Pathologic characteristics of prostatic adenocarcinomas: a mapping analysis of Korean patients

Outcomes of partial gland ablation using high intensity focused ultrasound for prostate cancer

BACKGROUND

To evaluate the clinical and oncological outcomes of partial gland ablation (PGA) using high intensity focused ultrasound (HIFU) technique for the clinically unilateral prostate cancer.

METHODS

We performed a retrospective analysis for the 163 patients who treated by PGA for clinically unilateral prostate cancer. The PGA was performed using Focal one system with concurrent trans-urethral prostatectomy. The oncological and functional outcomes were evaluated as well as risk factors for remnant disease after PGA. Clinically significant cancer was defined as grade group ≥2.

RESULTS

Among the entire subjects, grade group 2 or greater was present at pre-treatment biopsy in 76.7%. Median follow-up time was 17 months and 60.1% of total subjects had follow-up biopsy at postoperative 1 year. There were 25 subjects (24.2%) with any cancer and 13 subjects (12.6%) with CS cancer at the follow-up biopsy. The preoperative age and number of positive cores at preoperative biopsy were significantly associated with positive results at follow-up biopsy. Incontinence which requires 2 or more pads per day was observed at 4 subjects (2.5%) postoperatively. There were no subjects who needed intensive care or experienced rectal complications.

CONCLUSION

The PGA with HIFU was safe and showed good preservation of functional outcomes as well as satisfactory oncological control. The remnant disease was observed in the 24.5% of patients who underwent follow-up biopsy in the present study. Thus, further prospective study is needed to evaluate oncological and functional outcomes of PGA with HIFU more accurately.

Machine learning classifiers can predict Gleason pattern 4 prostate cancer with greater accuracy than experienced radiologists

OBJECTIVE

The purpose of this study was: To test whether machine learning classifiers for transition zone (TZ) and peripheral zone (PZ) can correctly classify prostate tumors into those with/without a Gleason 4 component, and to compare the performance of the best performing classifiers against the opinion of three board-certified radiologists.

METHODS

A retrospective analysis of prospectively acquired data was performed at a single center between 2012 and 2015. Inclusion criteria were (i) 3-T mp-MRI compliant with international guidelines, (ii) Likert ≥ 3/5 lesion, (iii) transperineal template ± targeted index lesion biopsy confirming cancer ≥ Gleason 3 + 3. Index lesions from 164 men were analyzed (119 PZ, 45 TZ). Quantitative MRI and clinical features were used and zone-specific machine learning classifiers were constructed. Models were validated using a fivefold cross-validation and a temporally separated patient cohort. Classifier performance was compared against the opinion of three board-certified radiologists.

RESULTS

The best PZ classifier trained with prostate-specific antigen density, apparent diffusion coefficient (ADC), and maximum enhancement (ME) on DCE-MRI obtained a ROC area under the curve (AUC) of 0.83 following fivefold cross-validation. Diagnostic sensitivity at 50% threshold of specificity was higher for the best PZ model (0.93) when compared with the mean sensitivity of the three radiologists (0.72). The best TZ model used ADC and ME to obtain an AUC of 0.75 following fivefold cross-validation. This achieved higher diagnostic sensitivity at 50% threshold of specificity (0.88) than the mean sensitivity of the three radiologists (0.82).

CONCLUSIONS

Machine learning classifiers predict Gleason pattern 4 in prostate tumors better than radiologists.

KEY POINTS

• Predictive models developed from quantitative multiparametric magnetic resonance imaging regarding the characterization of prostate cancer grade should be zone-specific. • Classifiers trained differently for peripheral and transition zone can predict a Gleason 4 component with a higher performance than the subjective opinion of experienced radiologists. • Classifiers would be particularly useful in the context of active surveillance, whereby decisions regarding whether to biopsy are necessitated.

Prostate focal therapy: the rule or exception?

PURPOSE OF REVIEW

Prostate focal therapy has the potential to preserve urinary and sexual function while eliminating clinically significant cancer in a subset of men with low-volume, organ-confined prostate cancer. This systematic review aims to examine current evidence to determine the efficacy and safety of focal therapy for standard clinical application.

