a thread for biochemistry geeks [split from Lance]


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a thread for biochemistry geeks [split from Lance]

Postby Pego » Fri Jan 18, 2013 10:08 am

guru wrote:Of course, he very well may have given himself the cancer in the first place with the chemical cocktails he was ingesting


Show me one established correlation of seminoma with transfusion/EPO/anabolic staroids/HGH. Just one.
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Re: A Very Bad Morning For Lance

Postby bambam » Sat Jan 19, 2013 6:08 am

Agree with Pego and EGH on the cancer thing - no evidence Lyle Alzado got cancer from drugs, and no evidence that seminoma has any association with PEDs. I was always suspicious about a couple female American athletes (will be careful, don't want to get banned), who had lots of hormonal issues, however.

On Lance Armstrong's cancer and I will also be careful here - cancer is a tough word, it has obvious emotional connotations to many people.

There are good cancers and bad cancers. If I was given the diagnosis of pancreatic cancer or glioblastoma (a brain cancer), I would not be treated, but would only ask for pain medicine and go off to die. But many cancers are now eminently treatable.

In about 1998 I was talking to my best buddy from med school, who is an eminent oncologist in Charleston, and commented that it was pretty amazing that Armstrong had survived his cancer. He told me it was not, that testicular cancer is among the most curable cancers out there. He said if you took your oral boards, and had a patient with testicular cancer who did not survive, you would fail your oncology board exam. I then asked him further, what about in Armstrong's case, with all the metastases, but he said it did not matter, it was completely curable anymore. Again, Armstrong has used this for his own end a lot, and again with connotations, maybe he felt this way, but he always talk about his "death sentence."

The hero here was the oncologist who did have to devise a chemotherapeutic cocktail that did not do major damage to Armstrong's lungs so he could race again.

Like to hear Pego or DrJay's thoughts on this.
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Re: A Very Bad Morning For Lance

Postby Blues » Sat Jan 19, 2013 8:21 am

bambam wrote:Agree with Pego and EGH on the cancer thing - no evidence Lyle Alzado got cancer from drugs, and no evidence that seminoma has any association with PEDs. I was always suspicious about a couple female American athletes (will be careful, don't want to get banned), who had lots of hormonal issues, however.


Although Pego's views are as usual valid and based on current facts, I still don't think they necessarily rule out the fact that Armstrong's drug use may have influenced his testicular cancer. Although A FEW (but most likely not ALL) risk factors for the condition have been established, the actual causes of seminoma type testicular cancers are still unknown. As recently as sixty to seventy years ago most people felt that there was no documented evidence that tobacco smoking could cause lung cancer, and even today in many cases there's still much we haven't discovered yet regarding the actual cause of quite a few medical conditions. Considering the fact that some of the drugs that Armstrong used can affect various hormonal and physiological processes in the body, there's always the possibility that something he used could have played a part in his cancer. That doesn't necessarily mean it caused the cancer in the first place, but if it didn't, there's still always a chance that it may have adversely affected the way, or accelerated the speed, in which the cancer developed...
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Re: A Very Bad Morning For Lance

Postby gh » Sat Jan 19, 2013 8:57 am

long leap from could to did. Scare stories aren't going to do anything to clean up sport.
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Re: A Very Bad Morning For Lance

Postby Pego » Sat Jan 19, 2013 9:26 am

Blues wrote:they necessarily rule out the fact that Armstrong's drug use may have influenced his testicular cancer


While this premise is logically sound (you cannot prove negative!), it really does not help much. Either there is a causal evidence of A causing (influencing) B, or there is not. As far as I know, there has been no carcenogenicity established for any agents LA was supposedly taking. I had been under impression that there is a causal link between anabolic steroids and some hepatocellular neoplasms, but my gastroenterologist/hepatologist son tells me that the evidence is highly questionable.
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Re: A Very Bad Morning For Lance

Postby Blues » Sat Jan 19, 2013 11:50 am

gh wrote:long leap from could to did. Scare stories aren't going to do anything to clean up sport.


I've seen dozens of defenses of the use of certain drugs and PEDs based on the premise that "there's no evidence or scientific studies that show that they cause certain harmful effects"...

