Radical prostatectomy for high-grade prostate cancer

Long-term biochemical control and cause-specific survival in men with Gleason grade Group 4 and 5 prostate cancer treated with brachytherapy and external beam irradiation

PURPOSE

Men with Gleason grade Group (GG) 4 and 5 prostate cancer have high failure rates when treated by conventional therapy. We investigated the effect of higher radiation doses on freedom from biochemical failure (FBF) and prostate cancer mortality (cause-specific survival [CSS]) in men treated with a combination of permanent implant and external beam irradiation (EBRT).

METHODS AND MATERIALS

Three hundred twenty men with GG4 (n = 186) and 5 (n = 134) prostate cancer were treated with I-125 or Pd-103 implant followed by 45 Gy of EBRT. Radiation doses were converted to the biological equivalent dose (BED). The median age, prostate-specific antigen (PSA), time on hormone therapy, BED, and followup were 69 years, 9.0 ng/mL, 9 months, 210 Gy, and 6.5 years, respectively. FBF and CSS were calculated by Kaplan-Meier method with associations determined by log rank and Cox regression.

RESULTS

Ten-year FBF for GG4 vs. 5 was 77.8 vs. 61.3% (p = 0.015), and CSS was 94 vs. 79.3% (p = 0.001). Men with lower PSA had improved FBF and CSS (p < 0.001). Thirty-one of 320 died of prostate cancer of which 10/186 (5.4%) had GG4 and 21/134 (15.7%) GG5 (OR 3.3, p = 0.002). BED <200 Gy was associated with a 2.2× greater BF (p = 0.004) and 2.4× prostate cancer mortality (p = 0.020). Significant covariates on regression analysis for FBF and CSS were PSA (p = 0.014), GG (p = 0.007), BED (p = 0.009), and GG (p = 0.001).

CONCLUSIONS

Survival rates for high-grade prostate cancer are favorable when diagnosed in men with lower PSA and treated with doses of BED > 200 Gy. Higher BED is achieved with a combination of I-125 (110 Gy) or Pd-103 (100 Gy) and 45 Gy EBRT.

SHISA2 enhances the aggressive phenotype in prostate cancer through the regulation of WNT5A expression

The present study aimed at identifying novel molecular cancer drug targets and biomarkers by analyzing the gene expression profiles of high-grade prostate cancer (PC), using a cDNA microarray combined with laser microbeam microdissection. A number of genes were identified that were transactivated in high-grade PC. First, a novel molecular target and diagnostic biomarker, shisa family member 2 (SHISA2), was identified as an overexpressed gene in high-grade PC cells. The reverse transcription-semi-quantitative polymerase chain reaction and immunohistochemical analysis validated the overexpression of SHISA2 (295 amino acids in length), specifically in high-grade PC cells with Gleason scores of between 8 and 10, relative to normal prostate epithelium. Knockdown of SHISA2 expression by short interfering RNA resulted in the marked suppression of PC cell viability. By contrast, exogenous SHISA2 expression in transfected cells promoted PC cell proliferation, indicating its oncogenic effects. Notably, as a result of cDNA microarray analysis, protein Wnt-5a (WNT5A) was focused upon and the expression of WNT5A was identified to be downregulated in SHISA2-knockdown. Western blot analysis validated significant downregulation of WNT5A by SHISA2-knockdown and upregulation of WNT5A by SHISA2 overexpression. The results of the present study indicated that SHISA2 may affect WNT5A synthesis. Furthermore, the secreted SHISA2 protein was determined in the culture medium of PC cells. We hypothesize that SHISA2 is involved in the regulation of WNT5A and in the aggressiveness of PC via the Wnt signaling pathway through WNT5A. Furthermore, SHISA2 may be a molecular target for cancer drugs, and a useful diagnostic biomarker for the prognosis and therapeutic effect in cancer.

Radical Prostatectomy for Locally Advanced Prostate Cancers-Review of Literature

Twenty-five to thirty percent of patients with prostate cancer present with locally advanced disease. While risk stratification remains the same with high incidence of upstaging of disease on imaging and histopathological evaluation; there have been progressive refinements in surgical therapy. With availability of reasonably robust data, radical prostatectomy in men with locally advanced prostate cancers seems to effect improvement in both cancer specific and overall survival rates in comparison to the current standard of care of radiation with androgen deprivation therapy. Studies using radical prostatectomy as a part of multimodality approach have also shown promising results. There is an imminent need for well-designed prospective studies of benefits of radical prostatectomy over radiation and androgen deprivation as well as benefits of multimodality therapy over monotherapy. Surgery for patients with locally advanced prostate cancer is technically challenging. Surgical outcomes are comparable to those of organ-confined disease when performed in high-volume centers. Neoadjuvant therapies prior to radical prostatectomy might improve surgical outcomes, but whether they will translate into a better cancer specific and overall survival are yet to be ascertained.

Locally advanced and high risk prostate cancer: The best indication for initial radical prostatectomy?

High risk prostate cancer is a deadly disease that needs aggressive treatment. High risk prostate cancer is often treated with androgen deprivation therapy or combined radiohormonotherapy while there is a place for surgery in cases of operable and resectable locally advanced or high risk disease. This review summarises the results of the different treatment strategies for locally advanced and high risk prostate cancer. Radical prostatectomy monotherapy or in combination with radiotherapy and/or hormonal treatment are analysed. They show that radical prostatectomy is an effective treatment modality for these tumours. After surgery, the results of the pathology and the follow-up of serum PSA may indicate the need of additional adjuvant or salvage treatment strategies.