the walls of nearby lymph nodes or blood vessels. Later on, it would travel through the lymphatic system and bloodstream to other parts of the body, which will stop in small blood vessels at a distant location, invading these walls, and moving to the surrounding tissue. The cancer cells would later grow in this tissue until a tumor forms, which will cause new blood vessels to grow, thus creating a blood supply that allows the tumor to continue growing.
When observed, metastatic cancers have the same features as those of primary cancers, not like the cells where the cancer was first found. The name, wherever the metastasis happened, remains the same, meaning that a metastasized lung from colon cancer is still called metastatic colon cancer, and not lung cancer.
It is considered as the leading cause of cancer death and has been labelled as one of the primary important steps in the prognosis of cancer.
However, there are still things that most scientists don’t know about cancers, and the study conducted in France would’ve solved this issue. The study, conducted by the National Institute of Health and Medical Research in France, has posited that blood flow may be an influence of how a cancer cell metastasizes the way it is. The paper, which is now in the Developmental Cell, has confirmed the theory that blood flow influences the locations at which migrating cancer cells “arrest” inside blood vessels, according to the Medical News Today.
The experiment, which was done on zebrafish and humans, has detailed on how cancer cells exit through the blood vessel walls and set up sites. Dr. Jacky Goetz of the University of Strasbourg in France has detailed why metastasis occurs this way, saying that “arrest is triggered when circulating tumor cells end up in capillaries with a very small diameter simply because of size constraints." According to Medical News Today, this is not only the main driver, given that blood flow also has a strong impact on “allowing the tumor cells to establish adhesion with the vessel wall.”
Recalling the fourth step of the “metastatic escapade, Goetz said that the study focused mainly on the fourth step, saying that “very little is known about how [circulating tumor cells] arrest and adhere to the endothelium of small capillaries and leave the bloodstream by crossing the vascular wall."
Using zebrafish embryos, they developed an approach by following tumor cells as they travelled through blood vessels. The results showed that there is a correlation between the locations in blood vessels at which the circulating tumor stops travelling and the flow rates.
It has also been proven that blood flow plays a part in the way tumor cells exit the blood vessels. “You need a certain amount of flow to keep the endothelium active so that it can remodel around the tumor cell,” Dr. Goetz told the Medical News Today.
When compared with brains of 100 human patients, and using the zebrafish model, they confirmed the preference of tumors to grow in areas where blood flow is within a certain range, making it responsible not only for location but for “metastatic outgrowth.”