The small, preliminary study states that short boys with "limited growth potential" who took tamoxifen had an increase in their predicted adult height.
Although the adolescent boys' skeletons indicated lower predicted adult height, other signs of puberty stayed on track, write Nerissa Kreher, MD, and colleagues.
Kreher works in the pediatric endocrinology section of Riley Hospital for Children at the Indiana University School of Medicine.
The study appears in Pediatrics.
Not a Direct Test
Kreher's team checked the records of seven short boys who had taken tamoxifen twice daily for six months to four years. The boys were nearly 15 years old, on average.
Almost all of the boys (six out of seven) were also taking growth hormones at the same time.
The boys' predicted adult height rose nearly 4 inches during tamoxifen therapy -- from 5 feet 6 inches to almost 5 feet 10 inches -- the researchers report.
Remember, those heights are predictions. The boys' actual adult height isn't known.
Was tamoxifen responsible for the results? It's hard to say, especially in the boys who were also taking growth hormones, the researchers note.
No side effects were recorded in the boys' medical charts, with one exception.
One of the boys reported having blurry vision when he started taking tamoxifen. After stopping and then resuming the drug, those problems went away, write Kreher and colleagues.
Tamoxifen's long-term effects weren't part of the study.
Estrogen may play a role in the mix of hormones that affect growth and physical maturation, write Kreher and colleagues.
The study was small and it didn't directly test tamoxifen's height effects, the researchers note.
They stress that more studies are needed to see if tamoxifen truly helps short, pubertal boys with limited growth potential improve their adult height.