Blood-based screening for bowel cancer may not resolve suboptimal screening participation in Australia

Colorectal Cancer Screening: Have We Addressed Concerns and Needs of the Target Population?

Despite the recognized benefits of colorectal cancer (CRC) screening, uptake is still suboptimal in many countries. In addressing this issue, one important element that has not received sufficient attention is population preference. Our review provides a comprehensive summary of the up-to-date evidence relative to this topic. Four OVID databases were searched: Ovid MEDLINE® ALL, Biological Abstracts, CAB Abstracts, and Global Health. Among the 742 articles generated, 154 full texts were selected for a more thorough evaluation based on predefined inclusion criteria. Finally, 83 studies were included in our review. The general population preferred either colonoscopy as the most accurate test, or fecal occult blood test (FOBT) as the least invasive for CRC screening. The emerging blood test (SEPT9) and capsule colonoscopy (nanopill), with the potential to overcome the pitfalls of the available techniques, were also favored. Gender, age, race, screening experience, education and beliefs, the perceived risk of CRC, insurance, and health status influence one’s test preference. To improve uptake, CRC screening programs should consider offering test alternatives and tailoring the content and delivery of screening information to the public’s preferences. Other logistical measures in terms of the types of bowel preparation, gender of endoscopist, stool collection device, and reward for participants can also be useful.

A Randomized Controlled Trial Testing Provision of Fecal and Blood Test Options on Participation for Colorectal Cancer Screening

Suboptimal participation is commonly observed in colorectal cancer screening programs utilizing fecal tests. This randomized controlled trial tested whether the offer of a blood test as either a "rescue" strategy for fecal test nonparticipants or an upfront choice, could improve participation. A total of 1,800 people (50-74 years) were randomized to control, rescue, or choice groups (n = 600/group). All were mailed a fecal immunochemical test (FIT, OC-Sensor, Eiken Chemical Company) and a survey assessing awareness of the screening tests. The rescue group was offered a blood test 12 weeks after FIT nonparticipation. The choice group was given the opportunity to choose to do a blood test (Colvera, Clinical Genomics) instead of FIT at baseline. Participation with any test after 24 weeks was not significantly different between groups (control, 37.8%; rescue, 36.9%; choice, 33.8%; P > 0.05). When the rescue strategy was offered after 12 weeks, an additional 6.5% participated with the blood test, which was greater than the blood test participation when offered as an upfront choice (1.5%; P < 0.001). Awareness of the tests was greater for FIT than for blood (96.2% vs. 23.1%; P < 0.0001). In a population familiar with FIT screening, provision of a blood test either as a rescue of FIT nonparticipants or as an upfront choice did not increase overall participation. This might reflect a lack of awareness of the blood test for screening compared with FIT.

The impact of sample type and procedural attributes on relative acceptability of different colorectal cancer screening regimens

OBJECTIVE

In Australia and other countries, participation in colorectal cancer (CRC) screening using fecal occult blood testing is low. Previous research suggests that fecal sampling induces disgust, so approaches not involving feces may increase participation. This study aimed to determine population preferences for CRC screening tests that utilize different sample collections (stool, blood, and saliva) and the extent to which specific attributes (convenience, performance, and cost) impact this preference.

MATERIALS AND METHODS

People aged 50-74 years completed a survey. Preference for screening for CRC through stool, blood, and saliva was judged through ranking of preference and attributes critical to preference and confirmed via a discrete choice experiment (DCE) where test attributes were described as varying by performance, cost, and sample type. Participants also completed a measure of aversion to sample type.

RESULTS

A total of 1,282 people participated in the survey. The DCE and ranking exercise confirmed that all test attributes had a statistically significant impact on respondents' preferences (P < 0.001). Blood and saliva were equally preferred over stool; however, test performance was the most influential attribute. In multivariable analyses, those who preferred blood to stool collection exhibited higher aversion to fecal (OR = 1.17; P ≤ 0.001) and saliva (OR = 1.06; P ≤ 0.05) sampling and perceived that they had less time for home sample collection (OR = 0.72, P ≤ 0.001). Those who preferred saliva to stool had higher aversion to fecal (OR = 1.15; P ≤ 0.001) and blood (OR = 1.06, P ≤ 0.01) sampling and less time for home sample collection (OR = 0.81, P ≤ 0.5).

CONCLUSION

Aversion to sample type and perceived inconvenience of sample collection are significant drivers of screening preference. While blood and saliva sampling were the most preferred methods, test performance was the most important attribute of a screening test, regardless of sample type. Efforts to increase CRC screening participation should focus on a test, or combination of tests, that combines the attributes of high performance, low aversion, and convenience of use.

Development of a multiplexed tumor-associated autoantibody-based blood test for the detection of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the most common malignancies worldwide, and early diagnosis is vital to improving prognoses. We explored the diagnostic potential of a multiplex autoantibody panel as a biomarker for the detection of CRC by ELISA.

METHODS

In total, 192 serum samples (92 CRC and 100 matched controls) were tested against a panel of 12 tumor-associated antigens (TAAs): RPH3AL, RPL36, SLP2, p53, survivin, ANAXA4, SEC61B, CCCAP, NYCO16, NMDAR, PLSCR1, and HDAC5. Individual and combined autoantibody signatures were examined.

RESULTS

Compared to individual autoantibody markers, the combinations of TAAs provided better discrimination between tumorous and normal sera. The overall sensitivity of a selected panel of four antibodies (anti-SLP2, -p53, -SEC61B, and -PLSCR1) was 64.1%, with a specificity of 80% that increased to 83.7% when carcinoembryonic antigen (CEA) measurement was added. Furthermore, the sensitivity of the panel of four antibodies for early and advanced stages of CRC was 66.7% and 62%, increasing to 88.3% and 84%, respectively, when CEA was added.

CONCLUSIONS

We identified a panel of four antibodies as a promising diagnostic biomarker for the detection of CRC.