Genitourinary Cancer

PV QA 1 - Poster Viewing Q&A 1

SU_33_2339 - Achieving "Zero PSA" Following Post-Prostatectomy Radiation Therapy for Lymph Node Positive Prostate Cancer in the Ultrasensitive PSA Era

Sunday, October 21
1:15 PM - 2:45 PM
Location: Innovation Hub, Exhibit Hall 3

Achieving “Zero PSA” Following Post-Prostatectomy Radiation Therapy for Lymph Node Positive Prostate Cancer in the Ultrasensitive PSA Era
M. C. Tom1, O. Y. Mian1, K. L. Stephans1, C. A. Reddy1, S. H. Xu2, B. Rini3, J. A. Garcia3, M. C. Ornstein3, E. A. Klein4, A. J. Stephenson4, and R. D. Tendulkar1; 1Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, 2Case Western Reserve University, Cleveland, OH, 3Solid Tumor Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, 4Glickman Urological Institute, Cleveland Clinic, Cleveland, OH

Purpose/Objective(s): Optimal management of patients (pts) with pathologically lymph node positive (LN+) prostate cancer (PCa) following radical prostatectomy (RP) is controversial. We report outcomes of LN+ pts who received postoperative radiotherapy (RT) at a single center in the ultrasensitive prostate specific antigen (PSA) era.

Materials/Methods: We reviewed an IRB-approved database of PCa pts who underwent RP with LN dissection and were found to be LN+ and M0 who subsequently received postoperative pelvic RT with or without (+/-) androgen deprivation therapy (ADT). We excluded pts who received neoadjuvant chemotherapy or ADT. Endpoints included freedom from detectable PSA (“zero PSA”) and freedom from biochemical failure (FFBF), defined as the time from completion of postoperative RT or ADT to detectable PSA (PSA >0.03 ng/ml) and BF (PSA >0.2 ng/mL), respectively. Overall survival (OS) and distant metastasis free survival (DMFS) were calculated from time of surgery to event by Kaplan Meier estimates using statistical software.

Results: Sixty-three pts underwent RP between 2003-2016 and met inclusion criteria, with a median age of 63 years (yr) (range 43-73) and a median follow up of 51 months (mo) (range 6-170) from surgery. Median initial PSA was 8.9 ng/mL (range 3.6-47.8). Median number of LNs removed was 11 (range 3-37), and median number of LN+ was 1 (range 1-10). Surgical Gleason score was 7 in 28 pts (44%), 8 in 10 pts (16%), and 9 in 25 pts (40%). Most pts were pT3b (70%), and 95% had either positive margins or pT3 disease. Median time from RP to RT was 6 mo (range 1-90). Twenty-seven pts (43%) had an initially undetectable post-RP PSA. Eleven pts (18%) had an undetectable PSA at initiation of adjuvant RT +/- ADT, while 52 pts (83%) were treated with salvage therapy for a detectable PSA (median 0.12 ng/mL; range 0.04-9.1). Twenty pts (32%) declined ADT and received RT alone, and 43 pts (68%) received concurrent RT + ADT with a median ADT duration of 12 mo (range 6-36). At last follow up, 51 pts had completed the planned post-RP therapy while 12 pts remained on ADT, 8 of whom maintained an undetectable PSA and 4 of whom developed PSA progression (castrate-resistant PCa). After completion of RT +/- ADT, a “zero PSA” was achieved in 44 pts (70%) off testosterone suppression. 2-yr rates of “zero PSA” and FFBF were 60% and 80%, respectively. 5- and 10-yr DMFS rates were 89% and 47%, and OS rates were 95% and 81%, respectively. Thirty-nine pts (62%) had a “zero PSA” at last follow up, none of whom developed DM. Of the 20 pts (32%) who received RT alone, 15 (75%) had a detectable PSA immediately prior to RT, 15 (75%) achieved a “zero PSA” post-RT, and the 2-yr rate of “zero PSA” was 65%.

Conclusion: For pts with nonmetastatic LN+ PCa in the ultrasensitive PSA era, post-RP RT +/- ADT can achieve “zero PSA” off of ADT. Further follow up and study are required to select pts most likely to benefit from RT and who may avoid long-term ADT.

Author Disclosure: M.C. Tom: None. O.Y. Mian: None. K.L. Stephans: None. C.A. Reddy: Statistical editor; ASTRO. S.H. Xu: None. J.A. Garcia: None. E.A. Klein: Chairman, Glickman Urological and Kidney Institute; Cleveland Clinic. A.J. Stephenson: None. R.D. Tendulkar: None.

Send Email for Martin Tom


Assets

SU_33_2339 - Achieving "Zero PSA" Following Post-Prostatectomy Radiation Therapy for Lymph Node Positive Prostate Cancer in the Ultrasensitive PSA Era



Attendees who have favorited this

Please enter your access key

The asset you are trying to access is locked. Please enter your access key to unlock.

Send Email for Achieving "Zero PSA" Following Post-Prostatectomy Radiation Therapy for Lymph Node Positive Prostate Cancer in the Ultrasensitive PSA Era