Pathological and oncological features of Korean prostate cancer patients eligible for active surveillance: analysis from the K-CaP registry

Has Active Surveillance for Prostate Cancer Become Safer? Lessons Learned from a Global Clinical Registry

BACKGROUND AND OBJECTIVE

Active surveillance (AS) has evolved into a widely applied treatment strategy for many men around the world with low-risk prostate cancer (or in selected cases intermediate-risk disease). Here, we report on the safety and acceptability of AS, and treatment outcomes for low- and intermediate-risk tumours over time in 14 623 men with follow-up of over 6 yr.

METHODS

Clinical data from 26 999 men on AS from 25 cohorts in 15 countries have been collected in an international database from 2000 onwards.

KEY FINDINGS AND LIMITATIONS

Across our predefined four time periods of 4 yr each (covering the period 2000-2016), there was no significant change in overall survival (OS). However, metastasis-free survival (MFS) rates have improved since the second period and were excellent (>99%). Treatment-free survival rates for earlier periods showed a slightly more rapid shift to radical treatment. Over time, there was a constant proportion of 5% of men for whom anxiety was registered as the reason for treatment alteration. There was, however, also a subset of 10-15% in whom treatment was changed, for which no apparent reason was available. In a subset of men (10-15%), tumour progression was the trigger for treatment. In men who opted for radical treatment, surgery was the most common treatment modality. In those men who underwent radical treatment, 90% were free from biochemical recurrence at 5 yr after treatment.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Our study confirms that AS was a safe management option over the full duration in this large multicentre cohort with long-term follow-up, given the 84.1% OS and 99.4% MFS at 10 yr. The probability of treatment at 10 yr was 20% in men with initial low-risk tumours and 31% in men with intermediate-risk tumours. New diagnostic modalities may improve the acceptability of follow-up using individual risk assessments, while safely broadening the use of AS in higher-risk tumours.

PATIENT SUMMARY

Active surveillance (AS) has evolved into a widely applied treatment strategy for many men with prostate cancer around the world. In this report, we show the long-term safety of following AS for men with low- and intermediate-risk prostate cancer. Our study confirms AS as a safe management option for low- and intermediate-risk prostate cancer. New diagnostic modalities may improve the acceptability of follow-up using individual risk assessments, while safely broadening the use of AS in higher-risk tumours.

Comparison of the clinicopathologic features of prostate cancer in US and Chinese populations

BACKGROUND

Prostate cancer (PCa) is the most common malignant tumor found among men in the United States. Incidence rates of PCa have recently grown in Asian countries, partially due to the comprehensive implementation of early detection systems. Interestingly, a prospective cohort study showed that adopting a westernized dietary pattern was associated with a higher risk of being diagnosed with PCa among Korean and Japanese men. However, a comparison of current clinicopathological features of PCa between American and Chinese men is lacking. In this study, we report the current clinicopathological features of PCa in Chinese men and compare them to those of patients in the USA.

MATERIALS AND METHODS

Case cohorts included, in total, 871 PCa cases with prostatectomy sequentially treated since 2017, including 299 cases from USA and 572 cases from two different academic hospitals in China. The parameters, including patient's age, preoperative Prostate-Specific Antigen (PSA) level, Gleason score, Grade Group, stage and tumor focality, were collected, analyzed and compared using two sample t-test, Wilcoxon rank sum test, Pearson's Chi-squared test and Fisher's exact test.

RESULTS

Significant differences were demonstrated in the mean age of patients, preoperative PSA levels, extra-prostatic extension, Gleason scores, and Grade Groups (p < 0.05). PCa patients in the Chinese group were older than patients in the USA group (67.81 vs. 63.53, p < 0.01). The preoperative PSA levels in the Chinese group were higher than those in the USA group (11.69 v.s 6.30, p < 0.01). A higher percentage of high Grade Groups (Groups 4 and 5) was observed in the Chinese group (25.7%) compared to the USA cohort (17.11%), while Grade Group 2 was more common in the USA group than in the Chinese group (51.68% vs. 32.52%, p < 0.01).

CONCLUSIONS

All these data suggest that the clinicopathologic features of PCa are different between the USA and Chinese populations, which may be influenced by treatment strategies (including surgical case selection criteria).

