Don’t understand smear testing

[Smearywindowsagain]

Can someone please explain how smear testing works?
I’ve always gone for regular smears. I actually started early and had my first at 21. Recently I’ve realised that they now only test for HPV and not cancerous cells. How does this work though? I thought that HPV was something that can come and go because it’s a virus. Isn’t it possible that you could have had HPV, it caused changes in cells but the virus itself clears and you’re left with the cell changes which aren't picked up because they only test for HPV. Am I being thick here?

Most people will not have HPV (an HPV negative result).

This means your risk of getting cervical cancer is very low. You do not need any further tests to check for abnormal cervical cells, even if you have had these in the past.

You'll be invited for screening again in 3 or 5 years.
www.nhs.uk/conditions/cervical-screening/your-results/

I was wondering the same, just saw another thread where people use the at home hpv tests - I don’t see the difference really, why have a smear test when one of the at home tests does the same thing?

www.mumsnet.com/talk/am_i_being_unreasonable/4598881-if-i-had-a-clear-smear-test-3-years-ago-is-it-likely-to-change

@LittleRen I saw that thread too.I wouldn’t trust myself to do it correctly tbh

They look for cancerous cells (or rather, pre-cancerous cell changes) if you test positive for HPV.

Statistically, it's very unlikely that if you are HPV negative you have pre-cancerous cell changes, but not completely impossible I would guess?

The home tests are usually a swab which is tested for the presence of HPV. It isn't possible to examine cells with one of these tests, so it isn't the same as a smear test.
When a cervical screening sample is taken, it's placed in liquid, tested for high risk HPV. If hrHPV is detected then the sample has a slide made with the cells on it. The cells are examined under the microscope to pick up abnormal changes.

It never used to be like this though, did it? Then it changed. Cost cutting exercise. Makes me so angry.

It changed in Dec 19. Prior to that it was checked. After Dec 19, HPV. We'll have to wait and see if it's damaging enough to be reversed.

So if you test positive for hpv, do they use the same sample from your smear to look at the cells, or are you asked to go back for another smear?

The vast majority of cervical cancers are caused by HPV, but not all. So the new system will undoubtedly miss some women's abnormal cells. I find it concerning too.

@WhatIsThisPlease 3 years ago I tested positive for HPV but no cell changes so they do use the same smear test. It seems they only look at the cells though if they pick up hpv in the sample

I queried this as I had had treatment for abnormal cells in my thirties and was confirmed HPV negative at that time. After 10 years of annual smears I returned to the normal schedule under the new testing system. My GP even queried it, but no, even under those circumstances I would still only be tested for HPV … honestly can’t see the point in bothering.

I read more than 99% of cervical cancers are caused by hpv. Therefore if you don't have the virus you are very unlikely to have cancerous cells.

@CasparBloomberg doesn’t seem right especially in those circumstances

But you can only get HPV through sexual transmission

right?

so if you’ve not been sexually active, there is no point in checking

for example

right?

HPV can lie dormant for years apparently

@Smearywindowsagain the home tests are very, very easy to do. There’s no erm ‘logistics’ involved as such. In answer to your earlier point about doing them correctly.

I have also wondered this. I know that most of us pick up HPV, but your body usually fights it off. But what if, you pick it up the week after your smear, it sits there for a couple of years causing cell changes, then your body fights it off before your next smear so you test negative and they don’t look at your cells, but you’ve actually started to develop cell changes? Could that not happen?

It takes years for HPV to cause cancer. So if you got it and cleared it within 3 years it most likely won't have had time to do any damage.

Saying that, I had CIN3 at my first ever smear, so I must have picked it up very early on in my sexual history.

I had a smear last year that detected HPV and I've been invited back this year. Have no idea what it all means but it's very worrying!

www.gov.uk/government/news/changes-to-cervical-cancer-screening

99.7% of cervical cancers are due to persistent HPV. Yes, this means the 0.3% may be missed.

With the previous test without the hpv test, a higher percentage were missed because sometimes the abnormal cells aren't seen or collected even though they are there.

Also lots of women have been over treated in the past for borderline changes which self resolve.

It's not a cost cutting exercise - it is an evidence based change in policy which allows earlier identification of women at higher risk.

Pretty much all cervical cancer is caused from hpv so if you test positive they then now look at the cells. It does feel like a way of saving money as why can't they just check all cell samples but I think the research is quite robust between the link with the two.

It means you will be more closely monitored - at the current time there were no worrying changes. You are at higher risk of this happening due to the HPV so your cells will be examined once a year instead of every three years as would have happened in the past, so any changes that do occur will be spotted and treated before they can develop further.

This is the exact reason the HPV testing is a positive thing.

Screening programmes are based on risk levels at a population level.

It just means they are monitoring the health of your cervix more regularly. It's not something to worry about.

Detecting HPV is done by a machine directly from your sample.

Looking at the cells requires a machine to make a slide and a human to look at that slide down a microscope - it takes much much longer. The new process allows the screeners time to look at the cases which are high risk instead of looking at the cells of every single patient when the chance of a negative HPV patient having concerning changes is extremely small.

No screening test will catch every case and the evidence says the new process catches more cases than the old way. Of course there will always be some unfortunate women where their changes aren't picked up for varying reasons.