Chemotherapy, Radiation Therapy and Immunotherapy

With the severity of many cancer cases, the treatment of cancer is regarded as a very sensitive area. Strict regulations surround the research and delivery of treatment, there are specific protocols used by doctors in diagnosis, and long established doctrine often governs which treatment option is used. Because of these factors, a few cornerstone treatments have surfaced over the years, which still make up the majority of treatments. The two options used most often, aside from surgery for early-stage tumors, are chemotherapy and radiation therapy. Today, we take a look at each therapy method and compare them to immunotherapy.


First used during World War II, during studies on mustard gas, chemotherapy has been around since the 1940s and in public use since the 1950s. Chemotherapy is a bit of a blanket term, as it literally means “drug treatment.” However, in recent years, chemotherapy has come to denote cytotoxic drugs: substances that kill, shrink or otherwise hinder cancer cells.

Cytotoxic drugs come in many forms: there are currently over 100 different chemotherapy drugs in use today. Some attack genetic material, some slow the spread (or metastasis) of cancer, and others block the absorption of nutrients or cell division. The aim of treatment with chemo is dependent on the type of cancer and the stage it is found in. Goals can range from total remission of the cancer to slowing cancer spread or simply to alleviate symptoms (palliative care).  Treatments often use combination therapy: using multiple drugs at once, to get multiple results (such as several of those listed above).



Radiation therapy uses x-rays, gamma rays and other types of radiation, in order to attempt to shrink tumors and destroy cancer cells. The radiation kills cells, through damaging their genetic structure in several different ways. Radiation can be delivered through mechanical delivery systems or it can be injected or otherwise placed inside of the body.

While radiation is part of our every day lives, radiation therapy bombards the body with a very high dosage. Similar to chemotherapy, it can be administered on its own or in a combination therapy: oftentimes alongside chemotherapy. However, radiation therapy is generally much more location specific; that is to say that, while chemotherapy treats the whole body, radiation is used on a more targeted area. The range of uses is also similar to chemo, as it can be used with the intention of destroying the cancer, slowing it down or being used to lessen symptoms of the disease.


Cancer Treatments, Immunotherapy, Surgery, Radiation, Drugs, Chemo
There are several dominant types of treatment, depending on the condition of the cancer and the patient. (Source: VCA Hospitals)


Comparison with Immunotherapy

Chemotherapy, radiation therapy and immunotherapy for the treatment of cancer all have similar and differing properties. As stated in a recent blog post, OncoSec sees a lot of potential in immunotherapy, including the possibility of higher effectiveness with lower side effects. While radiation can be more targeted than the blanket approach of chemotherapy, it can still damage surrounding cellular tissue, as it lacks the ability to differentiate between healthy and cancerous tissue. The known side effects of both chemo and radiation can be very abrasive and can also create long-term health risks, especially if used for childhood cancers.

It should be noted that, while immunotherapy techniques have shown very few side effects (and less serious ones) during clinical trials, it has not existed long enough to study the long-term effects. One way of decreasing the side effects of radiation and chemotherapy as well as boosting the effectiveness of treatment could be combination therapies with immunotherapy techniques. The effects of such treatment regiments could illicit a number of different outcomes, depending on the drugs and dosages used. We are currently testing ImmunoPulse alongside several drug therapies, with Old Dominion University.

We look forward to further study in immunotherapy, in order to hopefully deliver more effective therapy for cancer patients, while reducing the damage to the human body. There is a wealth of opportunity in combination therapies, as well. If you would like to stay up to date on developments at OncoSec, please join our online community on Facebook and Twitter.