We've reached the end of our allocated time - thanks very much to our experts for taking part, and to everyone who has posted a question, link or comment.
Sheridan2 asks:
"What strains of HPV are most likely to cause this kind of cancer? Is it possible for a female to pass the virus to a male?"
Guardian contributor @Sheridan2 - Hi, its types 16 (mainly) and 18, 6 and 11 in the recent studies of head and neck cancers associated with HPV in the UK and USA.
There are 100 types of HPV and some of the others can cause cancer too, but much less frequently.
Yes to transmission female to male.
JCambric asks:
I wonder whether folks think one has an obligation to tell future partners that one has HPV.
Two doctors have told me that HPV is so ubiquitous that a difficult conversation isn't necessary. They said that sexually active partners were themselves likely to have been exposed. However, I found this to be cold comfort for my conscience, particularly given the risks.
Without showing any visible symptoms myself, my last two partners had abnormal paps. (Without knowing for sure, these were likely due to me given their limited sexual histories.)
Guardian staff @JCambric - This is a really interesting and sensitive point. If you had two partners with abnormal smears and think you carry the virus you might want to get checked. What do others think about the question of whether if you have HPV you should tell future partners? If you met someone who said they had it would you stop you being sexually active with them?
Guardian contributor @JCambric - Interesting question (which I can't really answer for you). The docs are right, most adults who have sex will have been exposed to a strain of HPV and will either have it and not know or have it and clear it.
I think if you were to tell partners that you have it I think you could also say that it's most likely that their other sexual partners may have had it too. If you choose to tell, then telling the full story is factually correct as well as re-assuring.
Guardian contributor @JCambric - I agree with the comments posted above.
Remember that we know that the virus is cleared in lots of people so it is not possible to be certain that infection persists in any person.
Again, many HPV types are widely prevalent in our population. The recent increase in the cancers we are discussing here has produced a massive increase in research helping us understand more and so to improve the advice we can give.
At the minute I would agree with the two doctors you have spoken to. A difficult conversation on having had HPV found in the past is not necessary.
Updated
Guardian staff My colleague, health correspondent Denis Campbell, has just sent me this from Professor Ian Jones, a virologist at the University of Reading. He says:
Many head and neck cancers are caused by the same HPV viruses that cause cervical cancer. They are widely distributed in the population by middle age. Smoking is also a very significant risk factor.
There is a scientific case for vaccinating boys as well as girls with the current HPV vaccines as the vaccine prevents infection regardless of gender. However, the cost benefit of vaccinating boys is less clear and could take several decades to show.
rdwatkins asks:
"Hi - ive done a bit of reading and can see that the vaccine guardasil is aimed at 16-26 year olds, and best before you are sexually active. However, clinics will vaccinate at all ages. What would be the arguaments for getting/not getting the vaccination if you are over 26? thanks"
Guardian contributor @rdwatkins - It's just that the older you are the more likely you have already been exposed to it and thus it's too late. Obviously the fewer sexual partners someone has had the less likely they will have been exposed, so it's not just about age I don't think.
FluffyFairy asks:
"I've a HPV which causes genital warts, is it possible that I may also have the cancerous type of HPV?
"I used to have internal (vaginal) warts which were surgically removed, but they may have come back. Should I tell each new partner about my past problems with warts and that I am unsure if I still have them inside?
"Can women like me receive unprotected oral sex?"
Guardian staff @FluffyFairy - I'll let the medical experts handle this one but I think the language you use points out something would could be cleared up - HPV is not directly linked to cancer - certain strains of HPV have been show to increase the risk of precancerous cells forming but this is not cancer - is that right @bishtraining @jimmccaul? I think the immediate link between HPV and cancer can cause a lot of unnecessary worry when it's been shown so many people (90% of sexually active over 25) have some strain of the virus.
Guardian contributor @hrwaldram - that is correct, only certain viral types (mainly type16 in UK) have cancer causing potential.
Lots of other types exist that DO NOT cause cancer. This is a really important message.
Guardian contributor @hrwaldram - That's right. There are many different strains of HPV many of which are harmless. Our own immune systems often clear them (depending on how good our immune system is generally which is affected by other factors such as smoking and drinking).
If you're concerned @FlufflyFairy I would go back to your healthcare providers for a chat about this
Dominic123456 asks:
"As the father of 15 year old triplets my two daughters have had the vaccine, will the NHS vaccinate my son if he or I request it? As a general question, what symptoms should I look out for personally?"
Guardian contributor @Dominic123456 - currently the vaccine is not available on the NHS for boys Dominic. It is available privately though.
Updated
Eddie10011 asks:
"Would the current vaccine available be effective for adults? or just teenagers?"
Guardian contributor @Eddie10011 - Yes, it would be protective.
If someone already has the virus, we don't know if the vaccine will help clear it.
Early trials with vaccine in patients with viral related cancer are underway
A detailed query from Brimelow:
I am fairly sure I am right in saying that the proportion of HPV positive oropharyngeal cancers has increased relative to HPV negative (in developed countries at least, I know they have huge issues in India with chewing Betel etc).
Do the experts believe that this change in proportion is down to:
- the steady (though slowed) reduction in smoking in the last 40 years
- a change in sexual habits in the last 40 years - more genital-oral sex, more anal-oral sex, etc (I don't know if there has been a change in habits, are we erm, how do I phrase this, more adventurous than we were?)
- both
Guardian contributor @Brimelow - The honest answer is we are not sure.
It may be that practices have changed, it may be a change in the virus and the proteins it produces.
Really importantly, surviving this cancer depends on smoking as well as viral factors. Although smoking is reducing it is still responsible for far more e.g. mouth cancers (rather than throat) in the UK and worldwide.
Updated
Kentrel asks:
"What's the relation between HSV1 (cold sores) and HSV2(genital warts)?
