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Racial differences have long been evident in prostate cancer statistics. In particular, African American men are diagnosed with prostate cancer more often than white men, and they’re also nearly twice as likely to die of the disease.

But new research also shows that African American men who receive the most advanced treatments for late-stage prostate cancer can live at least as long — or even longer — than their Caucasian counterparts.

Why is this the case? Scientists are searching for an explanation. “The fact that African American men have better survival is of huge research interest,” said Dr. Stephen Freedland, a urologist at Cedars-Sinai Medical Center in Los Angeles. “If we can figure this out, we’ll obtain key insights into the factors driving survival in late-stage prostate cancer. And that in turn will help spur better treatments for all men — regardless of race.”

Each year, about 160 per 100,000 African American men receive a prostate cancer diagnosis. That’s three times higher than the comparable figure for white American men, and it’s also higher than the number of black men diagnosed annually with prostate cancer in Africa. It’s possible that dietary or environmental factors — perhaps in combination with genetic susceptibilities — put African American men at greater risk in the United States. But African American men also tend to have less access to health care than white Americans, and many of them are diagnosed after their tumors have already begun to metastasize, or spread.

A surprising survival advantage

What the new research shows, however, is that survival advantages can favor African Americans who undergo treatment for advanced prostate cancer in clinical trials. One study  pooled data from nine clinical trials, enrolling a combined 88,200 men with metastatic prostate cancer who were treated with a chemotherapy drug called docetaxel. The African American and white men had similar survival rates — 21 months and 21.2 months respectively. But after adjusting for factors such as age and prostate-specific antigen levels, the researchers found that African Americans were 20% less likely to have died during the course of those trials than their white counterparts.

Freedland co-authored another recent study showing that African Americans respond better to newer drugs that target testosterone, which is a hormone that drives prostate cancer to grow faster. Using data gathered by the Veterans Health Administration between 2013 and 2018, the researchers looked at how long African American and white men with metastatic prostate cancer lived after treatment with one of two drugs: abiraterone acetate or enzalutamide. They had access to records from nearly 3,000 men. The unpublished results, presented at a medical conference in February, showed that median survival among the African Americans lasted 30 months, compared to 26 months among their white counterparts. “So, the key takeaway is that if they get to advanced prostate cancer, and are treated equally in an equal access medical center, black men can have similar or even better outcomes,” Freedland said.

The data still need to be confirmed in additional research, Freedland emphasized. But in the meantime, the studies add to a growing body of evidence that’s changing how scientists look at racial differences in prostate cancer. Ideally, the research will reveal new biological insights into prostate cancer, and allow doctors to tailor treatments more effectively.

The post African American men respond better to treatments for advanced prostate cancer in clinical trials appeared first on Harvard Health Blog.

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Tumors that spread, or metastasize, in the body shed cells into blood that doctors can scrutinize for insights into what a patient’s cancer might do. Analyzing these so-called circulating tumor cells (CTCs) isn’t part of routine care yet, in part because they’re so hard to pick out of the millions of normal cells in a blood sample.

Still, scientists are making progress in this area. And in June, a research team reported that treatment decisions made on the basis of CTC testing had increased lifespans in men with an aggressive type of metastatic prostate cancer.

Doctors usually treat metastatic prostate cancer with drugs that interfere with how a man’s body makes or uses testosterone, which is the male hormone (or androgen) that accelerates the tumor’s spread. If the standard hormone-blocking treatments aren’t effective, then doctors have two other options: they can either give chemotherapy drugs known as taxanes, or shift to other hormone blockers that act specifically on the cancer cell’s androgen receptor. Known as androgen receptor signaling (ARS) inhibitors, these alternative hormone blockers include an agent called enzalutamide and another called abiraterone. But neither of them will work if the androgen receptor has a genetic mutation called AR-V7 that also makes the tumors grow very aggressively.

