Short-term versus long-term hormone therapy plus radiotherapy or prostatectomy for prostate cancer: a systematic review and meta-analysis

PURPOSE

To compare the efficacy and safety of short-term versus long-term hormonotherapy (HT) plus radiotherapy (RT) or prostatectomy (RP) for prostate cancer.

METHODS

Literatures were searched from Embase, PubMed, Web of science and Cochrane Library up to October, 2012. Quality of the study was evaluated according to the Cochrane's risk of bias of randomized controlled trial (RCT); the Grading of Recommendations Assessment, Development and Evaluation System was used to rate the level of evidence. RevMan 5.1 was used for statistical analysis. Two comparisons were of interest: RT plus short-term HT versus RT plus long-term HT and RP plus short-term HT versus RP plus long-term HT. Pooled risk ratio or standardized mean differences were calculated; HT adverse reactions were descriptively evaluated.

RESULTS

Nine RCTs (total 4,743 patients) were included, 7 RCTs compared RT plus short-term HT with RT plus long-term HT, 2 RCTs compared RP plus short-term HT with RP plus long-term HT. Meta-analysis showed there was no significant difference in overall survival, disease-free survival and PSA level before RP; long-term was superior to short-term hormonotherapy in biochemical failure rate, clinical progression rate, prostate cancer-specific mortality, positive surgical margin rate and prostate volume before RP. Systematic review demonstrated adverse events caused by the increased length of HT were more common.

CONCLUSIONS

Long-term HT plus RT showed a trend toward improved overall survival; long-term HT plus RP declined positive surgical margin rate and prostate volume before RP. So, long-term HT may benefit more, but it did not significantly improve the patients' overall survival, and the adverse reactions are inevitable.

Therapeutic targeting of the prostate cancer microenvironment

Solid tumors can be thought of as multicellular 'organs' that consist of a variety of cells as well as a scaffold of noncellular matrix. Stromal-epithelial crosstalk is integral to prostate cancer progression and metastasis, and androgen signaling is an important component of this crosstalk at both the primary and metastatic sites. Intratumoral production of androgen is an important mechanism of castration resistance and has been the focus of novel therapeutic approaches with promising results. Various other pathways are important for stromal-epithelial crosstalk and represent attractive candidate therapeutic targets. Hedgehog signaling has been associated with tumor progression, growth and survival, while Src family kinases have been implicated in tumor progression and in regulation of cancer cell migration. Fibroblast growth factors and transforming growth factor beta signaling regulate cell proliferation, apoptosis and angiogenesis in the prostate cancer microenvironment. Integrins mediate communication between the cell and the extracellular matrix, enhancing growth, migration, invasion and metastasis of cancer cells. The contribution of stromal-epithelial crosstalk to prostate cancer initiation and progression provides the impetus for combinatorial microenvironment-targeting strategies.

Long-term results after high-dose radiotherapy and adjuvant hormones in prostate cancer: how curable is high-risk disease?

PURPOSE

To analyze long-term outcome and prognostic factors for high-risk prostate cancer defined by National Comprehensive Cancer Network criteria treated with high-dose radiotherapy and androgen deprivation in a single institution.

METHODS AND MATERIALS

A total of 306 patients treated between 1995 and 2007 in a radiation dose-escalation program fulfilled the National Comprehensive Cancer Network high-risk criteria. Median International Commission on Radiation Units and Measurements radiation dose was 78 Gy (range, 66.0-84.1 Gy). Long-term androgen deprivation (LTAD) was administered in 231 patients, short-term androgen deprivation (STAD) in 59 patients, and no hormones in 16 patients. The Phoenix (nadir plus 2 ng/mL) consensus definition was used for biochemical control. Multivariate analysis was performed to determine the independent prognostic impact of clinical and treatment factors. Median follow-up time was 64 months (range, 24-171 months).

RESULTS

The actuarial overall survival at 5 and 10 years was 95.7% and 89.8%, respectively, and the corresponding biochemical disease-free survival (bDFS) was 89.5% and 67.2%, respectively. Fourteen patients (4.6%) developed distant metastasis. Multivariate analysis showed that Gleason score>7 (p=0.001), pretreatment prostate-specific antigen (PSA) level>20 ng/mL (p=0.037), higher radiation dose (p=0.005), and the use of adjuvant LTAD vs. STAD (p=0.011) were independent prognostic factors affecting bDFS in high-risk disease. The 5-year bDFS for patients treated with LTAD plus radiotherapy dose>78 Gy was 97%.

CONCLUSIONS

For high-risk patients the present series showed that the use of LTAD in conjunction with higher doses (>78 Gy) of radiotherapy was associated with improved biochemical tumor control. We observed that the presence of Gleason sum>7 and pretreatment PSA level>20 ng/mL in the same patient represents a 6.8 times higher risk of PSA failure. These men could be considered for clinical trials with addition of novel agents.