Mailing vaginal or urine self-sampling kits versus conventional invitation letters: a randomised trial to assess the effect on cervical cancer screening attendance

HPV testing on vaginal self-samples (VSS) has recently been offered in France as an option for women aged 30-65 years who are not regularly screened for cervical cancer (CC). HPV testing can also be performed on first void urine. CapU4 study is a three arm randomised controlled trial enrolling 14,997 women aged 30-65 years who had no screening test recorded since more than four years and who did not respond to an invitation letter twelve months before. Women were allocated to two experimental arms (mailing of a VSS or a urine self-sampling [USS] kits) or to a control arm (invitation to visit a physician to collect a cervical specimen). A total of 13,061 women were included. The intention-to-treat analysis demonstrated the participation rate increased in the self-sampling arms (USS: 23.6%; VSS: 23.5%) than in the control arm (12.9%). The per-protocol analysis did not show a favourable effect (USS: 11.1%; VSS: 12.6%), particularly for USS. Invitations including vaginal or urine self-sampling kits increased participation in CC screening by approximately 11%. Halve of the responding women in the self-sampling arms visited a physician to take a cervical specimen. There is evidence that sending vaginal self-sampling kits can increase attendance at cervical cancer screening. However, no data exist suggesting that sending urine collection kits may be effective as well to trigger participation compared to conventional invitation letters. The results of the CapU4 trial may generate innovative tools that may help in optimizing attendance at cervical cancer screening.