Natural fluorescence spectroscopy of human blood plasma in the diagnosis of colorectal cancer: feasibility study and preliminary results.
OBJECTIVE
Fluorescence spectroscopy of biomolecules is considered a promising method to discriminate in vivo normal tissue from malignant tissue at various sites including breast, cervix, lung, and colon. However, only few studies have been reported on the feasibility of exploiting fluorescence spectroscopy of blood to characterize pathological changes usable in diagnostic oncology. In this study, the fluorescence characteristics of human blood plasma have been studied in the visible spectral range in an attempt to discriminate patients with colorectal cancer from subjects of a control population.


METHODS
The study involved 341 subjects, including 169 blood donors with no evidence of disease, 143 patients bearing colorectal adenocarcinomas (36 in the colon, 38 in the sigmoid colon and 69 in the rectum), 11 patients with local relapse, 10 patients with familial adenomatous polyposis and 8 with single adenomas. Blood samples were collected from all subjects and plasma fluorescence spectrum was analyzed using a conventional spectrofluorometer.


RESULTS
The intensity of a fluorescence emission peak around 615-635 nm, which could reasonably be ascribed to endogenous porphyrins, was significantly different between patients bearing colorectal cancer and blood donors. The diagnostic capacity of the method was tested by ROC analysis, which resulted in an area under the curve of 0.72, close to that reported for the CEA test.


CONCLUSIONS
These results, although preliminary, suggest the potential of fluorescence measurements of blood plasma as an additional method for diagnostic application in colon cancer.
Lualdi
Manuela
M
Medical Physics Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy. manuela.lualdi@istitutotumori.mi.it
Colombo
Ambrogio
A
Leo
Ermanno
E
Morelli
Daniele
D
Vannelli
Alberto
A
Battaglia
Luigi
L
Poiasina
Elia
E
Marchesini
Renato
R
D000230:Adenocarcinoma / Q000175:diagnosis; D000236:Adenoma / Q000175:diagnosis; D011125:Adenomatous Polyposis Coli / Q000175:diagnosis; D000328:Adult; D000368:Aged; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000097:blood*; D001782:Blood Donors; D015179:Colorectal Neoplasms / Q000097:blood / Q000175:diagnosis*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010949:Plasma; D011166:Porphyrins / Q000097:blood*; D012372:ROC Curve; D013050:Spectrometry, Fluorescence
D014408:Biomarkers, Tumor; D011166:Porphyrins