Clinical and pathological features of screen vs non-screen-detected prostate cancers: is there a difference?

Prostate-specific antigen screening impacts on biochemical recurrence in patients with clinically localized prostate cancer

OBJECTIVE

To clarify the impact of prostate-specific antigen screening on surgical outcomes of prostate cancer.

METHODS

Patients who underwent radical prostatectomy were divided into two groups according to prostate-specific antigen testing opportunity (group 1, prostate-specific antigen screening; group 2, non-prostate-specific antigen screening). Perioperative clinical characteristics were compared using the Wilcoxon rank-sum and χ² -tests. Cox proportional hazards models were used to identify independent predictors of postoperative biochemical recurrence-free survival.

RESULTS

In total, 798 patients (63.2%) and 464 patients (36.8%) were categorized into groups 1 and 2, respectively. Group 2 patients were more likely to have a higher prostate-specific antigen level and age at diagnosis and larger prostate volume. Clinical T stage, percentage of positive cores and pathological Gleason score did not differ between the groups. The 5-year biochemical recurrence-free survival rate was 83.9% for group 1 and 71.0% for group 2 (P < 0.001). On multivariate analysis, prostate-specific antigen testing opportunity (hazard ratio 2.530; P < 0.001) was an independent predictive factor for biochemical recurrence after surgery, as well as pathological T stage, pathological Gleason score, positive surgical margin and lymphovascular invasion. Additional analyses showed that prostate-specific antigen screening had a greater impact on biochemical recurrence in a younger patients, patients with a high prostate-specific antigen level, large prostate volume and D'Amico high risk, and patients meeting the exclusion criteria of the Prostate Cancer Research International Active Surveillance study.

CONCLUSIONS

Detection by screening results in favorable outcomes after surgery. Prostate-specific antigen screening might contribute to reducing biochemical recurrence in patients with localized prostate cancer.

Prostate cancer outcomes for men who present with symptoms at diagnosis

OBJECTIVE

To compare clinical features, treatments and outcomes in men with non-metastatic prostate cancer (PCa) according to whether they were referred for symptoms or elevated prostate-specific antigen (PSA) level.

PATIENTS AND METHODS

This study used data from the South Australia Prostate Cancer Clinical Outcomes Collaborative database; a multi-institutional clinical registry covering both the public and private sectors. We included all non-metastatic cases from 1998 to 2013 referred for urinary/prostatic symptoms or elevated PSA level. Multivariate Poisson regression was used to identify characteristics associated with symptomatic presentation and compare treatments according to reason for referral. Outcomes (i.e. overall survival, PCa-specific survival, metastasis-free survival and disease-free survival) were compared using multivariate Cox proportional hazards and competing risk regression.

RESULTS

Our analytical cohort consisted of 4 841 men with localized PCa. Symptomatic men had lower-risk disease (incidence ratio [IR] 0.70, 95% confidence interval [CI] 0.61-0.81 for high vs low risk), fewer radical prostatectomies (IR 0.64, CI: 0.56-0.75) and less radiotherapy (IR 0.86, CI: 0.77-0.96) than men presenting with elevated PSA level. All-cause mortality (hazard ratio [HR] 1.31, CI: 1.16-1.47), disease-specific mortality (HR 1.42, CI: 1.13-1.77) and risk of metastases (HR 1.36, CI: 1.13-1.64) were higher for men presenting with symptoms, after adjustment for other clinical characteristics; however, risk of disease progression did not differ (HR 0.90, CI: 0.74-1.07) amongst those treated curatively. Subgroup analyses indicated poorer PCa survival for symptomatic referral among men undergoing radical prostatectomy (HR 3.4, CI: 1.3-8.8), those aged >70 years (HR 1.4, CI: 1.0-1.8), men receiving private treatment (HR 2.1, CI: 1.3-3.3), those diagnosed via biopsy (HR 1.3, CI: 1.0-1.7) and those diagnosed before 2006 (HR 1.6, CI: 1.2-2.7).

CONCLUSION

Our results suggest that symptomatic presentation may be an independent negative prognostic indicator for PCa survival. More complete assessment of disease grade and extent, more definitive treatment and increased post-treatment monitoring among symptomatic cases may improve outcomes. Further research to determine any pathophysiological basis for poor outcomes in symptomatic men is warranted.

