Dr. Helen Lambkin:

What that means - I am just explaining, not making a statement on it - is that if there are 100 women with high grade abnormalities and the cancer in all of them is detected by the screening test, they will be treated and, therefore, their pre-invasive cancer will not become invasive cancer and they will be cured by colposcopy and laser excision. If cancer is only detected in 70 women, the other 30 will develop invasive cancer. What we are all concerned with is that whatever test the cytology screening programme is doing would pick up preferably 100% of those high grade cases to ensure that there is no mortality from cervical cancer. However, there is no test that is 100% perfect at that-----