Q&A: John E. Marion II, Ph.D.
On Development Of Smart Probe For Breast Cancer Detection
D.F. Tweney, Special to SF GateTuesday, May 15, 2001
Breast cancer is the second leading cause of death among women in the UnitedStates. Last year, more than 182,800 women were diagnosed with breast cancer, and40,800 women died of the disease. Currently, breast cancer diagnosis requiresbiopsies, a procedure in which small tissue samples from suspicious lumps areremoved — many of which turn out to be benign.
A San Jose medical technology startup called BioLuminate is working with LawrenceLivermore National Laboratory to develop a new device, called the Smart Probe,that may eliminate the need to perform many of those painful biopsies. The SmartProbe is about the size of the needle used for drawing blood and contains asophisticated sensing system. Inserted into the breast, the Smart Probe useslaser light and electrical impedance measurements to determine whether it isinside normal breast tissue, a benign lump or a cancer.We spoke with John Marion, special studies leader in the medical technologyprogram at Lawrence Livermore, about the development of the Smart Probe, which isexpected to enter human trials this summer.
What’s the current procedure for detecting breast cancer?
A mammogram by a physician or palpable lumps found by the person herself are thetypical first signs.
Then, at some clinics, they do a fine needle aspiration, which is literallysticking a needle into the suspicious area, drawing out some blood andintercellular fluid, and then a pathologist looks at that. If it’s stillsuspicious, they would go to a core biopsy.
For core biopsies, they have this fairly complicated, horrific-seeming machinethat shoots the biopsy needle into the suspicious location and takes a sampleout. The needle is about 2 or 3 millimeters wide. The reason why they shoot it isbecause the breast is jiggly and you want to be able to get it to the spotwithout having the breast move. But they do from like 10 different spots to makesure they get the right location, so they make a lot of holes in this woman’sbreast. It’s not a nice thing. Then it goes to the lab for analysis, which takesa few days. If it’s still suspicious after a biopsy, then people generally arescheduled for lumpectomies or a mastectomy.
Would you rather die of breast cancer? Of course not. But we’re trying to make aprocedure that is comparable in accuracy to a biopsy but much less invasive andcan be done in real time. Those are the two keys.
Why is the Smart Probe project looking at breast cancer, as opposed to some otherform of cancer?
Breast cancer is kind of unique, because with a mammogram, when it says there’ssomething suspicious, it often ends up not being cancer. So you’ve got this hugegroup of women that are scared to death because they think they have cancer, butthey don’t actually have it.
The idea behind Smart Probe is this: Is there some kind of test you can do forthis class of women who have just had a suspicious mammogram? It needs to bequick, might even be done in a doctor’s office, and has to be quite reliable insaying, hmm, we’re still worried, let’s go on to the next set of tests. Or, ifyou look OK, let’s go on and just do another mammogram in a year.
So how does the Smart Probe actually know it’s been inserted into normal tissueor cancerous tissue?
Well, the Smart Probe is a needle, it’s sharp, and it’s hollow, and in thathollow area, there is a solid stainless steel wire in the center that’s used foran electrical impedance measurement. That’s been shown to be a pretty reliableway of differentiating between denser and regular tissue. Tumorous tissue tendsto be denser.
Then there are a couple of optical fibers. We’re shining lasers down one of thefibers and receiving inputs back up the other. The probe that we’re building forthese upcoming trials will have five different colors of light that go down thisone fiber.
What you find is that optical scattering is a function of wavelength and of thetissue. So, for example, if you shine a blue light down and you get a lot oflight back, it’s fat; if you shine green light down and you get a lot of lightback, it’s cancer.
The whole thing fits into a so-called 20 gauge needle, which is about amillimeter across.
You expect human trials to begin this summer at the University of California atDavis. How will those tests be conducted?
We’re starting with a set of tests on about 100 women that are scheduled to havea lumpectomy or a mastectomy. So after they have been anaesthetized, we’ll do theSmart Probe procedure. Then they’ll have that tissue excised. There’s apathologist who will look at the tissue and make a clinical diagnosis, and thatwill be used for the care of the patient. And then there will be a team ofpathologists that will do a more comprehensive report. It’s that combination ofthe comprehensive pathology report with the data that we get from the Smart Probethat will hopefully lead to a learning process.
What happens once the human trials are complete?
Well, of course what’s going to happen is we guessed wrong, and that set ofmeasurements that we’re so thrilled with right now won’t quite work. I would loveto be surprised. But I’m almost certain that it’s one of these things where thefirst set doesn’t work perfectly.
On the other hand, I would really be shocked if we didn’t get some great datathat showed we can really see some very distinctive differences between normal,benign and cancerous tissues.
Crystal balls are dangerous, but I think if things went very well, this could beon the market in two and a half to three years.
How is the Smart Probe project funded?
The way Livermore works with a company like BioLuminate is that they give usmoney and we do the work. They have to pay the whole bill, we actually can’t doit another way. The agreement with BioLuminate is $1.4 million over 18 months.
How does Lawrence Livermore benefit from the arrangement with BioLuminate?
Oh, well, that’s pretty easy. There are a lot of things that we want to dorelated to sensing degradation in aging weapons and being able to assess what’sgoing on inside a bomb without having to take it apart. So all thisminiaturization, fiber optics, new chemical sensors, new optical sensors, thoseinevitably will have feedback into the weapons program.
Do you think this will have application to other kinds of cancer?
Absolutely. For instance, questionable findings on the cervix are very, verycommon. And there’s a good screening test for that — the Pap smear. It would bevery nice if there could just be an optical probe that they set against thequestionable tissue and could characterize it as cancerous or not, without havingto poke it, or grab it, or grab a big chunk of it.
But like any small company, the last thing you want to do is start trying to cureall cancers. So the focus is on breast cancer at this point.
Will this be an expensive procedure for patients once it’s commerciallyavailable?
As far as cost, the goals are to have this be consistent with other early tests for breast cancer. You’ve not only got to have something that works as well, but it has to be of comparable cost.
In terms of the way the climate works right now, patient discomfort is fairly fardown the list of reasons to change to a new procedure. If it costs more or isless effective, but it’s better for the patient — [shrugs]. It has to cost about thesame, be just as effective, and then we can realize these other benefits.
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