With mounting evidence showing that the mutation doesn’t affect a man’s response to taxanes, researchers began to wonder if screening for AR-V7 in CTCs could guide them to the most appropriate treatment. That’s what a team at the Memorial Sloan Kettering Cancer Center in New York set out to investigate.

Here’s what they did

They began by collecting blood samples from 142 men with metastatic prostate cancer who weren’t responding to standard hormonal therapy. After their CTCs were screened for the AR-V7 protein, the men were treated either with ARS inhibitors or taxanes at their doctor’s discretion. The treating doctors had no knowledge of each patient’s AR-V7 status.

Half the men wound up being treated with ARS inhibitors and the other half with taxanes. And as it turns out, the men who tested negative for AR-V7 lived longer when treated with ARS inhibitors; their median survival was 19.8 months, compared to 12.8 months among the taxane-treated men. Conversely, the men who tested positive for AR-V7 lived longer when given taxanes: their median survival was 14.3 months, compared to 7.3 months among the men treated with ARS inhibitors.

The results mark a significant advance for AR-V7 as a guide to more effective, personalized treatment, and also for CTCs as “liquid biopsies” that doctors can easily sample for important prognostic information.

“The research adds to an expanding body of knowledge related to AR-V7 in prostate cancer,” said Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of HarvardProstateKnowledge.org. “Hopefully the utility and availability of this test will become more widespread, and further enhance our ability to select the best treatments for specific patients based on the molecular characteristics of their disease.”

— Charlie Schmidt

The post New blood test guides researchers toward the best treatment for aggressive prostate cancer appeared first on Harvard Health Blog.

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Back in 2012, the US Preventive Services Task Force (USPSTF) took aim at the prostate-specific antigen (PSA) screening test for prostate cancer with a blanket recommendation against it for all men. This was a big deal. The Task Force is widely seen as the top expert panel on cancer screening in the United States, and most men find out they have the disease only after a PSA test comes back with a positive result.

Cut to May 2018, and the Task Force has finalized a new statement. Instead of broadly recommending against PSA testing regardless of a man’s age, race, or family history of prostate cancer, the Task Force now states that for men ages 55 to 69, the decision to be screened “should be an individual one” informed by discussing the pros and cons with a clinician. The Task Force continues to recommend against the PSA test for men 70 and older, claiming there is no evidence they’ll live longer if treated for prostate cancer. And citing inadequate data, it makes no recommendation at all for African American men (who tend to be at higher risk for prostate cancer than men of other races), men with a family history of prostate cancer, or men younger than 55.

Why has the Task Force now made this age-specific change?

Several issues are at play. Importantly, more time has passed since the largest trials of prostate cancer screening were initially launched. And with longer follow-up, the evidence in support of screening is more favorable. For instance, the European Randomized Study of Screening for Prostate Cancer (ERSPC), which was initiated in the early 1990s, recently concluded that PSA testing in the 55–69 age group could prevent 13 prostate cancer deaths (and 30 tumors from spreading) for every 10,000 men screened over 13 years. In 2012, the ERSPC’s follow-up was limited to nine years, and the estimate then was that seven prostate cancer deaths would be prevented for every 10,000 men screened.

The task force cited yet another promising trend: more men with low-risk prostate cancer are opting for active surveillance instead of treatment. Active surveillance involves routine PSA tests, digital rectal exams, and scheduled biopsies (or MRIs), and reverts to therapy only in the event that a man’s tumor begins to grow, or if genetic tests predict the cancer could become active and spread later. With active surveillance growing in popularity, the pendulum on screening is swinging closer to its benefits and away from its harms.

Potential harms of the PSA test

Still, the harms from screening are substantial, and men need to be aware of them. Here are statistics cited by the Task Force in its new statement: It’s estimated that 15% of screened men will have false-positive results (the rate is even higher for men over 70), suggesting the presence of cancer that isn’t really there. Many such men will get a biopsy and be exposed to accompanying risks that include pain, bloody semen, and infection. And there’s a good chance the biopsy will detect a slow-growing tumor that doesn’t need treatment. Autopsy studies of men who died from other causes revealed that 20% of those ages 50 to 59 — and 33% of those 70 to 79 — had microscopic, slow-growing prostate tumors that hadn’t bothered them yet and likely never would have in the future.