The clinical impact of strict criteria for active surveillance of prostate cancer in Korean population: Results from a prospective cohort

Purpose

To evaluate the clinical impact of strict selection criteria for active surveillance (AS) of prostate cancer in a Korean population.

Materials and Methods

A single-center, prospectively collected AS cohort from December 2016 to February 2019 was used. Following pre-determined criteria, patients were categorized into “strict AS” and “non-strict AS” groups. Clinicopathological progression-free survival (PFS) and treatment-free survival (TFS) of the two groups were compared using the Kaplan–Meier curve and log-rank test. Age-adjusted hazard ratios for clinicopathological progression was calculated using Cox proportional regression analysis.

Results

Of 54 eligible patients, 25 and 29 were assigned to “strict AS” and “non-strict AS,” respectively. Clinicopathological progression and definitive treatment rates were 24.0% (6 of 25 patients) vs. 51.7% (15 of 29 patients) and 32.0% (8 of 25 patients) vs. 62.1% (18 of 29 patients) in “strict AS” and “non-strict AS” groups. Progress to high-risk cancer (pathologic T3 or surgical Gleason Grade 2 over) in radical prostatectomy was higher in “non-strict AS” than “strict AS”. PFS (mean 34.6±2.9 mo vs. 22.6±2.7 mo; p=0.025) and TFS (mean 31.8±3.2 mo vs. 19.6±2.4 mo; p=0.018) favor the “strict AS” group than “non-strict AS” group. Age-adjusted hazard ratio for clinicopathological progression of strict criteria was 0.36 (95% confidence interval, 0.14–0.94; p=0.04).

Conclusions

PFS and TFS were better in the “strict AS” group than in the “non-strict AS” group. This finding should be informed to relevant patients during decision making and considered in Korean guidelines.

A single-center long-term experience of active surveillance for prostate cancer: 15 years of follow-up

Purpose

To describe a single-center 15-year experience of active surveillance (AS) for prostate cancer (PCa).

Materials and Methods

We retrospectively reviewed patients who underwent AS between 2003 and 2018. One hundred fifty-three patients were selected according to the following criteria: (1) biopsy Gleason pattern ≤3+4 with (2) ≤two positive core(s) and (3) ≤50% core involvement, clinical-stage ≤T2a, and prostate-specific antigen (PSA) ≤20 ng/mL. Follow-up included PSA measurement every six months, prostate biopsies at one year and then every 2–3 years, and MRI every year. Intervention was triggered by (1) Gleason score (GS) upgrading, (2) >two positive cores, or (3) PSA doubling-time in <3 years.

Results

Mean (±standard deviation) follow-up was 36.4 (±31.9) months. Ninety-three (60.8%) and 20 (13.1%) patients received second and third biopsies, respectively. Seventy-two patients (47.1%) discontinued AS for various reasons (59, intervention; 13, follow-up loss). Reasons for intervention consisted of GS upgrading (42.4%), >two positive cores (8.5%), abnormal PSA kinetics (11.9%), and patient preference (37.3%). Notably, 12 (25.5%) patients had pathologic GS ≥4+3 (unfavorable disease) and 3 (6.4%) patients had pathologic stage ≥T3a at radical prostatectomy. Median time to treatment-free survival was 19.5 months. Of the 59 patients who switched to intervention, biochemical recurrence was reported in only one (0.7%) patient.

Conclusions

AS is an available option for low-risk PCa in carefully selected patients. Further larger prospective studies are needed to determine the optimal criteria for AS, especially in Korean PCa patients.

Urethral realignment with maximal urethral length and bladder neck preservation in robot-assisted radical prostatectomy: Urinary continence recovery

Purpose

To evaluate early recovery of urinary continence after robot-assisted radical prostatectomy (RARP) with urethral realignment using bladder neck preservation (BNP) and maximal urethral length preservation (MULP).

Methods

Patients who underwent RARP between 2014 and 2017 owing to prostate cancer with a Gleason score ≤ 7 (3+4), ≤ cT2c stage, and prostate-specific antigen level < 20 ng/ml were investigated. Patients with tumors of the bladder neck or apex on magnetic resonance imaging were excluded. A total of 266 patients underwent the operation using the standard method between 2014 and 2015 (group 1), while 305 patients underwent urethral realignment between 2016 and 2017 (group 2). Continence was defined as wearing no pad or one security pad.

