[Evaluation of functional periodicity of the pituitary gland by harmonic analysis.--IV) Circadian prolactin secretion in women with breast cancer].

Secretory periodicity of prolactin (PRL) is preserved in women with breast cancer in spontaneous or surgical menopause. Hormone titres occurring during the day may be occasionally significantly higher in respect to the ones observe in normal controls at the same hours. The periodicity features calculated by the Fourier's method show however normal indices, namely mesor (mean PRL titres in the 24 hours) phase, amplitude and frequency of oscillations.