Differences in time-domain and spectral indexes of skin-surface laser-Doppler signals between controls and breast-cancer subjects.

BACKGROUND

There is an urgent need to improve the early diagnosis of breast cancer.

OBJECTIVE

The present study applied spectral and beat-to-beat analyses to laser-Doppler (LDF) data sequences measured on the skin surface on the back of the right hands, with the aim of comparing the different peripheral microcirculatory-blood-flow (MBF) perfusion condition between breast-cancer and control subjects.

METHODS

ECG and LDF signals were obtained simultaneously and noninvasively from 23 breast-cancer patients and 23 age-matched control subjects. Time-domain beat-to-beat indexes and their variability parameters were calculated. Spectral indexes were calculated using the Morlet wavelet transform.

RESULTS

The beat-to-beat LDF pulse width and its variability were significantly smaller in cancer patients than in the controls. The energy contributions of endothelial-, neural-, and myogenic-related frequency bands were also significantly smaller in cancer patients.

CONCLUSIONS

The present study has revealed significant differences in the beat-to-beat and spectral indexes of skin-surface-acquired LDF signals between control subjects and breast-cancer patients. This illustrates that LDF indexes may be useful for monitoring the changes in the MBF perfusion condition induced by breast cancer. Since the breast-cancer patients were at TNM stages 0- 2, the present findings may aid the development of indexes for detecting breast cancer.