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Posts tagged ‘Prostate Cancer Treatment’

That was the question that I asked Walter Artibani, Professor and Chair of Urology at the University of Verona during the recent European Association of Urology (EAU) annual Congress in Paris.

Urologists have failed as scientists to generate evidence based medicine

Professor Artibani told the assembled media that urologists had failed as scientists in not generating robust clinical data to support the use of the da Vinci robotic system for the removal of the prostate gland (prostatectomy).

Something that I was not aware of until I attended the media briefing was that so called “robotic surgery” is not an automated robot performing the surgery on its own, but instead it’s actually robot assisted surgery.

The da Vinci surgical device (currently the only one on the market) is a telemanipulation system where the surgeon sits at a remote console and operates a surgical cart with three or four arms that are docked with endoscopic instruments that are inserted into the patient.

Professor Artibani in response to my question said:

“After 10 years, the urologic community missed the window to have prospective randomized clinical trial in order to have clear answers.”

What’s more he went on to say that he believed it would be unlikely we could now do a prospective trial that compared robot-assisted prostatectomy to laparascopic prostatectomy to open prostatectomy. The reason for this was that :

“Most of the patients are convinced that the new way, the novel way is the better way.”

The following is a video excerpt of Professor Artibani’s answer to my questions.  For digital accuracy, viewers should note that I added in some slides he presented earlier, and included a graphic of the paper he referenced.

Have the media sensationalized robotic surgery?

Artibani went on to say in his answer to my question that the media and journalists have not always reported the lack of robust data surrounding new surgical techniques:

“It is easy just to give the information that what is new is better and this must be demonstrated by robust data before giving the information. Unfortunately sensationalism is more important than to say and to write robust data.”

Healthcare journalists have an obligation to report on the limitations of new techniques and lack of evidence based medicine is an important one!  Gary Schwitzer’s healthcare journalist watchdog, Health News Review, attempts to hold the media to account.

We should clearly challenge surgical practice for which there is a lack of robust clinical data or evidence based medicine, and avoid sensationalism.

However, whatever the limitations of the media reporting, the reason for the lack of evidence based medicine rests firmly with the academic urology community.

Low quality of evidence for Robot-Assisted Laparoscopic Prostatectomy

In an editorial in the journal “European Urology,” Markus Graefen noted the low quality of urology research that was being published did not just apply to robot-assisted prostatectomy.  He noted that in urology,

“The number of low-quality papers is increasing; however, the body of evidence and the knowledge we have about the reported outcomes, unfortunately, is not.”

 

He went on to describe the need to counsel patients on the different surgical approaches available to them:

A patient with a newly diagnosed prostate cancer who is counselled for his therapeutic options today should be informed that several equal surgical approaches are available and that despite all the perfectly styled Web pages, it is not the robot that makes the difference.

He should be informed that there are indeed concerns about oncologic and functional outcomes and also evidence that in some significant papers the traditional surgical approaches look superior.

This editorial suggests that patients should ignore the marketing hype about new equipment or the notion that “new is better,” but instead focus on the experience of the surgeon with that equipment and the functional outcomes that a surgeon obtains in his/her patients.

Patients are interested in functional outcomes and low complication rates

What I heard at EAU from urologists is that patients are interested in a good functional outcome and low complication rate.

There is, however, no level 1 evidence that post-operative urinary incontinence and erectile dysfunction rates are generally better with robot-assisted radical prostatectomy.

Diana Kang and colleagues in a review of seventy-five research publications between 2005 and 2008 that reported robot-assisted laparscopic prostatectomy (RALP) data, concluded that there was a need to raise the standards of urology clinical research:

Our findings draw into question to what extent valid conclusions about the relative superiority or equivalence of RALP to other surgical approaches can be drawn and whether published outcomes can be generalised to the broader community.

There is an urgent need to raise the methodologic standards for clinical research on new urologic procedures and devices.

Men with prostate cancer who are considering surgery should be informed that there is no high-level or robust evidence to show the general superiority of robotic-assisted prostatectomy compared to other surgical techniques for radical prostatectomy.

Hopefully, the demand for evidence based urology treatment will grow, and that lessons have been learned from the way robotic-assisted surgery was introduced. Men with prostate cancer do deserve better.