I've had cold sores in the past, but haven't had any in years, and I suspect I might be one of those people who for whatever reason can rid themselves of the virus. Have I really been rid of it, or is it there but dormant?
Can someone with cold sores cause genital warts, etc?"
Guardian contributor @Kentrel - Confusingly HPV and HSV sound similar but are actually completely different. HPV are the viruses which can cause genital warts and are linked to some cancers (as we discuss here) but HSV 1 and 2 are different. HSV 1 causes coldsores and HSV2 causes genital herpes (though they can both be caught genitally too). They can be transmitted in similar ways to HPV (skin on skin contact, oral sex, even kissing) but cause painful blisters and sometimes flu like symptoms. Usually the first outbreak is the worst and many people don't have future outbreaks. Unless someone gets an outbreak during pregnancy, they are actually pretty harmless and have no long term affects. They can be treated at GUM clinics, find your nearest here Also I wrote about herpes at my site here
Thanks for all your comments and questions so far. Eurovaccine has posted a recommendation for further background reading:
"The European Centre for Disease Prevention and Control has published an updated guidance on HPV vaccination. "HPV vaccines currently in use for girls are generally safe, well tolerated and highly efficacious in the prevention of persistent infection"
curlscurls asks:
"How would people identify which types of HPV are cancerous/non-cancerous?"
Guardian contributor @curlscurls - Its not possible to do so. The virus types which cause warts are not the types which cause cancer though. So the cancer causing types are not usually visible to the naked eye.
garygarygary asks:
"I am a fit and healthy 24 year old male and I have had one or two genital warts. I am now very worried and stressed by this news-story. I have two questions:
(1) Is my HPV likely to go away (be cleared up) by itself?
(2) Should I have more regular screenings for these susceptible cancer types e.g. throat, etc."
Guardian contributor @garygarygary - Hi. You can visit your local GUM clinic (find where this is in the UK here) for a check up and treatment for that. They may actually not be genital warts but it's a good idea for a clinician to have a look to make sure. All clinics are confidential. All tests and treatment are free.
bishtraining also adds some suggested background reading:
"For some re-assuring words elsewhere about this story (see Debbie Herbenick quote) and also this from Cancer Research UK."
maxito asks:
"What about HPV and anal cancer? From what I've read it seems to be at least as significant in terms of public health and perhaps more stigmatized, so worthy of discussion too?"
Guardian contributor @maxito - I and THT would agree with you http://www.tht.org.uk/our-charity/About-us/Media-centre/Press-Releases/2013/June/Terrence-Higgins-Trust-statement-on-Michael-Douglas-HPV-comments
Updated
A question from whitewithextrasugar, who asks:
"Further to the question above, regarding the vaccination of teenage boys, Is there any likely downsides of the vaccination?"
Guardian contributor @WhiteWithExtraSugar - Vaccinations always carry a small risk of allergy to components of the injection.
Also, not all cancer causing types of HPV are covered (one available at the minute covers only two and another four cancer causing types).
Otherwise, not really
Justin Hancock, who runs the Bish Training sex and relationships education website, is also taking part in the webchat.
Guardian staff Hello
One question I've seen a few times on Twitter - should we be thinking of vaccinating teenage boys against HPV, as well as girls?
Guardian contributor @ClairePhipps - I think so yes. Males also at risk of certain cancers (penis and anus) from high risk strains of HPV
Guardian contributor @TheThirdMan - It seems to in some cases.
Again though, we understand that HPV is often acquired and then cleared over a period of weeks. So why is stays around and is involved in formation in cancers in some people is being closely examined currently.
The webchat is now underway. Please post your questions for the experts below the line.
First question is one that came up a lot on yesterday's Datablog post: Is there a cure for HPV? Professor Jim McCaul responds:
Guardian contributor Hi, regarding cure for HPV, currently there are trials running on HPV vaccines.
The whole process is interesting though as many people will aquire and then clear HPV virus spontaneously, without treatment.
Updated
Actor Michael Douglas created more than a stir in Cannes this week after revealing in a Guardian interview he believes his throat cancer was caused by oral sex.
Speaking to Xan Brooks, Douglas said his throat cancer diagnosis in 2010 was linked to a strain of the Human Papillomavirirus (HPV) - which he then linked to cunnilingus.
But on a following Datablog looking at the facts behind Douglas's theory revealed some holes in his thinking. The post highlighted the 100s of strands of HPV, how common the virus is, and the links between just a few strands and different types of cancers, including cervical, vaginal, anal and oral cancers:
"HPV increases cancer risk, but can't be explictly said to have caused any particular cancers (though some variants are HPV-related and others not): just because someone with cancer also has HPV doesn't necessarily mean they wouldn't have got it anyway. [...]
"It's calculated that between 25% and 35% of oral cancers are HPV-related – meaning it seems to be involved in somewhere between 1,500 to 2,000 diagnoses a year."
Readers in the comments began asking questions - if you have HPV are you more likely to pass this on to your partner through oral sex? Is there a cure for HPV? How is it contracted and if the symptoms lie dormant, how do you know when to get checked? Will the new vaccination for teenage girls make a difference?
Are the risks of developing cancer higher if you have HPV and what are the links between oral sex and throat cancer?
Joining us to discuss these issues are Professor Jim McCaul, a head and neck cancer specialist at Bradford Royal Infirmary, and Justin Hancock, who runs the Bish Training sex and relationships education website.
We've brought on two experts to answer your questions from 1-2pm BST in the comment thread on this article. Post your question below.
Updated
Hi all, it's 2pm (BST) and the webchat is due to finish now - thanks for all your questions and for @bishtraining and @jimmccaul for joining us to answer so many of them - hope that's cleared up some things and we'll keep this thread open for a little while too.