Timing of surgery during the menstrual cycle for breast cancer: possible role of growth factors.

Premenopausal patients undergoing surgery for breast cancer were prospectively studied. Data regarding menstrual history, pathological parameters and hormone receptor status were collected. Serum oestradiol, prolactin and progesterone levels, tumour epidermal growth factor receptor (EGFR) levels, tumour epidermal growth factor (EGF) levels and flow cytometry were measured. Patients were allocated to the follicular or luteal phase of their cycle both by history and progesterone level. No significant differences were seen in hormone receptor levels, pathological parameters or EGF levels between the two groups. EGFR levels were significantly higher in women undergoing surgery during the follicular phase of their cycle, when classified by menstrual history. Patients operated on during this phase have previously been found to have a poorer prognosis, and these results may provide a basis for this finding. This may have implications for prognosis and timing of surgery, and further investigation is warranted.