Introduction:
Lung cancer has the greatest death rate out of all cancers. In 2012, lung cancer accounted for 1.8 million cases worldwide. About 162,510 people died from lung cancer in the United States alone in 2016. Male to female ratio is 2:1, and men 60 years of age and older are the majority of cases diagnosed. Environmental factors, including the presence of lead, radon, and other harmful chemicals in the air, are thought to be the primary cause of the development of lung cancer. It is also observed that the number of lung cancer cases recorded is rising in direct proportion to the incidence of smoking, especially in developing countries.
Lung cancer is classified into two primary groups based on its morphological forms: small-cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). There are three subtypes of non-small cell lung cancer (NSCLC): adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. In the majority of nations worldwide, adenocarcinoma is more common than squamous cell carcinoma. Lung cancer is one of the most common and deadly cancers globally, presenting serious challenges to both patients and medical professionals. However, recent advancements in treatment have completely changed the treatment approach, especially with the introduction of immunotherapy and target therapies.
What Is Immunotherapy?
Immunotherapy medications activate or prepare the immune system to combat cancerous cells. A few therapies based on this strategy are being investigated or utilized to treat lung malignancies. These include cancer vaccines, immune checkpoint inhibitors, and chimeric antigen receptor (CAR) T-cell treatment.
1. Cancer Vaccines: Cancer vaccinations are therapies that prepare the body's immune system to identify and combat cancer. These vaccines show the body's cancer-related substances and proteins, which the immune system recognizes and destroys. Clinical trials are currently being conducted to investigate potential lung cancer vaccinations.
2. Immune Checkpoint Inhibitors: A molecule on immune cells known as an immune checkpoint has the ability to start or stop an immune response. These chemicals assist the immune system in identifying which things are normal and which need to be attacked. Occasionally, cancer cells use these checkpoints to trick the immune system and prevent the body from fighting them. Immunotherapy medications (checkpoint inhibitors) help stimulate a reaction against cancer cells and can stop the immune system from being misled.
3. Chimeric Antigen Receptor (Car) T-Cell Treatment: T-cells, a type of white blood cells in the immune system, are extracted from the body and modified in a lab to improve their ability to target particular cancer cells as a part of this therapy. The body is reinfused with the improved T cells to aid the fight against cancer. Plasmapheresis is a procedure that helps filter blood to identify certain types of blood cells. This can be also done by removing a portion of the tumor and isolating t cells from the surrounding tissue. Currently, this kind of therapy is being investigated in clinical trials.
What Are Targeted Therapies?
Unwanted side effects can result from lung cancer treatments that destroy cancer cells but also damage healthy cells. Targeted therapies, a class of new lung cancer medications, assist in minimizing harm to healthy cells. They target cancer cells by preventing their growth and function. Targeted therapy is frequently talked about for patients whose tumors have specific anomalies that can be identified by biomarker testing. Biomarker testing searches for alterations such as DNA rearrangements, insertions, deletions, or mutations in the DNA of the tumor. Targeted therapies can "target" these changes directly. They concentrate on addressing the specific issue with the cancer cell rather than killing healthy cells, and these lung cancer treatments frequently have fewer adverse effects.
1. Angiogenesis Inhibitors: Tumors require the formation of new blood vessels to sustain their growth, and this process is called angiogenesis. Angiogenesis inhibitors aid in preventing the growth of new blood vessels. These inhibitors, known as VEGF inhibitors, are usually monoclonal antibodies (lab-made variants of a particular immune system protein) that specifically target vascular endothelial growth factor (VEGF). This protein helps form new blood vessels for example, Bevacizumab and Ramucirumab.
2. KRAS Inhibitors: NSCLCs contain cancer cells with altered KRAS genes, which results in abnormal KRAS protein synthesis. This abnormal protein promotes cancer cell growth and metastasis. KRAS G12C mutations are a specific type of KRAS gene alteration that affects around 1 in 8 patients with NSCLC. KRAS inhibitors function by binding to the KRAS G12C protein, inhibiting cancer cell growth. Examples: Sotorasib, Adagrasib.
3. EGFR Inhibitors: A protein on the surface of cells called epidermal growth factor receptor (EGFR). Normally, it promotes cell division and growth. Sometimes, cancer cells have high EGFR protein, which helps them grow fast. The signal from EGFR that instructs cancer cells to proliferate can be blocked by drugs called EGFR inhibitors, for example, Osimertinib, Afatinib, and Amivantamab.
4. ALK Inhibitors: One in every 25 patients with NSCLC has a mutation in the anaplastic lymphoma kinase (ALK) gene. It produces defective ALK protein that can stimulate the growth of cancer cells. ALK inhibitors are medications that block the activity of this ALK protein—for example, Lorlatinib, Brigatinib, Alectinib, and Crizotinib.
5. BRAF Inhibitors: The BRAF protein aids in controlling cell growth. A mutation in the BRAF gene produces an abnormal protein that transmits signals that cause cancer and uncontrolled cell growth. BRAF inhibitors target this protein.
6. RET Inhibitors: NSCLCs have tumor cells that produce an abnormal form of the RET protein due to RET gene rearrangement. The abnormal protein promotes the growth of tumor cells. NSCLC with the RET rearrangement can be treated with medications called RET Inhibitors.
Conclusion:
Treatment for lung cancer is being revolutionized by immunotherapy and targeted medicines. Combining treatments and new targets are being investigated as research progresses to increase efficacy and overcome resistance. For those who are suffering from lung cancer, these developments provide a ray of hope, perhaps even extending their lives.
