What influences the decision to participate in colorectal cancer screening with faecal occult blood testing and sigmoidoscopy?

INTRODUCTION: Uptake is an important determinant of the effectiveness of population-based screening. Uptake of colorectal cancer (CRC) screening generally remains sub-optimal. AIM: To determine factors influencing the decision whether to participate or not among individuals invited for faecal occult blood test (FOBT) or flexible sigmoidoscopy (FS) screening. METHODS: A questionnaire was sent to a stratified random sample of individuals aged 50-74, previously invited for a randomised CRC screening trial offering FOBT or FS, and a reference group from the same population not previously invited (screening naïve group). The questionnaire assessed reasons for (non)-participation, individuals' characteristics associated with participation, knowledge, attitudes and level of informed choice. RESULTS: The response rate was 75% (n=341/452) for CRC screening participants, 21% (n=676/3212) for non-participants and 38% (n=192/500) for screening-naïve individuals. The main reasons for FOBT and FS participation were acquiring certainty about CRC presence and possible early CRC detection. Anticipated regret and positive attitudes towards CRC screening were strong predictors of actual participation and intention to participate in a next round. The main reason for non-participation in FOBT screening was lack of abdominal complaints. Non-participation in FS screening was additionally influenced by worries about burden. Eighty-one percent of participants and 12% of non-participants made an informed choice on participation. CONCLUSION: Only 12% of non-participants made an informed choice not to participate. These results imply that governments and/or organizations offering screening should focus on adequately informing and educating target populations about the harms and benefits of CRC screening. This may impact uptake of CRC screening.

Quality of life in participants of a CRC screening program.

BACKGROUND: Little is known about the effect of participating in a colorectal cancer (CRC) screening programme on quality of life (QOL), neither for participants with a negative nor for those with a positive test result. These findings, however, are important to evaluate the impact of CRC screening. METHODS: Participants from CRC screening trials were sent a questionnaire, which included validated measures on generic health-related QOL, generic anxiety and screen-specific anxiety. Both faecal immunochemical test (FIT) and flexible sigmoidoscopy (FS) participants, either with negative or positive test results, were addressed. RESULTS: The response rate was 73% (1289 out of 1772) for FIT and 78% (536 out of 689) for FS participants, with mean ages varying from 63-66 years. Positive FIT participants had worse physical (PCS-12, 47.1 vs 48.3, P=0.02), but equal mental QOL scores (MCS-12, 51.1 vs 51.6, P=0.26). Positive and negative FS participants had similar QOL scores. Both FIT and FS participants with a positive test result reported more screen-specific anxiety than negative FIT and FS participants. Positive and negative FS participants had similar generic anxiety scores. CONCLUSION: Our findings indicate that the burden of participating in CRC screening may be limited. Conducting a prospective study to confirm these results is recommended.

Immunochemical fecal occult blood testing is equally sensitive for proximal and distal advanced neoplasia.

OBJECTIVE: Fecal immunochemical testing (FIT) is increasingly used for colorectal cancer (CRC) screening. We aimed to estimate its diagnostic accuracy in invitational population screening measured against colonoscopy. METHODS: Participants (50-75 years) in an invitational primary colonoscopy screening program were asked to complete one sample FIT before colonoscopy. We estimated FIT sensitivity, specificity, and predictive values in detecting CRC and advanced neoplasia (carcinomas and advanced adenomas) for cutoff levels of 50 (FIT50), 75 (FIT75), and 100 (FIT100) ng hemoglobin (Hb)/ml, corresponding with, respectively, 10, 15 and 20 µg Hb/g feces. RESULTS: A total of 1,256 participants underwent a FIT and screening colonoscopy. Advanced neoplasia was detected by colonoscopy in 119 (9%), 8 (0.6%) of them had CRC. At FIT50, 121 (10%) had a positive test result; 45 (37%) had advanced neoplasia and 7 (6%) had CRC. A total of 74 of 1,135 FIT50 negatives (7%) had advanced neoplasia including 1 (0.1%) CRC. FIT50 had a sensitivity of 38% (95% confidence interval (CI): 29-47) for advanced neoplasia and 88% (95% CI: 37-99) for CRC at a specificity of 93% (95% CI: 92-95) and 91% (95% CI: 89-92), respectively. The positive and negative predictive values for FIT50 were 6% (95% CI: 3-12) and almost 100% (95% CI: 99-100) for CRC, and 37% (95% CI: 29-46) and 93% (95% CI: 92-95) for advanced neoplasia. The sensitivity and specificity of FIT75 for advanced neoplasia were 33% (95% CI: 25-42) and 96% (95% CI: 94-97). At FIT100, 71 screenees (6%) had a positive test result. The sensitivity and specificity of FIT100 were for advanced neoplasia 31% (95% CI: 23-40) and 97% (95% CI: 96-98), and for CRC 75% (95% CI: 36-96) and 95% (95% CI: 93-96). The area under curve for detecting advanced neoplasia was 0.70 (95% CI: 0.64-0.76). FIT had a similar sensitivity for proximal and distal advanced neoplasia at cutoffs of 50 (38% vs. 37%; P=0.99), 75 (33% vs. 31%; P=0.85) and 100 (33% vs. 29%; P=0.68) ng Hb/ml. DISCUSSION: Nine out of ten screening participants with CRC and four out of ten with advanced neoplasia will be detected using one single FIT at low cutoff. Sensitivity in detecting proximal and distal advanced neoplasia is comparable.

Advance notification letters increase adherence in colorectal cancer screening: a population-based randomized trial.

OBJECTIVE: The population benefit of screening depends not only on the effectiveness of the test, but also on adherence, which, for colorectal cancer (CRC) screening remains low. An advance notification letter may increase adherence, however, no population-based randomized trials have been conducted to provide evidence of this. METHOD: In 2008, a representative sample of the Dutch population (aged 50-74 years) was randomized. All 2493 invitees in group A were sent an advance notification letter, followed two weeks later by a standard invitation. The 2507 invitees in group B only received the standard invitation. Non-respondents in both groups were sent a reminder 6 weeks after the invitation. RESULTS: The advance notification letters resulted in a significantly higher adherence (64.4% versus 61.1%, p-value 0.019). Multivariate logistic regression analysis showed no significant interactions between group and age, sex, or socio-economic status. Cost analysis showed that the incremental cost per additional detected advanced neoplasia due to sending an advance notification letter was € 957. CONCLUSION: This population-based randomized trial demonstrates that sending an advance notification letter significantly increases adherence by 3.3%. The incremental cost per additional detected advanced neoplasia is acceptable. We therefore recommend that such letters are incorporated within the standard CRC-screening invitation process.