What Targeted Therapies Do
Targeted lung cancer therapies are drugs designed to attack cancer cells that have specific genetic changes or mutations. These drugs work like a lock and key, where the drug is the key that fits only cancer cells with a particular mutation. Common targets in lung cancer include EGFR mutations, ALK rearrangements, and PD-L1 proteins. Once the drug finds and attaches to its target, it either blocks the cancer cell's growth signals or kills the cell directly.
What Traditional Chemotherapy Does
Traditional chemotherapy uses powerful chemicals that damage the DNA of rapidly dividing cells. Because cancer cells divide much faster than most normal cells, chemotherapy kills more cancer cells than healthy cells. However, fast-growing normal cells like hair, bone marrow, and stomach lining cells are also damaged, which causes side effects. Chemotherapy works on many types of cancer and does not require genetic testing, making it widely available.
Side Effects and Quality of Life
Targeted therapies generally cause fewer and milder side effects than chemotherapy because they only affect cancer cells with the specific mutation. Patients may experience fatigue, skin rashes, or diarrhea. Chemotherapy typically causes more severe side effects including hair loss, severe nausea, vomiting, infections from low white blood cells, and anemia. These side effects can affect a patient's quality of life and ability to continue treatment.
Testing and Personalization
Before using targeted therapy, doctors must test the cancer cells to find which mutations are present. This genetic testing helps doctors match patients with the right targeted drug for their specific cancer. Not all lung cancers have targetable mutations, so not all patients can use targeted therapies. Chemotherapy does not require this testing and can be prescribed to any lung cancer patient.
Drug Resistance and Long-Term Effectiveness
Targeted therapies often work very well at first, but cancer cells can develop resistance by changing or losing the target mutation over time. When this happens, the drug stops working and doctors must switch to a different treatment. Chemotherapy can also face resistance, but through different mechanisms. Doctors sometimes combine targeted therapy with chemotherapy or other treatments to prevent or delay resistance.
Cost and Availability
Targeted therapy drugs are usually much more expensive than traditional chemotherapy because they are newer and require years of research. However, many insurance plans and patient assistance programs help cover these costs. The higher cost is often balanced by fewer side effects, fewer hospital visits, and potentially longer survival times for patients with matching mutations. 
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