The problems are that the "causes" of those harmful effects often haven't been adequately studied or determined yet, and that there are often no scientific studies that show that the drug doesn't cause the harmful effect. I think it's important to keep that in mind. Just because there's no scientific evidence yet that a drug or PED can cause certain harmful effects doesn't necessarily mean that it doesn't, since in many cases appropriate studies have not been carried out. I like to make that point clear, so people don't automatically get the impression that certain PEDs or other substances must be safe to use just because there may not be any scientific proof of harm yet, when the lack of proof could essentially be because there haven't been adquate studies to provide evidence one way or the other, or because enough case reports involving the harmful effect haven't been linked to the substance yet, even though the substance could very well be involved.

There's a big difference between choosing to use a substance that's proven to be safe, and choosing to use a substance that hasn't been proven to be harmful but hasn't been proven to be safe either, especially when adequate studies haven't been done. Often, many potential serious side effects of a substance aren't discovered until somebody finally connects the dots and links the substance to multiple case reports involving a particular harmful effect, and that can often take many years, especially for certain substances whose use may not be widely and publicly reported by some users for obvious reasons...
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Re: A Very Bad Morning For Lance

Postby Blues » Sat Jan 19, 2013 12:16 pm

Pego wrote:
Blues wrote:they necessarily rule out the fact that Armstrong's drug use may have influenced his testicular cancer


While this premise is logically sound (you cannot prove negative!), it really does not help much. Either there is a causal evidence of A causing (influencing) B, or there is not. As far as I know, there has been no carcenogenicity established for any agents LA was supposedly taking. I had been under impression that there is a causal link between anabolic steroids and some hepatocellular neoplasms, but my gastroenterologist/hepatologist son tells me that the evidence is highly questionable.


It's just my opinion, but I think there's enough evidence to link the chronic use of anabolic steroids to an increased risk of hepatic neoplasms, and also enough evidence to link EPO at least to increasing the proliferation/growth of various types of cancer, so although it may not have caused Armstrong's cancer, there's a chance it might have sped up the progression and aggressiveness of it..

There are various studies suggesting this, but this is from the required black box warning in the package insert of the prescription forms of EPO:

"Use of erythropoiesis-stimulating agents to achieve a target hemoglobin of 12 g/dL or greater in cancer patients shortened the time to tumor progression in patients with advanced head and neck cancer receiving radiation therapy; shortened overall survival and increased deaths attributed to disease progression in patients with metastatic breast cancer receiving chemotherapy; and increased the risk of death in patients with active malignant disease not under treatment with chemotherapy or radiation therapy. Erythropoiesis-stimulating agents are not indicated for this patient population."
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Re: A Very Bad Morning For Lance

Postby Pego » Sat Jan 19, 2013 2:32 pm

Blues wrote:It's just my opinion, but I think there's enough evidence to link the chronic use of anabolic steroids to an increased risk of hepatic neoplasms, and also enough evidence to link EPO at least to increasing the proliferation/growth of various types of cancer, so although it may not have caused Armstrong's cancer, there's a chance it might have sped up the progression and aggressiveness of it..


The reports I have seen on hepatocellular tumors related to anabolic steroids mentioned primarily incidence of benign adenomas that subsided after the application terminated. Occasional incidence of malignancies did not reach level of statistically significant degree. If you have something better, please let me know.
Your second half of above paragraph, I hate to sat that, but it is an unsupported speculation. I am not aware that LA's seminoma behaved differently from any other. It is a perfectly treatable malignancy at any stage.

I am not suggesting that anabolic steroids (or EPO) are panacea without risks, I just like to stick with evidence based medicine.
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Re: A Very Bad Morning For Lance

Postby Blues » Sat Jan 19, 2013 4:40 pm

Pego wrote:
Blues wrote:It's just my opinion, but I think there's enough evidence to link the chronic use of anabolic steroids to an increased risk of hepatic neoplasms, and also enough evidence to link EPO at least to increasing the proliferation/growth of various types of cancer, so although it may not have caused Armstrong's cancer, there's a chance it might have sped up the progression and aggressiveness of it..


The reports I have seen on hepatocellular tumors related to anabolic steroids mentioned primarily incidence of benign adenomas that subsided after the application terminated. Occasional incidence of malignancies did not reach level of statistically significant degree. If you have something better, please let me know.
Your second half of above paragraph, I hate to sat that, but it is an unsupported speculation.

I am not suggesting that anabolic steroids are panacea without risks, I just like to stick with evidence based medicine.



I like to stick with evidence based medicine too, but would rather err on the side of caution if there's evidence to support both positions or if adequate studies haven't been performed, especially when the positions of healthcare professionals could influence athletes regarding their beliefs pertaining to the safety of PEDs. Obviously most people who use anabolic steroids aren't going to end up with liver cancer, but I think that evidence does support the belief that many medical experts still hold, which is that long term or high dose use of anabolic steroids slightly increases the risk of developing hepatic carcinoma.

