ADT may up the risk for colon cancer

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rgmjr
New Member


Date Joined Nov 2010
Total Posts : 8
   Posted 11/14/2010 9:09 AM (GMT -6)   
Prostate Cancer Treatment May Up Colon Cancer Risk

NEW YORK (Reuters Health) – Men who opt for hormone-blocking therapy to treat prostate cancer may be increasing their risk of developing colon cancer, hints a study published this week in the Journal of the National Cancer Institute.

So-called "androgen deprivation therapy," or ADT, suppresses production of the male hormone testosterone, which helps drive the growth of prostate cancer. ADT is widely used to treat prostate cancer, despite increasing recognition that it carries serious potential risks, including diabetes and obesity, which are known risk factors for colon cancer.

Just last month, the U.S. Food and Drug Administration ruled that certain hormone treatments for prostate cancer must carry new warnings about an increased risk of diabetes and heart problems. Those medications include Lupron, Zoladex, Trelstar, and Eligard.

Studies in animals have also suggested that male hormones may protect against the development of colon cancer by suppressing signals the cancer cells need to grow, the authors write.

So it is "conceivable" that suppressing the hormones might increase the risk of colon cancer, Dr. Vahakn Shahinian, of the University of Michigan, Ann Arbor, told Reuters Health.

He and his colleagues looked for ties between the use of ADT and colon cancer in more than 100,000 older men who were diagnosed with prostate cancer between 1993 and 2002.

The men received ADT either in the form of drugs or surgery to remove the testicles, which produce more than 90 percent of the body's male hormones (androgens), including testosterone. Most opted for drugs. They were followed through 2004.

The researchers found that men who received ADT, relative to those who did not, had a 30 to 40 percent increased risk of developing colon cancer during the follow-up period.

The analysis took into account factors such as existing obesity and socio-economic environment that might influence colon cancer risk.

And the longer the men took ADT, the greater their risk of developing colon cancer, suggesting a "dose-response" relationship.

It's important to note, however, that this was an "observational" study, which can only point to a link (or lack thereof) between two variables - in this case, ADT and colon cancer. This type of study cannot prove cause-and-effect.

And, Shahinian told Reuters Health, the absolute risk of colon cancer in all of the men was small; over 5 years, it was just 2.2 percent for men on androgen-blocking drugs and 3.2 percent in those who had surgery, compared with 1.8 percent in the men who did not receive ADT.

Nevertheless, the impact may be large given that hundreds of thousands of men are on ADT for prostate cancer, the researchers note in their report.

"When considering starting ADT, men should carefully weigh the risks versus benefits of the therapy," advised Shahinian in an e-mail. "Since the risk of colorectal cancer is small, men shouldn't hesitate to use ADT when it is likely to be clearly beneficial for them," he added.

Dr. Jennifer H. Lin, of Brigham and Women's Hospital in Boston, and co-author of a commentary on the study, told Reuters Health that several simple measures may help prevent the development of colon cancer and "help to counter some of the drawbacks of ADT."

These include routine screening for colorectal cancer and adopting a healthy lifestyle, complete with plenty of physical activity.

Shahinian and colleagues say their findings have potential broader implications, beyond prostate cancer, given that testosterone deficiency is now recognized to be relatively common in the general population of men, affecting perhaps as many as 2.4 million men in the U.S., or about 2 percent of adult males.

Testosterone deficiency is generally considered to be a testosterone level below 3.2 nanograms per liter of blood, which is about half the "low-normal" level for a middle-aged man. (See Reuters Health story June 16, 2010.)

Whether these men are also at increased risk for colon cancer will need to be explored further, the researchers emphasize. In addition, they think future studies of testosterone replacement therapies should look for increased colon cancer cases to provide more data to analyze.

SOURCE: http://link.reuters.com/buc35q Journal of the National Cancer Institute, online November 10, 2010.

Casey59
Veteran Member


Date Joined Sep 2009
Total Posts : 3172
   Posted 11/14/2010 3:40 PM (GMT -6)   
Thanks for posting the article.  You didn't post any comment; so here's mine:
 
Basically, the "conceivable" increased risk (the study leader's phrase) for the future development of colon cancer seems to me to be an extremely nominal factor for an existing prostate cancer patient to weigh in the decision to start HT.  There are other additional factors for consideration (pro and con) which seem to weigh much more significantly.
 
The "absolute risk of colon cancer in all of the men was small; over 5 years, it was just 2.2 percent for men on androgen-blocking drugs..., compared with 1.8 percent in the men who did not receive ADT"...but the patient already has prostate cancer! 
 
Re-stating the phrease that my wife uses while dealing with multiple similar issues, "it's the least of my worries."  The slim increase in the "conceivable" possiblility of developing colon cancer in the future might be the least of a PC patient's worries if he is prescribed ADT.

goodlife
Veteran Member


Date Joined May 2009
Total Posts : 2691
   Posted 11/14/2010 3:48 PM (GMT -6)   
And, let's not forget to add the risk of radiation tumors from having adjuvant or salvage radiation.

Let's face it. Fighting for our lives with this PC is a risk to our health. Sure seems like needless warnings to me. It's not like we have a choice. Driving in a snowstorm has a much greater chance of injury or death, but pulling to the side of the road and freezing to death isn't a great option either.

