Dangers of Radiation Therapy?

[Guest guest]

On Friday last week on another List a statement was

made in a discussion on the values of Proton v Da Vinci, which included the

following:

<snip> ……there is study data from

the SEER database analyzed by Columbia Univ and Mount Sinai Medical Centre

showing the increased risk for secondary cancers from ionizing radiation.

" Compared to the men who underwent prostatectomy alone, external beam

irradiation was associated with an 88 percent increase in the relative risk of

developing bladder cancer, and a 26 percent increase in the relative risk of

developing rectal cancer. " <snip>

I must confess to being a little surprised by this statement

because I had always accepted the oft-stated position that 'There is no

evidence to show a greater risk of secondary cancers associated with radiation

therapies.' - or at least that is what I THOUGHT I heard whenever the subject

came up. Seems now that I have had a look around that there are several studies

that apparently contradict this view.

I've put two below, but would be really interested in

commentary or discussion on this topic. Do the studies come to the correct

conclusion? Are they produced by people with a bias away from radiation

therapies? If so, how can the danger be more properly evaluated? What kind of

'warning' should men be given who are contemplating radiation therapies? Are

men actually 'counselled' about the risks, as suggested by the studies? What

are the risks in language that men without statistical training can understand?

Here are two of the studies I found:

1. Int J Radiat Oncol Biol Phys. 2010 Feb

1;76(2):342-8. The rate of secondary malignancies after radical prostatectomy

versus external beam radiation therapy for localized prostate cancer: a

population-based study on 17,845 patients. Cancer Prognostics and Health

Outcomes Unit, University of Montreal Health Center,

Montreal, QC,

Canada. (A

retrospective study using records of about 18,000 patients from 1983 - 2003)

CONCLUSIONS: EBRT may predispose to clinically

meaningfully higher rates of secondary Bladder Cancer, Lung Cancer and Rectal

Cancer. These rates should be included in informed consent consideration.

2. J Urol. 2008 Nov;180(5):2005-9; discussion

2009-10. Epub 2008 Sep 17. Radiation therapy for prostate cancer increases

subsequent risk of bladder and rectal cancer: a population based cohort study.

Department of Urology, University of Miami

School

of Medicine, Miami, Florida, USA.

(A retrospective study using 243,000 records from the SEER database between

1983 and 2003)

CONCLUSIONS: Men who receive radiotherapy for

localized prostate cancer have an increased risk of bladder cancer compared to

patients undergoing radical prostatectomy and compared to the general

population. The risk of rectal cancer is increased in patients who receive

external beam radiotherapy compared to radical prostatectomy. Patients should

be counseled appropriately regarding these risks.

All the best

Prostate men need enlightening, not frightening

Terry Herbert - diagnosed in 1996 and still going strong

Read A Strange Place for unbiased information at http://www.yananow.net/StrangePlace/index.html

[Guest guest]

Terry Herbert

> ...<snip> there is study data from the SEER database analyzed

> by Columbia Univ and Mount Sinai Medical Centre showing the

> increased risk for secondary cancers from ionizing radiation.

> " Compared to the men who underwent prostatectomy alone,

> external beam irradiation was associated with an 88 percent

> increase in the relative risk of developing bladder cancer, and

> a 26 percent increase in the relative risk of developing rectal

> cancer. " <snip>

I also have read that there is a risk of secondary cancers. I

did not learn about it until after I had already had radiation,

though I'm not sure it would have changed my mind if I had known.

Here are the issues as I understand them.

1. Radiation increases the risk of secondary cancers in areas

that receive radiation. The bladder and the rectum may

receive some radiation from prostate cancer treatment and

therefore are vulnerable to this. I know for a fact that my

rectum has been damaged by radiation because I've seen the

scarring in a proctoscope.

2. The damage caused by radiation does not generally result in

cancer very soon. It may cause some damage to DNA in the

bladder and rectum cells, but it takes additional damage and

time before cancer can develop. I seem to recall once reading

that it can take 30 years. For that reason, older men are not

at risk of secondary cancers, but younger men are.

