Purpose: Recent reports from cancer screening trials in high-risk populations suggest that autoantibodies are present prior to clinical diagnosis. However there are few data on the role of autoantibody signatures in cancer screening in the general population. Methods: Informative p53 peptides were identified on an autoantibody microarray with 15-mer overlapping peptides covering the complete p53 sequence using sera from patients with colorectal cancer. The selected peptides were evaluated in a blinded case control study using stored serum from the multimodal arm of UKCTOCS where women gave annual blood samples. Cases were postmenopausal women who developed colorectal cancer following recruitment, with 2 or more serum samples preceding diagnosis. Controls were age-matched women with no history of cancer. Results: The 50,640 women randomised to the multimodal group were followed up for a median of 6.8 (inter-quartile range 5.9-8.4) years. Colorectal cancer notification was received in 101 women with serial samples of whom 97 (277 samples) had given consent for secondary studies. They were matched 1:1 with 97 controls (276 serial samples). The four most informative peptides identified 25.8% of colorectal cancer patients with a specificity of 95%. The median lead time was 1.4 (range 0.12-3.8) years prior to clinical diagnosis. Conclusion: Our findings suggest that in the general population, autoantibody signatures are present during preclinical disease and may be of value in cancer screening. In colorectal cancer screening in particular, where the current need is to improve compliance, it suggests that p53 autoantibodies may contribute towards risk stratification.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3643. doi:1538-7445.AM2012-3643