I agree that there's no "proof" that any PED affected Armstrong's testicular cancer, but as far as it being "unsupported speculation" regarding EPO increasing the proliferation or growth of certain cancers, below is the FDA warning report regarding EPO and cancer, with a study result table at the bottom. I'm not sure if your position is based on the fact that you feel there's no evidence that EPO can increase the proliferation of certain cancers, or rather, that it's based on the fact that there's no proof that it might affect testicular cancer in the same manner that it seems to be able to affect certain other cancers... Regarding Armstrong's cancer, my initial comment was that there was "a chance" that his EPO usage could have sped up the progression or growth of the cancer based on the way EPO has been shown to affect certain other cancers. My point wasn't that his PED use caused or affected his illness, but rather that it's not necessarily a sure thing that it didn't.

http://www.fda.gov/Drugs/DrugSafety/Pos ... 200297.htm

I don't know which anabolic steroids Lance Armstrong used over the years, but this relatively recent study is interesting since it pertains to certain anabolic steroids and testicular cancer.

http://www.ncbi.nlm.nih.gov/pubmed/21769864
Last edited by Blues on Sat Jan 19, 2013 5:42 pm, edited 1 time in total.
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Re: A Very Bad Morning For Lance

Postby Pego » Sat Jan 19, 2013 5:39 pm

Thank you for that last link.
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Re: A Very Bad Morning For Lance

Postby Blues » Sat Jan 19, 2013 5:44 pm

Pego wrote:Thank you for that last link.


I was editing my grammar in my last post when you posted this. Tried to get the edit in before anybody replied. Dang it. :x
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Re: A Very Bad Morning For Lance

Postby Blues » Sun Jan 20, 2013 7:32 am

Pego wrote:Thank you for that last link.


This isn't directed to Pego since he already knows this, but I wanted to post it as an FYI to make things a little clearer... From the study link:

"Taken together these data clearly indicate that the use of high doses of AAS (androgenic anabolic steroids), as it occurs in doping practice, enhances Leydig cell proliferation, increasing the risk of tumor development. This risk is higher when AAS are used in association with IGF-I (Insulin-like Growth Factor-1). To our knowledge this is the first report directly associating AAS and testicular cancer."


Regarding the quote above, Human Growth Hormone (HGH) stimulates the production of and increases levels of IGF-1 in the body. IGF-1 can also be used directly as a PED, and is also the main active ingredient in those "velvet deer antler" supplements that have been popular with athletes, including NFL athletes. So if this study is accurate, then using certain anabolic steroids together with HGH or IGF-1 increases the chances of testicular tumors and cancer developing, to a greater degree than either substance alone does.
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Re: A Very Bad Morning For Lance

Postby bambam » Sun Jan 20, 2013 8:24 am

Blues wrote:Regarding the quote above, Human Growth Hormone (HGH) stimulates the production of and increases levels of IGF-1 in the body. IGF-1 can also be used directly as a PED, and is also the main active ingredient in those "velvet deer antler" supplements that have been popular with athletes, including NFL athletes. So if this study is accurate, then using certain anabolic steroids together with HGH or IGF-1 increases the chances of testicular tumors and cancer developing, to a greater degree than either substance alone does.


Yes, but remember, that is a rat study. Cannot definitively be extrapolated to humans, although it is a piece of the puzzle.
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Re: A Very Bad Morning For Lance

Postby Daisy » Sun Jan 20, 2013 8:29 am

bambam wrote:
Blues wrote:Regarding the quote above, Human Growth Hormone (HGH) stimulates the production of and increases levels of IGF-1 in the body. IGF-1 can also be used directly as a PED, and is also the main active ingredient in those "velvet deer antler" supplements that have been popular with athletes, including NFL athletes. So if this study is accurate, then using certain anabolic steroids together with HGH or IGF-1 increases the chances of testicular tumors and cancer developing, to a greater degree than either substance alone does.


Yes, but remember, that is a rat study. Cannot definitively be extrapolated to humans, although it is a piece of the puzzle.


