5. The effect of screening on incidence and mortality

The effect of screening on incidence and mortality of carcinoma of the uterine cervix is difficult to establish because there was no randomised trial before it was started.  In some countries screening has been in place for more than 50 years although it may have been poorly organised in the past, or more recently organised on the background of opportunistic screening in countries where the risk of cancer and its precursors was changing. 

Effect of prevalence of high-risk HPV on cervical cancer rates

  • As the prevalence of cervical carcinoma and its precursors depends on that of high-risk HPV, it may change with time in different birth cohorts. 
  • The effect of screening may be masked or exaggerated by background changes in prevalence of high-risk HPV.

 

X