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MRI: No More “Hit-or-Miss” Biopsy!

Can MRI really make a difference in diagnosing prostate cancer?  Just ask Rob Gray.  It took nine years for his cancer to be diagnosed.  He felt like a human pincushion after going through numerous tests, exams, and five prostate biopsies – some of them saturation biopsies (each involving 20 or more needle samples!).  Doctors couldn’t find cancer, but they couldn’t rule it out, either.  The inconclusive “TRUS” (transrectal ultrasound) biopsies took their toll, as well: scar tissue developed in his prostate, making cancer even more difficult to detect with TRUS.   Rob is firmly convinced that, had it not been for an MRI-guided fusion biopsy, his cancer, which turned out to be Gleason 3 + 4, still might not have been found.  Today he is cancer-free.

Out with the “Hit-or-Miss” Biopsy!

With TRUS, unfortunately, Rob’s story is all too common, says radiologist Peter Choyke, M.D., Senior Investigator and Director of the National Cancer Institute’s Molecular Imaging Branch, and a pioneer in the rapidly evolving use of MRI to evaluate prostate cancer.  He is at the top of the MRI-prostate cancer field, and I was privileged to interview him recently for the Prostate Cancer Foundation’s website.

Why have so many men, like Rob, endured multiple inconclusive biopsies?  Choyke explains: “Let’s look at what until very recently was state of the art: 12 biopsies performed by the urologist under TRUS, six on one side and six on the other.  It really wasn’t targeted to anything in particular.”  The basic biopsy sampled the upper, mid and lower part of each side of the prostate (this, by the way, was an improvement over the old biopsies of 20 years ago, which took only six samples!).  Even with 12 samples, “there are a lot of opportunities to miss lesions.  And, because urologists don’t want to injure the urethra, which is in the center of the prostate, they tend to put the needles more towards the back of the gland, so the front part of the gland was relatively unsampled in a traditional TRUS biopsy.”

In other words, the traditional biopsy is largely hit or miss.  “Once we started doing MRIs,” says Choyke, “we realized that a lot of tumors are above where the needles usually went in; in fact, those lesions are more amenable to transperineal biopsy.  That was important in helping us detect the cancers in men who had multiple negative TRUS-guided biopsies.”

A targeted biopsy – done with TRUS, but using the MRI as a roadmap – can direct the needle to specific areas that look suspicious.  “Also, once you have the MRI, you realize how big the lesion is.  With TRUS, you just had a specimen that was positive.  You didn’t know if it came from a 3mm- or a 5 cm-sized lesion!  It was just ‘positive.’  Now with MRI, we have a much better feel: is this a big lesion, has it been there a long time, has it grown outside the prostate, possibly to the lymph nodes?  Are the seminal vesicles involved, is the bladder involved?  There’s a lot of anatomy that you can get from the MRI that you just don’t get from the biopsy information.  Was the needle in the center of the lesion, or the periphery – or did it biopsy something completely different than the main lesion?  Is this cancer caught very early, so it’s hard to see, or is it large and obvious?  That influences the discussion of treatment options, and allows the patient to make a much more informed decision.  With MRI, you’re way far ahead of the game.”

And this is why Choyke believes that “in the best of all possible worlds, every man with suspected prostate cancer would get an MRI.”  MRI is of even more benefit, he adds, as a man’s PSA rises.  “We did a study where we compared men with a PSA less than 5 with men with a PSA greater than 5.”  For men with a lower PSA, “the advantage of MRI was much smaller compared to a traditional TRUS biopsy.  But for those with PSA greater than 5, it was clearly superior to have an MRI.”

That said, there are some qualifiers:  Not every insurance policy pays for MRI, and good-quality MRI is not universally available.  The power of the MRI machine itself used to matter more, with 3 Tesla strength preferred.  But today, the major determinants are, “how old is the MRI unit, and is there a radiologist who is focused on prostate MRI, who has been to courses learning how to interpret it properly?  Or, is the radiologist a generalist without specific expertise?”  If you’re paying for part or all of the cost out-of-pocket, Choyke notes, “these scans are very expensive.  I don’t think it’s unreasonable to ask good questions.”

Another bonus to today’s prostate MRI:  With more sophisticated machines, very few men require the endorectal coil, a latex-covered probe, inserted in the rectum, that helped provide better-quality images of the prostate with earlier-generation equipment.  “We advocated for endorectal coils universally five years ago; but once we bought a new scanner, we now reserve coils for cases in which the patient’s already been treated and we’re looking for recurrent disease in the pelvis, which can be very subtle.”  With the recent approval of 18F DCFPyl PSMA-PET, which uses a highly specific molecular tracer to find prostate cancer cells anywhere in the body, “we’re using the coil less and less.  That’s associated with lower cost, better patient appreciation, and faster scans.  Nobody regrets to see the passing of the endorectal coil.”

This is part 1 of 3 stories on MRI, precision cancer screening, and MRI’s potential use in treatment.

In addition to the book, I have written much more about prostate cancer on the Prostate Cancer Foundation’s website, pcf.org. The stories I’ve written are under the categories, “Understanding Prostate Cancer,” and “For Patients.”  As Patrick Walsh and I have said for years in our books, Knowledge is power: Saving your life may start with you going to the doctor, and knowing the right questions to ask. I hope all men will put prostate cancer on their radar. Get a baseline PSA blood test in your early 40s, and if you are of African descent, or if cancer and/or prostate cancer runs in your family, you need to be screened regularly for the disease. Many doctors don’t do this, so it’s up to you to ask for it.

