Photograph by Mark Harmel
Street Wise
Oscar Streeter, Jr. uses new technology to increase the success level of standard treatments for cancer.
by Phil Davis
A warm, intelligent, giant of a man, Oscar Streeter, Jr., M.D., channels a passion for medicine, mathematics, computers and physics into an all-out effort to improve the technology and techniques of treating cancer. And while his clinical research may not be as financially rewarding as private practice, the ultimate payoff is the occasional meeting with a patient who beat cancer.
"It's fantastic to see patients that you haven't seen in years because they are doing so well," Streeter smiles. "I recently saw one patient I hadn't seen in a few years. She had pancreatic cancer, with a life expectancy of eight months-so it was especially great to see her eight years out."
Streeter is an associate professor of medicine and chief of radiation oncology at the USC/Norris Comprehensive Cancer Center and Hospital. This summer, he began a lung cancer clinical trial that may ultimately allow cancer specialists to direct more powerful doses of radiation specifically at cancer cells-killing the cancer faster and minimizing damage to healthy, non-cancerous cells. It is called conformal radiotherapy-the medical equivalent of military cruise missiles that fly down streets and into air vents to wipe out military targets with minimal damage to the surrounding areas.
Standard radiation oncology treatment requires irradiation of both good and bad cells, a sort of shotgun approach to treatment. The radiation often kills the cancer, but can lead to side effects like shortness of breath, pneumonia and nausea in lung cancer patients. But by using imaging software called the RT Simulator (virtual patient simulator)-developed by Melvin Astrahan, Ph.D., USC associate professor of radiation oncology, with clinical help from Streeter-a computed tomography (CT) scan can be converted into a 3D internal image of a patient's body. Unlike other complex medical imaging software, the RT Simulator is simple enough to run on a home computer. Streeter often takes a laptop home so he can make it home to eat dinner with his family and still be able to plan an attack on a patient's tumor without returning to the office.
The software enables physicians and patients to visualize the tumor from all possible angles and "literally plan a trip through the lungs," Streeter says. "We can guide the radiation to difficult to reach areas of the body and deliver it with minimal exposure to normal tissue."
Streeter and Astrahan hope to eventually combine CT and PET scans into single images with the program-increasing their capability to target cancer cells, which will ultimately lead to more effective cancer treatment, Streeter says.
Better targeting also allows physicians to increase the dose of radiation and more effectively eradicate the cancer. Streeter, in partnership with Valerie Israel, D.O., assistant professor of medicine, backs up high doses of radiation with a combination of powerful anti-cancer drugs like cisplatin and navelbine. The combined one-two punch of drugs and radiation has proven lethal in clinical trials on lung cancer.
Recently, Streeter's first patient in the lung cancer trial completed an eight-week treatment cycle. The patient was treated with radiation levels about 10 percent higher than the traditional dose with excellent results.
"He's tolerating the higher doses of radiation," Streeter says. "His tumor is shrinking and he's doing well. In fact, he has done so well he says he is actually stronger than when we started."
That is significant progress. Most patients who undergo radiation treatment end up feeling weaker-an unavoidable side effect of exposure to radiation. Streeter intends to increase the threshold on the next series of patients to determine the most powerful and effective radiation levels to destroy cancer. In the future, Streeter and colleagues from City of Hope Medical Center and the University of California, Davis, plan to expand this work with high-dose conformal radiotherapy in a consortium trial.
The more patients who participate in the study, the sooner the findings become available to all physicians. "We have to work together to accomplish our goal-which is to cure cancer," Streeter says.
As if that pursuit were not consuming enough, Streeter also donates considerable time to local charities. He is chair of the National Black Leadership on Cancer for the greater Los Angeles area; on the advisory board of the Foothill Wellness Community; and a founding member of the Women of Color Breast Cancer Survivors Support Project.
As an African-American scientist, Streeter also is working with the Radiation Therapy Oncology Group to increase minority participation in clinical trials. Traditionally, minorities have been underrepresented in clinical trials-in part because of the Tuskegee syphilis experiments on African-American men. Between 1932 and 1972, a federal government study based in Tuskegee, Ala., charted the effects of untreated syphilis by withholding treatment from 399 African-American men who were unaware they were infected with the disease. An Associated Press reporter exposed the unethical experiment in 1972 and last year President Bill Clinton offered a belated formal apology to the families who suffered. But a legacy of distrust lingers.
Streeter is at the forefront of an effort to earn back that lost trust. Last year he co-chaired a summit on medical ethics and minorities in Tuskegee, sharing his conviction that participation in clinical trials is good for patients. He points to studies that show minorities generally have poorer cancer survival rates-unless they participate in clinical trials. Minorities in clinical trials have as good a chance as non-minorities of surviving the cancer, Streeter says. Also, by including people of all races in cancer research, scientists gain a better overall understanding of how the disease affects all people.
Because the health of patients in clinical trials must be closely monitored, they often get additional medical services-including physical exams and blood screenings-free of charge. Everyone in the trial gets the same care. Equal care, Streeter says, means equal results.
"Sometimes people confuse biological realities with social realities," Streeter says. "People need to understand that something like Tuskegee cannot happen now, especially with safeguards and clinical review boards."
Streeter favors aggressive medicine. "I think we need to be more like pediatric oncologists who ask, `Is there a clinical trial for this patient?' and if the answer is no, then ask, `Why not?'" Streeter adds. "The cancer cure rate is higher in children than in adults."
Streeter envisions a paperless future where doctors will share research data on the Internet almost instantly. He believes that sharing of knowledge will lead to more rapid advancement in disease treatment.
"We'll be able to see trends-both good and bad-much faster," he says.
Back in his undergraduate days at USC, Streeter wanted to be a lawyer. The Watergate scandal cooled his desire to practice law and he instead devoted his life to the practice of medicine-an avocation he calls "the perfect profession." The influence, in part, comes from his family.
His mother, Betty Richardson, taught nursing at Los Angeles County+USC Medical Center. His stepmother, Betti Jo Warren, M.D., is a pediatrician at Martin Luther King Jr. Hospital in South Central Los Angeles.
Streeter is married to Paulette Y. Saddler, M.D., an internist specializing in medical acupuncture. She also is active in many local charities. Her efforts as founder and president of the Healthy Baby Alliance of Pasadena recently won her a Los Angeles Times community service award.
Their energetic 8-year-old daughter, Rebecca, seems to have inherited her parents' boundless energy. She plans to follow in the medical footsteps of her father, mother and grandmothers.
Well, sort of, Streeter chuckles.
"She wants to be a scientist and an entertainer."