Immunotherapy and chemotherapy are two of the most frequently talked about cancer treatment options. While both have their uses, they are very different in their work. Knowing the difference between these treatments can help you understand which option might be best for you.
Understanding Chemotherapy and Immunotherapy
Chemotherapy is one of the oldest cancer treatments. It uses medications to kill cancer cells or prevent them from developing. However, chemotherapy does not only target cancer cells; it can also impact healthy cells, resulting in adverse effects.
It is usually given through injections, oral pills, or an IV. The drugs travel throughout the body and attack cells that divide quickly, which includes cancer cells. However, healthy cells in areas like the digestive system and hair follicles also divide quickly and can be harmed by chemotherapy.
Immunotherapy, on the other hand, is a more recent treatment that aids the body’s immune system in combating cancer. Unlike chemotherapy, which directly targets cancer cells, immunotherapy strengthens the immune system, allowing it to detect and eliminate cancer cells.
There are various types of immunotherapy, including monoclonal antibodies, checkpoint inhibitors, and cancer vaccines. These treatments help the immune system recognize and target cancer cells more effectively, and they are becoming more common for treating cancers that are harder to treat with chemotherapy.
Key Differences Between Immunotherapy and Chemotherapy
Though known approaches to cancer treatment, immunotherapy is not the same as chemotherapy, each with its methods and effects. Here are the key differences between them.
Mechanism of Action
Chemotherapy targets all quickly dividing cells, both cancerous and healthy.
Immunotherapy strengthens the immune system, allowing it to selectively detect and fight cancer cells.
Duration of Action
Chemotherapy effects last only while the drugs are active in the body.
Immunotherapy can trigger an immune response that continues even after the treatment ends.
Target Specificity
Chemotherapy affects both cancer cells and healthy fast-growing cells.
Immunotherapy primarily targets cancer cells while sparing most healthy cells.
Effectiveness
The effectiveness of immunotherapy and chemotherapy varies according to the type of cancer, stage, and the patient’s overall health.
Chemotherapy is often the first treatment for many aggressive cancers because it can quickly reduce tumor size and ease symptoms. However, some tumors may become resistant over time, reducing the effectiveness of chemotherapy.
Immunotherapy has shown positive results in treating cancers that don’t respond well to chemotherapy, like melanoma and certain types of lung cancer. Some patients who didn’t succeed with traditional chemotherapy have experienced lasting improvements with immunotherapy, as shown in clinical trials.
Side Effects
One of the main differences between immunotherapy and chemotherapy side effects is how each treatment impacts the body. Chemotherapy has several adverse effects since it damages both malignant and healthy cells.
Chemotherapy Side Effects
- Can cause hair loss by damaging hair follicles.
- Chemotherapy often causes nausea and vomiting.
- Can make you feel extremely tired because it affects the bone marrow and blood cells.
- Since chemotherapy weakens the immune system, it increases the risk of infections.
- The drugs can cause sores in the mouth or throat, making it painful to eat and drink.
Immunotherapy Side Effects
While immunotherapy generally has fewer side effects, it can still cause problems. Since immunotherapy boosts the immune system, sometimes it can make the immune system attack healthy tissues.
Common side effects of immunotherapy include:
- Many patients experience skin rashes or other skin reactions due to immunotherapy.
- Like chemotherapy, immunotherapy can cause fatigue, but it is usually less intense.
- Gastrointestinal issues, such as diarrhea or inflammation of the digestive system, can occur with immunotherapy.
- Immunotherapy may create hormonal imbalances, which might lead to thyroid or adrenal gland disorders.
- Inflammation can occur in organs like the lungs or liver as a result of immunotherapy.
Cost
The cost of chemotherapy and immunotherapy can vary depending on factors like the type of cancer, how long treatment lasts, and how advanced the cancer is.
A 2020 study in the Journal of Clinical Oncology compared the cost of immunotherapy (specifically checkpoint inhibitors) and chemotherapy for lung cancer patients. The study found that in 20215, immunotherapy averaged $228,504, while chemotherapy cost about $140,970. In 2016, the cost of immunotherapy was $202,202, and chemotherapy cost $147,801.
Combining Therapies
In some cases, doctors may suggest using both chemotherapy and immunotherapy together for the best results. This combination can be effective since each medication enhances the effects of the other.
- Chemotherapy can shrink tumors, making them easier for immunotherapy to target.
- Immunotherapy can help keep cancer from coming back after chemotherapy has reduced the tumor size.
The Synergy Between Chemotherapy and Immunotherapy
Both treatments have their strengths and drawbacks, and knowing these differences helps patients make better choices about their cancer care. As research advances, new therapies may improve treatment options. In short, while chemotherapy is effective for quickly shrinking tumors, immunotherapy offers the potential for long-term control by boosting the body’s immune system. The future of cancer treatment may involve mixing both medicines based on each patient’s specific needs.