RT Journal Article
SR Electronic
T1 Low-molecular-weight Protein Tyrosine Phosphatase Is a Possible Biomarker for Predicting Postoperative Biochemical Recurrence in Prostate Cancer With Negative Surgical Margins
JF Anticancer Research
JO Anticancer Res
FD International Institute of Anticancer Research
SP 957
OP 964
DO 10.21873/anticanres.13199
VO 39
IS 2
A1 HIROFUMI KUROSE
A1 KOSUKE UEDA
A1 REIICHIRO KONDO
A1 SACHIKO OGASAWARA
A1 HIRONORI KUSANO
A1 SAKIKO SANADA
A1 YOSHIKI NAITO
A1 JUN AKIBA
A1 TATSUYUKI KAKUMA
A1 TSUKASA IGAWA
A1 HIROHISA YANO
YR 2019
UL http://ar.iiarjournals.org/content/39/2/957.abstract
AB Background/Aim: For prostate cancer, positive surgical margins are considered an important predictor of biochemical recurrence. However, biochemical recurrence is observed in approximately 20% of cases, even with negative surgical margins, and some cases require salvage therapy. The elevated expression of low-molecular-weight protein tyrosine phosphatase (LMW-PTP, MW 18 kDa) is associated with a poor prognosis of certain cancers. In this study, we investigated whether the LMW-PTP expression levels could be used as a biomarker of recurrence in prostate cancer with negative surgical margins. Materials and Methods: The subjects of this retrospective study were 119 patients who underwent total prostatectomy with negative resection margins. LMW-PTP expression was categorized either as a high-expression group or as a low-expression group bye two pathologists. Subsequently, we examined the relationship between LMW-PTP expression levels and clinicopathological factors including biochemical recurrence. Results: Evaluation of the immunostained samples by two pathologists was highly reliable, with an Intraclass correlation (ICC) score for two distinct measurements of 0.77 and 0.98, respectively. Seventy-three patients (61.3%) were placed in the LMW-PTP high expression group; and 46 patients (38.7%) were placed in the low expression group. The log-rank test revealed early biochemical recurrence in the high LMW-PTP expression group (p=0.0001). In addition, pathological T stage (p=0.004), lymphatic invasion (p=0.0456), Ki-67 labeling index (p=0.0002), and biochemical recurrence (p<0.0001) were more frequently identified in the LMW-PTP high expression group. Furthermore, multivariate analyses revealed that a high LMW-PTP expression level was an independent prognostic factor for biochemical recurrence (HR=3.14, 95% CI=1.37-8.07, p=0.0057). In addition, Ki-67 labeling indices were significantly higher in the high-expression group compared to the low-expression group (p<0.0001). Conclusion: LMW-PTP can be assessed using a single immunostaining protocol in a highly reproducible fashion. Tt may, thus, be applied clinically to establish the required postoperative follow-up period and determine the necessity for salvage therapy in cases of prostate cancer with negative surgical margins. LMW-PTP has the potential to be a highly useful prognostic biomarker and a therapeutic target in conjunction with other factors, such as the Gleason Score, the pathological T stage and the PSA level.