I really do get tired of some of these study conclusions.
Goodlife
 
Age 58, PSA 4.47 Biopsy - 2/12 cores , Gleason 4 + 5 = 9
Da Vinci, Cleveland Clinic  4/14/09   Nerves spared, but carved up a little.
0/23 lymph nodes involved  pT3a NO MX
Catheter and 2 stints in ureters for 2 weeks .
Neg Margins, bladder neck negative
Living the Good Life, cancer free  6 week PSA  <.03
3 month PSA <.01 (different lab)
5 month PSA <.03 (undetectable)
6 Month PSA <.01
1 pad a day, no progress on ED.  Trimix injection
No pads, 1/1/10,  9 month PSA < .01
1 year psa (364 days) .01
15 month PSA <.01

kbota
Regular Member


Date Joined Aug 2010
Total Posts : 486
   Posted 11/14/2010 5:02 PM (GMT -6)   
goodlife said...
And, let's not forget to add the risk of radiation tumors from having adjuvant or salvage radiation.

Let's face it. Fighting for our lives with this PC is a risk to our health. Sure seems like needless warnings to me. It's not like we have a choice. Driving in a snowstorm has a much greater chance of injury or death, but pulling to the side of the road and freezing to death isn't a great option either.

I really do get tired of some of these study conclusions.


Dang goodlife,....I was reading this thread, and thinking the exact same thing. You posted almost word for word what I was about to post.

I do get tired of some of these studies, but mainly because they introduce sooo much confusion into an already very confused topic. The layman doesn't stand a chance with PCa. At least with most other cancers, most docs will agree at some level.....with PCa...not so much.

And while reading new studies does bring me a degree of frustration, I'm okay with that, because without these studies, little progress would be made. While that progress may not help those of us on this forum today, they just might help some poor soul suffering in the future, and make his life just a little easier.

my two c

k
Age 57 at Dx
5/09 PSA 2.26
6/2010 PSA 3.07 FPSA 18% DRE +
Biopsy, 7 of 18+, >60%, 4+5=9
7/21/2010 - RRP
Nodes neg, Ves neg
tumor contained, still 4+5=9
pni ext.
9/3, 2010 PSA - 0.04
9/3/2010, I'm 99% continent
10/14/10, PSA still 0.04, and lupron #1, now 99.9% continent
Total ED, 3 caverject failed
10/20/10 OD'd .5cc trimix, after 3hrs, neo synephrine shot
tried .15 & .17 cc neg, next .2

Casey59
Veteran Member


Date Joined Sep 2009
Total Posts : 3172
   Posted 11/15/2010 10:59 AM (GMT -6)   
kbota said...

I do get tired of some of these studies, but mainly because they introduce sooo much confusion into an already very confused topic....

And while reading new studies does bring me a degree of frustration, I'm okay with that, because without these studies, little progress would be made...
 
 
kbota, I look at these studies in the same positive light as your 2nd statement above...adding to the existing base of knowledge. 
 
I understand your comment about seeming to introduce confusion, but to me this study simply elevated awareness and knowledge of one more possible side effect of the chemical treatment (just add it to the list).  When new drugs are introduced through the Phase-I, -II and -III trial procedures, most of the common side effects are identified and characterized.  I see this simply as one more effect which has such a slim chance of occurring that it wasn't identified in the thorough, yet limited, vetting process.
 
Life is full of tradeoffs which drives people to think through the question of whether a choice does "more good than harm."  For the vast majority, men who would benefit from ADT for PC will not hesitate with this new awareness of a possible risk to future development of colon cancer.  As the study leader said, "Since the risk of colorectal cancer is small, men shouldn't hesitate to use ADT when it is likely to be clearly beneficial for them."
 
My wife is taking some drugs which comes with 3-pages of possible side effects (bulleted, single spaced).  Nonetheless, we see them as providing more good than harm.

Terry Herbert
Regular Member


Date Joined Sep 2010
Total Posts : 92
   Posted 11/15/2010 5:09 PM (GMT -6)   
I don't know how many of you read the posts on The "New" Prostate Cancer Infolink, but I can recommend as an excellent source of informaiton, particulalry in the interpretation of new studies, press releases etc.

This particular study was discussed here Colorectal cancer among prostate cancer patients treated with ADT and as the summary says:

If Gillessen et al. are correct in their estimation, the relative increase in risk in risk for colorectal cancer in prostate cancer patients being treated with an LHRH agonist (as compared to men receiving no ADT) certainly appears to be 30-40 percent. However, the absolute increase in risk is 0.7/1,000 patient-years — which equates to 7 cases in every 1,000 men receiving ADT for 10 years. It isn’t negligible … but it also isn’t an enormous increase in their risk when the base rate is 37 cases/1,000 prostate cancer patients followed for 10 years who had no ADT.
Diagnosed ‘96: Age 54: Stage T2b: PSA 7.2: Gleason 7: No treatment. Jun '07 PSA 42.0 - Bony Metastasis: Aug '07: Intermittent ADT: PSA 2.3 Aug '10

It is a tragedy of the world that no one knows what he doesn’t know, and the less a man knows, the more sure he is that he knows everything. Joyce Carey
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