Clinical role of pathological downgrading after radical prostatectomy in patients with biopsy confirmed Gleason score 3 + 4 prostate cancer

OBJECTIVE

To identify preoperative factors predicting Gleason score downgrading after radical prostatectomy (RP) in patients with biopsy Gleason score 3+4 prostate cancer and to determine if prediction of downgrading can identify potential candidates for active surveillance (AS).

PATIENTS AND METHODS

We identified 1317 patients with biopsy Gleason score 3+4 prostate cancers who underwent RP at the Memorial Sloan-Kettering Cancer Center between 2005 and 2013. Several preoperative and biopsy characteristics were evaluated by forward selection regression, and selected predictors of downgrading were analysed by multivariable logistic regression. Decision curve analysis was used to evaluate the clinical utility of the multivariate model.

RESULTS

Gleason score was downgraded after RP in 115 patients (9%). We developed a multivariable model using age, prostate-specific antigen density, percentage of positive cores with Gleason pattern 4 cancer out of all cores taken, and maximum percentage of cancer involvement within a positive core with Gleason pattern 4 cancer. The area under the curve for this model was 0.75 after 10-fold cross validation. However, decision curve analysis revealed that the model was not clinically helpful in identifying patients who will downgrade at RP for the purpose of reassigning them to AS.

CONCLUSION

While patients with pathological Gleason score 3 + 3 with tertiary Gleason pattern ≤4 at RP in patients with biopsy Gleason score 3 + 4 prostate cancer may be potential candidates for AS, decision curve analysis showed limited utility of our model to identify such men. Future study is needed to identify new predictors to help identify potential candidates for AS among patients with biopsy confirmed Gleason score 3 + 4 prostate cancer.

Prevalence of inflammation and benign prostatic hyperplasia on autopsy in Asian and Caucasian men

Inflammation has been suggested to be involved in the pathogenesis of benign prostatic hyperplasia (BPH). We studied the prevalence of inflammation and BPH in Asian and Caucasian men on prostate glands (n=320) obtained during autopsy in Moscow, Russia (Caucasian men, n=220), and Tokyo, Japan (Asian men, n=100). We correlated the presence and grade of acute inflammation (AI) or chronic inflammation (CI) and BPH. AI, CI, and histologic BPH were analyzed in a blinded fashion using a grading system (0-3). We used the Cochran-Armitage test for associations between the degree of BPH and clinical variables and proportional odds logistic regression models in multivariable analysis. Histologic BPH was observed in a similar proportion of Asian and Caucasian men (p=0.94). CI was found in>70% of men in both the Asian and Caucasian groups (p>0.05). Higher BPH scores were associated with more CI (p<0.001). In multivariate analyses, individuals with CI were 6.8 times more likely to have a higher BPH score than individuals without (p<0.0001). Men included in this study presented at the hospital and their symptomatic status was not known. The prevalence of CI and BPH on autopsy is similar in Asian and Caucasian men despite very different diet and lifestyle. CI is strongly associated in both groups with BPH.

PATIENT SUMMARY

In this study, we looked at the prevalence of inflammation and benign prostatic hyperplasia (BPH) on autopsy in Asian and Caucasian men. We found chronic inflammation in>70% of men on autopsy. More chronic inflammation was associated with more BPH.

Management of low risk prostate cancer-active surveillance and focal therapy

Low-risk prostate cancer, defined as Gleason Score 6 or less with PSA <10 ng/ml, is diagnosed in about half of men undergoing screening. Approximately 30% of men diagnosed with low-risk disease harbour high-grade cancer that is unrepresented on the biopsy. Moreover, a small percentage of low-grade cancers have molecular alterations that result in progression to aggressive disease. Favourable-risk prostate cancer should be managed with close follow up. Active surveillance is appropriate for most patients with low-risk disease, and radical treatment should be reserved for cases in which higher-risk disease is identified. In turn, focal therapy aims to preserve tissue and function in men who have been diagnosed with localized disease, and should be offered to men with higher risk disease at baseline, as an alternative to whole-gland radiation or surgery, or when the patient transitions from low-risk to higher-risk disease. The two strategies should be viewed as complementary elements of care that can be applied in a risk-stratified manner. In this Review, we discuss the rationale and current status of active surveillance-which constitutes a standard of care in most evidence-based guidelines-and comment on whether and when focal therapy should complement it in those men wishing to continue a tissue-preserving strategy.

Estimating age and ethnic variation in the histological prevalence of prostate cancer to inform the impact of screening policies

OBJECTIVES

To estimate histological prevalence of prostate cancer by age and ethnic group.

METHODS

A literature review identified autopsy studies of men without clinical diagnosis of prostate cancer during their lifetime. A total of 25 studies fulfilled the inclusion criteria, and a Bayesian logistic meta-regression was carried out to examine the association between histological prevalence, age by decade and ethnic group (white, African American and Chinese/Japanese).

RESULTS

Histological cancer was estimated to increase with age from 2% (95% confidence interval 1-3%) between 20-29 years-of-age to 69% (95% confidence interval 51-83%) by 90-99 years-of-age in the white ethnic group. The African American group was associated with the highest prevalence of cancer, albeit non-significantly (odds ratio 1.2, 95% confidence interval 0.9-1.5), whereas the Chinese/Japanese group was significantly associated with the lowest prevalence relative to the white group (odds ratio 0.6, 95% confidence interval 0.4-0.9).

