Glowing Tumors That Could Improve Cancer Surgery Are Getting Closer To Reality
Emily Mullin, Contributor | Forbes Pharma & Health | January 22, 2016 | See Original Here
When a patient is diagnosed with a solid tumor cancer, one of the first options for treatment is often surgical removal of the tumor. But the biggest challenge for surgery as a treatment for cancer is determining, at a cellular level, the border between the tumor and healthy tissue surrounding it. As a result, sometimes surgeons aren’t able to remove the entire tumor and fragments of cancerous tissue may be left behind, or they accidentally remove some healthy tissue along with the cancerous mass.
But fluorescence detection for tumor removal could change that. Fluorescence detection involves using a type of dye that, when stimulated, emits light wavelengths close to infrared light. These light wavelengths can’t be seen by the naked eye and instead require the use of a special camera hooked up to a monitor that projects a sharper image from inside the body.
Here’s how it could work in a clinical setting: A breast cancer patient is connected to an IV that sends dye molecules into the bloodstream that travel to the site of the patient’ tumor or tumors. Then, the surgeon inserts a tiny camera into the patient’s chest so the tissue can be observed on a nearby monitor. The light that these optical probes emit can be picked up by a special camera that can see light that penetrates through skin and tissues. On the screen, the cancer cells glow a bright green color to help guide the surgeon to the tumor site.
At least, that’s how Matthew Bogyo, associate professor at Stanford University School of Medicine, imagines the future of cancer surgery. Bogyo writes about the progress of optical probes that use fluorescence in the Jan. 21 issue of Cell Chemical Biology, previously known as Chemistry & Biology.
“Fluorescence guidance would be useful for any kind of surgical procedure involving removal of a tumor mass. The idea is that with this technology the surgeon would be able to see what to remove and therefore get more of the tumor and less of the normal healthy tissue around the tumor,” Bogyo said in an interview.
Companies like LumiCell, Blaze, Cellectar, On Target and Aveles are working on such technology, and fluorescence-guided probes for ovarian cancer, skin cancer, breast cancer and sarcomas are already in Phase I and Phase II trials. In 2008, Bogyo helped found a company, Akrotome Imaging, to further develop some of his Stanford lab’s work into technology that could be used in the clinic. Bogyo believes tumor removal surgery using optical probes could be a common procedure in the next five to 10 years.
Bogyo said fluorescence detection for tumor removal could lead to increased surgery success rates, ideally reducing second and third surgeries that are required if residual tumor tissue is not removed during the initial surgery.
“Obviously, this would be more important if you are removing a brain tumor compared to a breast tumor but in all cases, getting more of the tumor and less of the normal tissues will result in better patient outcomes,” Bogyo said.
One of the major benefits to fewer surgeries for patients–and health insurers–is lower overall costs by cutting expenses associated with repeat surgery.
Currently, clinicians use several imaging methods to view tumors, including radiological, magnetic resonance (MR) and ultrasound. While these methods are integral in the early diagnosis and disease monitoring stages of cancer, they cannot be directly integrated into the operating room. Specifically, the bulky machinery makes their use during surgery difficult. On the other hand, fluorescence or optical contrast agents can be detected with a simple camera system that enable real-time monitoring of probe signals.
In the journal review, Bogyo said one of the major hurdles in translating these chemical tools from academic research laboratories to the clinic involves the regulation and approval process from the U.S. Food and Drug Administration. Currently, there is no defined pathway for approval of optical contrast agents needed for fluorescence-guided surgery. Clinical trial data will need to show that these contrast dyes are both safe and can effectively distinguish between cancerous and healthy tissue.
Another consideration for scientists working on these contrasting agents is whether fluorescent dyes will work for all types of tumors.
Fluorescence detection with non-targeted dye is already being used in surgery to help find blood vessels or detect whether tissue is receiving enough blood after a transplant. But over the past two decades, scientists have developed better chemical dyes that can bind to specific cancer cells, putting fluorescence-guided tumor removal closer to reality.