Meanwhile, prostate cancer treatment is life-altering. One in five men who have their prostates surgically removed will develop long-term incontinence, and two-thirds will develop long-term impotence. Among men treated with radiation, half will become impotent and one in six will develop bothersome bowel problems. Men diagnosed and treated over the age of 70 experience the highest rates of medical complications.

Experts weighing in with editorials on the Task Force’s new statement were mostly positive. But some emphasized the potential benefits of “smart” screening that targets the PSA test at specific groups. Dr. Peter Carroll, professor and chair of urology at the University of California, San Francisco, urged that men get a baseline PSA level at 45, and suggested that men with higher levels could be retested more frequently than those with lower levels. Older men in excellent health may also consider PSA testing, he wrote, since they’re at greater risk of dying from aggressive prostate cancer. And despite the limited evidence on screening high-risk populations, such as African American men and men with a family history of prostate cancer, the case for screening them with a PSA test “is strong,” he wrote.

Questions remain for men

Ultimately, the choice to have the test depends on meaningful discussions with a doctor focusing on the risks and benefits of follow-up procedures that could be undertaken if the PSA results exceed the normal range.

In the view of Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of HarvardProstateKnowledge.org, the Task Force correctly stated in 2012 that the harms of PSA testing outweigh its benefits. Too often the PSA test leads to a prostate biopsy, he says, followed by a cancer diagnosis and “almost inevitable treatment even in men who did not need to be diagnosed in the first place.” However, Garnick also emphasized that clinicians can now better predict a cancer’s likely behavior based on the molecular features of the tumor biopsy. And with that information, fewer men are being rushed toward immediate treatment.

“The identification of characteristics that would encourage a physician to advocate that the cancer be treated is an important step forward, and is the subject of intense research to help determine what that best type of treatment should be,” Garnick said.

— Charlie Schmidt

The post Influential task force issues new recommendations on prostate cancer screening appeared first on Harvard Health Blog.

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A specialized type of diagnostic MRI scan can reduce the number of invasive prostate biopsies by nearly a third, according to results from a newly published international study.

An MRI machine uses a very large magnet, a radio-wave transmitter, and a computer to construct detailed pictures of structures inside the body. The new study relied on an advanced form of this technology, called a multi-parametric MRI scan, which allows specially trained radiologists to detect prostate tumors. Radiologists can also gauge how aggressive those tumors are by looking at how tightly their cells are packed and how blood and water molecules flow through them.

 What the researchers did

During the study, researchers enrolled 500 men who were previously found to have suspicious findings from either a prostate-specific antigen (PSA) screening test for cancer or a digital rectal exam. Half the enrolled men got a standard prostate biopsy, which takes 10 to 12 cores from the gland under ultrasound guidance. The other half got a diagnostic MP-MRI scan. If the scan revealed potential cancer in the prostate, then the men had a biopsy guided by MP-MRI instead of ultrasound. If the scans detected no evidence of cancer, then the men were spared a biopsy.

What the study found

Among nearly a third of the men in the MP-MRI scanning group (28%), imaging results showed no evidence of cancer, so these men avoided a biopsy. Among the rest of the men in this group, scanning results did show evidence of cancer. Those men had a biopsy under MP-MRI guidance that turned out to be better at detecting aggressive tumors than the standard biopsy was. Specifically, aggressive cancer was detected in 38% of men biopsied with the MRI-guided method, compared to 26% of men who got the standard ultrasound-guided biopsy.

In other words, standard biopsies were more likely to miss aggressive tumors that could prompt treatment recommendations. Moreover, they also overdiagnosed clinically insignificant prostate cancers that might never become life-threatening, the results showed. Furthermore, since the MRI-guided biopsy takes fewer cores from the prostate than the standard biopsy does, it poses fewer risks of infections and other related complications, according to the study’s lead author, Veeru Kasivisvanathan, from University College London (UCL) in the UK.

