Tool For Early Cancer Diagnosis Research Articles

Investigation of urinary pteridine levels as potential biomarkers for noninvasive diagnosis of cancer

Background Biomarkers are good potential tools for early cancer diagnosis. Here we have analyzed eight different pteridines in the urine samples of cancer patients and compared them with samples from healthy subjects. Pteridines are important cofactors in the process of cell metabolism, and they have recently become a focal point of cancer screening research because certain pteridine levels have been shown to reflect the presence of cancers. Methods We analyzed 8 pteridines; 6,7-dimethylpterin, 6-biopterin, d-(+)-neopterin, 6-hydroxymethylpterin, pterin, isoxanthopterin, xanthopterin and pterin-6-carboxylic acid using a house-built high-performance capillary electrophoresis with laser-induced fluorescence detection (HPCE-LIF). The levels of pteridines were reported as a ratio of pteridine to creatinine. Statistical hypothesis testing was conducted and P values were calculated to analyze the data. Results Among the eight pteridines studied, 6-biopterin, 6-hydroxymethylpterin, pterin, xanthopterin, and isoxanthopterin levels were significantly higher in samples from cancer patients than in those from healthy subjects. Further, xanthopterin and isoxanthopterin levels were compared in breast cancer and lung cancer patients, but no significant difference was observed. Conclusion Some pteridine levels can be used as biomarkers for noninvasive diagnosis of cancer; however, more data is needed to support this hypothesis.

Molecular diagnosis in oncology

Recent advances of molecular genetics have made a noticeable impact in some areas of clinical medicine. Almost comprehensive understanding of the nature of hereditary tumors is frequently heralded as the most substantial practical achievement of molecular oncology. Proper diagnostic algorithms have already been developed for the vast majority of known familial cancer syndromes. Interestingly, an unexpectedly strong "founder" effect has been documented at least for some hereditary cancers occurring in Russia, that significantly simplifies the detection of the corresponding disease-associated gene variants. The number of tests aimed to customize cancer treatment continues to grow every year. EGFR mutation test appears to be the most impressive, as it allows to predict lung cancer response or non-response to gefitinib or erlotinib with indeed unique level of accuracy. The approaches helping to determine individual efficacy and safety profiles for fluoropyrimidines, platinum compounds, irinotecan etc. are currently under development Methods aiming to detect residual amounts of disseminated cancer cells represent another popular avenue of the research. It is expected that these technologies will improve the quality of prediction of local and distant metastases, facilitate monitoring of the minimal residual disease and, in the long perspective, provide the tool for early cancer diagnosis. One has to remember that the molecular detection of disseminated tumor cells is currently used mainly in research settings and is not yet incorporated into routine clinical practice.

Laser-induced autofluorescence microscopy of normal and tumor human colonic tissue

Laser-induced autofluorescence (LIAF) spectroscopy has been found to be a promising tool for early cancer diagnosis in various organs, but the reasons responsible for the spectral differences between normal and diseased tissue are still not well understood. In this study, a microspectrophotometer (MSP) system was used to identify the microscopic origins of tissue autofluorescence in the colon under the excitation of a helium-cadmium laser at 442 nm. Colonic tissue samples (normal: n=8, adenocarcinoma: n=10) were obtained from 12 patients with known or suspected malignancies of the colon. The intrinsic fluorescence spectra and images of fresh tissue sections prepared from normal and tumor colonic tissue were measured by the MSP system. Three distinct tissue layers of the colon were found for fluorescence, the mucosa, the submucosa and the muscularis propria, with submucosa being the most fluorescent. Differences in the spectral shape and intensity of the intrinsic fluorescence originating from different colonic layers indicate that fundamentally different fluorophores may be present in the respective tissue layers. There was no significant difference in the intrinsic fluorescence features of the submucosa between normal and tumor colonic tissue, but the fluorescence intensity of the submucosa in tumor tissue was significantly reduced due to the infiltration of tumor cells into the submucosa. The intrinsic fluorescence spectrum peaking at about 520 nm for tumor stroma appeared more evident than that of normal lamina propria. Limited areas of the lamina propria layer in some adenocarcinoma colon exhibited an emission band at about 635 nm, which was attributed to endogenous porphyrins in tumor. Autofluorescence microscopy revealed that differences in the clinically measured autofluorescence spectra between normal and tumor tissue were mainly due to thickening of the tumor mucosa resulting in a reduced submucosa fluorescence contribution, as well as the increased hemoglobin absorption in tumor tissue. Therefore, investigation of the microscopic origins of tissue autofluorescence and images can provide new insights into morphological structures and biochemical components of tissues, which are vital to improve the implementation of the LIAF technique for non-invasive in vivo tissue diagnostics.