BACKGROUND: Prostate-specific membrane antigen (PSMA) is a rational target for noninvasive detection of recurrent prostate cancer (PCa) and for therapy of metastatic castration-resistant prostate cancer (mCRPC) with PSMA-targeted agents. Here we conducted serial measurements of PSMA expression on circulating tumor cells (CTCs) to evaluate patterns of longitudinal PSMA dynamics over the course of multiple sequential therapies. METHODS: A retrospective investigation of men with mCRPC undergoing evaluation at medical oncology clinics at our institution assessed the dynamics of PSMA expression in the context of different systemic treatments administered sequentially. Eligibility included patients who began systemic therapies with androgen receptor (AR)-directed agents or taxane agents for whom peripheral blood samples were tested for CTC mRNA of AR splice variant-7 (AR-V7), prostate-specific antigen (PSA), and PSMA (with >2 CTC + results) in a CLIA-accredited laboratory. RESULTS: From August 2015 to November 2017, we identified 96 eligible men. Fifteen had greater than or equal to 2 sequential therapies and evaluable CTC samples, greater than or equal to 1 expressing PSMA (PSMA+). Among the 15 patients included in this analysis, a total of 54 PSMA status evaluations were performed in the context of 48 therapies during a median follow-up of 18 months. At baseline, PSMA signal was detected ("positive") in 11 of 15 (73.3%) patients, while for 4 of 15 (26.7%) patients PSMA signal was undetectable ("negative"). In all but two patients, the baseline collection corresponded with a change in treatment. On the second assessment, PSMA increases were detected in all 4/4 (100%) PSMA-negative patients and 8 of 11 (72.7%) PSMA-positive patients. PSMA significantly decreased in a patient treated with 177 Lu-PSMA-617. Serum PSA declines were seen in 7 of 8 (88%) of the treatment periods where PSMA decreased. CONCLUSIONS: PSMA expression in CTCs is a dynamic marker. PSMA transcript declines appear to be associated with concurrent decreases in serum PSA. Sequential CTC sampling could provide a noninvasive response assessment to systemic treatment for mCRPC.
BACKGROUND:Prostate-specific membrane antigen (PSMA) is a rational target for noninvasive detection of recurrent prostate cancer (PCa) and for therapy of metastatic castration-resistant prostate cancer (mCRPC) with PSMA-targeted agents. Here we conducted serial measurements of PSMA expression on circulating tumor cells (CTCs) to evaluate patterns of longitudinal PSMA dynamics over the course of multiple sequential therapies. METHODS: A retrospective investigation of men with mCRPC undergoing evaluation at medical oncology clinics at our institution assessed the dynamics of PSMA expression in the context of different systemic treatments administered sequentially. Eligibility included patients who began systemic therapies with androgen receptor (AR)-directed agents or taxane agents for whom peripheral blood samples were tested for CTC mRNA of AR splice variant-7 (AR-V7), prostate-specific antigen (PSA), and PSMA (with >2 CTC + results) in a CLIA-accredited laboratory. RESULTS: From August 2015 to November 2017, we identified 96 eligible men. Fifteen had greater than or equal to 2 sequential therapies and evaluable CTC samples, greater than or equal to 1 expressing PSMA (PSMA+). Among the 15 patients included in this analysis, a total of 54 PSMA status evaluations were performed in the context of 48 therapies during a median follow-up of 18 months. At baseline, PSMA signal was detected ("positive") in 11 of 15 (73.3%) patients, while for 4 of 15 (26.7%) patientsPSMA signal was undetectable ("negative"). In all but two patients, the baseline collection corresponded with a change in treatment. On the second assessment, PSMA increases were detected in all 4/4 (100%) PSMA-negative patients and 8 of 11 (72.7%) PSMA-positive patients. PSMA significantly decreased in a patient treated with 177 Lu-PSMA-617. Serum PSA declines were seen in 7 of 8 (88%) of the treatment periods where PSMA decreased. CONCLUSIONS:PSMA expression in CTCs is a dynamic marker. PSMA transcript declines appear to be associated with concurrent decreases in serum PSA. Sequential CTC sampling could provide a noninvasive response assessment to systemic treatment for mCRPC.
Authors: Anna Katharina Seitz; Isabel Rauscher; Bernhard Haller; Markus Krönke; Sophia Luther; Matthias M Heck; Thomas Horn; Jürgen E Gschwend; Markus Schwaiger; Matthias Eiber; Tobias Maurer Journal: Eur J Nucl Med Mol Imaging Date: 2017-11-28 Impact factor: 9.236
Authors: Glenn Heller; Robert McCormack; Thian Kheoh; Arturo Molina; Matthew R Smith; Robert Dreicer; Fred Saad; Ronald de Wit; Dana T Aftab; Mohammad Hirmand; Ana Limon; Karim Fizazi; Martin Fleisher; Johann S de Bono; Howard I Scher Journal: J Clin Oncol Date: 2017-12-22 Impact factor: 44.544
Authors: Pauliina Helo; Angel M Cronin; Daniel C Danila; Sven Wenske; Rita Gonzalez-Espinoza; Aseem Anand; Michael Koscuiszka; Riina-Minna Väänänen; Kim Pettersson; Felix K-H Chun; Thomas Steuber; Hartwig Huland; Bertrand D Guillonneau; James A Eastham; Peter T Scardino; Martin Fleisher; Howard I Scher; Hans Lilja Journal: Clin Chem Date: 2009-02-20 Impact factor: 8.327
Authors: Samuel R Denmeade; Lori J Sokoll; Susan Dalrymple; D Marc Rosen; Alyssa M Gady; Debra Bruzek; Rebecca M Ricklis; John T Isaacs Journal: Prostate Date: 2003-03-01 Impact factor: 4.104
Authors: Sara Sheikhbahaei; Ali Afshar-Oromieh; Matthias Eiber; Lilja B Solnes; Mehrbod S Javadi; Ashley E Ross; Kenneth J Pienta; Mohamad E Allaf; Uwe Haberkorn; Martin G Pomper; Michael A Gorin; Steven P Rowe Journal: Eur J Nucl Med Mol Imaging Date: 2017-08-01 Impact factor: 9.236
Authors: Ian M Thompson; Catherine M Tangen; Jorge Paradelo; M Scott Lucia; Gary Miller; Dean Troyer; Edward Messing; Jeffrey Forman; Joseph Chin; Gregory Swanson; Edith Canby-Hagino; E David Crawford Journal: J Urol Date: 2009-01-23 Impact factor: 7.450
Authors: C S Mathy; T Mayr; M H Muders; R A Bundschuh; S Kürpig; M Meisenheimer; R C Dolscheid-Pommerich; B Stoffel-Wagner; G Kristiansen; M Essler Journal: J Cancer Res Clin Oncol Date: 2021-03-24 Impact factor: 4.553