The abscopal effect is a rare phenomenon in which shrinking a tumor in one part of your body also shrinks untreated tumors elsewhere in your body. Using immunotherapy with radiation may increase the chances of this effect.
The abscopal effect is a rare phenomenon that occurs when doctors use radiation therapy to shrink a tumor in one part of your body, and it also ends up shrinking untreated tumors in other parts of your body.
Experts think the abscopal effect occurs when radiation stimulates your body’s immune system to fight cancer present everywhere in your body. But, they are yet to understand the exact process.
Researchers have documented the effect in cancers like melanoma, breast, lung, and liver cancers. But it’s rare, so
The abscopal effect occurs after the use of radiation therapy to treat tumors in your body. Researchers don’t yet fully understand how the abscopal effect works. Experts think your body’s immune system plays an important role.
Doctors have used radiation therapy to treat cancer since the 1890s.
Radiation kills cancer cells by damaging their DNA. This DNA damage may trigger the abscopal effect. In response to the damage from radiation, the tumor cells may release substances that your body’s immune system sees as a potential threat.
The immune system fights cancer cells not only at the site of the radiation but also elsewhere in the body. In other words, the irradiated tumor acts like a vaccine.
Doctors have observed the abscopal effect across a variety of cancers,
- skin cancer (melanoma)
- breast
- lung
- liver
- kidney
- lymphoma
Many
- the volume of tissue that receives radiation
- radiation dose
- fractionation (a process of dividing the radiation dose into multiple smaller doses)
- use and timing of treatments in combination with radiation therapy
The abscopal effect isn’t a reliable cancer treatment. Researchers currently can’t predict if and when it will happen.
Experts think combining radiation therapy with immunotherapy may increase the chances of experiencing the abscopal effect, but this approach still doesn’t always reliably produce it.
Scientists want to learn ways to optimize strategies to help make the abscopal effect a more reliable treatment option. Research is ongoing to understand which doses and methods of delivering radiation in combination with immunotherapy are most likely to trigger an abscopal effect.
How rare is the abscopal effect?
The abscopal effect is a very rare phenomenon observed in people with metastatic cancer. This occurs during the radiation therapy. New research suggests that combining radiotherapy with newer immunotherapies may increase the likelihood of having an abscopal response.
A 2019 systemic review found that 94 people reported the occurence of abscopal effect between 1969 and 2018. Of those, 47 received treatment with radiation only. The remaining 47 people received a combination of radiation and immunotherapy (all after 2012).
What’s the difference between the bystander effect and the abscopal effect?
The main difference between the bystander effect and the abscopal effect is the distance between the area receiving radiation and the affected cells.
The bystander effect affects unirradiated cells located close by (neighboring cells). The abscopal effect occurs in cells located much further away from the radiation field.
For this reason, you
What is the reverse abscopal effect?
Experts think a reverse abscopal effect may occur when a tumor that doesn’t respond to immunotherapy (cold tumor) changes the immune responses of a tumor that typically does respond to immunotherapy (hot tumor). This makes the tumor resistant to the effects of the treatment.
The abscopal effect is a fascinating and rare phenomenon in cancer treatment. In recent years, the emergence of new immunotherapies has rekindled interest in the abscopal effect. Research suggests that immunotherapy may increase the chances of experiencing the abscopal effect during radiation treatment.
Clinical trials are underway to test the combination of immunotherapy and radiation for treating cancer. But no large clinical trial has provided enough evidence to reproduce the abscopal effect reliably.