RECENT FINDINGS

Focal therapy reduces the rate of cancer progression and conversion to radical therapy in men on active surveillance for prostate cancer. As a strategy, success in focal therapy is heavily dependent on the use of imaging and targeted biopsies. Despite advances in these areas, there remains a small but significant risk of under-detecting clinically significant cancer. Similarly, under-estimation of tumor volume may contribute to infield recurrences and close attention must be paid to the ablation margin. Although long-term oncological outcomes remain lacking, focal therapy has a low complication rate, minimal impact on urinary continence and a moderate impact on erectile function.

SUMMARY

With the appropriate expertise in imaging, targeted biopsy and targeted ablation, focal therapy is a good option in men with low-intermediate risk cancer who are willing to maximize their urinary and sexual function. However, close posttreatment surveillance and the possibility of conversion to whole gland therapy must be accepted.

Single nucleotide polymorphisms in DKK3 gene are associated with prostate cancer risk and progression

We had investigated whether sequence variants within DKK3 gene are associated with the development of prostate cancer in a Korean study cohort. We evaluated the association between 53 single nucleotide polymorphisms (SNPs) in the DKK3 gene and prostate cancer risk as well as clinical characteristics (PSA, clinical stage, pathological stage and Gleason score) in Korean men (272 prostate cancer subjects and 173 benign prostate hyperplasia subjects) using unconditional logistic regression analysis. Of the 53 SNPs and 25 common haplotypes, 5 SNPs and 4 haplotypes were associated with prostate cancer risk (P=0.02-0.04); 3 SNPs and 2 haplotypes were significantly associated with susceptibility to prostate cancer, however 2 SNPs and 2 haplotypes exhibited a significant protective effect on prostate cancer. Logistic analyses of the DKK3 gene polymorphisms with several prostate cancer related factors showed that several SNPs were significant; three SNPs and two haplotypes to PSA level, three SNPs and two haplotypes to clinical stage, nine SNPs and two haplotype to pathological stage, one SNP and one haplotypes to Gleason score. To the author's knowledge, this is the first report documenting that DKK3 polymorphisms are not only associated with prostate cancer but also related to prostate cancer-related factors.

Multiple cores of high grade prostatic intraepithelial neoplasia and any core of atypia on first biopsy are significant predictor for cancer detection at a repeat biopsy

Purpose

To investigate the differences in the cancer detection rate and pathological findings on a second prostate biopsy according to benign diagnosis, high-grade prostatic intraepithelial neoplasia (HGPIN), and atypical small acinar proliferation (ASAP) on first biopsy.

Materials and Methods

We retrospectively reviewed the records of 1,323 patients who underwent a second prostate biopsy between March 1995 and November 2012. We divided the patients into three groups according to the pathologic findings on the first biopsy (benign diagnosis, HGPIN, and ASAP). We compared the cancer detection rate and Gleason scores on second biopsy and the unfavorable disease rate after radical prostatectomy among the three groups.

Results

A total of 214 patients (16.2%) were diagnosed with prostate cancer on a second biopsy. The rate of cancer detection was 14.6% in the benign diagnosis group, 22.1% in the HGPIN group, and 32.1% in the ASAP group, respectively (p<0.001). When patients were divided into subgroups according to the number of positive cores, the rate of cancer detection was 16.7%, 30.5%, 31.0%, and 36.4% in patients with a single core of HGPIN, more than one core of HGPIN, a single core of ASAP, and more than one core of ASAP, respectively. There were no significant differences in Gleason scores on second biopsy (p=0.324) or in the unfavorable disease rate after radical prostatectomy among the three groups (benign diagnosis vs. HGPIN, p=0.857, and benign diagnosis vs. ASAP, p=0.957, respectively).

Conclusions

Patients with multiple cores of HGPIN or any core number of ASAP on a first biopsy had a significantly higher cancer detection rate on a second biopsy. Repeat biopsy should be considered and not be delayed in those patients.

