Trends in incidence and mortality rates of squamous cell carcinoma and adenocarcinoma of cervix--worldwide.

The objective of the present paper is to summarize and quantify the trends in incidence and mortality rates of cervical squamous cell carcinoma (SCC) and adenocarcinoma (AC) worldwide. All indexed publications, which provided information on time trends in incidence or mortality rates of cervix cancer, published during the past 12 years were included. The details of studies have been identified through searches on the MEDLINE database. Cytology screening as well as changes in socio-economic profile have led to declines in cervical SCC incidence and mortality rates worldwide. Higher percentage decline in SCC is observed in countries where organized screening programmes are available. The results suggested that Pap smear screening has played a significant role in the reduction in SCC in the US, Canada, New South Wales, and in almost all European countries (except in Ireland) as well as in some of the Asian countries. Increasing incidence and mortality rates of cervical AC has reported in many countries such as the US, Canada, UK, Iceland, Sweden, England, Spain, Finland, Slovakia, Slovenia, the Netherlands particularly among young women. However the increase was mainly in earlier periods till 1995 and stable or declining trends in cervical AC have been observed in later periods in many of the above countries such as the US, UK, Canada, Sweden. The increasing risk of AC suggested a major role for an increasing prevalence of persistent oncogenic HPV infection and its cofactors, whereas the down-turn in period effects in several countries during the 1990 s provided evidence that cytology screening is detecting more preinvasive ACs than in previous decades and suggested that screening might be starting to have a protective impact on AC. The decline in AC incidence might be due to improved specimen collection as well as due to increased awareness of AC precursors among cytopathologists and clinicians, improvements in laboratory training and quality assurance. In conclusion, cytology screening in combination with HPV screening for high-risk HPV types may maximize the possibilities of having early cervical lesions detected and treated.