Cervical Cancer Risk Warrants Older Age Screening

Studies show that women continue to benefit from cervical screening in their later years as their risk for cancer increases

medwireNews: The importance of cervical cancer screening in older women has been highlighted in two population studies showing that patients with and without a history of abnormal cervical cells benefit.

The first study, published in PLoS Medicine, found that women in the UK who had not undergone cervical screening after the age of 50 years were six times more likely to be diagnosed with cervical cancer than women who had negative cytology results between the ages of 50 and 64 years.

This gave a 20-year rate of eight and 49 cases per 10,000 women for those with and without an adequate number of negative cytology results before the age of 65 years, compared with 86 cases per 10,000 women for those whom screening revealed abnormal cytology between age 50 and 64 years.

The research focused on the 1341 women in England and Wales aged 65 to 83 years who were diagnosed with cervical cancer between 2007 and 2012 and 2646 age-matched controls, explain Peter Sasieni and co-workers, from Queen Mary University of London in the UK.

Women who were screened at least once every 5.5 years between 50 and 64 years, regardless of cytology, were also 75% less likely to be diagnosed with cervical cancer between 65 and 79 years than those who were not screened.

“Stopping screening between ages 60 and 69 in women with adequate negative screening seems sensible, but further screening may be justifiable as life expectancy increases,” the researchers believe.

In the second study, published in the BMJ, a team of Swedish researchers show that women who have previously been treated for cervical intraepithelial neoplasia grade 3 (CIN3) are significantly more likely to die from invasive cervical or vaginal cancer than women without a history of CIN3.

Analysis of the entire Swedish female population gave a standardised incidence ratio (SIR) of 2.39 for the 150,883 women who were diagnosed with CIN3 and followed up for 3,148,222 person–years.

There was a steep increase in the risk for invasive cancer in women treated for CIN3 after the age of 60 years, rising to a SIR of 10.58, and again after the women reached 70 and 80 years, with SIRS of 16.54 and 28.67, respectively.

The standardised mortality ratio for cervical or vaginal cancer with attained age at diagnosis also increased rapidly after the age of 60 years, with a mortality rate of 50 cases per 100,000 women by age 72 years.

“The main implication of this study is that women previously treated for CIN3 also need surveillance in old age, perhaps as long as it is practical to visit a physician or a nurse to take a smear,” say Björn Strander, from the University of Gothenburg, and co-authors.

“Emphasis should be placed on continued surveillance in old age, rather than on follow-up for a specified number of years after treatment,” they recommend.

References

Strander B, Hällgren J, Sparén P. Effect of ageing on cervical or vaginal cancer in Swedish women previously treated for cervical intraepithelial neoplasia grade 3: population based cohort study of long term incidence and mortality. BMJ 2014;348:f7361. doi: 10.1136/bmj.f7361.

Castañón A, Landy R, Cuzick J, et al. Cervical Screening at Age 50–64 Years and the Risk of Cervical Cancer at Age 65 Years and Older: Population-Based Case Control Study. PLoS Med 11(1): e1001585. doi:10.1371/journal.pmed.1001585

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