Differences in the aggressiveness of prostate cancer among Korean, Caucasian, and African American men: A retrospective cohort study of radical prostatectomy

PURPOSE

We aimed to compare the pathologic aggressiveness of clinically localized prostate cancer (PCa) treated by radical prostatectomy in Korean and Western (Caucasian and African American [AA]) men by analyzing data from representative hospitals in the capitals of Korea (Seoul) and the United States (Washington, DC).

METHODS

We performed a retrospective cohort study of 1,939 patients who underwent radical prostatectomy for clinically localized PCa in the Asan Medical Center and Washington Hospital Center. After adjusting for confounding clinical variables, we used multivariate logistic regression analysis to assess differences in the aggressiveness of PCa.

RESULTS

We analyzed 1,152 Korean, 473 Caucasian, and 314 AA patients. There were significant differences between Korean and Western patients in terms of age at surgery, preoperative levels of prostate-specific antigen, and clinical stage (P<0.001). Overall, high-grade PCa (Gleason score≥8) was more common in Korean (19.4%) than in AA (6.1%) or Caucasian (5.5%) patients (P<0.001). The incidence of advanced-stage PCa (pT3 or higher) was higher in Korean (34.8%) than in AA (18.2%) or Caucasian (13.3%) patients (P<0.001). After adjusting for age, prostate-specific antigen, prostate volume, and clinical stage, multivariate logistic regression analysis showed that Korean men had a high risk of high-grade PCa (Korean vs. Caucasian, odds ratio [OR] = 3.48, P<0.001; Korean vs. AA, OR=3.14, P<0.001) or advanced-stage PCa (Korean vs. Caucasian, OR=2.40, P<0.001; Korean vs. AA, OR = 1.59, P = 0.009) than Western men.

CONCLUSIONS

There are differences in PCa aggressiveness between Korean and Western men. The incidence of high-grade or advanced-stage PCa is higher in Korean men.

The association of 5-alpha reductase type 2 (SRD5A2) gene polymorphisms with prostate cancer in a Korean population

Purpose

Steroid 5-alpha reductase type 2 (SRD5A2) modifies testosterone to dihydrotestosterone (DHT) in the prostate. Single-nucleotide polymorphisms (SNPs) of the SRD5A2 gene might affect DHT. We sought to understand the relationship of SRD5A2 SNPs to prostate cancer in the Korean population.

Materials and Methods

Twenty-six common SNPs in the SRD5A2 gene were assessed in 272 prostate cancer cases and 173 controls. Single-locus analyses were conducted by using conditional logistic regression. Additionally, we performed a haplotype analysis for the SRD5A2 SNPs tested.

Results

Among the 20 SNPs and 4 haplotypes, there were no statistically significant results in the prostate cancer patients and the controls. In the logistic analysis of SRD5A2 polymorphisms with prostate-specific antigen (PSA) criteria, two SNPs (rs508562, rs11675297) and haplotype 1 displayed significant results (odds ratio [OR], 1.76; p=0.05; OR, 1.88-2.02; p=0.01-0.04; OR, 0.59; p=0.02, respectively). rs508562, rs11675297, rs2208532, and haplotype 1 (OR, 1.49; p=0.05; OR, 2.02; p=0.05; OR, 2.01; p=0.04; OR, 0.56-0.64, p=0.03-0.04, respectively) had significant associations with Gleason score. rs508562, rs11675297, and haplotype 1 (OR, 1.41-2.34; p=0.004-0.05; OR, 1.74-1.82; p=0.03-0.05; OR, 0.42-0.67; p=0.0005-0.03, respectively) were significantly associated with clinical stage.

Conclusions

We conclude that there was no significant association between SRD5A2 SNPs and the risk of prostate cancer in the Korean population. However, we found that some SNPs and 1 haplotype influenced PSA level, Gleason score, and clinical stage.