ResearchBlogging.orgKang, D., Hardee, M., Fesperman, S., Stoffs, T., & Dahm, P. (2010). Low Quality of Evidence for Robot-Assisted Laparoscopic Prostatectomy: Results of a Systematic Review of the Published Literature European Urology, 57 (6), 930-937 DOI: 10.1016/j.eururo.2010.01.034

Graefen, M. (2010). Low Quality of Evidence for Robot-Assisted Laparoscopic Prostatectomy: A Problem Not Only in the Robotic Literature European Urology, 57 (6), 938-940 DOI: 10.1016/j.eururo.2010.02.004

The recent announcement from the United States Preventative Services Task Force (USPSTF) on prostate cancer screening has stimulated a lot of debate.  “Dr Len’s Cancer Blog” from the American Cancer Society has a thoughtful piece about the “to screen or not to screen” dilemma. It is reminiscent of the breast cancer mammography debate.

Scott Hensley’s post on “Shots”, the NPR health blog also provides a good overview of the debate and issues. I confess I was surprised by the vehemence of the response from some practising urologists on twitter such as Dr Benjamin J. Davies (@daviesbj), Assistant Professor of Urology at the University of Pittsburgh School of Medicine:

What do the US Preventative Task Force authors say? In the findings published in the October 7, 2011 issue of the Annals of Internal Medicine, the conclusion from their peer-review of the literature is that:

“screening based on PSA identifies additional prostate cancers, but most trials found no statistically significant effect on prostate cancer–specific mortality.”

This is nothing new – the evidence in favor of Prostate-Specific Antigen (PSA) screening for prostate cancer has for sometime been inconclusive at best. Research published in the British Medical Journal earlier this year suggested that indiscriminate screening for prostate cancer may not be of value until we obtain more sensitive biomarkers.

All the USPSTF have done is a retrospective literature review that confirms our current state of knowledge.

Despite the amount of $$$ that have been spent on PSA clinical studies, no convincing data in support of it as a screening tool for all men has been developed. That’s not to say that it has no utility or benefit.

If PSA screening does detect some prostate cancers and early treatment may save lives particularly in those with an aggressive form of the disease, then it’s hard not ask:

  • What is the alternative if PSA screening is now discouraged?
  • Will this mean more men will not be screened, even those at high risk, with a consequent increase in prostate cancer mortality or lower overall survival?
  • Will insurers refuse to cover PSA testing moving forwards?
  • Will family physicians actively discourage PSA testing?

One limitation of the USPSTF report that struck me while reading through the analysis and recommendations, was the absence of data from the Prostate Cancer Intervention versus Observation (PIVOT) trial that was presented in the plenary session at the American Urological Association (AUA) annual meeting earlier this year.

I wrote in a previous blog post about the PIVOT data presented at AUA 2011 by Dr Wilt. This VA/NCI/AHRQ randomized clinical trial showed in a 12 year follow-up of over 5000 men with localized prostate cancer, no benefit from radical prostatectomy in low risk early stage patients.

In my opinion it is practice changing data that sadly has not yet been published in a peer-reviewed journal which is why it was not included in the USPSTF analysis. A few photographs that I took at the presentation of the PIVOT data are shown below:

The 12 year survival data showed that in those patients with PSA <=10 ng/ml there was no significant difference in survival over observation versus RP.

However in those patients with PSA > 10ng/ml there was a significant difference in mortality (p=0.03 HR=0.36) suggesting that in the small sub-group of patients with high PSA, RP did provide a benefit over “watchful waiting.” PSA measurements may therefore help in the treatment and ongoing management of patients.

If one of the challenges of PSA screening is the issue of the harms from treatment, then the PIVOT data that showed no difference in mortality through watchful waiting over radical prostatectomy (RP) except for high risk patients is important.

Roger Chou and his colleagues in their Annals paper did note this:

“When available, results from the Prostate Cancer Intervention Versus Observation Trial, which compared prostatectomy with watchful waiting for screening-detected cancer, may help clarify which patients would benefit from prostatectomy or other active treatments, potentially reducing harms from unnecessary treatment.”

The issue may, therefore, not be one that PSA screening per-se is the problem, but that in too many men, a raised PSA results in unnecessary surgery or overtreatment with its consequent risks and harms.

As reported by Alemozaffar and colleagues in the September 21, 2011 issue of the Journal of the American Medical Association (JAMA), 2 years after RP only 35% of men could maintain a functional erection.

“At 2 years after treatment, erectile dysfunction was reported by 619 of 987 (63% [95% CI, 60%-66%]) men (334/511 [65% {95% CI, 61%- 69%}] in the prostatectomy group”

That’s depressing news when coupled with other side-effects from RP or other interventions such as incontinence or problems with bowel function.

It adds further support to the idea that the potential risks versus benefits from prostate cancer surgery and deciding who should actually have surgery or other intervention, is where there’s also a need for more debate.

