- Burnett School Cancer Division College of Medicine Faculty News
On a computer screen, the enemy is a misshapen neon-colored blob – a metastatic cell that’s spreading cancer to the lungs, brain and liver. Thanks to a donation from a Winter Park cancer patient’s family, UCF College of Medicine researchers now have machines that can isolate, photograph and count these cancer cells from a single tube of blood.
With the technology, scientists can see if the cancer cells are spreading from the original tumor and if new therapies are stopping the cells in their tracks.
The machines, called the CELLSEARCH System, have been FDA-approved since 2004 and remain the gold standard for isolating and counting individual circulating tumor cells in blood. The College of Medicine is only the second research entity in Florida with the machines. A gift from the Catherine McCaw-Engelman and Family Cancer Research Collaborative Fund made the purchase possible. The other CELLSEARCH system is at the Moffitt Cancer Center in Tampa.
Dr. Annette Khaled, who leads the College of Medicine’s cancer research division, recently began using the machines to test blood samples from 48 women with metastatic breast cancer who are being treated at Orlando Health’s UF Cancer Center. The first stage of Dr. Khaled’s research is to isolate and count the number of circulating tumor cells in the patient’s blood to evaluate the progress the cancer is making. The next step will be to study the makeup of the cells and how they respond to a new therapy Dr. Khaled has developed through funding from the Breast Cancer Research Foundation.
“There are thousands and thousands of cells in a drop of blood,” Dr. Khaled explained. “But before technology like the CELLSEARCH system, we couldn’t see these circulating tumor cells on their journey through the body. Now we can isolate individual circulating tumor cells and capture them as they go from Point A to Point B. Once we isolate these cells, it opens the door to more study.”
Physicians know that metastatic or spreading cancer cells are what cause death in most cancer patients because such cells invade key organs like the brain and lungs. They can appear even years after the original tumor has been removed through surgery or chemotherapy. Dr. Khaled’s specialty is breast cancer, and her goal is to find ways to destroy metastatic breast cancer cells, an effort that has earned her the nickname of “cancer assassin.”
In 2012 she discovered a peptide, called CT20 that kills metastatic cancer cells. The peptide disrupts chaperonin, a protein that prompts the folding mechanism inside cancer cells. If the inner workings of the cell can’t fold into 3D units, the cell dies.
Dr. Khaled’s previous studies have shown that the higher a patient’s levels of chaperonin, the sicker they are. One goal of the new CELLSEARCH technology is to document the levels of chaperonin in the circulating cancer cells before and after the peptide treatment.
Elizabeth (Beth) McCaw-McKinney’s family (shown above) said they were inspired to donate funds for the machine after their sister died of colon cancer in 2017. McCaw-McKinney was the family “rock,” the one who always ate healthfully and loved spin classes at the YMCA. She was the picture of health, they said, but was terrified to get a colonoscopy. She finally scheduled one but cancelled the day before the procedure. When McCaw-McKinney finally had a colonoscopy at age 52, doctors found Stage 4 colon cancer. They gave her three months to live. McCaw-McKinney lived three years.
Throughout her cancer battle, McCaw-McKinney urged everyone she knew and everyone she met to get a colon cancer screening.
“From the point she received her diagnosis, Beth was all about early detection,” said her sister, Catherine McCaw-Engelman. “We now have the technology to analyze cancer in that tube of blood. We couldn’t think of a better way to honor Beth and to give back.”
The technology is so advanced it can detect as few as two circulating tumor cells in 1 milliliter (1/5 of a teaspoon) of blood. Levels of five tumor cells in a sample are considered evidence of metastatic cancer. Detecting the number of circulating tumor cells in the blood can warn doctors that a patient’s cancer is spreading – before they have symptoms.
“What I want to do is get these guys,” Dr. Khaled said of the spreading cancer cells. “Thanks to this generous gift we are one step closer to stopping cancer.”