Patient-reported urinary incontinence and erectile dysfunction following radical prostatectomy: results from the European Prostate Centre Innsbruck

INTRODUCTION

Urinary and erectile functions were assessed by using self-administered validated questionnaires in patients undergoing radical prostatectomy.

MATERIALS AND METHODS

In a prospective observational study, a total of 253 consecutive patients diagnosed with clinically localised prostate cancer between 2008 and 2009 at the European Prostate Centre Innsbruck were included. Patient-reported outcomes were assessed before radical prostatectomy and 12 months postoperatively using the validated International Consultation on Incontinence Questionnaire (ICIQ) and the International Index of Erectile Function (IIEF). The Wilcoxon signed-rank test and Chi square statistics were used for analysis.

RESULTS

The study showed that before radical prostatectomy, urinary incontinence of various severity grades was reported in 18.8, postoperatively in 63.0% (p < 0.001) and erectile dysfunction of various degrees was reported in 39.6 at baseline compared to 80.1% 12 months postoperatively (p < 0.001).

CONCLUSIONS

This study suggests that radical prostatectomy is associated with a significantly increased risk of urinary incontinence and erectile dysfunction 12 months postoperatively.

Quantifying and monitoring overdiagnosis in cancer screening: a systematic review of methods

OBJECTIVE

To determine the optimal method for quantifying and monitoring overdiagnosis in cancer screening over time.

DESIGN

Systematic review of primary research studies of any design that quantified overdiagnosis from screening for nine types of cancer. We used explicit criteria to critically appraise individual studies and assess strength of the body of evidence for each study design (double blinded review), and assessed the potential for each study design to accurately quantify and monitor overdiagnosis over time.

DATA SOURCES

PubMed and Embase up to 28 February 2014; hand searching of systematic reviews.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

English language studies of any design that quantified overdiagnosis for any of nine common cancers (prostate, breast, lung, colorectal, melanoma, bladder, renal, thyroid, and uterine); excluded case series, case reports, and reviews that only reported results of other studies.

RESULTS

52 studies met the inclusion criteria. We grouped studies into four methodological categories: (1) follow-up of a well designed randomized controlled trial (n=3), which has low risk of bias but may not be generalizable and is not suitable for monitoring; (2) pathological or imaging studies (n=8), drawing conclusions about overdiagnosis by examining biological characteristics of cancers, a simple design limited by the uncertain assumption that the measured characteristics are highly correlated with disease progression; (3) modeling studies (n=21), which can be done in a shorter time frame but require complex mathematical equations simulating the natural course of screen detected cancer, the fundamental unknown question; and (4) ecological and cohort studies (n=20), which are suitable for monitoring over time but are limited by a lack of agreed standards, by variable data quality, by inadequate follow-up time, and by the potential for population level confounders. Some ecological and cohort studies, however, have addressed these potential weaknesses in reasonable ways.

CONCLUSIONS

Well conducted ecological and cohort studies in multiple settings are the most appropriate approach for quantifying and monitoring overdiagnosis in cancer screening programs. To support this work, we need internationally agreed standards for ecological and cohort studies and a multinational team of unbiased researchers to perform ongoing analysis.

Use of screening tests, diagnosis wait times, and wait-related satisfaction in breast and prostate cancer

BACKGROUND

Understanding factors relating to the perception of wait time by patients is key to improving the patient experience.

METHODS

We surveyed 122 breast and 90 prostate cancer patients presenting at clinics or listed on the cancer registry in Newfoundland and Labrador and reviewed their charts. We compared the wait time (first visit to diagnosis) and the wait-related satisfaction for breast and prostate cancer patients who received regular screening tests and whose cancer was screening test-detected ("screen/screen"); who received regular screening tests and whose cancer was symptomatic ("screen/symptomatic"); who did not receive regular screening tests and whose cancer was screen test-detected ("no screen/screen"); and who did not receive regular screening tests and whose cancer was symptomatic ("no screen/symptomatic").

