How often breast screening- not just every 3 years- slightly different question.

[purplepeony]

I am under the care of a gynae and as part of my HRT treatment, he advised me to have breast screening last year in August which was 2.5 years after my NHS one. His feeling is that I should be screened every 18 months or so.

I have just received my recall for NHS screening and it says not to go if I have been screened in the past 6 months. Well, it is 7 months so I have cancelled it.

Another reason for my cancelling was that privately they use digital screening and the images are looked at by an expert breast screening dr who works from King Edward VII hospital in London, and TBH I would rather pay to be screened privately and pay if it was a "better" screening.

BUT- out of interest, would the NHS even screen me after 7 months anyway?

Is it counter productive to be screened too often?

What is the gynae basing the 18/12 recall on, have they quoted any evidence based research/studies?
this is the NHS breast screening site. I'll have a look through tomorrow

Unless there are very specific reasons for getting a mammogram every 12-18 months, I would be a bit suprised at this tbh. The 3 year interval was set with great thought of balancing the risk from the radiation to the great majority of women who will not have a breast cancer detected vs the benefit of detecting a tumour before it forms a lump that can be felt. So, unless there are very specific reasons for a short recall time, by having mammograms more often increases your radiation dose to your breasts without increasing the benefit to you

The NHS breast screening service is astoundingly good, and everything (and everyone) is checked at very regular intervals to check that they are performing at peak levels and the tolerances are very tight. Digital is the standard of care, so you wouldn't be getting any better imaging in the private sector (and ime, the private units were never as good as the NHS ones when I was involved in checking them).

Okay- to answer your questions...

my gynae is very eminent - he treats the Royal family for what that is worth, so I assume he knows his stuff.

He is of the opinion that a screening every 3 years is not enough, especailly for someone on HRT. (It's a bit like the NHS used to do cervical screening every 5 years due to costs whereas now it is every 3 years.)

CMOT- are you medical or work in the NHS as you seem to have insider-knowledge of this?

I was never aware that they current 3 year interval was set after balancing risk v detection- I assume it was set due to risk v costs , like most NHS screening. Can you point me in the direction of the evidence for this?

Correct me if I am wrong, but does radiation used in breast screening affect the breasts directly- or does it just add radiation to the body overall?

I know that in Europe screening is every 2 years and begins before age 50 anyway.

As for the equipment used, all I can say is that last time I was screened I was told that the scanner was digital and the latest/newset machine.

Any other research/ experiences would be useful.

I'm a medical physicist, currently work in industry, used to work in the NHS, and was trained to be able to carry out screening mammography QA and QC.

Mammography is giving radiation directly to the breasts - only a very small amount, but obviously it does have an associated risk, and on a population level, could have a measurable effect.

http://www.cancerscreening.nhs.uk/breastscreen/EJC.38.11.pdf this paper shows why screening intervals are still at 3 years. I can't lay my hands on an electronic copy of the rationale they worked through.

There's an ongoing study for women aged 40-49 (details here), but the WHO have previously commented that there wasn't enough evidence that it was of benefit

Screening, especially when that screening carries any kind of risk, is an incredibly complicated subject, especially mass screening, which is why the people that make these decisions have to use a lot of statistician support

CMOY- that's a really intersting read. I have just had a quick scan through it ( sorry!) and it appears to show the follow rates by increasing screening to annual over triannually. However, there is certainly a difference in detection* by having a more frequent scan. It also points out the costs in £millions of introducing annual or bianual screening. It also mentions that the machines etc used for screening were from the 19990s and that better technology could produce different results.

Worth looking into a bit more i think.

sorry, lots of typos in that post and some of that post was lost- it seems to show no reduction in mortality by having annual screening, but does show a difference in detection.

Purplepeony - screening in the NHS is a balance of risk vs detection AND cost. The more frequent you screen the more you will detect - but the increase may not be of significant lesions. My area is cervical screening and you could screen everyone 6/12 but the rate of borderline pick ups would rocket and very very few of these women would be at risk of developing cancer. You would end up with women having additional repeats or being treated unnecessarily.
The cervical screening is 3 yearly 25-49 and 5 yearly between 50-65.

so are you saying Bel that outside the NHS more-frequent screening is advisable?

I always have smears done every 2-3 years and may for them- and the drs always advise that time scale.

I would have thought that with breast screening a 3-year interval was a long time given that very tiny tumours can grow which cannot be felt manually.

Unless it is proven that the radiation actually causes harm, then surely it is better to be screened more often rather than not quite enough?

PP - I can't comment on other screening programmes, they have different training, quality assurance and other ways of doing things, all of which inform the set-up that each country has.
E.g. in England reading the samples is done by screening staff who have a training period lasting 2 years, have to complete a City & Guilds qualification and pass a very tough exam. This is the minimum, many staff are also state registered, meaning that they have a degree and then training plus other qualifications. Our performance is monitored on a daily basis. In other countries there's different regulation and sometimes the gynaecologists read the samples.
These differences are part of the reason why you'll see variation in reported detection rates, sensitivity etc. The NHS CSP is recognised as (probably!) the best in the world.

Re Breast tumours CMOTd has explained it really well. You've answered your question - 'very tiny tumours' - a screening programme works because there's a known pre-cancerous or pre-invasive stage which lasts longer enough to allow one/more screening rounds in which to permit detection and treatment.
Deciding what constitutes something requiring treatment is where people differ in their opinion and part of the reason again why the screening intervals can vary.
The reason prostate cancer screening has been difficult to set up is because although 'abnormal' PSA levels can be detected, this can be associated with an non-malignant proliferation of cells - the treatment is quite radical and many men wouldn't actually need it because they would not develop prostate cancer.

Screening more frequently can be harmful in some cases, yes. This article has some useful links and I'm trying to find a BMJ article about the principles of screening.

Radiation does cause harm though - thats a definate. However, the dose from a well calibrated and used mammography unit is very small, so the risk to an individual is acceptable - but when you screen large numbers, there will be cases where women get breast cancer (I can't work out the risk in my head, but its at the level of 1 case in 100,000s of breast cancer detected, and in millions of women screened) attributable to the radiation.

The end point is lives saved - so, the difference in no of deaths between detecting cancers at 2mm and 1cm may be negligible - but the cost, anxiety etc of detecting at 2mm may be much greater.

Prostate cancer (an area I am very involved with now) is interesting as though the PSA test is easy, and determining whether a man has prostate cancer fairly straightforward, it is so very, very common in older men (virtually all 85 year olds will have it if you look), that the decision is whether to treat it or not as most men will die with prostate cancer, rather than of it as it is very slow growing in most cases. So is it worth screening, and dealing with those results, if many men would not have had any adverse effects from their cancer. It's very tricky

Hi CMOTd - thanks - you've put that more clearly than me. I think prostate ca is a really interesting one, particularly over the adverse treatment vs cancer debate.

PP - sorry I left out that the screening programme set up I was talking about is cervical screening which is my area.

I understand what both of you are saying on al accounts but with regard to breast screening, if I had to choose, I would rather have a 2mm tumour found early than a 1cm tumour found 2 years later. it seems a no-brainer really. I know of a few people who have had tiny tumours found by screening whereas if they were not due for the screening for another year or two it would have grown- okay maybe they would still be alive but perhaps had to have a mastectomy rather than a lumpectomy. Maybe these are the kind of details that the stats don't pick up if they are simply looking at mortality rates?

Interesting that this is one of the main news topics today- it was the topic of Radio 4 ten past eight interview today- and even the experts cannnot agree!