Colorectal Cancer Screening Can Reduce Death Risk by Up to 43%, Swedish Study Finds

Individuals who participate in colorectal cancer screening may experience as much as a 43 percent lower risk of dying from the disease, according to new findings published in JAMA Network Open by researchers from Karolinska Institutet and Umeå University in Sweden. This study utilized data spanning up to 14 years from the Stockholm-Gotland screening program.

Colorectal cancer ranks among the most prevalent cancers, but early detection significantly enhances treatment outcomes. Sweden has implemented a universal screening program offering testing every two years to residents aged 60 to 74. Participants receive a home screening kit and are asked to provide a stool sample for analysis, with hidden blood detected in the sample potentially leading to additional procedures, most commonly a colonoscopy.

Long-Term Data Reveals Greater Benefits

Routine colorectal cancer screening was initiated in Stockholm and Gotland in 2008. The recent analysis tracked participants from within this age group for up to 14 years, assessing the impact of screening on mortality rates associated with the disease. “A previous evaluation of the program showed that those who received an invitation to screening had a 14 percent lower risk of dying from the disease,” stated Johannes Blom, senior consultant and associate professor at the Department of Clinical Science and Education at Södersjukhuset, Karolinska Institutet, and the study’s corresponding author. “We have now been able to show that the mortality is significantly lower than that among those who actually take part in the screening.”

Participation Linked to Lower Death Risk

The research involved a comparison between individuals invited to screening from 2008 to 2012 and a control group that either received invitations later or not at all. The study employed statistical methods to account for various influencing factors, including control group members who later became eligible and those invited who opted out.

When factoring in these elements, receiving an invitation to screening correlated with a 26 percent lower risk of dying from colorectal cancer. For individuals who actively participated in the screening, this risk reduction rose to 43 percent. “Although screening is offered free of charge and the test is simple to carry out, around a third of people do not submit a sample,” noted Blom. “Our study highlights the importance of taking part in colorectal cancer screening, and shows that it can actually save lives.”

Study Scale and Implications

The study involved 376,511 participants, during which 1,668 deaths from colorectal cancer were recorded. Its significant sample size, extensive follow-up period, and access to Swedish health registers were key strengths. However, researchers caution that some uncertainty remains due to statistical adjustments made to mitigate bias.

The research was funded by the Swedish Cancer Society, the Swedish Research Council, and Region Stockholm, with no declared conflicts of interest among the researchers.