Men need to be able to make an informed decision. Some urologists may not be unbiased in their treatment recommendations given they have a vested interest in earning money from surgery or maintaining utilization rates of expensive robotics. Data from the PIVOT trial, when published, is evidence-based medicine that will impact their practice.

Use of prostate cancer risk calculators to assess those patients at high risk who might benefit from RP or other intervention could also help lower the harms that currently impact the utility of PSA screening.

How will men approach the PSA screening debate? Despite the USPSTF recommendations I will still be asking my physician for an annual PSA test, so long as it remains covered by my health insurance. The PSA test and digital rectal exam remain the main ways we have to detect prostate cancer early.

Psychologically I value the risk of picking up a disease early higher than the downside of a false positive. I would, however, not rush into any surgery or radiotherapy absent a clear finding that the benefits of intervention outweighed the potential harm.

My approach towards prostate cancer PSA screening again reminds me of the debate over mammography.  We all want to discover cancer early, and have the best possible treatment options as a result.

Hopefully, as our understanding of the biology of prostate cancers and associated biomarkers develop we may be able to generate new screening tests that have fewer false positives than PSA and provide for more accurate early diagnosis.

ResearchBlogging.orgAlemozaffar, M., Regan, M., Cooperberg, M., Wei, J., Michalski, J., Sandler, H., Hembroff, L., Sadetsky, N., Saigal, C., Litwin, M., Klein, E., Kibel, A., Hamstra, D., Pisters, L., Kuban, D., Kaplan, I., Wood, D., Ciezki, J., Dunn, R., Carroll, P., & Sanda, M. (2011). Prediction of Erectile Function Following Treatment for Prostate Cancer JAMA: The Journal of the American Medical Association, 306 (11), 1205-1214 DOI: 10.1001/jama.2011.1333

Roger Chou, MD, Jennifer M. Croswell, MD, MPH, Tracy Dana, MLS, Christina Bougatsos, BS, Ian Blazina, MPH, Rongwei Fu, PhD, Ken Gleitsmann, MD, MPH, Helen C. Koenig, MD, MPH, Clarence Lam, MD, MPH, Ashley Maltz, MD, MPH, J. Bruin Rugge, MD, MPH, & Kenneth Lin, MD (2011). Screening for Prostate Cancer: A Review of the Evidence for the U.S. Preventive Services Task Force Annals of Internal Medicine, E-375 (October 7)

One piece of hot news at the 2011 European Multidisciplinary Cancer Congress (twitter #EMCC2011) taking place in Stockholm this weekend is the data on radium-223 chloride (Alpharadin) in metastatic castration resistant prostate cancer. The phase 3 ALSYMPCA trial results were presented in yesterday’s presidential symposia by Dr Chris Parker, Consultant Clinical Oncologist at The Royal Marsden Hospital.

Dr-Chris-Parker-Alpharadin-Presentation-Stockholm-Cancer-Congress-2011

The Scandinavian location for the presentation could not have been better, given that Alpharadin was developed by the Norwegian company Algeta. Bayer Schering Pharma AG have the worldwide commercial rights, but Algeta maintains a co-promotion option in the United States.

I first picked up on Alpharadin in a presentation given at the American Urological Association (AUA) annual meeting by Oliver Sartor (Tulane) earlier this year when he reviewed new prostate cancer products in development.

Algeta-Radium-223-Chloride-ASCO 2011-Abstract-4620At the ASCO 2011 meeting in Chicago there was a poster on the Alpharadin Phase 2 trial data (see the figure on the right) that caught my attention given that it showed an overall survival (OS) advantage.  This news was, however, largely drowned by the interest in cabozantinib (XL184).

The result is that Alpharadin has to many come out of left field. It is a promising compound for the treatment of prostate cancer that will provide new treatment options for patients with metastatic disease. In particular, use in combination with other therapies such as abiraterone acetate (Zytiga) may prolong survival to a greater extent than either does individually.

Currently, radium-223 chloride (Alpharadin) is only in investigational use and is not approved in Europe or the United States. It is, however, on the fast track towards FDA approval in 2012.

ALSYMPCA phase 3 prostate cancer data presentation ESMO ECCO 2011What makes Alpharadin exciting as a new treatment option for castration resistant prostate cancer (CRPC) is that the ALSYMPCA trial data shows that it not only provides a significant median overall survival (OS) benefit of 2.8 months compared to placebo (14 months versus 11.2 months, p=0.00185, HR 0.695), but significantly delays the time to first skeletal event by 5.2 months (13.6 months versus 8.4 months, p=0.00046, HR 0.610).

