Timing of breast cancer surgery in relation to the menstrual cycle: an update of developments

It is well-established that hormones have multiple effects on breast cancer . Some, but not all studies indicate that the phase of the menstrual cycle (and hence hormonal status) at the time of breast surgery may influence sur vival. In this paper we review the literature in this area, explore how it is possible that such an association may occur, and note that randomised st udies which unambiguously determined the phase of the cycle at the time of the operation are lacking. We go on to describe an ongoing self-randomised trial designed to address this problem and present preliminary results whic h show that only about 75% of the women ovulated during the cycle in which the operation took place, and that the established prognostic factor Ki-67 varied with the phase of the cycle in women who ovulated. It is too early t o assess the significance of this finding. (C) 2001 Elsevier Science Irelan d Ltd. All rights reserved.