Offering self-sampled screening for cervical and colorectal cancers at the time of breast cancer screening can significantly boost participation in these programs without compromising satisfaction with breast cancer screening, show results of a large study in Denmark.
Breast cancer screening participation in Denmark exceeds 80% of those invited, but participation in cervical and colorectal cancer screening is consistently lower, explained study first author Anne Dorte Helgestad, from Randers Regional Hospital and Aarhus University in Denmark.
“This made us wonder whether the high participation rate in breast cancer screening could be used as leverage to encourage more women to take part in other programs, and whether breast cancer screening attendance could be a good opportunity to reach these women,” she said.
To investigate, Helgestad and team conducted a trial at five breast cancer screening units in the Central Denmark Region between September 2021 and May 2022. On each of 100 selected weekdays, one screening unit was randomly allocated as the intervention unit while the remaining units served as controls. In all, 27,116 women took part in the trial.
Women attending breast cancer screening at an intervention unit (n=5618) were offered an administrative check-up on their cervical screening status if they were aged 50 to 64 years and on their colorectal cancer screening status if they were aged 50 to 69 years. Those with overdue screening were offered self-sampled screening tests that were forwarded by mail after the intervention day along with screening program information and picture-based information material showing how to use the self-sampling kit.
Women in the control group (n=21,498) were not offered self-sampled screening tests at the time of breast screening but may have received standard screening offers according to Danish national programs.
Dorte Helgestad and co-investigators report in PLoS Medicine that, six months after the intervention, total screening coverage was significantly higher in the intervention group than in the control group for both cervical cancer screening (88.3 vs 83.5%) and colorectal cancer screening (79.8 vs 76.0%).
The study was not designed to determine what impact a 4.8 percentage point increase in cervical cancer screening and a 3.8 percentage point increase in colorectal screening might have on the number of cancer cases prevented as it focused solely on increasing screening participation.
However, Helgestad said that “it is promising that the intervention successfully encouraged both irregularly screened women to participate, as well as a large group of unscreened women, since we know that a significant number of cancer cases are found among unscreened women.”
Among women overdue for cervical cancer screening, participation in the intervention group was 32.0% after six months compared with 6.1% in the control group.
An increase was detected for both under-screened women, defined as those screened at least once within the 10 years leading up to study inclusion but overdue at baseline, and previously unscreened women.
For under-screened women, the participation rate for cervical cancer screening was 34.7% in the intervention arm and 7.9% in the control arm. The corresponding rates for previously unscreened women were 27.9% and 3.9%.
Among women overdue for colorectal cancer, overall screening participation rates were 23.8% in the intervention group and 8.9% in the control group, 29.8% versus 10.9% among under-screened women, and 19.7% versus 7.4% in previously unscreened women.
Most women in the intervention arm gave consent for the administrative check-up on their screening status (81.3% for cervical screening and 76.4% for colorectal cancer screening), with 5.3% declining the offer. The remainder either verbally affirmed having undergone timely screening or passed by the research assistant without contact.
The researchers also used questionnaires to measure the acceptability of the intervention. They found that more than 98% of respondents expressed satisfaction with breast cancer screening in both the intervention and the control group. In addition, 87.4% if respondents in the intervention arm indicated that they would accept a similar offer another time.
“We are initially very pleased that the study was successfully conducted, yielding positive results for screening and achieving a high level of satisfaction among the participating women,” said Helgestad. “Our hope is to eventually implement this in screening clinics within the Central Denmark Region. We also hope that it will serve as an inspiration for other regions in Denmark.”
However, she notes that, for the intervention to be directly applicable elsewhere, it would require similar healthcare systems to those in Denmark, where health services can be effectively combined.
Helgestad also stressed that “it was crucial that the intervention remained a choice, not a pressure to participate.” Despite this, some women agree to receive the self-sampling screening kits but do not return them. “Therefore, we are keen to investigate further why these women initially accept the offer but do not follow through with the screening,” she said.
