The role of menstrual cycle phase and AMH levels in breast cancer patients whose ovarian tissue was cryopreserved for oncofertility treatment.

PURPOSE: To determine the factors that affect oocyte extraction efficiency when using the "combined procedure". In the present "combined procedure" ovarian tissue cryopreservation and oocyte extraction from an isolated ovary, later used in In Vitro Maturation (IVM), are performed concurrently. METHODS: Data were analyzed retrospectively and obtained from the clinical records of 27 young breast cancer patients referred for fertility preservation. RESULTS: The patients' mean age was 33.7 (±3.8) years, mean serum anti-Müllerian hormone (AMH) concentration was 3.5 (±2.1) ng/ml, and mean number of extracted oocytes was 8.3 (±6.1). The phase of menstruation (follicular or luteal) did not affect either the number of oocytes extracted (P = 0.99) nor oocyte survival or maturation rates. Likewise, the number of oocytes that could be extracted was not affected by the type of laparoscopic procedure (multiple-port or single-incision laparoscopy; P = 0.94) or the molecular subtype of breast cancer (either Luminal A or B; P = 0.52). Analysis revealed that the number of extracted oocytes was well-correlated with the patient's AMH serum level and age (coefficient of correlation: 0.60 and -0.48, respectively). CONCLUSION: We conclude that the outcome of the "combined procedure" primarily depends upon the patient's serum AMH level and age. Importantly, the "combined procedure" may be used during any phase of the menstrual cycle to preserve the fertility of breast cancer patients.

Kinetics of nuclear status and kinase activities during in vitro maturation of canine oocytes.

In contrast to those of other mammals, canine oocytes are ovulated at the germinal vesicle (GV) stage and then progress to the metaphase II (MII) stage in the oviduct. In other species, oocytes at the MII are widely used for in vitro fertilization or as recipients in somatic cell nuclear transfer. Many researchers have tried to improve the in vitro maturation (IVM) of canine oocytes. However, the proportion of MII oocytes remains low, resulting in poor efficiency of embryogenesis in vitro. This leads us to the possibility that the in vitro cytoplasmic maturation of canine oocytes is insufficient. Furthermore, the optimal culture period for IVM of canine oocytes is controversial, and physiological evaluation is required to improve canine IVM. We show here the time-dependent changes in mitogen-activated protein kinase (MAPK) and p34(cdc2) kinase activities in canine oocytes during IVM, since it is well known that both MAPK and p34(cdc2) kinase are activated following meiotic progression and show high activities in the MII stage in other species. Immediately after collection from ovaries, most oocytes were arrested at the GV stage, which was maintained until 24 h of culture. At 48 h of culture, more than half of the oocytes had progressed beyond the MI stage. A higher proportion of MII oocytes were observed with 72 h of culture compared with other culture periods. MAPK activity was found to increase in a time-dependent manner and reached a plateau at 72 h of culture. The level of p34(cdc2) kinase activity also increased in a time-dependent manner, with its maximal level observed after 72 h of culture. Activity was decreased with 96 h of culture, although there was no significant difference in the proportion of MII oocytes between 72 and 96 h. Our data thus show that the optimal culture period for IVM of canine oocytes is 72 h because both MAPK and p34(cdc2) kinase showed high activities at that time.