Can I ask a question about HPV and cervical cancer screening

[bran]

I was lurking on another thread about the HPV vaccine and a poster mentioned that the govt is planning to phase out screening on the back of it. Is this true?

The reason I ask is that I don't have HPV but anytime I have mentioned this in relation to smear tests to a health care person they have always been very insistant that HPV is only one of the factors and I still need to be screened as I am at risk. (I wasn't trying to wriggle out of screening, just mentioning it when asked about screening results.) So if I am still at risk without HPV, how will it be different for those who have been vaccinated?

my practice nurse said that by 40 most sexually active women will have come in contact with the virus

my understanding was that having the virus does not mean you will have cervical cancer but most/all cervical cancer will have the virus
I may be wrong

Screening will still be required for women who haven't be vaccinated and for vaccinated women as HPV only protects against about 70% of cervical cancers. In the future (if the HPV vaccination continues) then there may well be questions over the cost benefits of the screening programme - but I haven't seen anything to suggest that there are imminent plans to phase it out.

No, it's not true - even if there were plans, vacc only came in 2 years ago, so it will be another 40 years before those girls are in the highest risk age for cervical cancer. And then they are only protected against a subgroup of hpv strains, and all other causes are still there.

Screening is very cost effective, and in most of the UK it is rare to see cervical cancer in women who have been for screening, which saves huge amounts of money on treatment, not to mention those women are healthy and contributing to the economy. So, I can't see any plans to reduce screening happening any time in the next 40 years at least

That's the impression I got from news stories about the vaccine (about most or all cervical cancer having the virus). That's not the party line at the GP surgery though.

I definitely don't have it, unless DH has been playing away since we were both tested.

No where near all women with cervical cancer have hpv - it's about 70%

HPV is a major factor in cervical changes but not the only factor, hence the need for screening.

I am not aware of any plans to reduce/restrict or stop the cervical screening programme.

I imagine over the next 20-30 years we will see a reduction in the numbers of women with HPV-related cervical changes.

good to know regarding percentages
I hope screening continues and good reliable screening too

30% without HPV is still quite a considerable number, and I imagine that it's hard to be definitive about HPV being the cause of the cancer for the 70% who do have it.

Yes, without the money to check each patients cells to see whether hpv is actually implicated for them, and which strain it is, you can't be sure. They'd like to, especially in areas where the behaviour of cervical cancer seems to be different from the norm, but is v v expensive

CMTdibbler - I think it's more likely to be about 70% of women with cervical cancer in Europe have one of either type 16 or type 18 HPV, which in Europe are the most common strains likely to cause cervical cancer. The vast majority of the remaining 30% have other strains of HPV detectable in their cervical cells, so I think your statistics on the percentage of women with cervical cancer who also have HPV infection are wrong. It still remains that case, though, that the vast majority of women with HPV infections in their cervix will never go on to develop cervical cancer. Most will clear the infection before it causes any serious problems and others will live with HPV DNA in their cervical cells without suffering from cervical cancer. HPV types 16 and 18 are just particularly good at evading the body's immune response and therefore most likely to hang around and cause a problem. At least, that's always been my understanding from what I've read on the subject.

As far as I know, I've still got a job! Obviously this is something as someone working in screening lab you wonder about and we've had a fair amount of discussion.

At least 90% of cervical cancer is associated with HOV of some type. The vaccine covers the main two (16 & 18 which prob does come to 70%) and there is some cross-reactivitiy which will cover others, but it won't cover all. So screening will stay but the screening labs will have to change.

Why? Because the vaccine will vastly reduce the number of abnormal tests we see. At the moment around 8% of tests are abnormal. That means the average screener reading 150 tests a week should on average see 3 abnormal tests a day, the rest are negative. With vaccination, that will be more like, well, 3% which will make the job much much harder.

Why? Because detecting something which happens infrequently is actually quite difficult. Screening cervical samples has been compared to the people doing luggage screening in airports for explosives. You have to maintain a high level of alertness for a problem which occurs infrequently.

Good news for women who will have less abnormal result and interesting times ahead for us in screening!

Development of CIN and cervical cancer requires HPV infection, HPV persistance and then HPV integration.
Many women have an infection and it is dealt with by the immune system, but if you have a screening test taken during this time, it is likely to come back with a low grade abnormality.

There is research developing molecular markers based on HPV oncogene integration, i.e. the virus is changing the body's normal cellular proliferation but these are not ready to be used in screening. If they can be developed so they are reproducible, reliable, consistent and cost-effective then this will be a big breakthrough as only the women whose test shows that the molecular changes are those which will lead to cancer if untreated could be targeted. At the moment we just can't tell, so everyone with a high grade abnormality is offered treatment.

Further reading for those interested:

Review paper by Bosch's group who did the major work on proving the link between HPV and cervical cancer.

Text by Koss on progression of CIN to cancer (slightly older) but includes summary of older studies from the 50s and 60s about women who were followed up without treatment.

PS any suggestions for an alternative career for me if they do shut the screening programme?