Monday, August 1, 2011
GnRH analogues for prevention of premature ovarian failure
Various glomerulonephritides unfortunately often require treatment with chemotherapeutic agents, such as cyclophosphamide. A potential adverse effect of these agents in females of child-bearing age, is premature ovarian failure. Nate previously posted about this. Since then, there have been a couple of papers published that address this dilemma further.
A meta-analysis of six randomized controlled trials reported that GnRH treated women had a higher odds of return of spontaneous menstruation than those not treated (OR 3.46; 95% CI 1.13 – 10.57), but this did not translate into a significant difference in the rate of spontaneous pregnancy after chemotherapy. However, many people are cautious in the interpretation of these results, given the small sample size in the trials, heterogeneity of protocols and varying follow-up times.
More recently, a randomized trial of triptorelin vs standard care in women with breast cancer was published. This study, performed in Italy, randomized 133 women to GnRH and 148 to standard care. Subjects were reviewed one year after the last cycle of chemotherapy for occurrence of early menopause (defined as no resumption of menstrual bleeding and postmenopausal levels of FSH and estradiol one year after cessation of chemotherapy).
The rate of early menopause was 25.9% in standard care vs 8.9% in the GnRH group (p for difference <0.001).
Whilst encouraging, these findings must be tempered by the fact that recovery of menses does not directly translate to fertility (limited data was available for this cohort at the time of publication). Furthermore, the chemotherapeutic regimens used, dosing and the duration of treatment make it hard to generalize the findings to a ‘nephrology disease’ population. There are alternative methods available, with somewhat stronger recommendations from experts in the field – these include embryonic cryopreservation.