Spectral changes of lung cancer serum in the process of tumor evolution

The discrimination and changes of serum fluorescence and Raman spectrum for normal human, lung cancer patient and one after operation in different period and extent were studied. We kept close watch on the tumor progression of a group of patients, and measured their serum spectra using 488.0 nm and 514.5 nm excitation of an Ar-ion laser once a week. There was no apparent change observed in fluorescence spectrum in different period. However, the relative intensity of three Raman peaks (mode A, B and C) decreased every week later. For quantitative analysis of such changes, a parameter I_r (relative intensity of C Raman peak) was introduced and I_r-value was calculated. Calculation showed that I_r-value was digressive with tumor evolution, but aˆ (I_r5145/I_r4880) varied irregularly To the end, no Raman peak was observed. We assumed that three Raman peaks were derived from beta carotene. It indicated that the content of beta carotene decreased with the aggravation of lung cancer.