To evaluate the efficacy and safety of docetaxel+ prednisone in the treatment of castrated resistant prostate cancer in patients over 75 years old.

In this study, 118 metastatic castration resistant prostate cancer (mCRPC) patients over 60 years old treated in Beijing Hospital from February 2013 to December 2019 were retrospectively analyzed. The median age of the patients was 72 (65, 77)years, ECOG scores ≤2. All 118 cases had bone metastasis, 5 cases had visceral metastasis. A total of 40 patients chose docetaxel as the first-line treatment of mCRPC, and the remaining 78 patients chose docetaxel as second-line or third-line treatment. The study included 53 patients >75 years old and 65 patients aged 60-75 years. The age of patients in the two groups were 67 (63, 71) years old and 78 (76, 83) years old, the difference was statistically significant ( P<0.05). Among them, there were 24 cases with Gleason score ≤7 and 41 cases with Gleason score >7 in 60-75 years old group, and 30 cases with Gleason score ≤7 and 23 cases with Gleason score >7 in the group of >75 years old, with significant difference between the two groups (P = 0.034). Sixty-one patients received endocrine therapy and 4 received orchiectomy in the 60-75 years old group; 43 patients received endocrine therapy and 10 received orchiectomy in the group of >75 years old, the difference was statistically significant ( P=0.035). There were 37 cases with ECOG 0 score, 25 cases with 1 scores and 3 cases with 2 scores in the group of 60-75 years old; there were 5 cases with ECOG 0 score, 38 cases with 1 score and 10 cases with 2 score in the group of >75 years old, with significant difference between the two groups ( P<0.05). There was no significant difference in PSA level[ 90 (35.5, 258) ng/ml vs. 115 (60, 296) ng/ml], G8 scale score [(14.3±2.1 vs. 13.6±1.1)], Mini-Cog score[3(2, 3) vs. 3(1, 3)], and visceral metastasis [2 cases (3.1%) vs. 3 cases (5.7%)](P>0.05). The efficacy and safety of docetaxel in the two groups were further observed.

The median follow-up time was 21.5 (6, 62) months. There was no significant difference in chemotherapy cycle [(6.1±1.3) vs. (6.8±1.7)] and chemotherapy dose [(70.3±4.3) mg/m² vs. (66.3±5.2) mg/m²] between the 60-75 years old group and the >75 year old group ( P> 0.05). The PSA response rate [72.3%(47/65)vs.66.0%(35/53)], pain relief rate [45.0% (9/20) vs. 54.5% (6/11)], and median progression-free survival[6.1 (1.4, 11.2) months vs. 5.9 (2.0, 12.0) months] had no statistical significance (P>0.05). There were no deaths in the two groups during chemotherapy. The median overall survival(OS) of patients aged 60-75 years and those >75 years old who received docetaxel as first-line treatment were 26.5 (16.1, 31.3) months and 24.8 (17.5, 28.4) months, respectively (P=0.223). The median OS of the two groups were 17.3 (13.2, 20.5) months and 15.4 (12.3, 20.0) months with docetaxel treatment as second or third line treatment (P=0.331). There were 3 cases (4.6%) and 5 cases (9.4%) of grade 3 adverse reactions in 60-75 years group and >75 years old group, respectively. Grade 3 leukopenia occurred in 1 case time (1.5%) and 2 cases (3.8%) respectively. Grade 3 neutropenia fever occurred in 1 case time in both groups. There was no significant difference in the incidence of above complications between the two groups ( P > 0.05).

The efficacy and safety of docetaxel + prednisone chemotherapy for mCRPC patients >75 years old were similar to those of 60-75 years old. Age should not be the absolute contraindication of docetaxel for prostate cancer chemotherapy.

Prostatic neoplasms; Castration-risistant prostate cancer; Docetaxel; Age; Efficacy; Adverse reaction