RESUMO
Objective To investigate the dose of docetaxel appropriate for patients with metastatic castration-resistant prostate cancer and its affects to the prognosis.Methods A retrospective analysis was performed on the clinical data of 75 patients with metastatic castration-resistant prostate cancer admitted from March 2010 to July 2016 who received docetaxel combined with prednisone chemotherapy.The patients were divided into the low-dose group (n =43,docetaxel ＜ 65 mg/m2),the middle-dose group (n =21,docetaxel 65-70 mg/m2) and the high-dose group (n =11,docetaxel ＞ 70 mg/m2).The median age in the low-dose group,middle-dose group and high-dose group was 67 (53-80),66 (56-78) and 61 (47-76) years old,respectively.Among 75 patients with bone metastasis,2 patients had no evidence of bone metastasis in the low-dose group.The lymph node metastasis was found in 26,13 and 6 cases in each group,respectively.And visceral and other metastasis were founded in 11,4 and 2 cases,respectively.The Gleason score in the low-dose group was≤7 points in 15 cases,≥8 points in 22 cases and no score in 6 cases.The Gleason score inthe middle-dose group was ≤7 points in 4 cases,≥8 points in 13 cases and no score in 4 cases.The Gleason score in the high-dose group was ≤7 points in 3 cases,≥8 points in 5 cases and no score in 3 cases.The number of patients with pain in the low-dose group,middle-dose group and high-dose group was 36,12 and 9,respectively,there were no significant differences in the above indicators (P ＞ 0.05),except age,which showed relatively more aged patients in the low-dose group,(P =0.045).Kaplan-Meier method was used to compare the overall survival (OS),progression-free survival (PFS) and the incidence of ≥CTCAE-4 grade 3 adverse reactions between the two groups.The Cox regression model was adopted to analyzed the factors that might affect patient prognosis,including the effective time of first-line endocrine therapy,hemoglobin level,ECOG score,pain score,number of cycles of chemotherapy,age,dose of docetaxel and alkaline phosphatase (ALP).Kaplan-Meier method was used to analyze the effect of dose of docetaxel on the prognosis,and log-rank method was used to test the significance of the results.Results The median OS was respectively 24.1,18.5 and 23.5 months in the low-dose group,middle-dose group and high-dose group,respectively.The median PFS was 5.3 months in all three groups,which didn't show statistically significant differences.The incidence of grade 3/4 adverse reactions in the low-dose group,middle-dose group and high-dose group was 15 cases (34.9％),8 cases (38.1％) and 5 cases (45.5％) respectively.It showed an increasing trend,but no statistically significant difference.The single factors related to OS mainly include the effective time of first-line endocrine therapy,hemoglobin level,ECOG score,pain score,number of cycles of chemotherapy,there was no significant correlation with age,docetaxel dose,ALP and PSA value.Conclusions It is common to receive lower doses of docetaxel in clinical practice for patients with metastatic castration-resistant prostate cancer in China.The efficacy of low-dose docetaxel is similar to that of high doses (standard dosage).There was no significant correlation between the OS and the actual dose of docetaxel in the tolerable range.