High-dose rate brachytherapy as monotherapy in prostate cancer: A systematic review of its safety and efficacy. / Braquiterapia de alta tasa de dosis como monoterapia en cáncer de próstata: una revisión sistemática sobre eficacia y seguridad.

CONTEXT: High-dose rate brachytherapy (HDR-BT) is an increasingly popular treatment for patients with localised prostate cancer (PC). OBJECTIVE: To assess the safety and efficacy of HDR-BT as monotherapy in PC. ACQUISITION OF EVIDENCE: A systematic literature review was conducted through searches on MEDLINE (PubMed), Cochrane Library, CDR, ClinicalTrials and EuroScan. We assessed safety and efficacy indicators. SUMMARY OF THE EVIDENCE: We selected 2 reviews and 12 uncontrolled studies, included in these 2 reviews. In terms of efficacy, local control in 6 studies was 97-100%. The biochemical progression-free survival varied as follows: 85-100% for low risk and 79-92% for high risk. Survival free of metastases was >95% at 8 years, except in one study where the survival rate was 87% at 5 years. The overall survival was ≥95% in 8 studies. In terms of safety, most of the studies recorded acute and long-term genitourinary and gastrointestinal complications, especially grade ≥2. Only 3 studies found grade 4 complications. All studies, except for one without complications, observed genitourinary complications that were more frequent and severe than the gastrointestinal complications. Two studies assessed the quality of life and showed an initial reduction in various domains and subsequent partial or total recovery, except in the sexual domain. CONCLUSIONS: HDR-BT is effective as monotherapy, especially in cases of low to intermediate risk. There is insufficient information on high-risk patients. The short to medium-term toxicity was acceptable. Further research needs to be funded to provide more information on the long-term safety and efficacy of this treatment.

Association between single-nucleotide polymorphisms in DNA double-strand break repair genes and prostate cancer aggressiveness in the Spanish population.

BACKGROUND: Novel predictors of prognosis and treatment response for prostate cancer (PCa) are required to better individualize treatment. Single-nucleotide polymorphisms (SNPs) in four genes directly (XRCC5 (X-ray repair complementing defective repair in Chinese hamster cells 5) and XRCC6 (X-ray repair complementing defective repair in Chinese hamster cells 6)) or indirectly (PARP1 and major vault protein (MVP)) involved in non-homologous end joining were examined in 494 Spanish PCa patients. METHODS: A total of 22 SNPs were genotyped in a Biotrove OpenArray NT Cycler. Clinical tumor stage, diagnostic PSA serum levels and Gleason score at diagnosis were obtained for all participants. Genotypic and allelic frequencies were determined using the web-based environment SNPator. RESULTS: (XRCC6) rs2267437 appeared as a risk factor for developing more aggressive PCa tumors. Those patients carrying the GG genotype were at higher risk of developing bigger tumors (odds ratio (OR)=2.04, 95% confidence interval (CI) 1.26-3.29, P=0.004), present higher diagnostic PSA levels (OR=2.12, 95% CI 1.19-3.78, P=0.011), higher Gleason score (OR=1.65, 95% CI 1.01-2.68, P=0.044) and D'Amico higher risk tumors (OR=2.38, 95% CI 1.24-4.58, P=0.009) than those patients carrying the CC/CG genotypes. Those patients carrying the (MVP) rs3815824 TT genotype were at higher risk of presenting higher diagnostic PSA levels (OR=4.74, 95% CI 1.40-16.07, P=0.013) than those patients carrying the CC genotype. When both SNPs were analyzed in combination, those patients carrying the risk genotypes were at higher risk of developing D'Amico higher risk tumors (OR=3.33, 95% CI 1.56-7.17, P=0.002). CONCLUSIONS: We believe that for the first time, genetic variants at XRCC6 and MVP genes are associated with risk of more aggressive disease, and would be taken into account when assessing the malignancy of PCa.

Hypofractionated radiation therapy versus conventional radiation therapy in prostate cancer: A systematic review of its safety and efficacy.

CONTEXT: New therapeutic alternatives can improve the safety and efficacy of prostate cancer treatment. OBJECTIVES: To assess whether hypofractionated radiation therapy results in better safety and efficacy in the treatment of prostate cancer. ACQUISITION OF EVIDENCE: Systematic review of the literature through searches on PubMed, Cochrane Library, CRD, ClinicalTrials and EuroScan, collecting indicators of safety and efficacy. SYNTHESIS OF THE EVIDENCE: We included 2 systematic reviews and a clinical trial. In terms of efficacy, there is considerable heterogeneity among the studies, and no conclusive results were found concerning the superiority of the hypofractionated option over the normal fractionated option. In terms of safety, there were no significant differences in the onset of acute genitourinary complications between the 2 treatments. However, one of the reviews found more acute gastrointestinal complications in patients treated with hypofractionated radiation therapy. There were no significant differences in long-term complications based on the type of radiation therapy used, although the studies did have limitations. CONCLUSIONS: To date, there are no conclusive results that show that hypofractionated radiation therapy is more effective or safer than normal fractionated radiation therapy in the treatment of localized prostate cancer.