3. The increase in risk has to be understood as a multiplier for

risk without radiation. If there is a 10% chance of

developing X cancer and a 50% increase in risk due to prostate

radiation, then the new risk becomes 15%. But if the risk of

developing Y cancer is only .1%, then the new risk becomes

.15%. I don't know what the incidence of bladder and rectal

cancers are.

Alan

[Guest guest]

The studies I referred to are for periods

a good deal shorter than 30 years and they also show the various incidences

both regular and enhanced – it is just that I can’t interpret them

with my lack of statistical knowledge – although I am sure there are

others who can - hint, hint.

All the best

Prostate men need enlightening, not

frightening

Terry Herbert - diagnosed in 1996 and

still going strong

Read A Strange Place for unbiased information at http://www.yananow.net/StrangePlace/index.html

From:

ProstateCancerSupport

[mailto:ProstateCancerSupport ] On Behalf Of Alan Meyer

Sent: Monday, 19 July 2010 12:06 PM

To:

ProstateCancerSupport

Subject: Re:

Dangers of Radiation Therapy?

Terry Herbert

> ...<snip> there is study data from the SEER database analyzed

> by Columbia Univ and Mount Sinai Medical Centre showing the

> increased risk for secondary cancers from ionizing radiation.

> " Compared to the men who underwent prostatectomy alone,

> external beam irradiation was associated with an 88 percent

> increase in the relative risk of developing bladder cancer, and

> a 26 percent increase in the relative risk of developing rectal

> cancer. " <snip>

I also have read that there is a risk of secondary cancers. I

did not learn about it until after I had already had radiation,

though I'm not sure it would have changed my mind if I had known.

Here are the issues as I understand them.

1. Radiation increases the risk of secondary cancers in areas

that receive radiation. The bladder and the rectum may

receive some radiation from prostate cancer treatment and

therefore are vulnerable to this. I know for a fact that my

rectum has been damaged by radiation because I've seen the

scarring in a proctoscope.

2. The damage caused by radiation does not generally result in

cancer very soon. It may cause some damage to DNA in the

bladder and rectum cells, but it takes additional damage and

time before cancer can develop. I seem to recall once reading

that it can take 30 years. For that reason, older men are not

at risk of secondary cancers, but younger men are.

3. The increase in risk has to be understood as a multiplier for

risk without radiation. If there is a 10% chance of

developing X cancer and a 50% increase in risk due to prostate

radiation, then the new risk becomes 15%. But if the risk of

developing Y cancer is only .1%, then the new risk becomes

..15%. I don't know what the incidence of bladder and rectal

cancers are.

Alan

[Guest guest]

Terry Herbert wrote:

> <snip> ... there is study data from the SEER database analyzed

> by Columbia Univ and Mount Sinai Medical Centre showing the

> increased risk for secondary cancers from ionizing radiation.

> " Compared to the men who underwent prostatectomy alone,

> external beam irradiation was associated with an 88 percent

> increase in the relative risk of developing bladder cancer, and

> a 26 percent increase in the relative risk of developing rectal

> cancer. " <snip>

I've done a little more noodling around on the two citations

Terry gave for increased cancer risk as a result of radiation.

I found the full text of one of the articles. It was one

examining the SEER database that came up with a relative risk of

developing bladder cancer of 1.88 for EBRT vs. surgery. That

means that if 100 men got bladder cancer after surgery for PCa,

188 got it after external beam radiation.

The study that I saw did not come from Columbia University but

from the University of Miami (Florida) Department of Urology. I

don't think that casts doubt on it, but I thought the names

" Columbia " and " Mount Sinai " might give it special credence

above its actual provenance.

The article is full of statistics that I have no way to evaluate.