The overal survival (OS) benefit seen in the ALYSMPCA phase 3 trial is comparable to other approved agents in the post-docetaxel setting for CRPC. However, where it is unique is in the additional effect it has on skeletal related events (SRE), a common occurrence in metastatic prostate cancer.  Bone metastases are painful and have a significant impact on quality of life.

Other compounds that target the bone microenviroment such as denosumab (Xgeva), provide a delay in the time to first skeletal event in prostate cancer patients but to-date have not been shown to confer an overall survival advantage. This means that Alphardin is the first bone targeted agent to confer both an overall survival and a delay in time to first skeletal event.

After Dr Parker’s presentation of the ALSYMPCA phase 3 trial data yesterday here in Stockholm,  Professor Wim Oyen of the Department of Nuclear Medicine in Nijmegen discussed the data.

What he noted was the high tolerability of Ra-223 chloride (Alpharadin) as compared to other radiopharmaceuticals for treatment of patients with bone metastases.  He discussed how the emission of alpha particles allows for a short range effect (a few cell diameters) that is very localized, but with a large biological effect.

Oyen highlighted the “opportunity for improving patient outcome by adding Ra-223 in regimens of combination therapy,” something that Dr Parker speculated about in his media briefing.

Professor Oyen also saw “an opportunity for improving patient outcome by using Ra-223 in an adjuvant setting.”  His conclusion based on the phase 3 ALSYMPCA trial data presented was that radium-223 chloride (Alpharadin) is an “effective, very well tolerated and convenient treatment modality.

Algeta-radium-223-chloride-alpharadin

Dr Parker mentioned to me, while waiting for a train back to Stockholm, that the ALSYMPCA trial data he presented had not yet been submitted for publication. He said he would be disappointed if it did not appear in the New England Journal of Medicine. Given that it is groundbreaking and “practice changing,” I would be surprised if it is not published in the NEJM in due course.

I am sure that we will be hearing more about radium-223 chloride (Alpharadin) in the forthcoming months, especially now it is on fast track to FDA approval in 2012.

Although not a cure for prostate cancer, the ALSYMPCA trial data presented here in Stockholm is further good news for patients, and will provide a potential new treatment option for urologists and oncologists.

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One of the sessions that I attended at the 2011 annual meeting of the American Urological Association (AUA) focused on research into advanced prostate cancer.  A particularly thought provoking presentation was:

Time trends of biochemical recurrence (BCR) following radical prostatectomy (RP) among 1574 BCR patients (Abstract #639)

Presented by Alex Haese from Hamburg, Germany, this paper was a retrospective analysis of 1,574 patients who had a biochemical recurrence (PSA > 0.2 mg/dl) following RP. Researchers looked at clinical progression and cancer specific survival rates and compared their findings to published United States data.

The results appeared to be somewhat depressing for European patients who experience a BCR, with a time to BCR of 1.8 years, compared to 2.1 years in the US research by Pound from Johns Hopkins and 2.4 years in the data published by Hull, at Memorial Sloan Kettering Cancer Center (MSKCC).

Once a BCR is experienced, the time to metastases is faster in Europe, 4.7 years in the research presented by Haese at AUA, as compared to 8 years in US research by Pound. Risk factors for metastasis free survival include time to BCR i.e.

“The longer the interval between RP and BCR, the greater the probability of being met-free.”

In other words delaying time to progression is associated with longer survival.

Following BCR, time to Prostate Cancer death was 6.0 years in the 1,574 European patients, compared to 13 years in the US Pound research.  Again, the data presented showed that,

“The longer the interval between RP and BCR, the greater the probability of being alive.”

This research must be put into context, as metastasis and death in BCR patients are rare (92% of the 1,574 patients with BCR were free of metastases at 5 years, 81% at 10 years).  However, for those patients who did progress, the results appear significantly different between the US and Europe.

What could explain this?

The presentation left this question unanswered, although in Q&A it was briefly touched upon. One person raised the question of whether differences in screening could be the difference in Europe vs. US?

Other questions that come to mind are whether the subject populations in the Hull and Pound data were comparable.  The German data also had more patients (1574) compared to 304 in the Pound research and 147 (Hull) raising the question that the larger sample size may be more accurate data?

Other factors that might possibly explain the difference include:

  • Androgen deprivation therapy (ADT)
  • Radiotherapy
  • Supportive care (eg bisphosphonates)

All of which tend to be more aggressively pursued as treatment options in the USA.

Overall, this presentation raised the interesting question of US/European differences in Prostate Cancer progression that hopefully will be answered by future research.

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