Impact of the National Cervical Screening Programme in New Zealand by age: analysis of cervical cancer trends 1985-2013 in all women and in Māori women.

BACKGROUND

New Zealand is an example of a country with a well-established cytology-based screening program. New Zealand's National Cervical Screening Programme (NCSP) commenced in 1990, and recommends three-yearly cytology-based screening for women aged 20-69 years. In 2018, the NCSP will transition to five-yearly HPV-based screening for women aged 25-69 years. The aim of this study was to assess the impact of the program to date in different groups, to provide a benchmark for the new program.

METHODS

Analysis of cervical cancer trends in New Zealand by age and ethnicity over the period 1985-2013, and by morphology over the period 1997-2013, using data from the New Zealand Cancer Registry was conducted.

RESULTS

The overall incidence of cervical cancer was 56% (95% CI 51-60%) lower in 2009-2013 than in 1985-1989, and significant reductions were observed in women aged 25-49, 50-69, and 70 + years. Relative reductions in cervical cancer were very similar for Māori and non-Māori women aged 25-49 (50% in Māori; 52% in non-Māori) and 50-69 years (65% in Māori; 69% in non-Māori). In contrast, incidence appeared to increase after around 1996 in women aged 20-24. The increasing trend was significant for women aged 20-24 overall and for non-Māori women (p < 0.01 in both cases).

CONCLUSION

There have been substantial reductions in cervical cancer among women aged 25 + years in New Zealand since the inception of the NCSP, and these reductions are similar in Māori and non-Māori women. Cervical cancer incidence among women 20-24 years has not declined since the NCSP began, and appears to be increasing.