If you are a patient, and you were given a diagnosis of cancer, I would say the best case scenario is if you surgeon can tell you, your doctor can tell you, you know what, we found it early and we’ve cut it out. You don’t need any adjuvant therapy, you don’t need to have any radiation any chemotherapeutics. Narrator NIBIB grantee Quyen Nguyen is a head and neck surgeon with an active research lab at the University of California San Diego. In the lab, Nguyen seeks ways to improve surgical outcomes for cancer and other diseases.
We do cancer surgery, where it’s important to understand where is the tissue margins. Currently, we do our best and then we have to take little samples from the tissue that’s left behind in the patient, what we think is now free of cancer, but then we have to send it to the pathology lab and wait for them to tell us piece by piece whether there’s any residual cancer. Narrator Not only does this process increase the amount of time patients are on the operating table but it’s also only moderately effective.
In many cases, microscopic cancer cells are left behind, only to be found during a more extensive assessment of the tumor margins after the surgery has been completed. Wanting to improve these outcomes, Nguyen collaborated with Nobel Laureate in Chemistry Roger Tsien, also at UCSD, to develop a fluorescent molecule that causes cancer to glow during surgery making it easier for them to be removed. The molecule has a horseshoelike structure one arm has a positive charge that causes it to stick to all cells in the body. The other arm has a strong negative charge that neutralizes the molecule,.
Advances in Cancer Surgery Making Tumors Glow
Preventing the positive arm from sticking to a cell until the right time. Attached to the ends of the arms are two different fluorescent dyes that cancel each other out when in close proximity. When the molecule comes in contact with enzymes that are found specifically in tumors, the back of the molecule is cut, freeing the positive arm with its dye attached to it to enter the tumor cells Though so far only tested in animals, Nguyen hopes to begin clinical trials in 2015. Here’s how it would work. Prior to surgery, a solution of the horseshoe molecules can be injected into the blood.
And once the surgery has begun, cells that have taken up the molecule can be visualized. But tumors aren’t the only tissue worth illuminating. Nguyen is also developing a near infrared probe that labels nerve tissue, which can be difficult to identify during surgery. Nerves are really, really small. I think that’s one of the biggest difficulties in identifying them. They’re small and they are very often buried. They’re buried in soft tissue, they’re encased in bone. When we have to do cancer surgery, they could be encased in the cancer itself.
And there’s no trial and error in doing dissections for nerves. It’s not that you can take a little piece and see if it’s nerve, you know ask the pathologist to help you, you have to identify that during the time that you’re doing the surgery because that’s the best way to preserve function. Accidental nerve damage can leave patients with chronic pain, paralysis, urinary incontinence, or sexual dysfunction. Nugyen has recently begun testing her fluorescent nerve probe in animals. For facial nerve, if you have a paralyzed facial nerve, the entire face doesn’t move.