Peter Wessel thought he was having a heart attack.
It was October 2020, and Wessel had just finished a steep climb on his mountain bike at the Buffalo Creek Recreation Area in Colorado’s Pike-San Isabel National Forest when he started feeling a tightness in his chest and experiencing pain when he took deep breaths.
“The friends I was mountain biking with drove me directly to the hospital,” says Wessel, an avid skier and mountain biker who lives in Denver. “I was admitted, and I spent a couple of days there. I got a lot of tests, and I ended up being diagnosed with pericarditis with effusion. Pericarditis is inflammation of the pericardium, the sac around the heart, and effusion means fluid. They discharged me after a couple of days, then I continued to get worse. I had pain. I had shortness of breath. I'd wake up in the morning in a pool of sweat.”
Wessel skiing after his treatment for metastatic sarcoma.
Further testing yielded no clear answers, but Wessel has a friend who is a radiation oncologist, and he pushed for Wessel to get a PET scan — an imaging test that reveals cancer inside the body. The results were alarming — Wessel had a large tumor inside his heart. The cancer was a sarcoma, a rare type of cancer that can form in various locations in the body, including the bones and the soft tissue that connects, supports, and surrounds other body structures.
“I had open-heart surgery in November 2020 to remove the tumor. The area in the heart that generates electrical signals was removed as well, so they had to give me a pacemaker,” says Wessel, who was 66 when he got the surgery. “So they get the tumor out of my heart, and then they say, ‘We’ve got one other problem now. This thing has metastasized. You've got tumors in your lungs, and you've got tumors on your adrenal gland.’”
That meant the cancer was stage IV, and Wessel was referred to an oncologist who told him there weren’t many options for treating his metastatic disease.
“She said, ‘None of the drugs that we would normally use are going to work here. It's not something you can surgically attack, and you’re not really a candidate for radiation therapy,’” he remembers her saying. “‘Your only option is to try to get into a clinical trial of immunotherapy drugs for sarcomas at CU Anschutz.’”
That trial — which was for patients like Wessel who had metastatic sarcomas that had not yet been treated or had only been treated with one line of chemotherapy — was led by Breelyn Wilky, MD, deputy associate director of clinical research at the University of Colorado Anschutz Cancer Center. Wilky was looking at using a new combination of drugs to more effectively treat metastatic soft-tissue sarcomas.
“The standard chemotherapy for metastatic soft tissue sarcomas is a chemotherapy drug called doxorubicin,” says Wilky, associate professor of medical oncology in the CU Anschutz School of Medicine. “One of the interesting things about chemotherapy, especially doxorubicin, is that while people think of chemo as suppressing the immune system, there's actually data that shows that when you first treat someone with doxorubicin, it acts as a danger signal to the immune system. The cancer cells, when they're treated, unleash these chemicals that look very similar to being infected by a virus.”
That danger signal triggers the immune system to attack the cancer cells, a process Wilky theorized would be augmented by adding immunotherapy drugs called checkpoint inhibitors to the doxorubicin. Checkpoint inhibitors work by removing the “brakes” that keep immune cells from attacking healthy tissue — a process that is often hijacked by cancer cells so they can continue to grow and spread.
“Immunotherapy aims to boost the immune response and keep the immune response going and get rid of those shut-off signals,” Wilky says. “The idea was, could we get better outcomes combining the chemo with checkpoint inhibitors and take advantage of that immune response early on?”
Funded in part by the Cancer League of Colorado, the clinical trial was an investigator-initiated trial, meaning it was a “homegrown” trial conceived and run by a cancer center investigator. It enrolled 61 patients overall, and Wessel was one of its most successful.
“There were two or three patients in the trial who had long-term benefit, and Peter was one of them,” Wilky says. “He had a lot of metastatic disease at the time he was enrolled, and now he has no evidence of any cancer remaining. He's close to five years from starting treatment, and he has no progression of his cancer, which is sort of unbelievable.”
Wessel, who began his treatments with Wilky in May 2021, counts himself lucky that a cancer researcher in the Denver metro area was conducting a study on sarcomas, and that he qualified.
“There aren't that many places in the United States where doctors are focused on doing sarcoma studies,” he says. “It would have been a totally different thing if I had had to fly to Boston or Texas or something like that in order to have treatments. This wasn't a sacrifice for me — it was really the only option I had. This was the Hail Mary.”
Wessel received eight treatments over the course of six months, and he was amazed to see observable benefit after the first infusion.
“The tumors immediately started to stabilize, or even shrink a little bit,” he says. “It seemed to have some effect right from the get-go. I continued the treatments until May of 2021, and I have been drug-free and cancer-free since then. I don't know whether there's going to be another phase, or whether the study is regarded as a success or failure, but it was a success for me.”
Wilky says the trial was a success for some patients but not all. She and her research team are now working to better identify the patients who will benefit from the drug combination and looking to see if changing the order in which the drugs are given has any effect on patient outcomes.
Whether or not there is a clinical trial for their specific situation, Wilky urges people diagnosed with sarcomas to come to centers like the CU Anschutz Cancer Center that offer a variety of treatment options and are accustomed to treating patients with this rare cancer.
“It's so important for patients who have sarcomas to get evaluated at a high-volume sarcoma center,” she says. “If you were to go online and look up cardiac angiosarcoma outcomes, it looks like a death sentence, but that's not true. There are patients who can be cured of their cancer with either chemotherapy or some of these newer agents.”
Wilky says that seeing Wessel’s reaction to the experimental treatment, and the way he approached the clinical trial, motivates her to keep the research going.
“He was a superstar,” she says. “This is a guy who never let the side effects or the complications get him down. He had an incredibly positive attitude. One of the most incredible things is to walk into a room with a patient who's on a study like this, where it was based on an idea that you had, and to see that patient actually getting benefit. To pull the scans up and go through them with Peter, that was the coolest thing that I've gotten to do in oncology. That's the whole reason we do clinical research.”