Posts Tagged ‘prostate cancer screening’

Cancer Screening Part one: Incidentalomas & PSA

Monday, August 5th, 2013

I was reading the New York Times online today and noticed an important article in the Health section. A working group from the National Cancer Institute (NCI) had just published an article in the pre-print edition of JAMA that will likely change a highly significant face of medicine for many of us.

The issue is cancer diagnosis and, in many cases, over-diagnosis. Some pre-malignant conditions, in the viewpoint of this distinguished group, now come with the word cancer attached. That may lead to extensive testing, surgery or chemotherapy (or radiation therapy) and much mental anguish (and potential physical harm) for the patient involved.

Abnormalities, potentially malignant, can be discovered while scanning or even examining for something else. Dr. Peter Libby, chief of cardiovascular medicine at Brigham and Woman's Hospital in Boston, a Harvard medical school teaching facility, wrote a June 8, 2010 piece in The New York Times titled "The 'Incidentaloma' Problem with Medical Scans." A columnist for that paper had a CT scan for other reasons; a kidney mass was detected and a three-hour operation and eventually a six-inch scar ensued, yet the mass was benign. Dr. Libby's review of the medical literature with his area of expertise in mind showed that greater than eight percent of cardiovascular imaging studies revealed incidental findings that led to further medical procedures.

His conclusion was we're doing far too many CT scans.

Another physician wrote an April, 2011 piece in US News and World Report about a woman referred to him as a followup of an ER visit for abdominal pain that turned out to be viral gastritis. She too had a CT scan which showed her liver and intestines were normal, but one of her kidneys had a tiny mass, almost certainly a benign cyst. But the radiologist, while noting this lesion had all the features of something non-cancerous, covered his or her behind by saying, "Cannot rule out malignancy. Clinical correlation required." Translation: it was almost certainly nothing serious, but there was a very small chance that it might be cancer, and now it was the surgeon's job to make sure it wasn't.

But it's not just those advanced radiologic procedures, or MRIs or other tests; It's the mentality involved and that includes physical exams.

Let me give you a personal vignette. In 1969, as a second year clinical fellow in Nephrology, I went to see the Chief of Urology because of an abnormal lab test that involved my kidney function. A few questions later, he determined it was due to a diet I was on for a research project.

"But as long as you're here, Peter," he said, "I'll check your prostate."

It wasn't quite normal, a tad bigger than it should have been. He said, "You'll have a TURP (transurtheral resection of the prostate) by the time you're sixty"

He recommended I monitor my symptoms (I had none at the time) and get repeat examinations at intervals.

Well, I'm seventy-two and haven't had that surgical procedure. But what I did have, for many years, was a yearly digital prostate exam and, after 1994, a PSA (prostate specific antigen) blood test done periodically. At some point not only was the gland enlarged, but it the urologist involved thought it was also slightly asymmetric, so I had multiple biopsies, even though my PSA had consistently been less than 1.0, e.g., way below the level of concern.

All those biopsies showed benign (non-cancerous) tissue.

Now that I'm over seventy I don't ask for a PSA test, wouldn't agree with one if it were suggested and had my last digital exam of the gland several years ago.

But if I had that cancer at age 28 or 40, I would have been in real trouble. I would have been concerned about a malignancy that would likely kill me and would have welcomed any logical treatment for the disease. The NCI webpage on prostate cancer estimates nearly 240,000 new cases will be diagnosed in the United States this year and almost 30,000 men will die from that disease.

But the natural history of the tumor in most older men (>70 years old) is such that they will most likely die from something else (e.g., heart disease).

The NCI's fact sheet on the PSA test is well worth reading. An initial statement is that the higher a man's PSA level is, the more likely he has cancer of the prostate. Then the caveats begin: there are other reasons for the PSA to be elevated (I now have one of those, BPH or benign prostatic hypertrophy, an enlarged prostate). Half of all men over the age of fifty have BPH that is symptomatic with some hesitancy in starting their urine stream and/or a smaller stream.

If I had actually had cancer of the prostate at age sixty, my PSA may have been elevated. Then I would likely have had surgery to remove the tumor if it was localized to the gland and my physicians would then have periodically repeated my PSA testing to monitor if I had a recurrence of the neoplasm (a new and abnormal growth of tissue in some part of the body, especially as a characteristic of cancer).

A PSA level under 4.0 (nanograms/mililiter) was considered to be normal (my last PSA, done three years ago, was 0.7 ng/mL). In the past, if a man had a PSA level above 4.0 his physician  would have likely suggested biopsy to see if he had prostate cancer. But there are men who have that malignancy and yet have a PSA under 4.0 and, as I mentioned above, other, benign conditions can elevate the PSAwhile some medications used for BPH can lead to a lower PSA level. Only a quarter of those guys who have a prostate biopsy because of a PSA that's elevated actually have cancer of the gland.

But now there's considerable question whether PSA testing should be a routine, even though medicare and many private medical insurance plans cover a yearly screening using this test. The consensus seems to be that men should hear the pros and cons of the test before giving consent for it to be performed.

If 1,000 men in the 55 to 69 age range get screened with this test every one to four years, 100-200 will have false-positive results (no cancer, but an elevated PSA) and may have a biopsy recommended and, of course, worry about what's going on with their prostate.

One hundred ten, according to the cancer.gov website, will be diagnosed as having prostate cancer and nearly half of those will have treatment complications (The National Cancer Institute website mentions sexual dysfunction, bowel or bladder control issues and infections.)

Four to five will actually die from prostate cancer, but five of every 1,000 who don't have the screening will die from that cancer.

So the net is 1,000 have been screened to save 0-1 life.

And to further complicate things, the research done to determine what the normal upper limit of PSA is has largely been done in white men only.

