I was presenting the results of a study that we did looking at whether or not the introduction of two-view mammography had an effect on interval cancer rates in the UK breast screening programme. Basically two-view mammography has been recently introduced in the screening programme, initially only a single view was taken. Research has been done already to show that the introduction of this two-view has led to a decrease in screen detected cancer rates but not much research has been done to look at whether or not subsequent interval cancer rates have fallen.

What defines two-view mammography?

Initially single view mammography was a mammogram taken from the side of the breast so it shows the breast tissue and the armpit and pectoral muscles. The second view is the cranio-caudal view and that takes a view of the breast from the top and it just allows you to see more of the breast tissue and might help in detecting cancers which are within the tissue that you can’t see on the medio-lateral oblique view.

What were you looking at and what were the findings?

We looked at whether or not interval cancer rates decreased, interval cancers being cancers which occur in women who have been screened and issued with a normal screening result and then a cancer occurs before their next screening appointment. Something got missed or maybe it wasn’t detectable at that time and then subsequently became detectable, so it could be for a variety of reasons.

In particular we were interested in whether or not the rate of interval cancers decreased in women in their subsequent screen, so not their first screen, because two-view was introduced in the mid-90s for women’s first screen but the subsequent screens it has only been introduced in the last few years so we wanted to see if it was making a difference. We found that the introduction of two-view did indeed make a difference on interval cancer rates. Our overall results found that there was an 18% reduction in interval cancers occurring in women in units that used two-view mammography, compared to units who were still using single view mammography. Our results coincided quite nicely with results that previous researchers have found and they found that there was the same level of increase in screen detected cancers so hopefully they’re picking up more at screening through two-view and therefore there are less subsequent interval cancers occurring.

Our evidence just adds more support to the fact that it is sensible to use two-view mammography for incident screens as well as women’s first screen.