When the diagnosis is prostate cancer, deciding how to treat the disease – or even whether to treat it at all – is somewhat controversial these days. The serious side effects associated with some current treatment options, combined with the knowledge that some men who are treated for the disease never would have developed symptoms in their lifetime anyway, have a lot of doctors recommending the "wait and see" approach.
Maybe if doctors had a way of knowing at the time of diagnosis how a particular patient's prostate cancer was going to develop, it would help them decide how, or even if, the cancer should be treated.
A company developing custom array-based tests believes its ProScan test, introduced just last week, might be the answer. According to CombiMatrix (Mukilteo, Washington), the test is based on peer-reviewed studies that identify several genetic tumor markers that enable a more precise stratification of the risk profile of cancer patients.
"Different people have different clinical courses of their disease ... there's always a few here and there that the cancer goes into remission. And then there's a larger number where the cancer is real prostate cancer," Amit Kumar, PhD, president/CEO of CombiMatrix, told Diagnostics & Imaging Week. "Doctors have known for many, many years that not all the cancers are going to develop in the same way."
Kumar said CombiMatrix has taken research data and tried to identify specific genetic markers, or genetic indications, that provide information on how cancer is going to develop in a particular patient. He said the company has validated the ProScan test internally with a number of cancer samples for patients in whom it knows the clinical history. Getting doctors to accept this new diagnostic technology is the next challenge.
"This is a revolutionary new way of looking at a patient," Kumar told D&IW. "It's going to take some time for us to educate the oncologist, it's going to take some time for us to educate the pathologist."
In general, he said, most oncologists and pathologists understand that personalized genetic analysis is "the wave of medicine that's coming," but they haven't used the technology because it is so "cutting edge."
While it would be tough to predict how quickly physicians will start to use the ProScan test, CombiMatrix is hoping adoption happens in a similar fashion as its other products have been.
"What we find is, there are always a few early adopters. Physicians who are up to speed on all the literature and the latest techniques ... tend to be at university centers," Kumar said. "Those doctors start using it, they start talking to their colleagues, and some do clinical trials using these."
Eventually, a broader group of physicians start using the tests too, a process that could take months, or even a couple of years, he said. Kumar said the company has introduced the ProScan as a launch and it anticipates over the next couple of months that it will start getting used at some academic medical centers and the company will work with collaborators at some of those places to do studies demonstrating the validity of the test.
According to CombiMatrix, the ProScan test comprises probes for specific genomic loci of which copy number gains and losses have been shown to correlate with risk of recurrence and metastasis in patients post-prostatectomy. These additional probes are a further enhancement of the CMDX solid tumor array platform design which enables whole-genome tumor profiling, or genomic grading, while also providing information about the copy-number status of specific disease-associated loci, the company said.
In August a group urged against prostate screening in older men, saying that there is more harm than benefit from the screening and treatment based on a positive diagnosis. The U.S. Preventative Services Task Force found that treatment based on routine screening causes "moderate-to-substantial" harm to men of all ages, such as erectile dysfunction, urinary incontinence, bowl dysfunction, and death.
In addition to "watchful waiting," management strategies for prostate cancer include radiation therapy, active surveillance (periodic biochemical monitoring with conversion to curative treatment if disease progresses), radical prostatectomy, and brachytherapy (or radioactive seed implantation therapy).
"The ProScan test is an important first step toward introducing the concept of genomic pathology through CombiMatrix's well-tested laboratory developed platform of array CGH," said Dr. Mercedes Gorre, VP of scientific affairs for Combimatrix Molecular Diagnostics (Irvine, California). "The ProScan test provides a valuable new tool to physicians and patients with the potential for making informed decisions about the benefits and risks of whether or not to treat their prostate cancer and, if so, in what manner."
In addition to operating its array-based tests "very rapidly," Kumar told D&IW another strength of the technology platform is that it allows the company to update its tests as new information gets published identifying new genetic markers. For example, he said in some cases the company has been able to incorporate new data into its tests within two weeks of the information being published. "That's a very powerful capability of our technology," he said.
Kumar said that the company tests about 250 patient samples a month using its technology. "We're small, but we're starting to gain critical mass," he said.