Tracking Breast Cancer Treatment

Jellydonut

Tracking Breast Cancer Treatment

Jellydonut

Very interesting...

http://www.ivanhoe.com/channels/p_channelstory.cfm?storyid=17746

Reported December 31, 2007

Tracking Breast Cancer Treatment -- In-depth Doctor's Interview

Ivanhoe interview with

Greg Czarnota, M.D., Ph.D., Radiation oncologist

Sunnybrook Health Sciences Centre/ Odette Cancer Centre

Toronto, ON

TOPIC: Tracking Breast Cancer Treatment

Date of interview: August 17, 2007

What kind of health issue is breast cancer?

 Dr. Czarnota: I think it's fair to divide breast cancer into locally advanced breast cancer -- that is breast cancers that are very aggressive, large and involve many lymph nodes -- and those which are not locally advanced. The treatment is, in principle, somewhat the same except that with women who have locally advanced breast cancer, because the disease is so aggressive, the way that the treatment is given is rather different. With a small breast cancer, someone who is 60 years of age will typically have surgery first, followed by chemotherapy, then followed by radiation. Women who have locally advanced breast cancer, because the disease is so aggressive, it's actually believed that giving the chemotherapy first, or the chemo combined with the radiation first and then going on and having surgery, may actually be potentially beneficial both in terms of preventing the very large aggressive tumor that's there from growing and continuing to grow during the treatment, and also in terms of overall survival and overall prognosis of the aggressive treatment.

What are the treatment options for patients with breast cancer?

Dr. Czarnota: There are many different options in terms of the treatment and many different clinical trials. It's not necessarily knowing which type of chemo therapy is best. In certain instances, these women may have hormone treatment or they may have very aggressive chemotherapy of which there may be various different flavors or different types of drugs given for different durations -- typically many months -- or even combined chemotherapy with radiation given simultaneously. If they do have chemo therapy, we're typically talking about three months to six months of treatment.

How often do these treatments not work for patients?

Dr. Czarnota: If you take all women with this aggressive form of breast cancer, this locally advanced breast cancer, only about 10 percent of them are ultimately cured of their disease at best, and 30 percent of them show some level of response, so that means potentially up to 70 percent of the people receiving this type of chemotherapy may not be deriving a benefit. It may work initially and then the tumor, for some reason becomes resistant to the chemotherapy and starts to grow again. Or right off from the onset it may actually be ineffective. The main question is, 'How do you determine whether the chemo therapy is having a response or not?' Up until now, physicians haven't had very good methods to do so other than physical examination and, in terms of imagining studies that can give objective and quantitative measures of response, there really aren't any. That's why we're testing the SoftScan diffuse optical tomography and spectroscopy technology.

What is this new technology called and what information does it give you?

Dr. Czarnota: The technology is called diffuse optical tomography or diffuse optical spectroscopy. It is known as SoftScan. The idea behind it is that is uses laser light to probe the metabolic function on the breast, and by doing so can tell if an area is potentially growing or metabolically active. It does more than just give numbers indicating metabolic activity. You can actually generate a 3-D image of the breast, but rather than looking at structures, which typically show up on X-rays or mammograms, you're looking at areas with are metabolically active. There are various different parameters related to light scattering that can tell you whether part of the tumor is growing or potentially dying.

How does this technology work?

Dr. Czarnota: So the simplest explanation is if you remember back to when you were a kid at Halloween, you might take a flashlight and shine it through your hand and you can actually see the light coming through your hand. This technology doesn't just use plain white light, but it uses lasers and specific wavelengths. How those various different wavelengths or colors of light interact with the tissue of breast cancer can tell us whether the cells there are growing, are hemoglobin and oxygen rich, or whether the cells are dying. It has to do with interactions of various different wavelengths with tissues and how they're differentially scattered.

How is this different from MRIs and CT scans?

Dr. Czarnota: Well, MRI works in a different way. It relies on large magnetic fields and contrast agents, which wash in and out of tumors, to tell us whether they're growing or potentially dying. But they don't give the same metabolic information that this technology does. CT scans again rely on X-rays, so they don't give us the type of information that this technology permits. Standard CT and standard MRI can tell you about the size of a tumor, but we typically find that the SoftScan indicated changes in metabolic activity that precede any changes in size.

How is the information displayed?

Dr. Czarnota: The information is typically color coded. The most common representation is blue for an area of inactivity or red for an area of activity. It has to do with the particular wavelengths of light that are scattered as the laser light passes through the tissue. One measure that perhaps has best worked out in terms of SoftScan technology is that it actually gives you an idea of the hemoglobin, or blood, concentration in a particular area. If you have an area in the tumor that's growing rapidly, it probably has a high concentration of oxygenated hemoglobin because it's growing. That's one of the things we can detect.

What formations are you looking for in the results?

Dr. Czarnota: This is an experimental technology, so we are right on the forefront of testing this technology. As we're doing these studies, we're also developing the response criteria. What we're looking for is both a diminishment in terms of the metabolic activity, in terms of its overall level, and also a diminishment in the size of the areas that are highly metabolically active.

