Early in her career as an oncologist, Dr. Celestia "Tia" Higano was frustrated by a lack of answers for her prostate cancer patients. Her desire to offer better options and odds for patients with advanced disease drove her to start a parallel career in research. Now, 20 years of significant studies have helped give patients answers and have made her a powerhouse in the field of prostate cancer.
Higano is a pioneer in testing therapeutic vaccines against prostate cancer, including a drug known as Provenge, whose FDA approval in 2010 made it the first approved therapeutic vaccine for any solid tumor cancer. Such vaccines are part of a growing field of cancer research called immunotherapy, which harnesses the natural power of the immune system to fight disease.
Traditional vaccines—like those received in childhood, such as mumps and measles—are designed to prevent disease. Therapeutic vaccinations treat illness. The goal is to provoke a stronger and faster response from the immune system to slow the progress of the disease.
Such vaccines are a long-sought holy grail for immunologists like Higano because they have the potential to radically change medical treatment. Until cures can be found, cancer vaccines may increase survival times, delay the spread of cancer, and help to maintain or improve the quality of life of patients, all with tolerable or no side effects.
Higano is excited about the potential of Provenge, which is intended for men with advanced prostate cancer who have stopped responding to hormone-blocking treatments and have few other treatment options. In recent studies conducted by Higano and other U.S. researchers, the vaccine lengthened survival for these men by an average of more than four months.
While not a cure, the increase in survival is double the benefit of the only approved treatment to date. Patients who took the vaccine and went on to receive chemotherapy survived even longer: an average of more than 34 months versus 25 months in patients receiving chemotherapy alone.
Higano, whose primary appointment is at the University of Washington School of Medicine, first saw the potential of harnessing the immune system in her early days of working with leukemia patients and bone marrow transplantation. "I was a convert about what immunotherapy could do and I was intrigued to bring that into solid tumor oncology," Higano said.
"If you asked most of us 10 years ago if we thought therapeutic vaccines would have a role in any solid tumor, we would have said probably not. We now have a better understanding of the immune system and we see how powerful it can be when you're trying to treat a tumor," said Higano, who sees patients though the Seattle Cancer Care Alliance, the Hutchinson Center's treatment arm.
Higano and her colleagues plan to study the novel vaccine in men with early stage prostate cancer who are at high risk of relapse. "They'll be getting the vaccine before surgery and then we'll be looking at their surgical tissue for evidence of immune reactions within the malignant prostate," she said. If that approach bears fruit, the vaccine could be used to prevent prostate cancer recurrence, much in the same way high-risk breast cancer patients are treated now.
Building strong relationships with patients and their families is one of the best parts of her role, Higano said.
"Because men with prostate cancer, even those with metastatic disease, often live for many years, I get to know a lot of them on a very personal level. I have a lot of patients I've seen for over 10 years," Higano said. "It's what makes me love what I do."