HPV testing and genotyping in primary screening in developed countries
Dr Mario Sideri – European Institute of Oncology, Milan, Italy
Mario, it’s been a very interesting situation in testing for cervical cancer recently, or screening for cervical cancer, because we’ve got the Pap smear, tried and trusted of course but in developing countries it’s different, they’ve got the acetic acid test coming along. But the situation in developed countries is importantly changing, according to you. Is that right?
Yes, we have this new and, as far as we proceed, the data on the protection that can be achieved by HPV testing are coming. So more frequent in European countries and in American countries the system is switching from cytology to HPV testing. This switch is very important because it affects millions of women worldwide and so it is a very high impact. The second point is we have a test that can reassure the negativity more than the Pap smear, so elongation between testing is possible up to five years and we can achieve better protection for cancer. So we do less, we pay less and we get more and this is unusual in our setting but this is due to the new technique, the new technology.
Why are there more false negatives with the Pap smears, for instance?
The cytology cannot see the subtle changes at the molecular level that the molecular test can see. This HPV testing is a molecular testing, molecular medicine, in screening.
And which subtypes of the virus do you look for? Are there any that you could miss?
There are forty virus HPV types that affect mucosal tissue but only fourteen are the most important related to cancer and most of them… 16 and 18 are very important.
So basically you go for 16 and 18, if you see those it’s a high risk patient?
Yes and we can manage this kind of patient differently. We do not need to treat but we can follow her more closely and we can follow the negative ones less intensively.
So you’re saving a lot of women the trouble of being tested and does this mean you really could get in with treatment earlier if it turns out to be needed?
Yes, also this. We can diagnose the precursor lesion earlier than the Pap smear.
When you see type 16 or type 18 in one of your patients, one of your women at this stage, then what do you refer her for? Is it regular Pap smears?
We refer these women to colposcopy, while the women that have high risk HPV but is not 16/18 we refer to check again in one year time while the negatives in five years. 90-95% of the population above year 30 is negative so we can assure a lot of women and we can follow the women at risk.
You surely will have some resistance to overcome because smears are tried and trusted?
Yes, there are a lot of resistant. The novelty, the change of approach, the change of meaning to screening positive in oncologic tests is a change. This is a test of risk, it’s not saying you are ill but you need to be carefully followed, you need to stay away from physicians, from gynaecologists. So we have some resistance for gynaecologists.
So what should the health services all over the world in developed countries be doing about this new finding that virologic testing at the molecular level is more useful, basically?
Also in developing countries it’s something that is very useful because the protection that can give one test in life is very high, much more than the single Pap smear and to do this test you do not require a lot of education and training, as for cytology. That’s the only machine that does a lot of tests. And if you use it on a large scale also the cost of the single test is going very low.
So finally what is your recommendation to doctors?
To read the literature carefully and switch from Pap smear to HPV testing to protect the women better.
Thank you very much for joining us, Mario.