Empirical evaluation demonstrated importance of validating biomarkers for early detection of cancer in screening settings to limit the number of false-positive findings. J Clin Epidemiol. 2016;75:108-114. [PMID: 26836253 DOI: 10.1016/j.jclinepi.2016.01.022]

Multiplex quantitation of 270 plasma protein markers to identify a signature for early detection of colorectal cancer

Blood-based protein biomarker signatures might be an alternative or supplement to existing methods for early detection of colorectal cancer (CRC) for population-based screening. The objective of this study was to derive a protein biomarker signature for early detection of CRC and its precursor advanced adenoma (AA). In a two-stage design, 270 protein markers were measured by liquid chromatography/multiple reaction monitoring/mass spectrometry in plasma samples of discovery and validation sets. In the discovery set consisting of 100 newly diagnosed CRC cases and 100 age- and sex-matched controls free of neoplasm at screening colonoscopy, the algorithms predicting the presence of early- or late-stage CRC were derived by Lasso regression and .632 + bootstrap. The prediction algorithms were then externally validated in an independent validation set consisting of participants of screening colonoscopy including 56 participants with CRC, 99 with AA and 99 controls without any colorectal neoplasms. Three different signatures for all-, early- and late-stage CRC consisting of five-, three- and eight-protein markers were obtained in the discovery set with areas under the curves (AUCs) after .632 + bootstrap adjustment of 0.85, 0.83 and 0.96, respectively. External validation in the representative screening population yielded AUCs of 0.79 (95% CI, 0.70-0.86), 0.79 (95% CI, 0.66-0.89) and 0.80 (95% CI, 0.70-0.89) for all-, early- and late-stage CRCs, respectively. The three-marker early-stage algorithm yielded an AUC of 0.65 (95% CI, 0.56-0.73) for detection of AA in the validation set. Although not yet competitive with available stool-based tests for CRC early detection, the identified proteins may contribute to the development of powerful blood-based tests for early detection of CRC and its precursors AAs.

Multiplex screening of 275 plasma protein biomarkers to identify a signature for early detection of colorectal cancer

Blood-based protein biomarkers may be an attractive option for early detection of colorectal cancer (CRC). Here, we used a two-stage design to measure 275 protein markers by proximity extension assay (PEA), first in plasma samples of a discovery set consisting of 98 newly diagnosed CRC cases and 100 age- and gender-matched controls free of neoplasm at screening colonoscopy. An algorithm predicting the presence of early- or late-stage CRC was derived by least absolute shrinkage and selection operator regression with .632+ bootstrap method, and the algorithms were then validated using PEA again in an independent validation set consisting of participants of screening colonoscopy with and without CRC (n = 56 and 102, respectively). Three different signatures for all-, early-, and late-stage CRC consisting of 9, 12, and 11 protein markers were obtained in the discovery set with areas under the curves (AUCs) after .632 + bootstrap adjustment of 0.92, 0.91, and 0.96, respectively. External validation among participants of screening colonoscopy yielded AUCs of 0.76 [95% confidence interval (95% CI), 0.67-0.84], 0.75 (95% CI, 0.62-0.87), and 0.80 (95% CI, 0.68-0.89) for all-, early-, and late-stage CRC, respectively. Although the identified protein markers are not competitive with the best available stool tests, these proteins may contribute to the development of powerful blood-based tests for CRC early detection in the future.

Development and validation of a panel of five proteins as blood biomarkers for early detection of colorectal cancer

Objective

Reliable noninvasive biomarkers for early detection of colorectal cancer (CRC) are highly desirable for efficient population-based screening with high adherence rates. We aimed to discover and validate blood-based protein markers for the early detection of CRC.

Patients and methods

A two-stage design with a discovery and a validation set was used. In the discovery phase, plasma levels of 92 protein markers and serum levels of TP53 autoantibody were measured in 226 clinically recruited CRC patients and 118 controls who were free of colorectal neoplasms at screening colonoscopy. An algorithm predicting the presence of CRC was derived by Lasso regression and validated in a validation set consisting of all available 41 patients with CRC and a representative sample of 106 participants with advanced adenomas and 107 controls free of neoplasm from a large screening colonoscopy cohort (N=6018). Receiver operating characteristic (ROC) analyses were conducted to evaluate the diagnostic performance of individual biomarkers and biomarker combinations.

Results

An algorithm based on growth differentiation factor 15 (GDF-15), amphiregulin (AREG), Fas antigen ligand (FasL), Fms-related tyrosine kinase 3 ligand (Flt3L) and TP53 autoantibody was constructed. In the validation set, the areas under the curves of this five-marker algorithm were 0.82 (95% CI, 0.74–0.90) for detecting CRC and 0.60 (95% CI, 0.52–0.69) for detecting advanced adenomas. At cutoffs yielding 90% specificity, the sensitivities (95% CI) for detecting CRC and advanced adenomas were 56.4% (38.4%–71.8%) and 22.0% (13.4%–35.4%), respectively. The five-marker panel showed similar diagnostic efficacy for the detection of early- and late-stage CRC.

Conclusion

The identified most promising biomarkers could contribute to the development of powerful blood-based tests for CRC screening in the future.

International scientific communications in the field of colorectal tumour markers

AIM

To analyze scientometrically the dynamic science internationalization on colorectal tumour markers as reflected in five information portals and to outline the significant journals, scientists and institutions.

METHODS

A retrospective problem-oriented search was performed in Web of Science Core Collection (WoS), MEDLINE, BIOSIS Citation Index (BIOSIS) and Scopus for 1986-2015 as well as in Dervent Innovations Index (Derwent) for 1995-2015. Several specific scientometric parameters of the publication output and citation activity were comparatively analyzed. The following scientometric parameters were analyzed: (1) annual dynamics of publications; (2) scientific institutions; (3) journals; (4) authors; (5) scientific forums; (6) patents - number of patents, names and countries of inventors, and (7) citations (number of citations to publications by single authors received in WoS, BIOSIS Citation Index and Scopus).

RESULTS

There is a trend towards increasing publication output on colorectal tumour markers worldwide along with high citation rates. Authors from 70 countries have published their research results in journals and conference proceedings in 21 languages. There is considerable country stratification similar to that in most systematic investigations. The information provided to end users and scientometricians varies between these data-bases in terms of most parameters due to different journal coverage, indexing systems and editorial policy. The lists of the so-called “core” journals and most productive authors in WoS, BIOSIS, MEDLINE and Scopus along with the list of the most productive authors - inventors in Derwent present a particular interest to the beginners in the field, the institutional and national science managers and the journal editorial board members. The role of the purposeful assessment of scientific forums and patents is emphasized.

CONCLUSION

Our results along with this problem-oriented collection containing the researchers’ names, addresses and publications could contribute to a more effective international collaboration of the coloproctologists from smaller countries and thus improve their visibility on the world information market.