Colorectal Cancer Screening Shows Promising Results

According to a new study published in JAMA Network Open, participating in colorectal cancer screening may reduce the risk of dying from the disease by as much as 43 percent. Researchers at Karolinska Institutet and Umeå University in Sweden conducted the study, which drew on 14 years of follow-up data from the Stockholm-Gotland screening program.

Colorectal cancer is one of the most common cancers, but outcomes are generally favorable when the disease is detected early. Sweden has introduced universal screening, offering testing to people aged 60-74 every two years. The screening process involves providing a stool sample at home, which is then checked for tiny amounts of blood that cannot be seen with the naked eye. If blood is found, additional testing is offered, often in the form of a colonoscopy.

The Stockholm-Gotland screening program began in 2008, and researchers from Karolinska Institutet and Umeå University have been tracking participants for up to 14 years to examine how screening affects the risk of dying from the disease. The study compared people invited to screening between 2008 and 2012 with a control group who were either invited later or not invited at all.

After accounting for factors that could influence the findings, including people in the control group who later became eligible to participate and those who were invited but chose not to take part, the researchers found that receiving an invitation to screening was associated with a 26 percent lower risk of dying from colorectal cancer. Among people who actually participated, the risk was 43 percent lower.

The study included 376,511 people and recorded 1,668 deaths from colorectal cancer over the follow-up period. The researchers note that the estimates depend on statistical adjustments designed to account for different sources of bias, so some uncertainty remains. The study was funded by the Swedish Cancer Society, the Swedish Research Council, and Region Stockholm.

According to senior consultant and associate professor Johannes Blom, the study highlights the importance of taking part in colorectal cancer screening and shows that it can actually save lives. ‘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,’ Blom notes. ‘Our study highlights the importance of taking part in colorectal cancer screening, and shows that it can actually save lives.’

The researchers state that they have no conflicts of interest and that the study’s key strengths include the large number of participants, the lengthy follow-up period, and access to Swedish health registers.