On 2015 Sep 27, S Sundar commented:

We noticed re-induction of hormone sensitivity in more patients and we presented our experience at the ASCO GU conference in 2008. The conference abstract is unfortunately no longer available from ASCO website.

We have reproduced our submission below for the benefit of clinicians and researchers interested in our manuscript.

Citation:<br> Cox RA, Sundar S. Re-induction of sensitivity to diethylstilbestrol in docetaxel-treated androgen refractory prostate cancer. In: American Society of Clinical Oncology Genitourinary Symposium. 2008. Abstract No: 172. ....................................

Control/Tracking Number: 08-AB-20299-ASCOGU Activity: Abstract Submission Current Date/Time: 1/29/2008 10:04:47 AM

Re-induction of sensitivity to Diethylstilbestrol in Docetaxel treated androgen refractory prostate cancer

Author Block: S. Sundar, R. Cox; Nottingham City Hospital, Nottingham, United Kingdom

Abstract:

Introduction: Diethylstilbestrol (DES) is a standard second line hormone therapy for prostate cancer in the UK. Following introduction of Docetaxel, DES is increasingly being used as third line therapy. We audited our patients (pts) response to DES after treatment with Docetaxel.

Methods: Pts (n=56) who received Docetaxel within an 18-month period were identified from a pharmacy database and the sub-group (n=16) treated with DES after Docetaxel was identified. PSA Response rate (50% decline) to Docetaxel was 60%. All pts had androgen refractory disease and had castrate levels of testosterone (LHRH-agonist therapy/orchidectomy). Pts with a history of ischaemic heart disease, stroke, pulmonary embolism (PE) or thrombosis were not offered DES. Pts were treated with DES 1mg daily with aspirin 75mg daily for thrombotic prophylaxis.

Results: 16 pts subsequently received DES on disease progression following Docetaxel. (1 pt unable to tolerate DES due to nausea was excluded from analysis). Median age of pts given DES after Docetaxel was 70yrs (52-79). 12 of 15 (80%) responded to DES 'after' Docetaxel, with 6 (50%) having a >50% reduction in PSA. Significantly 7 pts were treated with DES 'prior' to Docetaxel. 6 of these 7 pts (86%) who were previously refractory to DES 'prior' to Docetaxel responded to retreatment with DES 'following' Docetaxel chemotherapy. Currently, 6 pts remain on therapy after a median follow up of 2.5 months. 5 pts who progressed, did so after a median treatment duration of 4 months. 1 responding patient stopped after 2 months due to a PE. DES was otherwise very well tolerated. 1 patient stopped treatment after 1 week due to nausea. There were no other documented cardiovascular, cerebrovascular or thrombotic events.

Conclusions: DES is an option for patients with androgen refractory prostate cancer who have relapsed after treatment with Docetaxel. Previous work (Shamash et al, Br.J.Cancer.2005) found re-induction of hormone sensitivity following failure of Chlorambucil and Lomustine chemotherapy. Further investigation of this interesting phenomenon of re-induction of DES sensitivity could provide further insight into molecular mechanisms underlying androgen refractory prostate cancer. : Author Disclosure Information: S. Sundar, None; R. Cox, None. ..........................................................................

On 2015 Sep 27, S Sundar commented:

We noticed re-induction of hormone sensitivity in more patients and we presented our experience at the ASCO GU conference in 2008. The conference abstract is unfortunately no longer available from ASCO website.

We have reproduced our submission below for the benefit of clinicians and researchers interested in our manuscript.

Citation:<br> Cox RA, Sundar S. Re-induction of sensitivity to diethylstilbestrol in docetaxel-treated androgen refractory prostate cancer. In: American Society of Clinical Oncology Genitourinary Symposium. 2008. Abstract No: 172. ....................................

Control/Tracking Number: 08-AB-20299-ASCOGU Activity: Abstract Submission Current Date/Time: 1/29/2008 10:04:47 AM

Re-induction of sensitivity to Diethylstilbestrol in Docetaxel treated androgen refractory prostate cancer

Author Block: S. Sundar, R. Cox; Nottingham City Hospital, Nottingham, United Kingdom

Abstract:

Introduction: Diethylstilbestrol (DES) is a standard second line hormone therapy for prostate cancer in the UK. Following introduction of Docetaxel, DES is increasingly being used as third line therapy. We audited our patients (pts) response to DES after treatment with Docetaxel.

Methods: Pts (n=56) who received Docetaxel within an 18-month period were identified from a pharmacy database and the sub-group (n=16) treated with DES after Docetaxel was identified. PSA Response rate (50% decline) to Docetaxel was 60%. All pts had androgen refractory disease and had castrate levels of testosterone (LHRH-agonist therapy/orchidectomy). Pts with a history of ischaemic heart disease, stroke, pulmonary embolism (PE) or thrombosis were not offered DES. Pts were treated with DES 1mg daily with aspirin 75mg daily for thrombotic prophylaxis.

Results: 16 pts subsequently received DES on disease progression following Docetaxel. (1 pt unable to tolerate DES due to nausea was excluded from analysis). Median age of pts given DES after Docetaxel was 70yrs (52-79). 12 of 15 (80%) responded to DES 'after' Docetaxel, with 6 (50%) having a >50% reduction in PSA. Significantly 7 pts were treated with DES 'prior' to Docetaxel. 6 of these 7 pts (86%) who were previously refractory to DES 'prior' to Docetaxel responded to retreatment with DES 'following' Docetaxel chemotherapy. Currently, 6 pts remain on therapy after a median follow up of 2.5 months. 5 pts who progressed, did so after a median treatment duration of 4 months. 1 responding patient stopped after 2 months due to a PE. DES was otherwise very well tolerated. 1 patient stopped treatment after 1 week due to nausea. There were no other documented cardiovascular, cerebrovascular or thrombotic events.

Conclusions: DES is an option for patients with androgen refractory prostate cancer who have relapsed after treatment with Docetaxel. Previous work (Shamash et al, Br.J.Cancer.2005) found re-induction of hormone sensitivity following failure of Chlorambucil and Lomustine chemotherapy. Further investigation of this interesting phenomenon of re-induction of DES sensitivity could provide further insight into molecular mechanisms underlying androgen refractory prostate cancer. : Author Disclosure Information: S. Sundar, None; R. Cox, None. ..........................................................................