Complete Remission of Hormone Refractory Adenocarcinoma of the Prostate in Response to Withdrawal of Diethylstilbestrol

Abstract

The phenomenon of regression of adenocarcinoma of the prostate after the withdrawal of antiandrogens is well documented. However, to our knowledge we report the first case of durable complete remission of hormone refractory prostate cancer after cessation of diethylstilbestrol. The drug was discontinued because the patient had disease progression while on diethylstilbestrol and withdrawal resulted in durable remission. In more than 3 years of followup since discontinuing diethylstilbestrol there has been no evidence of clinical or biochemical recurrence.

Antiandrogen withdrawal in castrate‐refractory prostate cancer

“…16 Although improvements in cancer-related anemia, pain palliation, and radiographic regression of measurable disease have been documented, PSA declines have been most commonly detected. In addition to antiandrogens, withdrawal responses in prostate cancer patients have been documented after their cessation of megestrol acetate, 17,18 diethylstilbestrol, 19 13-cis-retinoic acid, 20 and estramustine. 21 In general, withdrawal responses occur several weeks after drug withdrawal; however, bicalutamide, which has a relatively long serum half-life, may not have evident withdrawal responses until 6 to 8 weeks after ceasing administration of this medication.…”

Endocrine Withdrawal Syndrome and Its Relevance to the Management of Hormone Refractory Prostate Cancer

“…While this phenomenon was first described with flutamide, others have reported similar withdrawal effects with bicalutamide, megestrol acetate, diethylstilboestrol, chlormadinone acetate, and cis-retinoic acid (table 1) [10, 11, 12, 13, 14, 15, 16, 17]. The proportion of patients involved and the durability of the responses to these agents are similar to flutamide except patients withdrawn from bicalutamide may take longer to respond due to the long half-life of bicalutamide [12].…”

Combined androgen blockade for advanced prostatic carcinoma

“…10 of 27 patients who were treated with CAB and subsequently stopped¯utamide during time of disease progression experienced signi®cant remission and PSA decline which continued for an average of ®ve months. This syndrome has also been observed with other pure and steroidal antiandrogens, 56,57 megestrol acetate, 58 , and DES 59 The mechanism of this syndrome is not fully understood. Several hypotheses have been offered to explain this syndrome; but, clinically, none has yet been con®rmed in patients with treated antiandrogen monotherapy.…”