This has been discussed so many times on this board... Aromatase inhibitors are not successful at treating gyno. Two agents are: Tamoxifen and Raloxifene.
ESPE: Tamoxifen, Raloxifene Prove Effective In Pre-Pubertal Gynecomastia
By Cameron Johnston
Special to DG News
MONTREAL, QC -- July 12, 2001 -- Doctors in Canada, have determined that both tamoxifen and raloxifene can be used to treat pre-pubertal gynecomastia.
This condition, an excessive development of male breasts, occurs in up to 65 percent of young boys and may be deemed clinically significant in 10-15 percent.
While the condition resolves spontaneously in approximately 90 percent of cases over a three year period, the psychological and emotional impact in the meantime can be devastating for these young patients.
The investigators, headed by Dr. Sarah Muirhead, an associate professor of medicine at the University of Ottawa and staff endocrinologist at Children's Hospital of Eastern Ontario (CHEO), presented these findings yesterday (July 11th, 2001) at the 6th joint meeting of the Lawson Wilkins Pediatric Endocrine Society and the European Society for Paediatric Endocrinology (ESPE), in collaboration with the Australasian Paediatric Endocrine Group, the Japanese Society for Pediatric Endocrinology, and the Latin American Society for Paediatric Endocrinology held in Montreal, Quebec, Canada.
The tamoxifen/raloxifene breakthrough is significant because surgery used to be the only management option. Previous attempts to manage the condition medically by altering the testosterone/estrogen ratio have only been partially effective and have included such drugs as danazol (normally used to treat endometriosis), aromatase inhibitors, and dihydro-testosterone
Tamoxifen is a competitive inhibitor of estrogen binding in the breast, whereas raloxifene is a selective estrogen receptor modulator, the investigators explained.
In the study, 14 subjects received tamoxifen 10-20 mg/day for three to six months, while nine subjects received 60 mg/day of raloxifene for three to six months. A group of 13 received no medications and were used as a control group.
The mean age of these boys was 14 years, and all were of normal body mass index. Those who received tamoxifen had had the condition for a mean period of 18.9 months, while those randomized to raloxifene had the condition for an average of 37.2 months.
Both of these estrogen receptor blockers were effective in treating gynecomastia, although the response was greater for raloxifene. In the tamoxifen group, the mean nodule size was 4.6 cm before treatment and 2.1 cm post-treatment, for a reduction in size of 56 percent.
In the raloxifene group, pre-treatment nodule size was 4.9 cm and post-treatment size was 1.6 cm -- a reduction in size of 73 percent. It was not stated over what period of time these changes occurred.
The investigators report that overall, 91 percent of the subjects showed a positive response. These results were especially encouraging given that the subjects had had the condition for extended periods of time, and given that the breast nodules were large. It was also encouraging that no side effects were seen in either group of patients, including to liver function.
Despite the safety of the drug and the seemingly impressive results seen here, Dr. Muirhead and her group caution that, due to the lack of follow-up in untreated patients, it is not clear whether treatment was more effective than observation alone. To resolve that question, a larger, randomized, placebo-controlled trial using raloxifene has been planned, she said.