Title: Radiation Oncologist, Diplomate of the American Board
of Radiology
Employer: Cancer
Treatment Centers of America, in the Southeastern Region
When and why did you become a SITC member?
I joined SITC a few years ago due to a long-standing
interest in immunity. One of my earliest
experiences with my immune system was at age 12 during a Boy Scout project in
Utah clearing trails through the woods. I was exposed to poison oak, causing a mild rash on my legs and
arms. When we went back a few weeks
later, I volunteered to take care of all the poison oak bushes, thinking my
prior exposure had inoculated me against it. I was dead wrong. A few days
later I was in the doctor’s office with my face swollen up like a balloon and
weepy sores all over my body. I had to
take a cortisol injection to turn down my T-cell immune response which was
attacking the poison oak antigens on my skin and even attacking areas where I
wasn’t directly exposed. Needless to
say, I learned a lot that day about the power of the immune system and how
little I understood it, and that not all exposures are protective – in fact
they can rev up the immune response. We
see that with cancer immunotherapy.
Can you briefly explain the work you are doing in the field?
I see many patients in clinic each week who have failed
multiple lines of chemotherapy. Many are
on immunotherapy, sometimes as the last hope. Spread of the cancer to bones, liver, lungs and skin can cause pain or
symptoms for many of these patients, and also an opportunity for radiation to
be of service in giving pain relief and improved control of life-threatening
tumors. It also provides an opportunity
for radiation to help synergize locally with immunotherapy, in much the same
way that we have found chemotherapy given at the same time as radiation to
improve tumor control and cure rates for earlier stage tumors.
Who or what inspired you to choose this specific career path?
Two of my mentors at UCLA, Dr. Steve P. Lee and Dr. Guy
Juillard, gave me insights into the pairing of the immune system and
radiation. Dr. Juillard noted decades
ago that patients without an immune response didn’t clear their tumors after
radiation. In essence, the radiation damages
the cancer, but it’s the immune system that gets rid of it. He was also a pioneer in intra-lymphatic
immunotherapy, by injecting irradiated tumor cells into lymph channels, he
could spur a cellular immune response. Radiation
was the most effective way to transform a patient’s extracted tumor into a
vaccine.
Dr. Steve P. Lee would often talk with patients about how in
order for a tumor to get big, it must have already escaped the immune system;
and how failure of immune surveillance in organ transplant and AIDS patients
can lead to skin cancers and lymphomas. I remember treating patients at UCLA with Kaposi’s sarcoma, a
virus-induced skin tumor that is normally kept in check by the immune system,
until the later stages of AIDS cause loss of cellular immunity. Radiating these sarcomas, even to a very low
dose, brought back control.
What are some of the biggest challenges you are facing in the field?
Right now, it is very humbling to go to immunotherapy
meetings. The unknown is so vast. It was truly said by John Berger, “Never
suppose that the advance of knowledge reduces the extent of the unknown.” Fortunately, drug approvals are happening so
fast that it is never boring. A basic
limitation, though, is that very few patients on clinical trials for immunotherapy
(or any drug for that matter) can receive radiation while on the trial, even
for palliation of painful growing tumors. This means that we aren’t capturing as much knowledge about the
interaction of radiation and immunotherapy as we might, so progress is slow and
often limited to looking back at how people responded who coincidentally got
radiation and immunotherapy at the same time. Fortunately, some very promising things appear to be happening when
patients get radiation therapy after initially responding to immunotherapy.
What topic(s) do you plan to write about for The Sentinel, SITC’s new blog?
I plan to write about how radiation can be combined with
immunotherapy for greatest effect, and the safety of doing so.
What do you hope readers will gain from this new blog?
I hope that the patients and doctors who read my blog may
overcome some of the fear of the unknown that exists at the intersection of two
expanding frontiers: immunotherapy and focused radiation.
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