SXRT should ideally be given to a patient with a prostatic fossa only recurrence, reflected by a delayed rise in PSA, a PSA DT of >6 months and pathologic Gleason scores of 7 or less. However, they point out that with 6 years followup, other investigators paradoxically found the survival benefit from SXRT only in men with a PSADT of ≤6 months. The objective of this study was to evaluate SXRT for an association with decreased risk of death from all causes in patients with either a rapid or slow PSA rise after RP. The patient data was adjusted for known CaP prognostic variables, age, and cardiac comorbidities.
The database from Duke University included 4,036 men who underwent RP between 1988 and 2008. All had initial post-RP PSA levels <0.2ng/ml and no pelvic lymph node metastasis. After exclusions for adjuvant treatments and missing data, they identified 519 men who developed a PSA failure from a cohort of 3,044. These 519 patients had at least two PSA increases of 0.2ng/ml separated by 3 months. They received either no salvage therapy, SXRT alone, SXRT with androgen deprivation therapy (ADT), or ADT alone. Men with cardiac comorbidities prior to PSA failure were considered to have cardiac comorbidity, and thus 87 were identified and excluded from subsequent comorbidity analysis. SXRT consisted of 66Gy delivered to the surgical bed and anastomosis. PSADT was calculated.
Median PSADT was 10.2 months; 158 men (30.4%) had a PSADT of <6 months and 361 (69.6% had a PSADT of ≥6 months. The shorter PSADT group were younger and more likely to have Gleason score ≥7 tumors. Positive surgical margin rates were similar among the two PSADT groups and SXRT was given to PSADT ≥6months in 57% of cases compared to 73% for PSADT <6 months. Regarding the primary study endpoint, all-cause mortality, there were 195 deaths (37.6%) among the 519 patients; 115 of 361 (31.9%) in men with PSADT ≥6 months and 80 of 158 men (50.6%) with PSADT <6 months. SXRT was associated with a significant reduction in all-cause mortality for patients with a PSADT <6 months (adjusted HR 0.53) and for patients with a PSADT ≥6 months (AHR 0.52). A significant increase in the risk of all-cause mortality was found for pathologic Gleason score 8-10 (AHR 1.93) and increasing age (AHR 1.05). In men receiving ADT in addition to SXRT there was a significant reduction in all-cause mortality (AHR 0.53). Among men with cardiac comorbidities, XSRT was associated with significant reduction in all-cause mortality for both fast and slow PSADT groups. Furthermore, cardiac comorbidity correlated with an increased risk of all-cause mortality (AHR4.73). In healthy men, SXRT decreased risk of all-cause mortality in PSADT <6 months and ≥6 months.
Cotter SE, Chen MH, Moul JW, Lee WR, Koontz BF, Anscher MS, Robertson CN, Walther PJ, Polascik TJ, D'Amico AV
Cancer. 2011 Mar 22. Epub ahead of print
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