The study results are clear,” Kasivisvanathan said. “I would not want to have a biopsy without having an MP-MRI scan of the prostate first. And the MRI-guided biopsy is better at identifying men who actually need treatment for prostate cancer, as well as those who won’t benefit from it.” Kasivisvanathan emphasized that the enrolled men with negative scanning results who didn’t get a biopsy will still be monitored with PSA surveillance. “Such men should not be lost in the system,” he said.

Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of HarvardProstateKnowledge.org, affirmed that this is an important study. The current practice now, he said, is to give a standard biopsy first and then follow-up with MRI to guide treatment if the biopsy results are positive. Garnick worries that men with high PSA levels who avoid a biopsy on the basis of a diagnostic MP-MRI scan may still have cancer that the biopsy could otherwise have detected. Diagnostic scanning “requires radiologists who are skilled in the interpretation of MP-MRI as well as state-of-the-art machinery,” he said. “Those two requirements need to be in place before the current standard is disrupted.”

— Charlie Schmidt

The post Diagnostic MRIs allow some men flagged by PSA screening to avoid a biospy, new study shows appeared first on Harvard Health Blog.

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To screen or not to screen for prostate cancer? This remains an important question. Screening relies on a highly imperfect measure, the prostate-specific antigen (PSA) blood test, which is prone to false-positive results. And with mounting evidence that survival benefits from screening pale in comparison with the harms from overtreatment — particularly incontinence and impotence — the pendulum has steadily swung away from it. Still, screening research continues, in the hopes that some lifesaving benefits may be found.

Now the latest study once again casts doubt on PSA screening as an effective public health tool.

British scientists divided more than 400,000 men between the ages of 50 and 69 into two groups: one was screened for prostate cancer with a single PSA test, and the other wasn’t tested for the disease at all. After an average of 10 years of follow-up, prostate cancer death rates in both groups were nearly identical. Cancer was detected more often in the screened group, but mostly it was low-grade, with a questionable need of treatment.

“This was the largest study of PSA screening to date, and the results don’t support it,” said Dr. Michael J. Barry, a professor of medicine at Harvard Medical School, and author of an editorial accompanying the published study.

Called the Cluster Randomized Trial of PSA Testing for Prostate Cancer (CAP), the study’s approach of giving men a single PSA test differs from the more traditional strategy of testing men repeatedly every few years. However, prior studies investigating repeated PSA tests have reached similar conclusions. One European study with 162,000 men, for instance, concluded that for every life saved by screening, 27 men would be diagnosed and treated for prostate cancer that wouldn’t have been lethal if left undetected.

During the CAP study, 189,386 men were assigned to screening and 219,439 men were assigned to a non-screening control group. After 10 years on average, 549 of the screened men had died from prostate cancer, compared to 647 men in the control group who hadn’t gotten a PSA test. The number of prostate cancer deaths among the controls was higher, but so was the number of men in that group to begin with. So the researchers adjusted for the different sample sizes with a statistical tweak: they compared death rates in terms of person-years, or the total number of years that men in either group had participated to the study. Analyzed that way, the study revealed 0.30 prostate cancer deaths per 1,000 person-years in the screened group, and 0.31 deaths from prostate cancer per 1,000 person-years in the controls, which amounts to a negligible difference.

Dr. Barry, who was recently a member of the US Preventative Services Task Force, an influential group of independent experts who publicly discourage PSA screening, emphasized that most men who opt for the test get it more than once. And with each additional PSA test, he said, the odds of being diagnosed with prostate cancer grow higher. “But is repeat screening worth the risk of a low-grade cancer diagnosis and all the treatment complications that come with it?” he asked. “It’s hard for us as clinicians to make those decisions for our patients. We need to make them with our patients to determine if they feel those risks are worth taking on.”

Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of HarvardProstateKnowledge.org, agreed. “This study adds to the discouraging screening literature, and again, simply does not support screening of asymptomatic individuals,” he said.

Fortunately, Garnick added, men diagnosed with prostate cancer following a PSA test may not have to be treated either in the short or long term. Depending on tumor characteristics, some can opt to have their cancer monitored with active surveillance, which relies on periodic prostate biopsies or MRI to look for new signs that treatment may be necessary. “Hopefully, current research that uses sophisticated genetic testing or biomarkers of prostate cancer may help provide more precise information about those who are likely to most benefit from screening and treatment,” Garnick said. “But we are not there yet.”

—  Charlie Schmidt

The post New study once again casts doubt on PSA screening appeared first on Harvard Health Blog.

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For men diagnosed with aggressive cancer that’s confined to the prostate and nearby tissues, the overarching goal of treatment is to keep the disease from spreading (or metastasizing) in the body. Doctors can treat these men with localized therapies, such as surgery and different types of radiation that target the prostate directly. And they can also give systemic treatments that kill off rogue cancer cells in the bloodstream. Hormonal therapy, for instance, is a systemic treatment that kills prostate cancer cells by depriving them of testosterone, which fuels their growth.

Now a new study shows that a mix of different treatments, or a “multimodal” approach to prostate cancer therapy, lengthens survival in men who have this diagnosis. The study was limited to men with Gleason 9 and 10 cancers. The Gleason grading system ranks tumors by how likely they are to spread, and 10 is the highest rank on the scale.

“The takeaway finding is that men with high-grade, localized prostate cancer do better when they get multimodal care,” said Dr. Amar Kishan, an assistant professor of radiation oncology at the University of California, Los Angeles David Geffen School of Medicine, who led the study. “If they can tolerate it, then that’s what should be offered.”

Kishan and collaborators from 12 large hospitals in the United States and Norway pooled nearly 20 years of patient data from their respective institutions. The 1,809 men included in the study had each been treated in one of three different ways:

  • with surgery to remove the prostate
  • with a combination of external beam radiation (which directs high-energy rays at the tumor from sources outside the body) directed at the prostate, along with anti-testosterone hormonal therapy
  • with hormonal therapy given together with external beam radiation and brachytherapy (which involves placing radioactive beads directly into the prostate gland).

After an average of five years of follow-up, 3% of the men given all three treatments (external beam radiation, brachytherapy, and hormone therapy) had died from prostate cancer. By contrast, 12% of the men treated with a combination of hormonal therapy and external beam radiation, and 13% of the men treated with surgery only, had died of their illness. Findings of metastatic cancer were similar, averaging 8% in the group given all three treatments, and 24% in the two other groups.

Side effects data from each group were not available.

This is the largest study yet to compare the three approaches, and importantly, it was restricted to men who began treatment no earlier than 2000. Radiation therapy has improved over time: the doses are higher and the treated areas are more precisely defined. Therefore, the evaluated approaches are consistent with the kind of treatments men would still get today.

Kishan said it’s possible that combining hormonal therapy with high-dose radiation and brachytherapy eliminates cancer in the prostate completely, so that metastases are held in check. Or, he says, radiation might stimulate the immune system to attack cancer. These hypotheses are now under investigation by researchers around the world.

Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of HarvardProstateKnowledge.org, said the study adds to growing evidence that therapies directed solely to the prostate gland, namely radiation or surgery by itself, may be improved by adding other treatments; in this case, hormonal therapy and a second form of radiation. “The study didn’t evaluate the addition of hormonal therapy to surgery, which would have been of interest,” he added. “However, the findings support multimodal therapy, though many unknowns, such as the potential for greater long-term side effects, still need to be addressed.”

— Charlie Schmidt

The post A mix of treatments may extend life for men with aggressive prostate cancer appeared first on Harvard Health Blog.