It's also cell culture, not invivo.
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Re: A Very Bad Morning For Lance

Postby Blues » Sun Jan 20, 2013 10:27 am

Daisy wrote:
bambam wrote:
Blues wrote:Regarding the quote above, Human Growth Hormone (HGH) stimulates the production of and increases levels of IGF-1 in the body. IGF-1 can also be used directly as a PED, and is also the main active ingredient in those "velvet deer antler" supplements that have been popular with athletes, including NFL athletes. So if this study is accurate, then using certain anabolic steroids together with HGH or IGF-1 increases the chances of testicular tumors and cancer developing, to a greater degree than either substance alone does.


Yes, but remember, that is a rat study. Cannot definitively be extrapolated to humans, although it is a piece of the puzzle.


It's also cell culture, not invivo.


Good points by you and bambam. It's still interesting though, and could very well end up applying to humans in-vivo too. Agreed that more research is needed.

I believe it's already been established that there's a definite correlation between higher IGF-1 levels and significantly increased risks of certain types of cancer in humans, but I'll be interested to see if the results of the study in the link are confirmed as they relate to humans and the use of certain anabolic steroids.
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Re: A Very Bad Morning For Lance

Postby Pego » Sun Jan 20, 2013 11:30 am

Blues wrote:I'll be interested to see if the results of the study in the link are confirmed as they relate to humans and the use of certain anabolic steroids


Do you have data of seminoma incidence in athletes? Does it exceed the general population?
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Re: A Very Bad Morning For Lance

Postby Blues » Sun Jan 20, 2013 12:07 pm

Pego wrote:
Blues wrote:I'll be interested to see if the results of the study in the link are confirmed as they relate to humans and the use of certain anabolic steroids


Do you have data of seminoma incidence in athletes? Does it exceed the general population?


At this point in time no. I'm not aware of a case study compilation or other study so far that's used athletic participation (or PED use) as a demographic for seminoma or general testicular cancer incidence.

There may be additional studies out there that I haven't come across yet... This somewhat dated study from 2000 isn't what you asked for, but could possibly be remotely related...

http://aje.oxfordjournals.org/content/151/1/78.full.pdf
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Re: A Very Bad Morning For Lance

Postby Pego » Sun Jan 20, 2013 1:05 pm

Blues wrote:
Pego wrote:
Blues wrote:I'll be interested to see if the results of the study in the link are confirmed as they relate to humans and the use of certain anabolic steroids


Do you have data of seminoma incidence in athletes? Does it exceed the general population?


At this point in time no. I'm not aware of a case study compilation or other study so far that's used athletic participation (or PED use) as a demographic for seminoma or general testicular cancer incidence.

There may be additional studies out there that I haven't come across yet... This somewhat dated study from 2000 isn't what you asked for, but could possibly be remotely related...

http://aje.oxfordjournals.org/content/151/1/78.full.pdf


This study raises an interesting question about the results of the study you cited earlier. The subjects in that study were athletes on anabolic steroids. Now, did the increased activity of Leydig cells result from the steroids, activity, or perhaps yet something different?
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Re: A Very Bad Morning For Lance

Postby gh » Sun Jan 20, 2013 1:18 pm

Blues wrote:
Pego wrote:
Blues wrote:I'll be interested to see if the results of the study in the link are confirmed as they relate to humans and the use of certain anabolic steroids


Do you have data of seminoma incidence in athletes? Does it exceed the general population?


At this point in time no. I'm not aware of a case study compilation or other study so far that's used athletic participation (or PED use) as a demographic for seminoma or general testicular cancer incidence.

There may be additional studies out there that I haven't come across yet... This somewhat dated study from 2000 isn't what you asked for, but could possibly be remotely related...

http://aje.oxfordjournals.org/content/151/1/78.full.pdf


If we're going to start talking epidemiology, are there any studies that show any "clusters" of any kind of cancers in pro athletes? Or that pro athletes as a whole have any higher incidences thereof?

Without a hint along that line (and almost 50 years now of top-end athletes sucking up anabolics in copious amounts), you've not got a very good starting point.
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Re: A Very Bad Morning For Lance

Postby Blues » Sun Jan 20, 2013 3:21 pm

gh wrote:If we're going to start talking epidemiology, are there any studies that show any "clusters" of any kind of cancers in pro athletes? Or that pro athletes as a whole have any higher incidences thereof?

Without a hint along that line (and almost 50 years now of top-end athletes sucking up anabolics in copious amounts), you've not got a very good starting point.


I've never said that we have proof one way or another as to whether athletes have an increased risk for testicular cancers. Pego asked me a question and I replied. There's definitely evidence that suggests that there could be a connection between certain PEDs and an increased risk of certain cancers, and with some PEDs there is evidence that they're associated with an increased risk of certain cancers, or possibly an increased rate of growth of certain cancers. These risks may be higher with higher doses and a longer duration of use though.

