Objective   This study aimed to investigate the expression of serum HMGB1 and prostate-specific antigen (PSA) in diagnosing the recurrence of localized prostate cancer (Pca) in patients who had undergone cryotherapy treatment.

  Methods   Enzyme-linked immunosorbent assay (ELISA) was performed to measure the serum HMGB1 levels of 80 prostate cancer patients pre-and post-operation, as well as the PSA levels in 30 benign prostatic hyperplasia (BPH) and 20 healthy subjects.During follow-up, PSA analysis, MRI, and pathology biopsy confirmed nine cases of local recurrence and three cases of metastasis.The post-operative serum HMGB1 expression and its diagnosis value in Pca recurrence were also determined.

  Results   First, the HMGB1expression level in Pca (94.0 ± 77.4 ng/mL) was significantly higher than those in BPH (33.2 ± 7.4 ng/mL) and healthy (24.7 ± 7.3 ng/mL) subjects (P < 0.001).Second, post-operative serum HMGB1 was 55.03 ± 11.00 ng/mL, which significantly differed from the pre-operative level (P = 0.005).Post-operative serum HMGB1 in the recurrence group significantly different from that in the recurrence-free group (70.8 ± 2.7 vs.55.0 ± 10.8 ng/mL).Serum HMGB1 in the three metastatic cases were significantly higher than in the nine cases of local recurrence (94.2 ± 17.9 vs.73.1 ± 7.9 ng/mL).The single diagnostic value of serum HMGB1 was more sensitive than PSA in predicting the recurrence of Pca after local treatment (83.3% vs.66.7%), and the overall diagnostic specificity was higher than that of PSA alone (95.6% vs.82.4%).Third, serum HMGB1 in Pca patients after cryotherapy was related to the clinical stage and recurrence (P < 0.001), but was not correlated with the Gleason score.

  Conclusion   Our findings indicated that serum HMGB1 levels were higher in Pca subjects, suggesting that serum HMGB1 can be used as a predictive and prognostic factor.Moreover, co-detection of serum HMGB1 andPSA can improve the early diagnosis of Pca recurrence after cryotherapy.