antiandrogen withdrawal response; a decrease in PSA seen upon stopping an antiandrogen such as Flutamide® or Casodex®; it is believed that this occurs because the antiandrogen has induced a mutation in the androgen receptor (AR) which is allowing the antiandrogen to stimulate PC growth rather than inhibit it

Anti-Androgen Withdrawal Response. A term used most often by those who are practicing intermittent CHT. They monitor their PSA to check for the response.