RESULTS

Although there were no group differences with respect to having a long wait (greater than the median of 47.5 days) for breast cancer patients (47.8% screen/screen, 54.7% screen/symptomatic, 50.0% no screen/ screen, 40.0% no screen/symptomatic; p = 0.814), a smaller proportion of the screen/symptomatic patients were satisfied with their wait (72.5% screen/ screen, 56.4% screen/symptomatic, 100% no screen/ screen, 90.9% no screen/symptomatic; p = 0.048). A larger proportion of screen/symptomatic prostate cancer patients had long waits (>104.5 days: 41.3% screen/screen, 92.0% screen/symptomatic, 46.0% no screen/screen, 40.0% no screen/symptomatic; p = 0.011) and a smaller proportion of screen/ symptomatic patients were satisfied with their wait (71.2% screen/screen, 30.8% screen/symptomatic, 76.9% no screen/screen, 90.9% no screen/symptomatic; p = 0.008).

CONCLUSIONS

Diagnosis-related wait times and satisfaction were poorest among patients who received regular screening tests but whose cancer was not detected by those tests.

Overdiagnosis and overtreatment of prostate cancer

CONTEXT

Although prostate cancer (PCa) screening reduces the incidence of advanced disease and mortality, trade-offs include overdiagnosis and resultant overtreatment.

OBJECTIVE

To review primary data on PCa overdiagnosis and overtreatment.

EVIDENCE ACQUISITION

Electronic searches were conducted in Cochrane Central Register of Controlled Trials, PubMed, and Embase from inception to July 2013 for original articles on PCa overdiagnosis and overtreatment. Supplemental articles were identified through hand searches.

EVIDENCE SYNTHESIS

The lead-time and excess-incidence approaches are the main ways used to estimate overdiagnosis in epidemiological studies, with estimates varying widely. The estimated number of PCa cases needed to be diagnosed to save a life has ranged from 48 down to 5 with increasing follow-up. In clinical studies, generally lower rates of overdiagnosis have been reported based on the frequency of low-grade minimal tumors at radical prostatectomy (1.7-46.8%). Autopsy studies have reported PCa in 18.5-38.5%, although not all are low grade or low volume. Factors influencing overdiagnosis include the study population, screening protocol, and background incidence, limiting generalizability between settings. Reported rates of overtreatment vary widely in the literature, although contemporary international studies suggest increasing use of conservative management.

CONCLUSIONS

Epidemiological, clinical, and autopsy studies have been used to examine PCa overdiagnosis, with estimates ranging widely from 1.7% to 67%. Correspondingly, estimates of overtreatment vary widely based on patient features and may be declining internationally. Careful patient selection for screening and reducing overtreatment are important to preserve the benefits and reduce the downstream harms of prostate-specific antigen testing. Because all of these estimates are extremely population and context specific, this must be considered when using these data to inform policy.

PATIENT SUMMARY

Screening reduces spread and death from prostate cancer (PCa) but overdiagnoses some low-risk tumors that may not have caused harm. Because treatment has potential side effects, it is critical that not all patients with PCa receive aggressive treatment.

Historical prostate cancer screening and treatment outcomes from a single institution

OBJECTIVE

To quantify outcomes of individuals diagnosed and treated for prostate cancer in a single institution.

DESIGN

Retrospective electronic chart abstraction.

SETTING

Marshfield Clinic, the largest private multispecialty group practice in Wisconsin, and one of the largest in the United States, provides health care services annually to approximately 385,000 unique patients through 1.8 million annual patient encounters.

PARTICIPANTS

Individuals within the Marshfield Clinic cancer registry who had been diagnosed with prostate cancer between 1960 and 2009.

METHODS

Electronic chart abstraction from the cancer registry and the electronic medical record was conducted (N=6,181). Data abstracted included age at diagnosis; stage and grade of tumor; prostate specific antigen (PSA) values before, at, and after diagnosis; initial cancer treatment; follow-up time; subsequent cancer treatments; evidence of metastasis; age of death; and cause of death, if known.

