Validation of Assaying Carcinoembryonic Antigen in Human Serum by Using Immunomagnetic Reduction

Immunomagnetic reduction (IMR) is a method to assay biomolecules by utilizing antibody functionalized magnetic nanoparticles. For clinical validation, important analytic performances of assaying carcinoembryonic antigen (CEA) using IMR are characterized. Furthermore, IMR is applied to assay carcinoembryonic antigen (CEA) in human serum for clinical validation. A total of 118 healthy controls and 79 patients with colorectal cancer (CRC) are recruited in this study. For comparison, assays using chemiluminometric immunoassay (CLIA) are also done for quantizing CEA in these serum samples. The results reveal a high correlation in terms of serum CEA concentration detected via IMR and CLIA is found (r = 0.963). However, IMR shows higher clinical sensitivity and specificity than those of CLIA. Moreover, the rate of false positives for smoking subjects is clearly reduced through the use of IMR. All the results demonstrate IMR is a promising alternative assay for serum CEA to diagnose CRC.

Cigarette smoking and adenomatous polyps: a meta-analysis

BACKGROUND & AIMS

Through the past 2 decades, a consistent association between cigarette smoking and colorectal adenomatous polyps, recognized precursor lesions of colorectal cancer, has been shown. We performed a meta-analysis to provide a quantitative pooled risk estimate of the association, focusing on the different characteristics of the study populations, study designs, and clinical feature of the polyps.

METHODS

We performed a comprehensive literature search of studies linking cigarette smoking and adenomas. We used random effects models to evaluate pooled relative risks and performed dose-response, heterogeneity, publication bias, and sensitivity analyses.

RESULTS

Forty-two independent observational studies were included in the analysis. The pooled risk estimates for current, former, and ever smokers in comparison with never smokers were 2.14 (95% confidence interval [CI], 1.86-2.46), 1.47 (95% CI, 1.29-1.67), and 1.82 (95% CI, 1.65-2.00), respectively. The association was stronger for high-risk adenomas than for low-risk adenomas. Studies in which all controls underwent full colonoscopy showed a higher risk compared with studies in which some or all controls underwent partial colon examination.

CONCLUSIONS

This meta-analysis provides strong evidence of the detrimental effect of cigarette smoking on the development of adenomatous polyps. Smoking is important for both formation and aggressiveness of adenomas.

Effect of Opium Smoking on Concentrations of Carcinoembryonic Antigen and Tissue Polypeptide Antigen

Previous studies have related opium and its pyrolysates to the risk of developing certain cancers. The aim of this work was to evaluate the clinical usefulness of determining carcinoembryonic antigen (CEA) and tissue polypeptide antigen (TPA) levels in habitual opium smokers. Serum CEA concentrations were measured in 128 opium smokers and in 44 controls of cigarette only smokers and 47 normal non-smokers by an EIA-based assay. TPA levels were also determined in serum and urine of a subgroup in the study population. The results indicated that serum CEA concentrations are higher in opium smokers than in healthy tobacco smokers (p=0.004) and non-smokers (p=0.001). The amount of opium used correlated with the serum CEA level (r=0.276, p<0.0001). The mean urine and serum TPA levels of the opium-addicted population were also higher than that of the non-smoking control group, but the differences were not statistically significant. We conclude that opium smoking is associated with elevated serum CEA levels. Therefore, for management of opium users with neoplastic diseases, increased levels of serum CEA should be viewed with caution to avoid misdiagnosis.

Variability of neoplastic parameters in colon tumours, and its significance in diagnostic practice

We have reviewed the value of individual variability in the reaction of tissues to treatment with carcinogens, and the manifestation of this variability in different morphological (histological, morphometric, and ultrastructural), histochemical and immunohistochemical parameters generated in tumorous tissues. Moreover, we also reviewed data in the literature on individual variability in the manifestation of some biochemical and immunochemical markers which are accumulated in the serum of tumour-bearing patients and which are characteristic for the different phases of tumourigenesis. The high variability of different tumorous parameters suggests that none can be utilized alone as a conclusive marker of neoplasia and that only their combined use can give objective information. We also reviewed the impact of this variability in the evaluation of various pathological methods to detect different stages of neoplastic transformation in the colon. It has been concluded that none of the present approaches can be absolutely conclusive and without false results, and that objective information regarding early cancerous changes may be obtained only by use of combined analyses utilizing several laboratory methods. The diagnostic procedures should be based on the complex utilization of all appropriate methods using the quantitative interpretation of the obtained data. Multivariate analysis of many parameters should be very effective for the prediction of therapeutic results.