How Cancer Tumors Form
All cancers begin in cells, with changes in one cell or a small group of cells. Usually, we have just the right number of each type of cell, and the cell signals how much and how often it divides. If the signals are faulty, cells start to multiply too often, and a tumor begins to form.
For cancer to start, certain changes take place within the genes of a cell or a group of cells. Generally, cells grow and reproduce in a controlled way. This ensures all the cells produced are needed to keep the body healthy. But if a change happens in the genes when a cell divides, it is called a mutation – a gene has been damaged or lost or copied.
Mutations may signal a cell to start producing proteins that trigger cell division. Or the cell may stop producing proteins that stop the cell from dividing. Regardless, there have to be several different mutations before a normal cell turns into a cancer cell.
Once cell mutation and multiplication begin, tumors – benign or malignant – may form.
Benign tumors usually grow slowly and do not spread to other parts of the body. This type of tumor usually has a covering made up of normal cells
Benign tumors are composed of cells similar to normal cells and can cause problems, including the release of hormones that affect how the body works.
Malignant tumors are made up of cancer cells. They usually grow faster than benign tumors and spread (metastasize) into surrounding tissues and cause damage to the bloodstream or through the lymph system.
There are three ways that tumors may grow into surrounding tissues: pressure from the growing tumor, by using enzymes to break down normal tissues, and by moving through the tissue. However, the place where cancer starts in the body is called primary cancer. As cells from the primary site spread to other parts of the body, this is known as metastases.
When the cancer cells get into the bloodstream they are called circulating tumor cells (or CTCs). The blood carries the cancer cells throughout the body until they get stuck somewhere, usually in a small blood vessel.
Researchers are studying circulating tumor cells to diagnose cancer. The hope is that this would avoid the need for biopsies (a tissue sample taken from the body for examination). Scientists also are testing CTCs to predict which treatments will work best for a cancer patient.
In August 2018, Drs. Anna Sokolenko and Evgeny Imyanitov published findings in Frontiers in Molecular Biosciences that “so-called liquid biopsy, i.e., the analysis of circulating DNA or some other tumor-derived molecules, holds a great promise for non-invasive monitoring of cancer disease, analysis of drug-sensitizing mutations and early cancer detection. Some tumor- or tissue-specific mutations and expression markers can be efficiently utilized for the diagnosis of cancers of unknown primary origin (CUPs).”
Cancer and the Lymphatic System
You have heard of lymph nodes – the small, bean-shaped glands in your armpits, neck, chest, groin, stomach, and pelvis. Other organs in the lymphatic system include adenoids, spleen, thymus, and tonsils. These nodes filter lymph fluid.
White blood cells, such as B cells (responsible for producing antibodies) and T cells (active participants in the immune response), attack bacteria or viruses in the lymph.
The lymphatic system encompasses all parts of the body, like arteries and veins that circulate blood. The lymphatic system filters body fluid and fights infection. It also traps damaged or harmful cells such as cancer cells.
As mentioned earlier, cancer cells usually grow faster and metastasize via the bloodstream or through the lymph system.
However, cancer cells can get into lymph vessels close to the primary tumor and
travel to nearby lymph glands. These cells ultimately may form tumors in one or more lymph nodes.
Blood tests can detect certain proteins released by the cells in some types of cancer. The tests may signal metastases too small to show up on a scan. For most cancers, there is not a blood test to say whether cancer has spread. At most, doctors can only say whether it is likely or not that cancer has metastasized.
As part of the immune system, the lymph system plays a role in destroying old or abnormal cells, such as cancer cells, and fighting bacteria and other infections. (The lymph contains a type of white blood cells – lymphocytes – that destroy damaged or abnormal cells and fight infection.
However, when cancer cells break away from a tumor, they get trapped in the nearest lymph nodes. This is why doctors first check the lymph nodes when trying to determine if or how far cancer has metastasized. (Swollen lymph nodes are called lymphadenopathy. Infection is the most common cause, but cancer also can cause swollen nodes.)
Cancer and the Immune System
The immune system involves a multitude of cells, organs, proteins, and tissues. An optimum immune system recognizes foreign matter as well as dead and faulty cells and sweeps out the trash. In short, the immune system protects against disease or other potentially damaging antigens – a bacteria, fungus, parasite, toxin, or virus.
There are five structure and organs of the immune system: lymphatic system, lymphoid tissue, lymph nodes, spleen, and thymus.
There are two parts to the immune system:
- The innate immune system is always “on” – protecting the body; there is no special preparation to stop infection.
