The flare in alkaline phosphatase activity post-orchidectomy predicts which patient may benefit from early chemotherapy in metastatic prostate cancer

BACKGROUND: A flare in serum alkaline phosphatase (ALP) activity post-orchidectomy has been shown to be of negative prognostic value for progression-free survival (PFS) in patients with prostate cancer. The aim of this study was to investigate whether a flare in ALP may help identify patients in whom prognosis could be positively influenced by early chemotherapy. METHODS: A retrospective analysis of the database of a Dutch multicenter study was conducted to evaluate the prognostic value of the flare in ALP post-orchidectomy for survival and PFS in 112 patients treated with orchidectomy (previously reported) compared to 121 age- and stage-matched patients additionally treated with estramustine-phosphate (EMP) as first line therapy. RESULTS: There was no overall difference in PFS and survival between the two treatment regimen. Subgroup analysis of patients demonstrating a greater than 50% increase in ALP post-orchidectomy showed, however, a significant increase in PFS in patients additionally treated with EMP. CONCLUSIONS: Our data suggest that the simple measurement of ALP activity within 4 weeks of castration represents a useful adjunct in assessing which patients with prostate cancer undergoing androgen ablation may benefit from additional early chemotherapy