Effect of screening on deaths from cervical cancer in Sweden

Cytological screening identifies precursors of cervical cancer (high grade cervical intraepithelial neoplasia) and, by early treatment, prevents progression to invasive cancer. Multiple case-control studies, cohort studies, and trend analyses have shown that cytological screening is generally associated with a substantial drop in the incidence of and mortality from cervical cancer.1 Where screening is not widely established or is poorly organised, such as in several eastern European countries, the incidence of cervical cancer and cervical cancer related mortality is not decreasing, and in some countries it is even increasing.2 3 Whether the drop in mortality from cervical cancer is a result of prevention of invasive disease, down staging of invasive cases, more effective cancer treatment, or other mechanisms is unclear.

In the linked paper (doi:10.1136/bmj.e900), Andrae and colleagues evaluate and compare five year relative survival and cure rates for women with cervical cancer detected through screening (within one to six months of an abnormal Papanicolaou smear), and for women with cervical cancer detected after presentation with symptoms (six months or more after screening), taking into account staging, histological classification, and age.4 A case-control study by the same authors, which compared the screening …