MD Anderson Cancer Center
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Lisa Garvin: Welcome to Cancer Newsline, a podcast series from the University of Texas, MD Anderson Cancer Center. Cancer Newsline helps you stay current with the news on cancer research, diagnosis, treatment and prevention providing the latest information on reducing your family's cancer risks. I'm your host Lisa Garvin. Today our guest is Dr. Jack Roth he is a professor of Thoracic and Cardiovascular Surgery here at MD Anderson and he is also director of the WM Keck Center for innovative cancer therapies. And we'll be talking about one of those therapies today, it's the STARS trial for early stage lung cancer patients. What is STARS, Dr. Roth?
Dr. Jack Roth: Well, STARS is actually an acronym and it abbreviates stereotatic radiation therapy versus surgery, that's the way the clinical trial is designed. Were comparing a new type of radiation treatment called stereotatic radiation therapy and we're comparing that to a conventional treatment for early stage lung cancer which is surgical resection.
Lisa Garvin: And typically, early stage cancers, lung cancer is one of those where it's generally not caught early. How many people are we catching in the early stages of lung?
Dr. Jack Roth: Well, fortunately were catching more and more people and this is due to the wider use of screening technologies such as CT scanning and in fact that people are getting more examinations. Sometimes for other types of problems which pickup incidental lung cancers. Overall I would say probably about 25 percent of all the lung cancer patients that we see have early stage lung cancer.
Lisa Garvin: Lets talk about stereo tactic radiation therapy. What is that exactly and how does it differ from conventional delivery methods of radiation?
Dr. Jack Roth: Well, stereotatic radiation therapy delivers the radiation being an extremely small doses at a variety of different positions for the patient. The beam basically rotates around the patient, and by doing this very little of the radiation is deliver to normal tissue but very high levels of radiation are focus on the tumor so the doses of radiation that the tumor receives are much higher than the doses that are given with conventional fractionated radiation therapy. Now, I'm not a radiation oncologist, I'm a thoracic surgeon so I'm giving you a very simplify description of this. But fractionated radiation therapy usually gives a doses over about a five to six week period of time and the maximum dose for most lung cancer patients is generally in the range of 60 gray, a gray is a measurement of the dose of radiation. And that would be considered a fairly high dose but by focusing the radiation beam in the way that stereotatic radiation therapy does the tumor receives doses in excess of a hundred gray. So you can see it's a much, much higher dose. And when you talk to the radiation oncologists who give this modality they consider this an ablative dose. In other words, a dose of radiation that basically kills all of the tumor cells as opposed to the lower doses of radiation conventionally given which can induce cell death but may not be as effective in killing all the tumor cells.
Lisa Garvin: 'Cause typically in lung cancer cases, if you're using radiation, its really in addition to surgery or like would it shrink the tumor before surgery or perhaps clean up after surgery?
Dr. Jack Roth: Well, the most general application for radiation therapy is in patients who can't undergo surgery. And these are patients generally with pretty advanced disease. And in most cases, the radiation therapy is given along with chemotherapy, and chemotherapy does a couple things. It can circulate in a body and it can kill tumor cells and other organs. It can also improve the effectiveness of the radiation treatment by sensitizing the tumor to the radiation. We--radiations given in that aspect and also radiation is sometimes given following surgery if there is some indication that there might be some residual cells left behind after the surgical procedure. But this idea of giving a stereotatic radiation therapy as a curative treatment for early stage lung cancer is relatively new.
Lisa Garvin: Lets talk about the trial itself. It's been open a couple of years. How many people do you hope to accrue overtime?
Dr. Jack Roth: We are trying to accrue very large numbers of patients. Our first goal is to get at least 180 patients before we'll do a statistical analysis, but we can accrue more patients if needed in the study up to 420 patients.
Lisa Garvin: In this being done across several institutions?
Dr. Jack Roth: It's been done as an international trial. We have centers in Europe that are entering patients and also centers in Asia that are entering patients as well in the US.
Lisa Garvin: What sort of eligibility criteria. I mean what are you looking for in patients for the STARS trial?
Dr. Jack Roth: Well, the first criteria is of course they have to have early state lung cancer. By this we means stage I. The tumor needs to be four centimeters or less in its largest diameter and the patient has to clinically not have any evidence that their spread either to lymph nodes or any other organs.
Lisa Garvin: And do they have to travel to Houston or I guess they would travel to the nearest institution that's participating.
Dr. Jack Roth: Yes. There are web sites that have information on the institutions that are entering patient into the study and you can go to clinicaltrials.gov and looks those up and you can also see the protocol itself and read it in detail.
Lisa Garvin: This sounds to me as a lay person to be kind of exciting because we really haven't seen a whole lot of movement in the way we treat lung cancer other than maybe more minimally invasive surgical techniques. This seems like a whole new avenue of treatment for lung cancer.
Dr. Jack Roth: It is. One of the things that we try to do with lung cancer in our treatment strategies is to reduce the side effects, the toxicity of the treatment. This is very, very important because often times patients who have lung cancer are elderly and they may have poor lung function or they may have difficulty with, you know, heart disease or other problems and so any type of surgical procedure has, you know, the potential for some side effects, some treatment related toxicity. And anyway we can reduce this would be helpful. I think one of the advantages of this treatment is that it may be able to reduce the side effects of the treatment and it may be able to preserve the lung function. However, we don't know the long term outcome for patients who are undergoing this type of stereotatic radiation, and that's one of the reasons we're running this clinical trial is to have long term followup and see ultimately where there is going to be a successful in curing patients with lung cancer as surgery.
Lisa Garvin: Where else is stereotatic radio surgery used in the cancer world. Is it used effectively another types of cancer?
Dr. Jack Roth: Well, it started out with the use for our brain tumors. This is how it was originally developed. There are various [inaudible] I think one technology was called Gamma Knife and that's still been used very extensively here at MD Anderson, other cancer centers around the world. And gradually, a different platforms utilizing this type of technology were developed, and now it has application to a wide variety of different tumors. For example, prostate cancer is often times treated with stereotatic radiation therapy. It's being used to treat not only primary lung cancer but also metastatic tumors to the lung. And there are other--other organ systems where it's being used extensively as well for example in the liver.
Lisa Garvin: Despite the trial being open for a couple of years, it sounds like you really aren't even at the point where you even have preliminary data to look at or--
Dr. Jack Roth: No, that's true. That's very important that the statistical analysis of the study like this needs to be extremely rigorous. The patients who screened carefully to meet the entry criteria and we have to have special milestones set up before we can review any data. We have an excellent statistician involved with the design in the trial Dr. Dan Barry who's been a leader in adoptive clinical trial design and that's the type of trial design that we're using for this particular study.
Lisa Garvin: What is your hope down the road for the STARS trial looking into the future?
Dr. Jack Roth: Well, this is a very promising technology. Its not going away, its gonna be with us for a long time and it will probably develop into even more advanced types of applications when a new technology like this comes along, we need to know which patients are going to benefit. We need to know if there are serious, you know, side effects or complications in the short term or long term and we need to know how this fits in to our overall multi disciplinary treatment plan. I think the STARS trial is going to give us that information.
Lisa Garvin: And again, for people who want to look into STARS, just go to your web site and type in clinicaltrials.gov and put STARS trial in the search box. Thank you very much Dr. Roth.
Dr. Jack Roth: Thank you.
Lisa Garvin: If you have questions about anything you've heard today on Cancer NewsLine, contact/ask MD Anderson at 1877MDA6789 [background music] or online at www.mdanderson.org/ask. Thank you for listening to this episode of Cancer NewsLine. Tune in for the next podcast in our series.
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