One of the problems is that in order to track incidence in athletes , somebody has to be able to link these cases together, has to accurately know which patients were top end athletes, as well as what PED's athletes who develop cancers have taken, has to receive funding to do the studies, etc.. Often things like race, age, gender, and geographical area are reported, but I'm not so sure that standard reporting forms ask if a patient was a pro athlete or not, or whether they definitely used PEDs or not...

The nature of testicular cancer makes it a condition that some people prefer to keep private, and the prohibited nature of PED use makes the practice something that some athletes might prefer not to admit to. Current patient privacy laws are stronger than ever now too. IF a study suggests that PED users MIGHT have an increased risk of certain cancers based on certain lab studies, as the anabolic steroid/IGF-1 study suggests, then maybe somebody will start tracking this stuff. But because it hasn't been reported doesn't mean a correlation doesn't exist. It may just mean that nobody's undertaken the study before or that nobody's been able to obtain and compile the necessary data yet. There's not much money to be made by rich drug manufacturers who might be more willing to sponsor a study like this if there was a chance the results could benefit them financially. Also, the fact that testicular cancer and other cancers may not be diagnosed until years after the drug exposure can make studies like this more difficult to undertake as well.

Differences in other habits of athletes could be responsible for a difference in cancer rates too. It's possible that a lower incidence of certain cancers due to possibly a lower smoking rate, healthier diet, or better overall health among athletes as a group, for example, could offset any possible higher incidence of cancer due to PED usage, possibly skewing the results of a simple study comparing cancer rates of athletes to those of the general public.
Last edited by Blues on Sun Jan 20, 2013 4:40 pm, edited 2 times in total.
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Re: A Very Bad Morning For Lance

Postby Blues » Sun Jan 20, 2013 4:24 pm

Pego wrote:
Blues wrote:
At this point in time no. I'm not aware of a case study compilation or other study so far that's used athletic participation (or PED use) as a demographic for seminoma or general testicular cancer incidence.

There may be additional studies out there that I haven't come across yet... This somewhat dated study from 2000 isn't what you asked for, but could possibly be remotely related...

http://aje.oxfordjournals.org/content/151/1/78.full.pdf


This study raises an interesting question about the results of the study you cited earlier. The subjects in that study were athletes on anabolic steroids. Now, did the increased activity of Leydig cells result from the steroids, activity, or perhaps yet something different?


Actually, the subjects were from a rat Leydig tumor cell line, and the conditions were controlled in-vitro. The following study, also from the University of Calabria and with similar results, used the same PEDs but used a human breast cancer cell line in-vitro..

http://www.ncbi.nlm.nih.gov/pubmed/22906881
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Re: A Very Bad Morning For Lance

Postby Pego » Sun Jan 20, 2013 6:50 pm

Blues wrote:Actually, the subjects were from a rat Leydig tumor cell line


Yes, I missed that :oops: .

Edit.
Now I see bambam's and Daisy's observation of that study. Rat's cells treated in tissue culture is much less evidence than I gave it previously.
Last edited by Pego on Mon Jan 21, 2013 7:38 am, edited 2 times in total.
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Re: A Very Bad Morning For Lance

Postby Daisy » Mon Jan 21, 2013 8:56 am

Pego wrote:Rat's cells treated in tissue culture is much less evidence than I gave it previously.

I read the paper and they make an assertion in the introduction that seems strange to me.

Taking into account that Leydig cell tumors are common in young men, the same age group commonly abusing anabolic androgenic steroids (AAS), we wanted to investigate the effects of AAS and IGF-I on Leydig cell tumors.

They have no evidence that those who got testicular cancer were taking any kind of AAS, let alone HGH. This seems to indicate a conformation bias exists in this paper.

Their conclusions are a little misleading too. They say that:
Taken together these data clearly indicate that the use of high doses of AAS, as it occurs in doping practice, enhances Leydig cell proliferation, increasing the risk of tumor development. This risk is higher when AAS are used in association with IGF

First, they have not shown convincing evidence that the dose their culture cells receive is the same as that seen by cells in an athlete taking these drugs. Another problem is that the culture cells are probably receiving an extended dose of these drugs compared to a more transient dose for cells in athletes who are taking the drugs in a training regime.