I can only assume that the professors entered the data correctly

and applied their computer programs correctly. Without repeating

the research, we can't prove that one way or the other. However

I did notice a few odd facts. The most surprising one to me was

that patients undergoing brachytherapy had a lower rate of rectal

cancer than patients undergoing surgery! Why in the world should

that be? Does it mean that surgery causes more rectal cancers

than brachytherapy, or that brachytherapy protects against rectal

cancer? And if it doesn't mean that, then are we still entitled

to interpret the relative risks we saw for EBRT patients as being

due to EBRT.

I also saw some comments on the paper. One fellow wrote:

" ... I might present it to a 70-year-old patient as, 'Your

chances of dying from a second cancer due to EBRT at 15 years

is probably less than your risk of dying after a radical

prostatectomy (0.66%) within 30 days, but potency and

continence rates are better with EBRT.' Most patients

could probably understand this comparison and make an

informed decision. "

The authors responded with a critique of the assumptions

underlying this. I don't know which is right and, as I often say

in these situations, I don't know if anyone does.

An additional problem in evaluating retrospective radiation

studies is the difference in radiation technique between today

and the study period. In the bad old days, before IMRT, more

of the radiation would have gone to the bladder and rectum than

today. On the other hand, doses are higher today. I don't know

if the total radiation delivered to the bladder or rectum is

higher or lower today, though I hope it's lower.

We don't know what form of radiation the patients in the study

had? Did some of them have general pelvic radiation - a common

practice a couple of decades ago. If so, they had MUCH more

radiation to the bladder and rectum than 3D conformal techniques.

And even if all of the patients had 3DCRT, we don't know how

the numbers would work out for IMRT, IGRT, CyberKnife, HDR

brachytherapy, LDR brachytherapy with different isotopes, or

proton therapy.

We also don't know how treatable the secondary cancers are,

whether certain people are more likely than others to get them,

how likely one is to die of them, or whether long or short term

complications of surgery are more or less dangerous to the

patient than secondary cancers induced by radiation.

I don't want to downplay the dangers or discredit the research.

I think that, in general, medical practice has been cavalier

about radiation dangers and is only slowly waking up to the

dangers. We still have way too many CT scans and other forms of

x-rays, and we probably get them at too high doses. (As an

aside, my dentist was recently forced by an inspector from the

State of land to replace his x-ray machine because the dose

was too low!!! She told him that the machine was out of spec and

that was that. Never mind that the actual x-ray photos looked

perfect. No argument was allowed or considered. He had to spend

tens of thousands of dollars for a new machine in order to harm

his patients more!)

My take away conclusions are:

If you're younger, worry a little more about this. If you're

older, worry less. If your child or especially your grandchild

is offered radiation therapy, worry a lot and argue with the

doctors about it - though you might be faced with a choice of

having a child die now without x-rays, or risk dying later with

them.

However I haven't seen anything in the research to incline me to

make a primary decision based on the danger of secondary cancers.

I see that it's a factor, but I think a number of other factors

are probably still more important (side effects, cancer control

outcomes, suitability for your particular physiology and cancer

characteristics, ability and experience of the surgeon or

radiation oncologist available to you.)

But I understand that that's all arm waving. As with so much in

cancer treatment, we have little more than ambiguous statistics

and personal gut feelings to guide our decisions. We pays our

money and takes our choice.

Alan

[Guest guest]

> I've done a little more noodling around on the two citations

> Terry gave for increased cancer risk as a result of radiation.

" Radiation treatment today is *not* your grandfather's radiation

treatment. "

-- Rose, MD

Radiation Oncologist

At the 2007 PCRI Conference

[Guest guest]

The studies referred to were not done in

my grandfather’s time. He died in 1965 about 20 years before the start of

the data referred to.

You can’t have long term results

without starting to measure results from as far back as is reasonable. And yes,

there have been changes in radiation treatment, but are the the short term

results that different? If you have information – other than quotes from

a radiation oncologist – perhaps you’d share them with us?

