New research shows innovative light therapy might help more effectively treat brain cancer while improving the body’s immunity.
A new study reveals that a cutting-edge light-generated therapy could help detect and treat an aggressive type of brain cancer that is almost always deadly if left untreated. An approach known as ‘photoimmunotherapy’ combines a fluorescent dye with a cancer-targeting compound, which improves the body’s immune response.
The study, conducted by an international team of researchers from the The Institute of Cancer Research and the Medical University of Silesia, used laboratory mice and discovered that the compound improves the visibility of cancer cells during surgery. This could ultimately help surgeons to remove cancers like glioblastoma entirely and with greater success while boosting immunity post-surgery.
Glioblastoma multiforme (GBM) is one of the most common and aggressive types of brain cancer, accounting for “47.7% of all cases” of this type of cancer. “Glioblastoma has an incidence of 3.21 per 100,000 population,” according to the American Association of Neurological Surgeons (AANS). “Median age of diagnosis is 64 years, and it is more common in men as compared to women,” the AANS reports. Survival rates are on the very low end.
There are many factors associated with the risk of developing glioblastoma risk including previous “therapeutic radiation, decreased susceptibility to allergy and impaired immune response,” the AANS warns. There are also hereditary factors that cause some individuals to be more susceptible to developing this type of cancer than others.
Surgeons tend to use a technique called Fluorescence Guided Surgery to treat GBM and other forms of brain cancer, which uses dyes to locate the tumor mass to be removed. However, because these tumors tend to grow in sensitive areas of the brain, residual cells can be very hard to treat without devastating post-surgical effects, including the loss of motor and/or cognitive function. Leaving behind residual cells means the cancer can return.
“The new research builds on Fluorescence Guided Surgery using a novel technique called photoimmunotherapy (PIT),” the team noted, “which utilizes synthetic molecules called ‘affibodies’ – small proteins engineered in the lab to bind with a specific target with high precision.”
The team “combined an ‘affibody’ created to recognize a protein called EGFR, which is mutated in many cases of glioblastoma, with a fluorescent molecule called IR700, which is used in surgery,” the paper indicates. “Shining light on these compounds causes the fluorescent dye to glow, highlighting microscopic regions of tumors left in the brain, while switching to near-infrared light triggers anti-tumor activity that kills tumor cells.”
They concluded, “Shining near-infrared light on the tumor cells activated the anti-tumor effect of the compound, killing cancer cells: scans of mice treated with the compound showed distinct signs of tumor cell death compared with untreated mice.”
A previous study, conducted in 2016, and presented at the American Association for Cancer Research (AACR) annual meeting in New Orleans, showed that near-infrared photoimmunotherapy (NIR-PIT) “could unleash immune activity against tumors in mice by depleting the tumor microenvironment of certain immune cells that act to restrain the immune response against tumors,” according to its authors.
In the current study, photoimmunotherapy also proved to trigger “immune responses in the body that could prime the immune system to target cancer cells, so the treatment could help prevent glioblastoma cells from coming back after surgery,” the authors reported.