Second, they do not show more cell proliferation when growth hormone is added to the cocktail above and beyond what is seen for the AAS drugs. They did, however, show a higher expression level of the enzyme aromatase. This last observation is the one that seems lead to their conclusion above, "This risk is higher when AAS are used in association with IGF-I".

This conclusion leads from two pieces of evidence they cite in their introduction.
First they wrote:About half of the male transgenic mice over-expressing aromatase and presenting enhancement of circulating 17 beta-estradiol (E2) levels are infertile and/or have enlarged testis and show Leydig cell hyperplasia and Leydig cell tumors (Fowler et al., 2000)

But what is not mentioned is that these increased levels of aromatase are permanent in these mice. That is very different to a transient spike that would seen when taking drugs.

Second they wrote:In a previous study we have shown that Leydig cell tumor is characterized by aromatase over-expression and consequent increased estrogen production, that contributes to inducing tumor cell proliferation (Sirianni et al., 2007)

I have a problem with this too. Just because the signature of a cancerous cell is high levels of aromatase, this does not mean aromatase causes the cell to be cancerous.

So what to make of their conclusions? If transient increases in aromatase can cause cancer they they might have a point. But I don't think they have enough evidence to show that this is true. Especially, as gh mentioned above, since we do not see a significant spike in testicular cancer in athletes.
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Re: A Very Bad Morning For Lance

Postby Daisy » Mon Jan 21, 2013 9:04 am

Blues wrote:As recently as sixty to seventy years ago most people felt that there was no documented evidence that tobacco smoking could cause lung cancer

But I think that is a little different since there was a statistically significant correlation of lung cancer with smoking. Even if there was no strong evidence. Here it is flipped, there is no statically significant correlation of PED's usage in athletes with cancer, but scientists are looking for evidence.
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Re: a thread for biochemistry geeks [split from Lance]

Postby meninblack » Mon Jan 21, 2013 10:46 am

Determining the effect(s) of a cocktail of PEDs is very difficult irrespective of the "known" cancer inducing effects currently in the medical literature. In particular, I am referring to the effects of contaminants, metabolites and drug-drug interactions.

PEDs don't necessarily exist in a pure and FDA-approved form. Who knows where they come from, their level of purity or what contaminates they carry along for the ride.

The fate of PEDs in the body is also subject to individual differences in metabolism. Remember, drugs can effect the body but the body (esp. the liver) can also effect how drugs works.
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Re: a thread for biochemistry geeks [split from Lance]

Postby 26mi235 » Mon Jan 21, 2013 12:29 pm

I would guess that impure and widely mixed PEDs would lead to more problems than we would see in a single-drug, controlled trial. Given that we have had a huge, if not very documented, trial of PEDs for many years in many sports without a lot of clusters of drug-induced cancers, it seems unlikely that it makes any sense to attribute Armstrong's cancer to drug use, especially since there is not much identified information on his PED use prior to his development of cancer in 1996, and developing cancer by '96 from usage in the prior year or two is awfully quick.
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Re: a thread for biochemistry geeks [split from Lance]

Postby El Toro » Mon Jan 21, 2013 5:12 pm

Blues point about EPO enhancing cancer may have some value because cells do better with a better oxygen supply. Duh! Do you really want to provide better oxygenation to fast proliferating cells? Treatments are moving in the opposite direction - http://www.news.cornell.edu/stories/Feb ... 91.kr.html

HOWEVER, despite the seeming logic, gh's point remains valid. You would expect that cancer in EPO endurance athletes would be observable earlier and advance more quickly compared to a normal population but if there is no evidence of actual outcomes like this then the logic doesn't matter, irrespective of how seductive it might be.

Given that EPO has been used by likely tens of thousands of athletes over about 20 years there should have been some indication although you may not see much effect given that the age cohort of EPO users is not very cancer prone.
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Re: a thread for biochemistry geeks [split from Lance]

Postby Blues » Mon Jan 21, 2013 5:48 pm

And even if it turns out that the incidence of certain cancers isn't greater in PED users than in non-PED user athletes, it's still very possible that certain PEDs, including IGF-1 and HGH (that can increase IGF-1 levels) can increase the growth and spread of certain cancer cells that may already be present. So although the incidence of cancer might not turn out to be greater in PED users, it's still possible that certain PED users might end up having a larger number of cancers that are more advanced and more difficult to treat or cure at the time of diagnosis, which is still something to be concerned about. I hope we'll see large scale, well controlled and comprehensive studies done in the not too distant future to answer our questions, but I won't hold my breath.
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