All the best

Prostate men need enlightening, not

frightening

Terry Herbert - diagnosed in 1996 and

still going strong

Read A Strange Place for unbiased information at http://www.yananow.net/StrangePlace/index.html

From:

ProstateCancerSupport

[mailto:ProstateCancerSupport ] On Behalf Of Steve Jordan

Sent: Wednesday, 21 July 2010

11:06 AM

To:

ProstateCancerSupport

Subject: Re:

Dangers of Radiation Therapy?

> I've done a little more noodling around on the two citations

> Terry gave for increased cancer risk as a result of radiation.

" Radiation treatment today is *not* your grandfather's radiation

treatment. "

-- Rose, MD

Radiation Oncologist

At the 2007 PCRI Conference

[Guest guest]

Thank you for that Alan. Your informed

comments match my uninformed views. It was good of you to take the trouble you

did.

All the best

Prostate men need enlightening, not

frightening

Terry Herbert - diagnosed in 1996 and

still going strong

Read A Strange Place for unbiased information at http://www.yananow.net/StrangePlace/index.html

From: ProstateCancerSupport

[mailto:ProstateCancerSupport ] On Behalf Of Alan Meyer

Sent: Wednesday, 21 July 2010

10:38 AM

To:

ProstateCancerSupport

Subject: Re:

Dangers of Radiation Therapy?

Terry Herbert wrote:

> <snip> ... there is study data from the SEER database analyzed

> by Columbia Univ and Mount Sinai Medical Centre showing the

> increased risk for secondary cancers from ionizing radiation.

> " Compared to the men who underwent prostatectomy alone,

> external beam irradiation was associated with an 88 percent

> increase in the relative risk of developing bladder cancer, and

> a 26 percent increase in the relative risk of developing rectal

> cancer. " <snip>

I've done a little more noodling around on the two citations

Terry gave for increased cancer risk as a result of radiation.

I found the full text of one of the articles. It was one

examining the SEER database that came up with a relative risk of

developing bladder cancer of 1.88 for EBRT vs. surgery. That

means that if 100 men got bladder cancer after surgery for PCa,

188 got it after external beam radiation.

The study that I saw did not come from Columbia University

but

from the University of Miami (Florida)

Department of Urology. I

don't think that casts doubt on it, but I thought the names

" Columbia " and " Mount

Sinai " might give it special credence

above its actual provenance.

The article is full of statistics that I have no way to evaluate.

I can only assume that the professors entered the data correctly

and applied their computer programs correctly. Without repeating

the research, we can't prove that one way or the other. However

I did notice a few odd facts. The most surprising one to me was

that patients undergoing brachytherapy had a lower rate of rectal

cancer than patients undergoing surgery! Why in the world should

that be? Does it mean that surgery causes more rectal cancers

than brachytherapy, or that brachytherapy protects against rectal

cancer? And if it doesn't mean that, then are we still entitled

to interpret the relative risks we saw for EBRT patients as being

due to EBRT.

I also saw some comments on the paper. One fellow wrote:

" ... I might present it to a 70-year-old patient as, 'Your

chances of dying from a second cancer due to EBRT at 15 years

is probably less than your risk of dying after a radical

prostatectomy (0.66%) within 30 days, but potency and

continence rates are better with EBRT.' Most patients

could probably understand this comparison and make an

informed decision. "

The authors responded with a critique of the assumptions

underlying this. I don't know which is right and, as I often say

in these situations, I don't know if anyone does.

An additional problem in evaluating retrospective radiation

studies is the difference in radiation technique between today

and the study period. In the bad old days, before IMRT, more

of the radiation would have gone to the bladder and rectum than

today. On the other hand, doses are higher today. I don't know

if the total radiation delivered to the bladder or rectum is

higher or lower today, though I hope it's lower.

We don't know what form of radiation the patients in the study

had? Did some of them have general pelvic radiation - a common

practice a couple of decades ago. If so, they had MUCH more

radiation to the bladder and rectum than 3D conformal techniques.