 ©Janet Farrar Worthington

 

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Do You Need Prostate MRI?

Prostate MRI is on the upswing in cancer diagnosis.  Should it play a role in screening, too?  

Many men with suspected prostate cancer are getting MRI, because the information it provides is so good:  MRI can show the size and location of tumors and guide a personalized, targeted biopsy aimed at suspicious areas – instead of a best-guess biopsy that tries to sample tissue from each part of the prostate.

Traditionally, if a man’s doctor suspects he has prostate cancer, the next step has been a biopsy.  But that’s changing:  Today, ideally, the next step should be an MRI, says radiologist Peter Choyke, M.D., Senior Investigator and Director of the National Cancer Institute’s Molecular Imaging Branch.  And even more ideally, maybe MRI should be part of regular screening.  I recently interviewed Choyke for the Prostate Cancer Foundation’s website.

“Prostate cancer is not one disease: it’s a broad spectrum ranging from cancer that is slow-growing, indolent and probably will never bother the man, to cancer that is very aggressive, as bad as pancreatic cancer in its severity,” Choyke explains. “It’s important to pick out who has that really aggressive type, and who has the indolent type.”  In large, multicenter studies in the United Kingdom, prostate MRI is part of regular screening.  If the MRI is negative, “men go back in the screening pool and are monitored with regular PSA tests.  If the PSA goes up, they repeat the MRI,” and undergo biopsy only if anything suspicious shows up on the MRI.  “The virtue of this approach is that in the UK, almost one-third of men avoid biopsy, which is very significant.  If you don’t do the biopsy, you don’t detect incidental Gleason 6 disease,” which does not always require treatment. “But in the U.S., biopsies continue to be done even when the MRI is normal or equivocal.”

Do higher-risk men need MRI sooner than others?  Choyke is investigating this question in studies of targeted populations, including men with a family history of prostate cancer, men of African descent, and men identified with “genetic predispositions to prostate cancer,” he says.  “We’re doing a study now of men who come from families with known genetic abnormalities that predispose to cancer.”  Eligible for the study are men without prostate cancer, ages 30 to 70, who have tested positive for mutations in one or more of these genes:  BRCA1, BRCA2, HOXB13, ATM, NBN, TP53, MLH1, MSH2, MSH6, PMS2, EPCAM, CHEK2, PALB2, RAD51D, and FANCA.

Already, Choyke says, “We are finding cancers in younger men from those families.”  This is important:  Many family doctors don’t recommend prostate cancer screening until men are in their fifties.  Men at higher risk should start screening earlier, in their early forties.  Men with a family history of prostate cancer, or of other types of cancer (such as colon, breast, or ovarian) tend to develop prostate cancer at a younger age.  Some men can develop prostate cancer in their thirties and even younger.  MRI, Choyke hopes, may one day play a role in diagnosing higher-risk men sooner.  “It may be that if you have one of these predisposing genetic conditions, you would get an early MRI, way earlier than it’s now recommended and catch the disease at a curable state,” as part of a precision medicine approach to screening and diagnosis.

Also at higher risk of developing prostate cancer at an earlier age are men of African descent.  “African American men have a greater predisposition to prostate cancer, and are much more likely to die of it,” says Choyke.  “Many of these men live in medically underserved communities, so this is a population I would think well worth targeting for MRI.”

What if you want an MRI but your insurance won’t pay for it?  “We see this problem all the time,” says Choyke.  His advice:  get your urologist to help!  For many doctors in the U.S., trying to get past an insurance company gatekeeper is a daily occurrence – which means, you’re not the first person this has happened to.  Your doctor is used to it, and may be able to cut through the bureaucracy.  Here’s a battle plan suggested by Choyke:  “First, discuss the need for MRI with your urologist and make sure you’re on the same page.”  Then, if your urologist agrees that an MRI would be beneficial, team up:  “The patient and urologist working together have a better shot at convincing the insurance company than either alone.”

Another issue: prostate MRI is not available everywhere.  “MRI scanners are difficult enough to access, and centers with expertise in prostate MRI are even less common.”  You may need to travel to a bigger medical center in another city.  Even if you’re in a major city, this doesn’t guarantee easy access, Choyke adds:  “I know of patients and urologists in Washington, D.C., who can’t get MRIs.  We will be conducting a study with patients from underserved parts of Washington to determine if we can make earlier diagnoses and have better outcomes.  If we can show that patients in this community benefit – and I think they will! – then maybe those communities can argue for more resources based on data.  In contrast, in the UK, every patient gets an MRI, no questions asked, because of their more socialized system of medical care.”

This is part 2 of 3 stories on MRI, precision cancer screening, and MRI’s potential use in treatment.

In addition to the book, I have written much more about prostate cancer on the Prostate Cancer Foundation’s website, pcf.org. The stories I’ve written are under the categories, “Understanding Prostate Cancer,” and “For Patients.”  As Patrick Walsh and I have said for years in our books, Knowledge is power: Saving your life may start with you going to the doctor, and knowing the right questions to ask. I hope all men will put prostate cancer on their radar. Get a baseline PSA blood test in your early 40s, and if you are of African descent, or if cancer and/or prostate cancer runs in your family, you need to be screened regularly for the disease. Many doctors don’t do this, so it’s up to you to ask for it.

 ©Janet Farrar Worthington

 

 

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