Results

The continence rates immediately after Foley catheter removal, at 2 weeks, and at 1, 3, 6, and 12 months after operation in group 2 were 46.9%, 63.0%, 73.4%, 90.1%, 94.8%, and 98.7%, respectively. The continence rate at 1 month in group 2 was significantly higher than that in group 1 (65.4% versus 73.4%, p = 0.037). The multivariate regression analysis showed that age and surgical method were factors affecting early continence recovery. The positive surgical margin rates were 18.0% and 14.8% in groups 1 and 2, respectively (p = 0.288). Biochemical recurrence occurred in 14.7% and 8.2% in groups 1 and 2, respectively (p = 0.015).

Conclusion

Urethral realignment using BNP and MULP resulted in rapid continence recovery and good oncological results after RARP in young patients with a Gleason score ≤ 7 and organ-confined disease.

Effects of age and comorbidity on survival vary according to risk grouping among patients with prostate cancer treated using radical prostatectomy: A retrospective competing-risk analysis from the K-CaP registry

A multicenter Korean Prostate Cancer Database (K-CaP) has been established to provide information regarding Korean patients with prostate cancer (PCa). We used the K-CaP registry to investigate the value of age and comorbidity for predicting cancer-specific mortality (CSM) and other-cause mortality (OCM) according to risk grouping.The K-CaP registry includes 2253 patients who underwent radical prostatectomy (RP) between May 2001 and April 2013 at 5 institutions. Preoperative clinicopathologic data were collected and stratified according to the National Comprehensive Cancer Network risk criteria. Survival was evaluated using Gray's modified log-rank test according to risk category, age (<70 years vs ≥70 years), and Charlson comorbidity index (CCI) (0 vs ≥1).The median follow-up was 55.0 months (interquartile range: 42.0-70.0 months). Competing-risk regression analysis revealed that, independent of CCI, ≥70-year-old high-risk patients had significantly greater CSM than <70-year-old high-risk patients (P = .019). However, <70-year-old high-risk patients with a CCI of ≥1 had similar CSM relative to ≥70-year-old patients. Survival was not affected by age or CCI among low-risk or intermediate-risk patients. Multivariate analysis revealed that a CCI of ≥1 was independently associated with a higher risk of CSM (P = .003), while an age of ≥70 years was independently associated with a higher risk of OCM (P = .005).Age and comorbidity were associated with survival after RP among patients with high-risk PCa, although these associations were not observed among low-risk or intermediate-risk patients. Therefore, older patients with high-risk diseases and greater comorbidity may require alternative multidisciplinary treatment.

Current status and progress of focal therapy in Asia

PURPOSE OF REVIEW

With the increasing incidence of low-to-intermediate risk of prostate cancer (PCa) by the introduction of prostate-specific antigen (PSA) screening, focal therapy has become one of the promising treatment options in the world. In Asia, same movement are occurring using several technologies including cryoablation, high-intensity focused ultrasound, brachytherapy and irreversible electroporation. However, these are still not common strategies to treat organ-confined PCa. The purpose of this review is to summarize the most updated experience and future direction of focal therapy in Asian countries.

RECENT FINDINGS

The prevalence and diagnosis of PCa are increasing in Asian countries. This increase is related to various factors including the widespread implementation of PSA testing and lifestyle changes to more Westernized diets. With the increasing detection rate of early stage PCa, overdetection and overtreatment are recognized even in Asia. In this setting, accumulating data on multiparametric MRI and MRI-targeted biopsy as well as MRI-transrectal ultrasound (TRUS) fusion biopsy suggest the potential in improving the detection of clinically significant PCa in Asia. Furthermore, targeted focal therapy has emerged as a promising treatment strategy aiming for both providing oncological outcome and maintaining functional preservation in many Asian countries.

SUMMARY

At present, focal therapy is not a current standard choice for the treatment of localized PCa in Asian countries. However, with the increase of localized PCa and patient's preference for less invasive treatment with preservation of organ-function, focal therapy should become a definite treatment option for localized PCa in Asia.