In Denmark, screening for cervical cancer with liquid-based cytology (LBC) is offered every three years in the age-group 23-49 years, and every five years in women aged 50-64 years. For women aged 60-64 years cytology screening can be replaced by an HPV- DNA test, and the woman is checked-out of the screening programme if she is HPV negative. At present, the age-specific incidence of cervical cancer in Denmark shows a bipolar pattern with peaks both in younger and older ages. A considerable part of new cases and deaths from cervical cancer occur in women over 60 years of age. It has, therefore, been suggested to increase the upper age-limit for cervical cancer screening.
We analyzed incidence and mortality from cervical cancer and data on screening participation in women 64+ years. Data on incidence and mortality were extracted from Danish and Nordic registers. Data on screening participation were obtained from the Central Denmark Region, where 8,868 women 64+ years were invited to screening in 2014 to remedy a previous mistake in the invitation software.
The number of incident cervical cancer cases decreased from an average of 860 per year in 1958-62 to 372 in 2008-12, and the number of cervical cancer deaths decreased from an average of 320 per year in 1958-62 to 98 in 2008-12. During the same period, the age-standardized incidence (Nordic Standard Population) for women 60+ years decreased from 45.7 to 16.8 per 100,000 and mortality from 28.8 to 8 per 100,000. The relative share of cervical cancer cases in women 60+ years increased from 21% in 1958-62 to 30% in 2008-12. Analysis of incidence by birth cohort indicated that younger generations are expected to experience a considerably lower incidence level in older ages than the level seen at present in elderly women. Out of the 8,868 women 64+ years invited to screening in 2014, 11.3% participated and 5.5% of the participants were high-risk HPV-positive.
Today one third of new cervical cancer cases and two thirds of cervical cancer deaths occur in women 60+ years. However, the pattern we see today is a result of different cervical cancer risks across birth cohorts. The current incidence peak of cervical cancer in elderly women could motivate a one-time offer of HPV screening of women aged 65-79, but the evidence does not support a permanent change in the present screening programme because future generations of elderly women will have a lower risk of cervical cancer.