And what would that formation indicate to you?

Dr. Czarnota: As far as we've been able to ascertain, based on the patients that have come through the study, that's one of the indicators of response. There has been a fairly high concordance between women who show a response both on the imaging technology and what happens to them in the clinic.

What impact does months of ineffective treatment have on a patient, both physically and psychologically?

Dr. Czarnota: Let's start with the psychological impact. It's very worrisome for women with such aggressive breast cancers, first of all to have such a cancer, and then they know right from the beginning how poor the expected outcome is. Also, there is the lost time, both in terms of the time they may potentially have left to them and also lost time in terms of finding the perhaps the best drugs or the best chemotherapy regimen for them. So obviously, there is a psychological benefit from being able to quickly customize a patient's chemotherapy. In terms of the health benefit, I think the benefit is obvious if one can, as a physician, very quickly, within 24 hours, 48 hours or even a week after giving the first chemotherapy, know that it's not going to work. It makes sense in that point of time to investigate another alternative. As yet, there is now clear-cut mechanism for making such decisions.

How long does it take to find out if treatment is working?

Dr. Czarnota: It can be as long as six months after chemotherapy is given. It's very difficult to ascertain whether there is a response or not because most clinicians are limited to feeling the breast or feeling the tumor -- sometimes they can even feel it if it's very deep-seeded. The other thing is sometimes CT scans and MRI scans are ordered incidentally during these studies, but there is no rhyme or reason as to when they should be done or what particular test should be done. That's why we're systematically testing this technology.

Is this testing method working?

Dr. Czarnota: We know from studies where we've done the imaging within seven days of first dose of chemotherapy, there has been a fairly good correlation in terms of the imaging of the SoftScan indications of response. Whether or not we can do it sooner than that we haven't yet tested, but it may actually be possible to do so as well.

What are your goals using this new method?

Dr. Czarnota: Our goal is to try to be able to recommend a different chemotherapy, a switch from the standard chemo to a different chemical regimen, or even a different type of treatment all together, where possible. That's for the future. Right now we're at the point that we're finding out that this technology is working and working quite well. Once we finish the initial studies, we'll be at a point where we can actually start doing clinical trials, recommending changes in the chemo. Right now, physicians have no good indication of when to change the chemo or even what to change other than clinical intuition and experience.

How novel is this technology?

Dr. Czarnota: It's very novel. There's been a great deal of background work done in terms of the laboratory work and the understanding of the basic physics behind it. But in terms of the novel metabolic imaging approach for women, ours is probably the only study so far that's using this technology to monitor the effects of chemo. This technology has been around and has been used to help in the detection and diagnosis of breast cancer, although we believe that this is new and innovative and an even more powerful use of this type of technology.

Where is your company based?

Dr. Czarnota: The company is Montreal-based. The study has actually been started here at Sunnybrook. In order to speed things up and include more patients, we're now expanding it to a second sight here in Toronto, The Princess Margaret Hospital. After the first pilot study when between 10 and 20 patients are done, our goal is to do a more extensive comparison, probably multiple centers all throughout North America.

How long will that be?

Dr. Czarnota: We hope to have our 10 to 20 patients wrapped up in the next six to eight months and hopefully the study will begin shortly thereafter. So about a year away.

If testing goes well, will this technology be widely available within five years?

Dr. Czarnota: We hope so. The device can be used as an imaging device here in Canada and it's approved by the Canadian equivalent of the FDA, so I think the opportunity is right to turn it into a clinical tool that it can help physicians treating cancer to make logical and rational decisions.

What would this technology mean to women with advanced breast cancer?

Dr. Czarnota: To be able to have this technology and use it to customize someone's chemotherapy could mean to be honest, between life and death. Rather than giving someone six months of ineffective chemotherapy and then you run out of time because the disease has progressed, we may be able to very quickly switch it to a type of chemotherapy that works. It means that that woman gets to see her kids grow up and lead a normal healthy life. There are many potential years of life that are saved.

As a doctor, what do you think about this new technology?

Dr. Czarnota: I think it's very wonderful to see things that have been developed in the lab now making their way into the clinics quite quickly and especially this technology, having a potential technology that can actually have a huge clinical impact. Very often on the scientific side, it's hard for scientists to make connections with clinicians in terms of what they can offer for patient healthcare, but I think there's a very good connection here between the two -- between what goes on in the laboratory and the clinical technology, which has quite significant ramifications.

How great of an advance is this in the field of breast cancer?

Dr. Czarnota: If it works, it can be a significant advance in the field of breast cancer. There are other technologies also being investigated here at Sunnybrook -- mainly MRI and ultrasound technology. The advantage here is that it's relatively inexpensive compared to MRI. So it's a non-invasive imaging probe of metabolic activity that can tell us whether a tumor is living or growing or dying in response to the therapy.

So this is not being studied in the United States right now?

Dr. Czarnota: Not in terms of marking responses to chemotherapy, but I understand that the ERT company that manufactures this is moving quite quickly to establish contacts. There are a lot of American centers which are interested in participating in the second phase of the research.

 

END OF INTERVIEW