Correlation of elevated alkaline phosphatase (ALP) and survival in metastatic castration-resistant prostate cancer (CRPC) treated with docetaxel chemotherapy: Results of SWSW Uro-oncology Group study from three U.K. centers.

Abstract

206 Background: Treatment with docetaxel in CRPC based on the results of the TAX 327 study has been recommended by NICE guidance in UK. Paucity of UK data on any significant difference in median survival of CRPC patients receiving chemotherapy with normal or elevated ALP is a possible contributory factor to the delayed consideration of chemotherapy in CRPC. We therefore analysed differences in survival in metastatic CRPC patients with normal or elevated ALP treated with docetaxel chemotherapy in 3 cancer centres in UK with a contemporary referral population. Methods: Survival data were collected on consecutive cases of metastatic CRPC treated with at least 1 cycle of docetaxel chemotherapy in these 3 centres. Variables analysed included: presence or absence of pain, PSADT, Gleason score, Haemoglobin, Alkaline phosphatase and number of previous lines of hormone therapy. Results: Median overall survival in 170 eligible patients was 18.1 months (15.3-20.7) with median follow-up of 30.1 months. 84 cases had normal ALP and 86 cases had elevated ALP at time of commencing docetaxel chemotherapy. Median survival was 14.1 months (95% CI= 11.1-17.1) in the elevated ALP group and 22.2 months (95% CI= 17.5- 26.9) in the normal ALP group. The difference between group medians was significant (p<0.001). In multivariate analysis, elevated ALP was a significant prognostic factor for outcome after docetaxel chemotherapy in metastatic CRPC. Conclusions: Regular monitoring of ALP along with PSA monitoring can be a relatively simple way of ensuring that patients with metastatic CRPC are referred for chemotherapy appropriately. To our knowledge this is the first UK data on the impact of ALP level on survival in this group of patients after docetaxel chemotherapy. It is important that decision regarding chemotherapy is based on the parameters of disease progression and regular ALP monitoring may be a relatively simple and practical way of ensuring the right timescales for referral for chemotherapy in metastatic CRPC. [Table: see text]