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A newly approved drug called apalutamide is giving hope to thousands of men confronting a tenacious problem after being treated for prostate cancer. Prostate-specific antigen (PSA) levels should plummet to zero after surgery, and to near zero after radiation therapy, but in some men, they continue rising even when there’s no other evidence of cancer in the body. Doctors typically respond to spiking PSA with drugs that block the production of testosterone, which is the male sex hormone that fuels prostate cancer. However, this type of medically induced castration, called hormonal therapy, doesn’t always reduce PSA. Moreover, prostate cancer cells can become resistant to hormonal therapy, after which PSA resumes its upward march. This is called non-metastatic castration resistant prostate cancer (nmCRPC), and it often precedes the appearance of metastatic tumors that show up later.

The dearth of approved treatments for nmCRPC has long frustrated patients and their doctors alike. But in February, the US Food and Drug Administration approved apalutamide for men who have nmCRPC after results from the SPARTAN clinical trial showed the drug could delay metastases by up to two years. “Based on these clinical trial results, apalutamide should be considered the new standard of care for nmCRPC,” said Dr. Matthew Smith, a medical oncologist at Massachusetts General Hospital who led the study. “The drug addresses a great clinical need and holds the promise of longer survival for men whose cancer defies hormonal therapy.”

The SPARTAN trial enrolled 1,207 men whose PSA levels doubled within 10 months or less after initial treatment despite ongoing hormonal therapy. Enrolled men were assigned to either daily apalutamide tablets combined with hormonal therapy, or to hormonal therapy combined with placebo. Doctors usually stick with hormonal therapy even after PSA levels rise, since it prevents the body from recovering its ability to make testosterone. Men continued on the study until the first metastases were detected, and then they were given other drugs used for treating metastatic prostate cancer.

According to the results, those taking apalutamide avoided metastases for a median of 40.5 months (meaning half were free of metastases for longer than that, and the other half for less). The placebo-treated men, meanwhile, remained free of metastases for a median of 16.2 months, about two years less. Furthermore, apalutamide treatment “delayed symptomatic progression, pain, and other symptoms that patients experience as a consequence of their cancer,” Smith said. But apalutamide, which prevents testosterone from interacting with its receptor on cancer cells, was also associated with more frequent significant side effects, such as fatigue, rash, weight loss, falls, and skeletal fractures.

Based on accumulating evidence, Smith anticipates that longer freedom from metastases equates with longer overall survival in men with nmCRPC. However, whether that’s true remains to be seen. “So far, outcomes suggest men will live longer on apalutamide,” said Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of HarvardProstateKnowledge.org. “The anxiety most patients experience when PSA increases after what was thought to be curative is significant. Continuing with this new therapy should be considered between appropriately selected patients and their doctors after a full discussion of the potential benefits and risks.”

—  Charlie Schmidt

The post FDA approves new drug for men at high risk of prostate cancer spread appeared first on Harvard Health Blog.

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Tumors that spread, or metastasize, in the body shed cells into blood that doctors can scrutinize for insights into what a patient’s cancer might do. Analyzing these so-called circulating tumor cells (CTCs) isn’t part of routine care yet, in part because they’re so hard to pick out of the millions of normal cells in a blood sample. Still, scientists are making progress in this area. And in June, a research team reported that treatment decisions made on the basis of CTC testing had increased lifespans in men with an aggressive type of metastatic prostate cancer.

Doctors usually treat metastatic prostate cancer with drugs that interfere with how a man’s body makes or uses testosterone, which is the male hormone (or androgen) that accelerates the tumor’s spread. If the standard hormone-blocking treatments aren’t effective, then doctors have two other options: they can either give chemotherapy drugs known as taxanes, or shift to other hormone blockers that act specifically on the cancer cell’s androgen receptor. Known as androgen receptor signaling (ARS) inhibitors, these alternative hormone blockers include an agent called enzalutamide and another called abiraterone. But neither of them will work if the androgen receptor has a genetic mutation called AR-V7 that also makes the tumors grow very aggressively.