And even if all of the patients had 3DCRT, we don't know how

the numbers would work out for IMRT, IGRT, CyberKnife, HDR

brachytherapy, LDR brachytherapy with different isotopes, or

proton therapy.

We also don't know how treatable the secondary cancers are,

whether certain people are more likely than others to get them,

how likely one is to die of them, or whether long or short term

complications of surgery are more or less dangerous to the

patient than secondary cancers induced by radiation.

I don't want to downplay the dangers or discredit the research.

I think that, in general, medical practice has been cavalier

about radiation dangers and is only slowly waking up to the

dangers. We still have way too many CT scans and other forms of

x-rays, and we probably get them at too high doses. (As an

aside, my dentist was recently forced by an inspector from the

State of land

to replace his x-ray machine because the dose

was too low!!! She told him that the machine was out of spec and

that was that. Never mind that the actual x-ray photos looked

perfect. No argument was allowed or considered. He had to spend

tens of thousands of dollars for a new machine in order to harm

his patients more!)

My take away conclusions are:

If you're younger, worry a little more about this. If you're

older, worry less. If your child or especially your grandchild

is offered radiation therapy, worry a lot and argue with the

doctors about it - though you might be faced with a choice of

having a child die now without x-rays, or risk dying later with

them.

However I haven't seen anything in the research to incline me to

make a primary decision based on the danger of secondary cancers.

I see that it's a factor, but I think a number of other factors

are probably still more important (side effects, cancer control

outcomes, suitability for your particular physiology and cancer

characteristics, ability and experience of the surgeon or

radiation oncologist available to you.)

But I understand that that's all arm waving. As with so much in

cancer treatment, we have little more than ambiguous statistics

and personal gut feelings to guide our decisions. We pays our

money and takes our choice.

Alan

[Guest guest]

>

> You can’t have long term results without starting to measure

> results from as far back as is reasonable. And yes, there have

> been changes in radiation treatment, but are the the short term

> results that different? If you have information – other than

> quotes from a radiation oncologist – perhaps you’d share them

> with us?

I'd recommend asking the rad onc I quoted. Presumably, he had

what he considered good reason for saying what he said at the

PCRI conference.

A brief CV can be found here:

http://www.vantageoncology.com/executive.php

....and he can be contacted via the site.

Regards,

Steve J

[Guest guest]

But he's not a member of this List, so I can't ask him in a way that any

other members can benefit from his answer. I would have thought that you

would regard hearsay evidence as being in the same category as anecdotal

evidence i.e. of very little value. Hence my asking if you had any studies

to which we might refer. I assume you do not.

All the best

Prostate men need enlightening, not frightening

Terry Herbert - diagnosed in 1996 and still going strong

Read A Strange Place for unbiased information at

http://www.yananow.net/StrangePlace/index.html

Re: Dangers of Radiation Therapy?

>

> You can't have long term results without starting to measure

> results from as far back as is reasonable. And yes, there have

> been changes in radiation treatment, but are the the short term

> results that different? If you have information - other than

> quotes from a radiation oncologist - perhaps you'd share them

> with us?

I'd recommend asking the rad onc I quoted. Presumably, he had

what he considered good reason for saying what he said at the

PCRI conference.

A brief CV can be found here:

http://www.vantageoncology.com/executive.php

....and he can be contacted via the site.

Regards,

Steve J

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[Guest guest]

On 7/22/10, Terry Herbert replied to me:

> But he's not a member of this List, so I can't ask him in a way

> that any other members can benefit from his answer.

C'mon Terry. You know better than that. Copy & paste if you must.

> I would have thought that you

> would regard hearsay evidence as being in the same category as

> anecdotal evidence i.e. of very little value. Hence my asking if you had

> any studies to which we might refer. I assume you do not.

I cited Dr. Rose as a reliable source, and provided contact

guidance leading to further details. Anyone who would rather not

follow that guidance should be prepared to accept the consequences.

Regards.

Steve J