- The acquired immune system needs to be “primed” – and it is effective only after it has previously seen an infective agent.
When a virus or other germs attack the body, the immune system defends you. It “sees” and kills the germs that might hurt you. This is called an immune response.
Here’s how an immune response works:
- The immune system sounds the alarm, so your body knows there’s an infection.
- Antibodies are released to fight the germ. (Think of antibodies as soldiers designed to fight off the specific germ. This process can take a few days.)
- The antibodies work to attack, weaken, and destroy the germ.
- Afterward, the immune system remembers the germ. If the germ invades again, your body recognizes it and quickly sends out the right antibodies, so you don’t get sick!
- This protection against a certain disease is called immunity. In many cases, immunity lasts your entire life.
But when the system doesn’t work right, immune cells can mistake the body’s cells as invaders and attack. This is called autoimmunity. The part of the immune system that orchestrates all of this is the acquired immune system. It remembers foreign antigens, so it can fight them if they come back.
Yet these two immune systems do not work independently of each other. They complement each other in any reaction to a germ or harmful substance and are closely connected with each other.
“A person with a depressed immune system under constant, low-grade attack tends to have more chronic degenerative diseases,” said Dr. Sunil Pai, a Deacon of the House of Sanjevani Integrative Medicine Health and Lifestyle Center in Albuquerque, New Mexico. “Over long periods of time, that can lead to cancer.”
While the immune system protects the body against illness and infection, it is crucial to cancer patients (and a bit of a Catch-22) because cancer and cancer treatments can weaken the immune system, which is key to fighting cancer.
Our bone marrow produces blood cells, called red blood cells, platelets, and white blood cells. If cancer cells spread into bone marrow it will weaken the immune system (most often in leukemia or lymphoma) by stopping the bone marrow from making necessary blood cells, especially white blood cells.
Also, conventional cancer treatments – chemotherapy, radiation, targeted cancer drugs, and high doses of steroids – are more likely to weaken the immune system.
Neutrophils are the most abundant type of white blood cells and are an essential part of the innate immune system. Chemo and targeted cancer drugs, as well as some radiation treatments, can lower the neutrophil count in the blood. (This makes you more susceptible to infections after conventional cancer treatments.)
Immunotherapy For Treating Cancer
Cancer immunotherapy includes treatments that harness and enhance the immune system to fight cancer. Literally, hundreds of clinical trials involving immunotherapy, alone or combined with other treatments, are underway for nearly every type of cancer.
Researchers are focused on two types of immunotherapy:
- In T-cell therapy, some T cells are removed from a patient’s blood. Then, the cells are changed in a laboratory, so they have specific proteins called receptors. The receptors allow those T cells to recognize the cancer cells.The changed T cells are grown in large numbers in the lab and returned to the patient’s body, where they seek and destroy cancer cells.
- Checkpoint inhibitors are designed to release the brakes on the immune system, so it can destroy cancer cells. PD-1/PD-L1 and CTLA-4 pathways are key to the immune system’s ability to control cancer growth. These pathways are called immune checkpoints. Many cancers use these pathways to escape the immune system.
The immune system responds to cancer by blocking the pathways with specific antibodies – immune checkpoint inhibitors. Once the immune system is able to find and respond to cancer, it can stop or slow growth. Examples of FDA-approved immune checkpoint inhibitors include Ipilimumab (Yervoy), Nivolumab (Opdivo), Pembrolizumab (Keytruda), Atezolizumab (Tecentriq), Avelumab (Bavencio), and Durvalumab (Imfinzi).
“For the longest time, people did not believe this was possible,” said Dr. Lawrence Fong, associate professor of medicine at the University of California-San Francisco and one of the university’s lead investigators in the expanding use of immunotherapy.
“Now we can treat cancer by treating the patient instead of the disease,” he said. “That’s the biggest change. We can treat cancer without delivering chemotherapy or radiation to kill cancer or performing surgery to get rid of the tumor.”
However, there are potential side-effects with checkpoint inhibitors. Each manufacturer lists the side-effects for its drug, including intestinal problems (colitis) that can cause perforations in the intestines; liver problems (hepatitis) that can lead to liver failure; nerve problems that can lead to paralysis; lung problems (pneumonitis); and hormone gland problems (especially the pituitary, adrenal, and thyroid glands).
As with any medical decision, patients are encouraged to have a frank discussion with their oncologist. A second opinion is not out of the question. There are conventional, integrative, and natural options. You should explore all modalities before deciding on a cancer treatment.