German medical investigators based their conclusions on an analysis of three cancer registry studies involving more than 1,000 men who were tracked for about two decades.
 

"Although considerable evidence exists indicating no relationship between testosterone and increased risk of developing [prostate cancer], decades of physician training with the notion that testosterone is fuel for [cancer] made it difficult to dispel such fallacy and the myth continued to persist,” noted lead researcher Ahmad Haider, a urologist from Bremerhaven, Germany.
 

“[But] in view of the current evidence, clinicians are compelled to think this over and cannot justify withholding [testosterone] therapy in hypogonadal men, also in men who have been successfully treated for [prostate cancer]."
 

The new research  was published in The Journal of Urology.