So where do we go from here? There are studies being done to look at precursors of PSA, rate of change of PSA. free versus bound PSA etc.

We need  a better method to tell us if a man has a cancer or a benign prostate condition and to determine which prostate cancers are highly malignant fromt hose that are slow growing.

And all that's just one cancer-screening tool.

 

My prostate and yours: benign and malignant

Wednesday, April 10th, 2013
At my age, I'm not scheduling this.

At my age, I'm not scheduling this.

I just printed an article from the Annals of Internal Medicine that confirms my own leanings toward prostate screening tests. In one of my old posts I told the story of having an abnormal blood test for kidney function and seeking out our senior urologist at Duke. I was a clinical Nephrology fellow at the time and when I was seen, the Chief of Urology asked what kind of diet I was on.

I groaned at that point since I realized I was in the middle of a research project and eating a very high-protein diet. That's why the more accurate of the two blood chemistry tests was entirely normal and the other, clearly influenced by my diet, was high.

He then said, "As long as you're here, Peter, let me check your prostate.

The digital rectal exam (DRE) revealed I had a mildly enlarged gland for my age and the urologist said, "You're going to have a TURP by the time you're sixty.

I knew a TURP was a transurethral resection of the prostate. If you look at the Mayo Clinic website I've provided, you'll see it's a procedure to relieve partial obstruction of the urethra, the tube that runs from the bladder through the penis to allow normal urination. The prostate itself, whose major task is to provide seminal (sperm-carrying) fluid, is a walnut-shaped, one ounce gland, or at least it is in younger men. As men age the prostate commonly enlarges. If it does so in a non-cancerous way, the condition is called BPH, benign prostatic hyperplasia (or hypertrophy as I was taught in medical school; the first term implies more cells; the other a bigger gland without specifying how it got that way).

As the prostate gets bigger and partially blocks the outflow of urine, men have a decreased urine stream, difficulty starting its flow, dribbling after urination or a more frequent need to pee, especially at night.

Urologists do about 150,000 TURPs a year in America, although there are a number of other procedures to treat BPH. And they want to do a DRE and draw blood for a PSA on more of us guys than I would agree with. There are other tests in their repertoire: rectal ultrasound, urine flow study and cystoscopy (inserting an instrument into the urethral to actually look at how narrow the passageway is).

The American Urological Association's (AUA) webpage on the surgical management of the condition says 88% of men who have a TURP will have significant improvement in their symptoms. But there are lots of complications that can occur right after the procedure: infection in 15%, bleeding requiring blood transfusion in 5-10%, impotence in 14%, incontinence in 1%. Ten percent may require a second operation within 5 years.

There also are medical therapies for BPH; I take two different pills a day for my BPH and will turn 72 in two weeks. I haven't needed a TURP yet.

But that's benign disease: how about prostatic cancer?

The ACP says there's debate on screening; what does your physician think?

The ACP says prostate cancer screening should be individualized; what does your physician think?

The recent Annals article I mentioned looked at four sets of prostate cancer screening recommendations, all from national organizations: the American College of Preventive Medicine, the American Cancer Society; the AUA and the U.S. Preventive Services Task Force (USPSTF).

After doing so, the Clinical Guidelines Committee of the American College of Physicians (ACP), a national society of internal medicine physicians, issued two guidance statements. ACP wants all clinicians to tell their male patients who are 50 or older and under age 70 that the positive effects of screening for this malignancy are limited and there are considerable potential negative effects.

That being said, if I were an African American man in that age range I'd be much more likely to ask to be screened. Both the incidence rate and the mortality rate from prostate cancer are higher in black men. And if I had a family history of the disease in a first-degree relative (father, brother or son), I might be first in line for a PSA and possibly a DRE. With one such having had it, my risk doubles and with two close relatives having the disease, my chances go up fourfold. That's especially true if they were diagnosed before they turned 65.

Overall a sixth of all men will eventually be diagnosed with cancer of the prostate. It will lead directly to death in a much lower percentage (2.9% was the figure the ACP quoted from a National Cancer Institute fact sheet). So although 2.3-2.5 million men in this country are living with this malignancy and last year nearly a quarter of a million got the diagnosis of prostate cancer in the U.S., a considerably smaller number were likely to die from the cancer itself.

Why does this make sense?

Well let's start with the second of the ACP's guidance statements: the organization says that men with an average risk of the disease shouldn't be screened until they are 50 and those of us 70 and older also should avoid having a PSA as a cancer screening tool. They go further and say men who are not expected to live more than 10 to 15 more years also should not be screened.

The fact sheet from the Prostate Cancer Foundation says it is the most common non-skin cancer in America with a new case very 2.2 minutes and a death every 17.5 minutes. But it's rare in men under 40 with 1 in 10,000 being diagnosed with the ailment versus 1 in 14 who are aged 60 to 69.

If we look at the totals: 97% of men diagnosed with prostate cancer are 50 or older and nearly two-thirds  are over 65.

The USPSTF came out with an update to their take on screening guidelines in 2012. They agree that the benefits of these tests, primarily the PSA, are less than the potential harm associated: false-positive tests, psychological effects, biopsies that are not necessary and over-diagnosis of cancers that often do not reach any clinical significance in the lifetime of the patient involved.

In other words, elderly men may well have prostate cancer, but they most commonly die from something else. And screening men at age 40, as the AUA suggest, doesn't appear to be based on any major studies.

If you are a man over 50, but less than 70, or black or first-degree relatives (father or brothers) have had the disease, have a sincere talk with your doc about the risks and benefits of screening.

But I don't fit into any of those groups, so I don't plan to get a PSA unless or until I see different data.

Thank you, ACP, for clarifying the subject, especially since you agree with me.