Link between goats and lung cancer? Really?

[Rolfe]

My friend at Moredun forwarded my email to a colleague of hers who works specifically with OPA. She got straight back to me with very useful information.

In the past both our group and others have looked hard for any evidence of JSRV (the virus that causes OPA) in human bronchioalveolar carcinoma (BAC) which is the type of lung cancer that looks like OPA - (it appears to have been given a different name, P-ADC, in this report). There is an antibody which we raised against a component of the virus that cross-reacts with some human BAC samples, but we could not find any evidence of JSRV nucleic acid in any human case, or even of any related virus. The other group who have published looked only for JSRV by PCR/RT-PCR and found nothing.

Further, the disease OPA is very rare in goats (in fact I’ve only ever seen reports of it in experimental infections of young kids with JSRV). However, JSRV has been reported to be present in goats with enzootic nasal tumour which is caused by a related but distinct virus called ENTV. The fluid produced from ENT contains ENTV and not JSRV (we have looked at quite a few samples for this).

On the other hand, sheep with OPA often produce copious amounts of JSRV in the lung fluid produced by the tumour, but there is no evidence of an increased prevalence of lung tumours in people regularly handling OPA-affected sheep.

A result. Someone has actually looked at sheep JSR as a possible zoonosis and found nothing.

She also notes the lack of detail in the press release, and suggests that the theory of a link to OPA is "just a (wild?) theory". She spoke of contacting the researcher to follow this up further.

And as I type that, I have a new email.

It is indeed scary to see how many sites have picked up on this press release. I just googled “Dr Nicolas Girard, Louis Pradel Hospital, Hospices Civils de Lyon” to see if I could find his contact details and up came sites from all over the world. I sincerely hope it is just scaremongering as I would be way up at the top of the exposure list for JSRV which is currently only considered a cat[egory] 1 pathogen!

I really wish people would follow their theories up with people who know about stuff before going public with their "wild theories". I'm now going to sit back and let the people who actually know about OPA and JSR deal with these guys.

Rolfe.

 

[Rolfe]

I have now seen the actual poster presentation which is at the bottom of all this. Here's the comment that came with it.

It is clear that the press release bears little resemblance to the actual data and that the data suggesting that exposure to goats is a risk factor is tenuous already, even before they start talking about involvement of a JSRV-related virus. In fact, the association with never smoking is much stronger than the association with exposure to goats!

It seems the authors have started by hypothesising that this tumour many be related to JSR (a disease of sheep), even though previous studies seemed to show no relationship. They then morph this into exposure to "small ruminants", then suddenly (with no explanation) into exposure to goats.

I'm not clued-up enough on the statistics to know how strong the relationship really is, but my informant seems to believe it's not strong. Also, there is no evidence of any attempt to investigate whether any relevant viral infection (JSR or a related virus which causes nasal tumours in goats) was actually present in the goats the patients had been exposed to.

I think it's bunkum. If I were refereeing the paper, I'd bounce it on the unsupportable assumption that the virus they are referring to is present in all goat herds.

Rolfe.

 

[Amapola]

Thank you so much for your sleuthing on this, Rolfe.

At first I thought it was some sort of miscommunication or translation error, but it really sounds like it goes further than that. And your correspondent is right, a lot of goat people are having this forwarded to them which of course is upsetting them, so it is indeed spreading around quite a lot. Well. I'll just see if I can't do a little of my own spreading.

Some of this stuff can be kind of scary because the assumption is that these people know what they are doing and would not publish if there were not something really there. I'd love to find out the real story behind this; human error probably, but who knows at this point, and I really doubt we'll ever find out.

 

[Rolfe]

It's people with an unlikely hypothesis who have found a minor statistical correlation in a porly-designed study, and now seem to be hyping it to promote their hypothesis. I don't think the possibility that this might cause alarm and concern among goat people has even crossed their minds.

Rolfe.

 

[GlennB]

Judging by the outrageous behaviour of our various neighbours' goats, I'm tempted to think that keeping goats just drives the owners to excessive smoking.

 

[Amapola]

Judging by the outrageous behaviour of our various neighbours' goats, I'm tempted to think that keeping goats just drives the owners to excessive smoking.

Ah, but you see, that is the whole appeal of goats - what I say is, they are all trying to overthrow the government, and I simply can't help but sympathize.

I actually tell people this if they want to buy a goat from me. I warn them ahead of time that goats act like goats, not like dogs, cats, other humans etc. but like goats. That means they are contrary, friendly, obstreperous, cooperative, personable and stubborn. Not to mention they are consummate escape artists. I personally find them utterly charming and can't imagine life without them. And, I can make some pretty fantastic cheese from the milk. If you keep goats you are certainly never bored.

 

[Psi Baba]

Don't smoke goats.

Don't stare at them either.

 

[Rolfe]

Rolfe.