Anthony D’Amico, MD, PhD
Currently one in six men is diagnosed with prostate cancer in their lifetime in the United States, comprising about 250,000 people in the US population. This number has risen over the course of time due to the introduction of a blood test know as protein-specific antigen (PSA). It has come under some scrutiny lately because of studies of which early results have suggested only one life saved for every 1,000 men screened, but there is follow up suggesting that number might be closer to one in 300 or 400. And that’s number of men screened. The number of men you actually need to treat to save a life screening with PSA is closer to one in twe3lve to fifteen; very, very close to what we have for colonoscopy and mammography.
So the current screening recommendations that I tell people to think about with regards to prostate cancer is to have a baseline PSA at the age of 35, again at 40, and every year thereafter, particularly if they’re in a high risk population; that is men who have a family history of prostate cancer; either dad, a brother, essentially a first degree relative; or those who are African American, Hispanic or Latino because these populations are at a much higher risk for getting aggressive disease. Therefore, screening and catching it earlier can lead to a higher cure rate.
Once you are screened and your PSA is elevated, considered above 4 if you’re over the age 60, but if it’s above 2.5 and you’re between the ages of 40 and 60, you also will be considered for the next step, which is a biopsy. Twelve samples are taken, six from the right and six from the left, and they are examined by a pathologist who looks for whether prostate cancer is present or not. If prostate cancer is diagnosed, it’s stratified into risk categories. There are three risk categories – low, intermediate, and high. Low risk prostate cancer currently is not often treated unless a man is younger and in excellent health. So for a man in his 40s, 50s or 60s in good health, low risk prostate cancer would still be considered for definitive treatment; either surgical removal, or implantation of radioactive seeds, or external beam radiation which is delivered from the outside in. These treatments are all considered standards. But in men with low risk prostate cancer who are not in good health, particularly if they’ve had a heart attack, a stroke, or congestive heart failure, or they’re on dialysis. The reason we consider watching those men as opposed to treating them right away, is simply because in those men it takes 10-15 years for the prostate cancer, if it’s low risk, to progress to a point where it could actually cause symptoms. If they have a life expectancy that is less than that due to other health issues, than watching is best. The other risk groups, intermediate and high risk, are exactly what I’m talking about. These are the cancers that need treatment and need it urgently, because these are the cancers – intermediate risk can progress at a five to ten year window, high risk in less than five years, to a point where the person actually has symptoms and quality of life is taken down as a result.
One of the novel things currently being done for these men at Brigham and Women’s Hospital (BWH) is the multiparametric MRI. This is a very sophisticated staging study which not only can tell if prostate cancer is likely to be present or not, but how aggressive it is. Something called diffusion weighted imaging, which has only been discovered in the last few years, can be used on this scan to tell us if this man with low risk prostate cancer really is low risk or was something actually missed; was there some higher grade cancer that the needle biopsy missed. So before we put someone on surveillance, and we don’t recommend treatment for their low risk prostate cancer, we obtain an MRI. If there are any suspicious areas that could suggest higher grade disease, we do what’s called an MRI guided biopsy in our AMIGO (Advanced Multimodality Imaging Operating) suite. That’s a suite that’s really state of the art, very few places in the country have it and we’re one of the few places that are very fortunate to have it, and what that allows us to do is under MRI guidance, put the needle right into the suspicious area and ascertain whether or not that area is truly a low risk prostate cancer area or not. I can tell you from our own experience, when we send people with low risk prostate cancer into the AMIGO suite and check to see if they have more aggressive disease, somewhere between one in three and one in two times they actually do, and that can change the entire picture because these cancers can progress more quickly and treatment is indicated.
We’ve just completed a study looking at the value of multi MRI in telling us who is it with intermediate risk prostate cancer who really has high risk. And this is really an important study because the treatment of intermediate risk requires two treatments, usually radiation and a short course of hormonal therapy, a treatment that takes away a man’s testosterone temporarily and kills prostate cancer while it’s doing that because testosterone is food for prostate cancer. And it’s important because with intermediate risk prostate cancer we use radiation, six months of hormonal therapy but with high risk, it’s the same radiation but 18-28 months of hormonal therapy. There have been large studies that show significant increases in cure rates for high risk prostate cancer when you use 18-28 months versus only six months.
Another unique characteristic is that most multidisciplinary teams across the country, and really around the world that treat prostate cancer, include a urologist, a radiation oncologist, a medical oncologist and a pathologist. But here, in addition, we have MRI specialists in prostate cancer who do the multiparametric MRI and the MRI guided biopsy. So we have another team player who provides an additional boost to what we can offer with men, and gets us more towards that personalized approach.
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