The association between KL polymorphism and prostate cancer risk in Korean patients

The Klotho (KL) gene is a classical "aging suppressor" gene. Although recent studies have shown that KL participates in the progression of several types of human cancers, the relationship between KL polymorphism and prostate cancer was unknown. The present study aimed to investigate the association between KL genetic polymorphisms and prostate cancer. Twenty-five common single nucleotide polymorphisms (SNPs) in KL gene (including KL gene polymorphism C1818T in exon 4) were assessed in 272 prostate cancer cases and 173 controls. Single-locus analyses were conducted using unconditional logistic regression. In addition, we did a haplotype analysis for the 25 KL SNPs tested. CC genotype of C1548T KL polymorphism had approximately twofold increased prostate cancer risk compared with the homozygous genotype TT and heterozygote CT (odds ratio 1.85 [95% CI, 1.09-3.12], P = 0.02). We also found that non-T allele carriers had significantly higher prostate cancer risk associated with the prostate cancer clinical characteristics (tumor stage or Gleason score). Our findings suggested that the C1548T polymorphism of KL gene is associated with the prostate cancer and may act as a risk factor for the development of prostate cancer.

Genetic variations in VDR associated with prostate cancer risk and progression in a Korean population

Low levels of vitamin D are implicated as a potential risk factor for prostate cancer, and the vitamin D receptor (VDR) gene may be important in the onset and progression of prostate cancer. In this study, sequence variants in the VDR gene were investigated in a Korean study cohort to determine whether they are associated with prostate cancer risk. We evaluated the association between 47 single nucleotide polymorphisms (SNPs) in the VDR gene and prostate cancer risk as well as clinical characteristics (prostate-specific antigen level, clinical stage, pathological stage and Gleason score) in Korean men (272 prostate cancer patients and 173 benign prostatic hyperplasia patient who underwent a prostate biopsy, which was negative for malignancy) using unconditional logistic regression. The statistical analysis suggested that two VDR sequence variants (rs2408876 and rs2239182) had a significant association with prostate cancer risk (odds ratio [OR]. 1.41; p=0.03; OR, 0.73; p=0.05, respectively). Logistic analyses of the VDR polymorphisms with several prostate cancer related factors showed that several SNPs were significant; nine SNPs to PSA level, three to clinical stage, two to pathological stage, and three SNPs to the Gleason score. The results suggest that some VDR gene polymorphisms in Korean men might not only be associated with prostate cancer risk but also significantly related to prostate cancer-related risk factors such as PSA level, tumor stage, and Gleason score. However, current limitation for small cohort with not-healthy control group might have false positive effects; therefore it should be overcome via further large-scale validating studies.

Prostate MRI: who, when, and how? Report from a UK consensus meeting

The current pathway for men suspected of having prostate cancer [transrectal biopsy, followed in some cases by magnetic resonance imaging (MRI) for staging] results in over-diagnosis of insignificant tumours, and systematically misses disease in the anterior prostate. Multiparametric MRI has the potential to change this pathway, and if performed before biopsy, might enable the exclusion of significant disease in some men without biopsy, targeted biopsy in others, and improvements in the performance of active surveillance. For the potential benefits to be realized, the setting of standards is vital. This article summarizes the outcome of a meeting of UK radiologists, at which a consensus was achieved on (1) the indications for MRI, (2) the conduct of the scan, (3) a method and template for reporting, and (4) minimum standards for radiologists.

Variants in the HEPSIN gene are associated with susceptibility to prostate cancer

BACKGROUND

HEPSIN (HPN) gene is one of the most consistently overexpressed genes in patients with prostate cancer; furthermore, there is some evidence supporting an association between HPN gene variants and the risk of developing prostate cancer. In this study, sequence variants in the HPN gene were investigated to determine whether they were associated with prostate cancer risk in a Korean study cohort.

METHODS

We evaluated the association of 17 single-nucleotide polymorphisms (SNPs) in the HPN gene with prostate cancer risk and clinical characteristics (Gleason score and tumor stage) in Korean men (240 case subjects and 223 control subjects) using unconditional logistic regression.

RESULTS

The statistical analysis suggested that three SNPs (rs45512696, rs2305745, rs2305747) were significantly associated with the risk of prostate cancer (odds ratio (OR)=2.22, P=0.04; OR=0.73, P=0.03; OR=0.76, P=0.05, respectively).

CONCLUSIONS

The results of this study suggest that, in Korean men, some polymorphisms in the HPN gene might be associated with the risk of developing prostate cancer.

