Salvage radiotherapy for rising PSA or clinically palpable local recurrence following radical prostatectomy

Purpose: To evaluate the efficacy of salvage radiotherapy (RT) for rising PSA and/or clinically palpable local recurrence following radical prostatectomy (RP).Materials and Methods: Retrospective, single institution study.A total of 98 prostate cancer patients, who had had PSA failure or clinically palpable local recurrence following RP, underwent salvage RT between 1991 and 1997. Patients were divided into 3 groups: Group A: Persistently detectable post-RP PSA in which PSA never became undetectable (< 0.2 ng/ml) within 6 months following RP, Group B: Delayed PSA rise after initially undetectable PSA in the first 6 months post-RP, Group C: Clinically palpable or biopsy proven local recurrence with rising PSA. All patients had no evidence of distant metastasis and received salvage RT with curative intent. 84 received salvage RT alone, while 14 had a short course (max: 4 months) of hormone therapy (HT) prior to salvage RT. RT doses ranged from 60 to 66 Gy in 30 to 33 fractions. 70%, 58%, and 82% had PT3, positive resection margin, and GS ≥7 respectively on their RP pathology reports. Median pre-RP PSA was 11.2.Results: Table. Complete PSA response (CR) was defined as PSA < 0.2, and partial PSA response (PR) as PSA decrease, but fail to reach < 0.2. PSA progression free survival (PFS) was defined as survival with no evidence of local progression, distant metastasis, or PSA failure(> 0.2). Despite a high initial PSA response rate (RR), only 26 remained relapse-free with undetectable PSA at the time of their last follow-up. 51, 20, and 1 had PSA failure only, distant metastasis and local progression respectively. On Cox regression analysis, there was no significant predictive factor (pre-RT PSA, pT stage, GS, or interval from RP to RT) for PFS.Conclusion: The efficacy of salvage RT was limited in our series. This can be explained, in part, by initial adverse pathological and clinical features that predict a high risk of harboring occult distant metastasis at the time of referral for salvage RT. 4-year PFS ranged from only 14% to 39%, despite a high initial PSA RR (86-94%). In our series, salvage RT was the least effective for clinically palpable local recurrence, while being the most effective for delayed PSA failure. Clinical local control was achieved in all except one, suggesting that salvage RT was effective in controlling local tumor. New treatment strategies such as combination of salvage RT with adjuvant HT need to be explored for this poor prognostic group. Tabled 1Group A (n=36)Group B (n=26)Group C (n=36)Median Age (years)656566Median interval from RP to RT (years)0.452.142.60Median follow-up from RT (years) (range)4.21 (2.48-9.71)3.32 (0.52-5.82)3.95 (2.06-8.12)Median Pre-RT PSA (ng/ml) (range)0.8 (0.3-9.9)1.2 (0.3-14.2)3.7 (0.5-48.5)Complete PSA response58%62%53%Partial PSA response28%27%42%No PSA response14%12%6%4-year PFS26%39%14%4-year survival89%95%94% Open table in a new tab Purpose: To evaluate the efficacy of salvage radiotherapy (RT) for rising PSA and/or clinically palpable local recurrence following radical prostatectomy (RP). Materials and Methods: Retrospective, single institution study. A total of 98 prostate cancer patients, who had had PSA failure or clinically palpable local recurrence following RP, underwent salvage RT between 1991 and 1997. Patients were divided into 3 groups: Group A: Persistently detectable post-RP PSA in which PSA never became undetectable (< 0.2 ng/ml) within 6 months following RP, Group B: Delayed PSA rise after initially undetectable PSA in the first 6 months post-RP, Group C: Clinically palpable or biopsy proven local recurrence with rising PSA. All patients had no evidence of distant metastasis and received salvage RT with curative intent. 84 received salvage RT alone, while 14 had a short course (max: 4 months) of hormone therapy (HT) prior to salvage RT. RT doses ranged from 60 to 66 Gy in 30 to 33 fractions. 70%, 58%, and 82% had PT3, positive resection margin, and GS ≥7 respectively on their RP pathology reports. Median pre-RP PSA was 11.2. Results: Table. Complete PSA response (CR) was defined as PSA < 0.2, and partial PSA response (PR) as PSA decrease, but fail to reach < 0.2. PSA progression free survival (PFS) was defined as survival with no evidence of local progression, distant metastasis, or PSA failure(> 0.2). Despite a high initial PSA response rate (RR), only 26 remained relapse-free with undetectable PSA at the time of their last follow-up. 51, 20, and 1 had PSA failure only, distant metastasis and local progression respectively. On Cox regression analysis, there was no significant predictive factor (pre-RT PSA, pT stage, GS, or interval from RP to RT) for PFS. Conclusion: The efficacy of salvage RT was limited in our series. This can be explained, in part, by initial adverse pathological and clinical features that predict a high risk of harboring occult distant metastasis at the time of referral for salvage RT. 4-year PFS ranged from only 14% to 39%, despite a high initial PSA RR (86-94%). In our series, salvage RT was the least effective for clinically palpable local recurrence, while being the most effective for delayed PSA failure. Clinical local control was achieved in all except one, suggesting that salvage RT was effective in controlling local tumor. New treatment strategies such as combination of salvage RT with adjuvant HT need to be explored for this poor prognostic group. Tabled 1Group A (n=36)Group B (n=26)Group C (n=36)Median Age (years)656566Median interval from RP to RT (years)0.452.142.60Median follow-up from RT (years) (range)4.21 (2.48-9.71)3.32 (0.52-5.82)3.95 (2.06-8.12)Median Pre-RT PSA (ng/ml) (range)0.8 (0.3-9.9)1.2 (0.3-14.2)3.7 (0.5-48.5)Complete PSA response58%62%53%Partial PSA response28%27%42%No PSA response14%12%6%4-year PFS26%39%14%4-year survival89%95%94% Open table in a new tab