Is Immunotherapy Effective For Prostate Cancer?

The prevalence of prostate cancer has significantly rose over the past few decades in the United States. The conventional approach to treat prostate cancer is usually radiotherapy, chemotherapy, surgery or at times a combination of these interventions.

New researches have suggested that there is yet another option to combat prostate cancer, which is immunotherapy. Immunotherapy targets the immune system and makes it stronger and capable of fighting against cancerous cells. Immunotherapy does impose certain risks that are often linked to the medications used. Immunotherapy drugs involves a wide range of medications that include monoclonal antibodies and several vaccines to fight off the cancer.

How Is Immunotherapy Used For Prostate Cancer Management?

Immunotherapy can be used via two ways:

• Individualized medicine: In this approach, the patient’s immune cells are removed front h body and are then genetically modified so they become destructive against cancerous cells. Once modified, these fighter cells are then placed back in the body where they further divide and form more cancer-fighting-cells and combat against the prostate cancer.
• Medications that block the certain aspect of cancerous cells: In this approach, the patient is administered specific drugs that retard the ability of cancer cells to suppress the immune system. The cancer cells do that in order to weaken the immunity so the system does not fight against them.

Side Effects And Risks Associated With Immunotherapy

The long-term ramifications of immunotherapy are not extensively known as it is a latest treatment option for prostate cancer treatment and still requires a lot of research. However, the available research work suggests that it can impose an evident risk on the overactive immunity. The medications used in the treatment can lead to hyper-activation of immune system which caneven trigger autoimmune responses i.e. the immune cells may begin to attack the healthy cells and tissues along with attacking the cancerous cells. This hyperactivity of immune system may target other organs along with the prostate gland such as kidneys, lungs, liver and intestine. The medications used in immunotherapy can also cause tissue inflammation that may be quite detrimental for the patients.

Is Immunotherapy Approved By FDA?

According to FDA Sipuleucel-T, available as Provenge, can be given as a drug of choice when offering immunotherapy to patients having prostate cancer. Provenge is administered via intravenous route after every two weeks for a period of six weeks. Based on classification, Provenge is actually a vaccine and its administration is specific for every man.

The process involves isolation of WBCs (white blood cells) present in the blood sample of the patient. These cells are then trained using certain chemicals in the lab, in order to make them aggressive against the cancerous cells. This is done through exposing the isolated cells to PAP (prostatic acid phosphatase) which is a protein, made by cancer cells. This assists the exposed cells to become capable of killing the cancerous cells. Followed by this the drug and these aggressive cells are infused into the body on the desired day. American Cancer Society says that immunotherapy obviously doesn’t cure cancer but it assists in improving the quality of life and extends the survival period up to several months.

Given below are the general side effects of the treatment which often subside on their own within 3 days of the infusion:

• Chills
• Nausea
• Muscle aches
• Fever

Is Immunotherapy Effective Against All Prostate Cancers?

Provenge is effective in treating prostate cancer that:

• Has metastasized to other organs
• Has become irresponsive to other therapies like hormone therapy
• Is not associated with exacerbating pain.

Such prostate cancers are often referred to as:

• AI prostate cancer (androgen independent)
• mCRPC (metastatic castrate resistant prostate cancer)
• Hormone refractory, asymptomatic and metastatic cancer

Immunotherapy is still under investigation therefore it is not known which types of prostate cancers are more likely to be treated by it. However, it is a very costly treatment option that often troubles the patients.

References

• Lu, X., Horner, J. W., Paul, E., Shang, X., Troncoso, P., Deng, P., ... & Zebala, J. A. (2017). Effective combinatorial immunotherapy for castration-resistant prostate cancer. Nature, 543(7647), 728-732.
• Kwon, E. D., Drake, C. G., Scher, H. I., Fizazi, K., Bossi, A., Van den Eertwegh, A. J., ... & Ng, S. (2014). Ipilimumab versus placebo after radiotherapy in patients with metastatic castration-resistant prostate cancer that had progressed after docetaxel chemotherapy (CA184-043): a multicentre, randomised, double-blind, phase 3 trial. The lancet oncology, 15(7), 700-712.