HNF1B polymorphism associated with development of prostate cancer in Korean patients

OBJECTIVE

To identify whether the genetic variations in HNF1B are associated with the development of prostate cancer in Korean patients. Genome-wide association studies have found the HNF1B gene at 17q12 to be a major causal gene for the risk of prostate cancer.

METHODS

We evaluated the association of 47 single nucleotide polymorphisms (SNPs) in the HNF1B gene with prostate cancer risk and clinical characteristics (Gleason score and tumor stage) in Korean men (240 case subjects and 223 control subjects) using unconditional logistic regression analysis.

RESULTS

Of the 47 SNPs, 14 were associated with prostate cancer risk (P = .002-.02); 9 SNPs were associated with a lower risk of prostate cancer (odds ratio 0.67-0.71, P = .005-.05), and 5 SNPs were associated with a greater risk of disease (odds ratio 1.49-1.51, P = .002-.02). In an analysis involving only patients with prostate cancer, 1 SNP (rs11868513) in the HNF1B gene was more frequent in patients with tumors with a greater stage than in those with a lower tumor stage. Two SNPs (rs4430796 and rs2074429) and 1 haplotype (Block3_ht1) were more frequent in patients with Gleason score of ≥7 than in those with Gleason score <6.

CONCLUSION

As in studies from other populations, our findings indicate that HNF1B is also associated with prostate cancer risk in the Korean population.

Inflammation-related signaling pathways implicating TGFβ are revealed in the expression profiling of MCF7 cell treated with fermented soybean, chungkookjang

Chungkookjang is a Korean fermented soybean containing microorganisms, proteinase, and diverse bioactive compounds, including a high concentration of isoflavones and peptides. Growth of breast cancer MCF7 cells decreased dependent on the concentration of fermented soybean extracts. The effect of fermented soybean on cellular gene expression was determined in a systematic manner comprehensively. DNA microarray analysis was performed using 25,804 probes. Ninety one genes whose expression levels were significantly changed were selected. TGFβI and Smad3 were upregulated. Downregulation of inflammation-related CSF2, CSF2RA, and CSF3 was found. Differential expression of chemokines CCL2, CCL3, CCL3L3, CXCL1, and CXCL2 were observed. Network analysis identified ERβ in the network. Based on the experimental results, taking fermented soybean might be helpful for preventing breast cancer by a mechanism activating TGFβ pathway and depressing inflammation.

Preoperative prediction of multifocal prostate cancer and application of focal therapy: review 2007

Prostate cancer is a leading malignancy among men. Early prostate cancer is most commonly treated with radical surgery and radiotherapy. In the era of prostate-specific antigen and newly emerging highly specific screening tests, a greater number of men are given a diagnosis earlier in life, and disease is more often confined. Less-invasive treatments, such as focal therapy, are becoming increasingly popular, yielding shorter hospital stays, faster recovery, and fewer complications. Potential drawbacks to focal therapy include the risk of incomplete treatment, which may result from missed cancer foci and inadequate ablation to target tissues. Furthermore, this approach is not universally applicable to all patients--for example, those who have periurethral and extraprostatic extension of the tumor may not benefit from focal treatment. This article reviews the importance of multifocal prostate cancer and the application of focal treatment.

Rising prostate cancer rates in South Korea

BACKGROUND

Prostate cancer incidence and mortality rates in South Korea are relatively low, but rising steadily.

METHODS

We examined age-standardized incidence and mortality trends of prostate cancer in South Korea to gain further insight into prostate cancer etiology.

RESULTS

Although prostate cancer incidence has been low (7.9 per 100,000 man-years), it has increased up to 28.2% between 1996-1998 and 1999-2001. Prostate cancer mortality increased 12.7-fold over a 20-year period. Despite the increase in prostate cancer incidence and mortality rates, marked differences in rates remain for Koreans, Korean Americans, and Caucasian Americans.

CONCLUSIONS

The rising rates of prostate cancer in South Korea cannot be attributed entirely to PSA screening due to the low PSA screening prevalence; this trend is most likely related to increased westernization among Koreans. Interdisciplinary epidemiological studies incorporating the collection of biological samples are needed to clarify the extent to which lifestyle and genetic factors contribute to the observed racial disparity.