Lymphadenectomy in minimally invasive urologic oncology:

Exogenous SPARC suppresses proliferation and migration of prostate cancer by interacting with integrin β1

BACKGROUND

The matricellular protein secreted protein acidic and rich in cysteine (SPARC) plays an important role on tumor metastasis and progression in several cancers. However, the roles of SPARC in prostate cancer (PCa) remain unclear.

METHODS

To identify SPARC protein in prostate tissue, immunohistochemical analysis of SPARC was conducted using human prostate tissue microarray. To detect SPARC expression in prostate cancer (LNCaP, DU145, and PC-3) and stromal cells, RT-PCR, western blot analysis, and ELISA was conducted. To reveal the function of exogenous SPARC in PCa cells, AKT phosphorylation was confirmed by western blot analysis after coculture with stromal cells. Proliferation and migration of PCa cells were examined by addition of SPARC. The interaction between SPARC and integrin β1 was confirmed by western blot analysis after immunoprecipitation.

RESULTS

SPARC protein was expressed well in normal tissue compared with PCa tissue. ELISA showed high secreted SPARC protein in normal prostate-derived stromal cell (PrSC) compared with PCa-derived stromal cell (PCaSC) and PCa. PCa cells cocultured with PrSC showed reduced AKT phosphorylation more than with PCaSC. PCa cells cocultured with PrSC whose SPARC was knocked-down restored AKT phosphorylation. Moreover, PCa cells treated with SPARC led to reduced AKT phosphorylation. Immunoprecipitation with SPARC revealed interaction of SPARC and integrin β1 in PCa cells. Inhibited proliferation and migration of PCa cells by SPARC was restored by integrin β1 neutralizing antibody.

CONCLUSIONS

Reduced SPARC secretion from stromal cells might affect PCa progression mediating through limiting AKT phosphorylation after interaction with integrin β1.

Temporal trends and predictors of pelvic lymph node dissection in open or minimally invasive radical prostatectomy

BACKGROUND

Pelvic lymph node dissection (PLND) is an important component of prostate cancer staging and treatment, especially for surgical patients who have high-risk tumor features. It is not clear how the shift from open radical prostatectomy (ORP) to minimally invasive radical prostatectomy (MIRP) has affected the use of PLND. The objectives of this study were to identify predictors of PLND and to assess the impact of surgical technique in a contemporary, population-based cohort.

METHODS

In Surveillance, Epidemiology, and End Results (SEER) cancer registry data linked with Medicare claims, the authors identified men who underwent ORP or MIRP for prostate cancer during 2003 to 2007. The impact of surgical approach on PLND was evaluated, and interactions were examined between surgical procedure, prostate-specific antigen (PSA), and Gleason score with the analysis controlled for patient and tumor characteristics.

RESULTS

Of 6608 men who underwent ORP or MIRP, 70% (n = 4600) underwent PLND. The use of PLND declined over time both overall and within subgroups defined by procedure type. PLND was 5 times more likely in men who underwent ORP than in men who underwent MIRP when the analysis was controlled for patient and tumor characteristics. Elevated PSA and biopsy Gleason score, but not clinical stage, were associated with a greater odds of PLND in both the ORP group and the MIRP group. However, the magnitude of the association between these factors and PLND was significantly greater for patients in the ORP group.

CONCLUSIONS

PLND was less common among men who underwent MIRP, independent of tumor risk factors. A decline in PLND rates was not fully explained by an increase in MIRP. The authors concluded that these trends may signal a surgical approach-dependent disparity in prostate cancer staging and therapy.

Case report: loss of hernia mesh after simultaneous laparoscopic extraperitoneal lymphadenectomy, radical prostatectomy, and hernioplasty

We present a case of prosthetic mesh hernia repair of a unilateral inguinal hernia following laparoscopic extraperitoneal pelvic lymph node dissection and radical prostatectomy. After an uneventful intraoperative and early postoperative period, the patient developed a lymphocele. This resulted in the detachment of the mesh from the abdominal wall, which necessitated its removal.