Abstract:  Background and purpose: The incidence of prostate cancer is on the rise, and some of these cases have low prostate-specific antigen (PSA) levels even when they are diagnosed with advanced or metastatic prostate cancer. This study aimed to investigate the outcome in patients with Gleason score 8-10 prostate cancer and low preoperative PSA level. Methods: Clinical data of 72 cases of high-grade prostate cancer receiving radical prostatectomy in Subei People’s Hospital of Jiangsu Province from Jan. 2013 to Jan. 2018 were collected. Based on the preoperative PSA level, the patients were divided into four groups: group A ［<4.0 ng/mL (9 cases)］, group B [4.0-10.0 ng/mL (12 cases)], group C [10.0-20.0 ng/mL (15 cases)] and group D [>20.0 ng/mL (36 cases)]. In the group A, B, C and D, the mean age was (68.8±8.6), (68.9±6.0), (71.6±6.0) and (68.4±6.4) years, while the mean follow-up time was (21.6±12.1), (18.8±7.2), (25.0±13.4) and (24.8±12.5) months respectively. The cases with positive margin were 3 (33.3%), 5 (41.7%), 5 (33.3%) and 15 (41.7%). The cases with seminal vesicle invasion were 6 (66.7%), 2 (16.7%), 2 (13.3%) and 14 (38.9%). The cases with lymph node metastasis were 2 (22.2%), 3 (25.0%), 4 (26.7%) and 13 (36.1%). The prognostic measures were biochemical progression-free day (bPFD) and prostate cancer-specific death (PCSD). The mean PFD was (90.00±38.40), (306.17±79.00), (223.14±63.30) and (145.03±62.50) d in the four groups. The number of PCSD was 4 (44.4%), 0 (0.0%), 1 (6.7%) and 5 (13.9%). Age, follow-up time and PFD among groups were analyzed by single factor variance analysis, and least significant difference (LSD) method was used for further pairwise comparison. Clinical and pathological features were analyzed by χ ² and Fishers exact test. PCSD was analyzed by Kaplan-Meier survival analysis, and comparison between survival curves was analyzed by log-rank test. Results: There was no significant difference in age, follow-up time, positive margin and lymph node metastasis between group A and the other three groups (P>0.05). There was statistically significant difference in seminal vesicle invasion and PFD between group A and group B and C (P<0.05). However, there was no statistically significant difference in seminal vesicle invasion and PFD between group A and group D (P>0.05). Survival analysis showed that group A had a worse survival than group B in the follow-up time, which was not statistically significant (P=0.092), and the survival difference between group A and group C and D was statistically significant (P<0.05). Conclusion: Patients with high-grade prostate cancer and low preoperative PSA level have less satisfactory prognosis than those with higher PSA level, who are prone to seminal vesicle invasion, rapid biochemical recurrence and high PCSD.

Key words: Prostatic neoplasm, Prostate-specific antigen, Gleason score, Cancer outcome