RESULTS

The average age of prostate cancer diagnosis has decreased from 70-71 years in the 1960's and 1970's to an average age at diagnosis of 67 years in the 2000's (P<0.001). This decrease in age occurred within the decades of implementation of PSA screening. Approximately 74% of men diagnosed with prostate cancer within the PSA screening era had at least one PSA test, and the presence of a PSA test did not appear to change treatment outcome. Age, grade, and stage were the biggest predictors of prostate cancer outcome. There was no difference in event-free survival between current treatment types (radical prostatectomy, brachytherapy, photon treatment, or intensity-modulated radiation therapy) (2003 or later) when stratified by age (greater than 85%, 5-year event-free survival P=0.85); however, more events occurred with older external beam radiation treatment regimens (1993-2003) (70% to 75%, 5-year event-free survival P=0.001).

CONCLUSION

Individuals diagnosed and treated for prostate cancer within the Marshfield Clinic comprehensive care setting follow national trends with a decreased age of diagnosis since the advent of PSA screening. Outcomes for individuals treated within the Clinic system are also comparable to national trends.

Margin status after laparoscopic radical prostatectomy and the index lesion: implications for preoperative evaluation of tumor focality in prostate cancer

PURPOSE

The objective of this study was to evaluate the impact of tumor focality on positive surgical margins (PSM) after laparoscopic radical prostatectomy.

PATIENTS AND METHODS

Ninety-five consecutive whole-mount laparoscopic radical prostatectomy samples (January 2007 to November 2009) were evaluated for tumor focality, laterality, Gleason score, and volume of individual foci, total tumor volume, pathologic stage, and surgical margin status.

RESULTS

Thirty-nine percent, 36%, and 25% were in low, intermediate, and high D'Amico risk categories. Thirty-three percent (31/95) had PSM. Overall, 269 tumor foci were identified. The incidence of PSM within lesions ≤ 0.5 cc and ≤ 0.2 cc was 1.2% (2/160) and 0% (0/132), respectively. Among the 71 multifocal cases, 19 (27%) exhibited PSM. In 13 of these, the index lesion appeared at the inked surface (mean volume 5.4 cc, range 0.63-26.9 cc) compared with 6 in which both index and satellite foci appeared at the inked margins. Mean volume of these satellite foci was 1.06 cc (range 0.22-2 cc); three had Gleason score 6 and three had Gleason score 7 (3+4).

CONCLUSIONS

PSM is usually attributed to the index lesion and lesions larger than commonly used thresholds for clinically significant lesion volumes. Because such lesions might be detected by multiparametric magnetic resonance imaging (MRI) or template mapping biopsies, the information from these staging modalities could be used intraoperatively to reduce PSM.

Measurements of cancer extent in a conservatively treated prostate cancer biopsy cohort

The optimal method for measuring cancer extent in prostate biopsy specimens is unknown. Seven hundred forty-four patients diagnosed between 1990 and 1996 with prostate cancer and managed conservatively were identified. The clinical end point was death from prostate cancer. The extent of cancer was measured in terms of number of cancer cores (NCC), percentage of cores with cancer (PCC), total length of cancer (LCC) and percentage length of cancer in the cores (PLC). These were correlated with prostate cancer mortality, in univariate and multivariate analysis including Gleason score and prostate-specific antigen (PSA). All extent of cancer variables were significant predictors of prostate cancer death on univariate analysis: NCC, hazard ration (HR) = 1.15, 95% confidence interval (CI) = 1.04-1.28, P = 0.011; PPC, HR = 1.01, 95% CI = 1.01-1.02, P < 0.0001; LCC, HR = 1.02, 95% CI = 1.01-1.03, P = 0.002; PLC, HR = 1.01, 95% CI = 1.01-1.02, P = 0.0001. In multivariate analysis including Gleason score and baseline PSA, PCC and PLC were both independently significant P = 0.004 and P = 0.012, respectively, and added further information to that provided by PSA and Gleason score, whereas NNC and LCC were no longer significant (P = 0.5 and P = 0.3 respectively). In a final model, including both extent of cancer variables, PCC was the stronger, adding more value than PLC (χ² (1df) = 7.8, P = 0.005, χ² (1df) = 0.5, P = 0.48 respectively). Measurements of disease burden in needle biopsy specimens are significant predictors of prostate-cancer-related death. The percentage of positive cores appeared the strongest predictor and was stronger than percentage length of cancer in the cores.