Effect of anti-cancer medicament on the validity of a fluorescence-based technique for cancer diagnosis

It is well known that the metabolizing of porphyrin is a normal physiological activity of animals, and one's illness would lead to the abnormality of the porphyrin metabolism in his body. Based on the extensive studies of the serum fluorescence, a diagnostic technique of cancers in human body has been developed with high sensitivity and specificity. From its clinical investigations, however, it was found that the characteristic of the serum fluorescence would varied since some medicine's taking, hence highly affected the validity of the cancer diagnosis with the serum fluorescence. In this paper, the excitation and fluorescence spectra of common used photo-sensitizes, anti-cancer drugs, antibiotics and hormones were taken to investigate how the medicament affect the monitoring the fluorescence of blood serum for cancer diagnosis. From the spectral analysis, it was found those drugs would affect the fluorescence monitoring of carotenoid and porphyrin in the human blood serum in four ways. The mechanisms of each way have been discussed. The detected limit for each drug investigated was determined to be 1x10-7g/ml to 1x10-3g/ml. It is concluded that once the dose exceeds 500mg, the medicament would affect the diagnosis. For the medicine of Fluorouracilum, Methotrexate, Aspirin and Diethylstilbestrol, the diagnosis would be interfered seriously even with the dose just above 10mg. It is strongly suggested that to achieve high accuracy of diagnosis, the person to be tested should not take medicine during the 3 days before the test proceeding.