With mounting evidence showing that the mutation doesn’t affect a man’s response to taxanes, researchers began to wonder if screening for AR-V7 in CTCs could guide them to the most appropriate treatment. That’s what a team at the Memorial Sloan Kettering Cancer Center in New York set out to investigate.

Here’s what they did

They began by collecting blood samples from 142 men with metastatic prostate cancer who weren’t responding to standard hormonal therapy. After their CTCs were screened for the AR-V7 protein, the men were treated either with ARS inhibitors or taxanes at their doctor’s discretion. The treating doctors had no knowledge of each patient’s AR-V7 status.

Half the men wound up being treated with ARS inhibitors and the other half with taxanes. And as it turns out, the men who tested negative for AR-V7 lived longer when treated with ARS inhibitors; their median survival was 19.8 months, compared to 12.8 months among the taxane-treated men. Conversely, the men who tested positive for AR-V7 lived longer when given taxanes: their median survival was 14.3 months, compared to 7.3 months among the men treated with ARS inhibitors.

The results mark a significant advance for AR-V7 as a guide to more effective, personalized treatment, and also for CTCs as “liquid biopsies” that doctors can easily sample for important prognostic information.

“The research adds to an expanding body of knowledge related to AR-V7 in prostate cancer,” said Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of HarvardProstateKnowledge.org. “Hopefully the utility and availability of this test will become more widespread, and further enhance our ability to select the best treatments for specific patients based on the molecular characteristics of their disease.”

The post New blood test may someday help guide the best treatment for aggressive prostate cancer appeared first on Harvard Health Blog.

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To screen or not to screen for prostate cancer? This remains an important question. Screening relies on a highly imperfect measure, the prostate-specific antigen (PSA) blood test, which is prone to false-positive results. And with mounting evidence that survival benefits from screening pale in comparison with the harms from overtreatment — particularly incontinence and impotence — the pendulum has steadily swung away from it. Still, screening research continues, in the hopes that some lifesaving benefits may be found.

Now the latest study once again casts doubt on PSA screening as an effective public health tool.

British scientists divided more than 400,000 men between the ages of 50 and 69 into two groups: one was screened for prostate cancer with a single PSA test, and the other wasn’t tested for the disease at all. After an average of 10 years of follow-up, prostate cancer death rates in both groups were nearly identical. Cancer was detected more often in the screened group, but mostly it was low-grade, with a questionable need of treatment.

“This was the largest study of PSA screening to date, and the results don’t support it,” said Dr. Michael J. Barry, a professor of medicine at Harvard Medical School, and author of an editorial accompanying the published study.

Called the Cluster Randomized Trial of PSA Testing for Prostate Cancer (CAP), the study’s approach of giving men a single PSA test differs from the more traditional strategy of testing men repeatedly every few years. However, prior studies investigating repeated PSA tests have reached similar conclusions. One European study with 162,000 men, for instance, concluded that for every life saved by screening, 27 men would be diagnosed and treated for prostate cancer that wouldn’t have been lethal if left undetected.

During the CAP study, 189,386 men were assigned to screening and 219,439 men were assigned to a non-screening control group. After 10 years on average, 549 of the screened men had died from prostate cancer, compared to 647 men in the control group who hadn’t gotten a PSA test. The number of prostate cancer deaths among the controls was higher, but so was the number of men in that group to begin with. So the researchers adjusted for the different sample sizes with a statistical tweak: they compared death rates in terms of person-years, or the total number of years that men in either group had participated to the study. Analyzed that way, the study revealed 0.30 prostate cancer deaths per 1,000 person-years in the screened group, and 0.31 deaths from prostate cancer per 1,000 person-years in the controls, which amounts to a negligible difference.

Dr. Barry, member of the US Preventative Services Task Force, an influential group of independent experts who make evidence-based recommendations about clinical preventive services, emphasized that most men who opt for the test get it more than once. And with each additional PSA test, he said, the odds of being diagnosed with prostate cancer grow higher. “But is repeat screening worth the risk of a low-grade cancer diagnosis and all the treatment complications that come with it?” he asked. “It’s hard for us as clinicians to make those decisions for our patients. We need to make them with our patients to determine if they feel those risks are worth taking on.”

Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of HarvardProstateKnowledge.org, agreed. “This study adds to the discouraging screening literature, and again, simply does not support screening of asymptomatic individuals,” he said.

Fortunately, Garnick added, men diagnosed with prostate cancer following a PSA test may not have to be treated either in the short or long term. Depending on tumor characteristics, some can opt to have their cancer monitored with active surveillance, which relies on periodic prostate biopsies or MRI to look for new signs that treatment may be necessary. “Hopefully, current research that uses sophisticated genetic testing or biomarkers of prostate cancer may help provide more precise information about those who are likely to most benefit from screening and treatment,” Garnick said. “But we are not there yet.”

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For men diagnosed with aggressive cancer that’s confined to the prostate and nearby tissues, the overarching goal of treatment is to keep the disease from spreading (or metastasizing) in the body. Doctors can treat these men with localized therapies, such as surgery and different types of radiation that target the prostate directly. And they can also give systemic treatments that kill off rogue cancer cells in the bloodstream. Hormonal therapy, for instance, is a systemic treatment that kills prostate cancer cells by depriving them of testosterone, which fuels their growth.

Now a new study shows that a mix of different treatments, or a “multimodal” approach to prostate cancer therapy, lengthens survival in men who have this diagnosis. The study was limited to men with Gleason 9 and 10 cancers. The Gleason grading system ranks tumors by how likely they are to spread, and 10 is the highest rank on the scale.

“The takeaway finding is that men with high-grade, localized prostate cancer do better when they get multimodal care,” said Dr. Amar Kishan, an assistant professor of radiation oncology at the University of California, Los Angeles David Geffen School of Medicine, who led the study. “If they can tolerate it, then that’s what should be offered.”

Kishan and collaborators from 12 large hospitals in the United States and Norway pooled nearly 20 years of patient data from their respective institutions. The 1,809 men included in the study had each been treated in one of three different ways:

  • with surgery to remove the prostate
  • with a combination of external beam radiation (which directs high-energy rays at the tumor from sources outside the body) directed at the prostate, along with anti-testosterone hormonal therapy
  • with hormonal therapy given together with external beam radiation and brachytherapy (which involves placing radioactive beads directly into the prostate gland).

After an average of five years of follow-up, 3% of the men given all three treatments (external beam radiation, brachytherapy, and hormone therapy) had died from prostate cancer. By contrast, 12% of the men treated with a combination of hormonal therapy and external beam radiation, and 13% of the men treated with surgery only, had died of their illness. Findings of metastatic cancer were similar, averaging 8% in the group given all three treatments, and 24% in the two other groups.

Side effects data from each group were not available.

This is the largest study yet to compare the three approaches, and importantly, it was restricted to men who began treatment no earlier than 2000. Radiation therapy has improved over time: the doses are higher and the treated areas are more precisely defined. Therefore, the evaluated approaches are consistent with the kind of treatments men would still get today.

Kishan said it’s possible that combining hormonal therapy with high-dose radiation and brachytherapy eliminates cancer in the prostate completely, so that metastases are held in check. Or, he says, radiation might stimulate the immune system to attack cancer. These hypotheses are now under investigation by researchers around the world.

Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of HarvardProstateKnowledge.org, said the study adds to growing evidence that therapies directed solely to the prostate gland, namely radiation or surgery by itself, may be improved by adding other treatments; in this case, hormonal therapy and a second form of radiation. “The study didn’t evaluate the addition of hormonal therapy to surgery, which would have been of interest,” he added. “However, the findings support multimodal therapy, though many unknowns, such as the potential for greater long-term side effects, still need to be addressed.”

The post A mix of treatments may extend life for men with aggressive prostate cancer appeared first on Harvard Health Blog.

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