When someone has stage IV lung cancer, he or she cannot be treated by surgery and removal of the cancerous part of the lung. The option of treatment for such patients is various types of medications that work by reaching the cancerous area by flowing through the blood. Types of medications used are as follows:
Targeted Therapy or Tablet Therapy
The part of the lung that develops cancer is due to the cells in that part undergoing certain mutation which unleashes chemical reactions in the cells that signal them to start multiplying rapidly in an uncontrolled manner.
Several types of such mutations have been recognised. The biopsy specimen that led to the diagnosis of cancer is analysed further for these mutations and takes additional time. Some of the mutations that have been identified and which are targetable by the medications are as follows:
For instance, if there is an EGFR mutation, it means that cancer cells are carrying out cell division at an excessive rate. You may then be given tyrosine kinase inhibitors, targeted therapy drugs that send signals to the cells to stop that growth. Medications are approved by the U.S. Food and Drug Administration (FDA) for several other abnormalities, including ALK, ROS-1, NTRK, MET, RET, and BRAF V600E.
These drugs stop the cancer cells from multiplying. These medications tend to have fewer side effects than chemo and will not kill healthy cells. The introduction of targeted therapy medications over the past decade has given patients new opportunities to stop lung cancer from advancing while improving survival rates and quality of life.
The targeted therapy drugs Tagrisso (osimertinib), Tareva (erlotinib), and Iressa (gefitinib) are known as tyrosine kinase inhibitors because they prevent the EGFR protein on mutated cells from triggering tyrosine kinase, an enzyme within cells that activates cell division and, thus, multiplies cancer cells.10 Tagrisso is now recommended as a first line treatment for EGFR mutations because it’s best able to penetrate into the cerebrospinal fluid and help fight lung cancer which has spread to the brain.
The most common side effect of tyrosine kinase inhibitors is a skin rash. Less frequently, diarrhea may also occur. The rashes from tyrosine kinase inhibitors resemble acne, occurring on the face, upper chest, and back. If no whiteheads are present, a topical corticosteroid cream is used. If whiteheads are present and the rash looks infected, oral antibiotics are prescribed. In some cases, the tyrosine kinase inhibitor dose may be reduced.14
Resistance to Treatment
Unfortunately, though lung cancers may respond very well to targeted therapy medications at first, they almost always become resistant over time. When this happens, doctors look to other targeted therapy drugs or new approaches to treatment, which may include combining treatments.
The length of time it takes for targeted therapy resistance to develop varies, but nine to 13 months is common; although, for some people, medications can continue to be effective for many years.15 If there are signs that the cancer is starting to grow again or spread, your doctor will order a repeat biopsy and additional genetic testing to determine if there are further mutations or drug resistance.
Historically, chemotherapy was the main option available to advanced lung cancer patients. These medications kill cancer cells, but they also have difficult-to-manage side effects that not all people are able to tolerate.
With new chemotherapy drugs, side effects are less severe, and there is the benefit of long survival with treatment. If genetic testing shows no treatable genomic alterations, chemotherapy will likely be recommended, often along with immunotherapy. Some of the drugs that are used are cisplatin, and etoposide.
Immunotherapy is another newer type of treatment for lung cancer that stimulates your own immune system to recognize and fight cancer cells.7 Immune system checkpoints are natural proteins of the immune system that prevent the destruction of healthy, normal cells.
Cancer cells may differ from a person’s healthy cells in ways that trigger the T-cells of the immune system to recognize and destroy them before they can cause problems.
But when cancer cells bind to and inactivate immune system checkpoint proteins, the body’s immune system may ignore them, allowing the cancer to grow and spread. Immunotherapy drugs block certain immune system checkpoints so the body will recognize the cancer cells as abnormal and launch an attack on them. There are a variety of immune checkpoint inhibitors, some of which are used for treating NSCLC.
People who have tumors that are PD-L1 positive and/or have a high number of mutations (called a high tumor mutational burden) may respond best to these medications. Those who have genomic alterations, such as EGFR mutations, tend not to respond as well. While they don’t work for everyone, some people with advanced non-small cell lung cancer have experienced long-term control of their disease with these drugs.
Several immunotherapies are approved for treating NSCLC. Opdivo (nivolumab), Keytruda (pembrolizumab), Tecentriq (atezolizumab), and Durvalumab (Imfinzi) interfere with PD-1 action; Yervoy (ipilimumab) interacts with the CTLA-4 receptor, another immune protein. All of these drugs are given as intravenous (IV, through the vein) infusions approximately every two to three weeks.
Radiation therapy delivers high doses of radiation directly to a tumor to kill it. This won’t stop aggressive stage 4 non-small cell lung cancer that has spread, but it may be recommended as palliative therapy.
This can be helpful for some people to control symptoms of brain metastases, bone pain, bleeding from the lungs, or difficulty breathing caused by tumors that are obstructing the airways.