Aims Colorectal cancer (CRC) is a major health concern. Sweden initiated a nationwide,
population-based CRC screening program between April 2021 and September 2022, targeting
all individuals aged 60-74. This study aimed to evaluate the participation rate and
outcomes of the first round of screening invitations.
Methods Data were retreived from the Swedish Colorectal Cancer Screening Register (SveReKKS),
a nationwide electronic database where registration of screening data is mandatory.
Individuals aged 60-74 were invited by letter to participate in the screening program
by submitting an enclosed fecal immunochemical test (FIT) (OC-Sensorä [Eiken Chemical
Co, Tokyo, Japan]). A positive test was defined as≥40 µg Hb/g for females,≥80 µg Hb/g
in feces for males. Those with a positive FIT result were given contact information
to book a colonoscopy. Colonoscopy results, including the Boston Bowel Preparation
Scale (BBPS), cecal intubation rate, the number of polyps identified and removed,
and histopathological diagnoses, were recorded in SveReKKS.
Results In total, during first round of invitation, 884,867 screening invitations were sent
out and of these, 569,176 individuals responded with a complete test, resulting in
a participation rate of 64.3%. The mean age of participants was 62.9 (95%CI 62.9-62.9)
and 47.3% were male (47.2-47.4%). In a logistic regression model with participation
as outcome, older age and female sex were independent variables associated with higher
participation (age 65-69 years vs. age 59-64=OR 1.28 [1.26-1.29]; age 70-73 vs. 58-64=OR 2.8 [2.7, 3.0], female sex=OR 1.36 [1.35, 1.37]).The FIT positivity rate
was 2.7%, with no significant differences observed across age or sex. Among those
with a positive FIT, 82.0% underwent a colonoscopy. The colonoscopy rate was slightly
higher for females compared to males (OR 1.15 [1.05, 1.24]). Overall, the cancer detection
rate was 6.3% (5.8, 6.7), the adenoma detection rate (ADR) was 44.3% (43.4, 45.2),
and advanced ADR was 28.7% (27.9, 29.5). Sessile serrated lesions were found in 4.8%,
and the polyp detection rate (PDR) was 68.1%.Regarding other quality indicators, 98%
had a BBPS of≥6 in total and≥2 in every segment, the cecal intubation rate was 96%,
and 99% reported withdrawal of≥6 minutes or biopsy/endoscopic therapy during withdrawal.
Both early and late complications were rare, 0.5% and 0.7%, respectively.
Conclusions The implementation of the Swedish CRC screening program demonstrates promising results
with high participation and detection rates, as well as strong performance on other
quality indicators. The results are very encouraging, suggesting that the program
is effectively identifying individuals with CRC and precancerous lesions. However,
it is important to consider the specific age range and FIT cutoff values used in this
program when comparing its detection rates to those of other screening programs.