CONCLUSIONS

The present study provides an updated and improved analysis of the histological prevalence of prostate cancer. The results confirm ethnicity as a potential predictor of prevalence, but highlight the need for further research in the area. The findings are valuable for understanding the epidemiology and natural history of prostate cancer across ethnicities, and increasing the body of evidence aimed at estimating benefits and risks associated with prostate cancer screening programs.

Prostate cancer risk profiles of Asian-American men: disentangling the effects of immigration status and race/ethnicity

PURPOSE

Asian-American men with prostate cancer have been reported to present with higher grade and later stage disease than white American men. However, Asian-American men comprise a heterogeneous population with distinct health outcomes. We compared prostate cancer risk profiles among the diverse racial and ethnic groups in California.

MATERIALS AND METHODS

We used data from the California Cancer Registry on 90,845 nonHispanic white, nonHispanic black and Asian-American men diagnosed with prostate cancer between 2004 and 2010. Patients were categorized into low, intermediate and high risk groups based on clinical stage, Gleason score and prostate specific antigen at diagnosis. Using polytomous logistic regression we estimated adjusted ORs for the association of race/ethnicity and nativity with risk group.

RESULTS

In addition to the nonHispanic black population, 6 Asian-American groups (United States born Chinese, foreign born Chinese, United States born Japanese, foreign born Japanese, foreign born Filipino and foreign born Vietnamese) were more likely to have an unfavorable risk profile compared to nonHispanic white men. The OR for high vs intermediate risk disease ranged from 1.23 (95% CI 1.02-1.49) for United States born Japanese men to 1.45 (95% CI 1.31-1.60) for foreign born Filipino men. These associations appeared to be driven by higher grade and prostate specific antigen rather than by advanced clinical stage at diagnosis.

CONCLUSIONS

In this large, ethnically diverse, population based cohort Asian-American men were more likely to have an unfavorable risk profile at diagnosis. This association varied by racial/ethnic group and nativity, and was not attributable to later stage at diagnosis. This suggests that Asian men may have biological differences that predispose to more severe disease.

Multifocal epithelial tumors and field cancerization: stroma as a primary determinant

It is increasingly evident that cancer results from altered organ homeostasis rather than from deregulated control of single cells or groups of cells. This applies especially to epithelial cancer, the most common form of human solid tumors and a major cause of cancer lethality. In the vast majority of cases, in situ epithelial cancer lesions do not progress into malignancy, even if they harbor many of the genetic changes found in invasive and metastatic tumors. While changes in tumor stroma are frequently viewed as secondary to changes in the epithelium, recent evidence indicates that they can play a primary role in both cancer progression and initiation. These processes may explain the phenomenon of field cancerization, i.e., the occurrence of multifocal and recurrent epithelial tumors that are preceded by and associated with widespread changes of surrounding tissue or organ "fields."

Evaluation of D'Amico criteria for low-risk prostate cancer

OBJECTIVE

The aim of the study was to identify the risk of unfavourable disease (≥ pT3 and/or Gleason score ≥ 7) in radical prostatectomy (RP) specimens and biochemical progression-free survival (BPFS) after RP in patients with low-risk prostate cancer detected by D'Amico criteria before surgery.

MATERIAL AND METHODS

Between 2004 and 2007, 690 men underwent prostate biopsy and RP at a single university hospital. Of those, 248 patients (35.9%) had low-risk prostate cancer criteria. The endpoints of the study were detection of low-risk (pT2 and Gleason score ≤ 6) or unfavourable (≥ pT3 and/or Gleason score ≥ 7) prostate cancer, and BPFS. The risk of progression was analysed using multivariate Cox regression model and BPFS was established using Kaplan-Meier analysis.

RESULTS

The median follow-up was 60 months (1-112 months). pT3 was detected in 14.1%, and Gleason score ≥ 7 in 32.7% of patients. Unfavourable prostate cancer was detected in 37.5% of patients. Overall biochemical relapse rate was 13.6%. The estimated probability of 3-, 5- and 8-year BPFS for all study patients was 90.6%, 88.1% and 77.9%, respectively. Eight-year BPFS was 83.3% for low-risk prostate cancer and 68.2% for unfavourable prostate cancer (p = 0.007). Positive surgical margins (p = 0.0001) and postoperative Gleason score (p = 0.023) were the most significant predictors of biochemical relapse in Cox regression analysis.

CONCLUSIONS

The D'Amico criteria may underestimate potentially aggressive prostate cancer in up to 37.5% of patients. Consequently, caution is recommended when the decision concerning the treatment modality is based on D'Amico criteria alone.

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.

Management of prostate cancer in Asia: resource-stratified guidelines from the Asian Oncology Summit 2013

Many local and systemic options for prostate cancer have emerged in recent years, but existing management guidelines do not account for diversity in health resources between different countries. We present recommendations for the management of prostate cancer, stratified according to the extent of resource availability-based on a four-tier system of basic, limited, enhanced, and maximum resources-to enable applicability to Asian countries with differing levels of health-care resources. This statement of recommendations was formulated by a multidisciplinary panel from Asia-Pacific countries, at a consensus session on prostate cancer that was held as part of the 2013 Asian Oncology Summit in Bangkok, Thailand.

Childhood height and birth weight in relation to future prostate cancer risk: a cohort study based on the copenhagen school health records register

BACKGROUND

Adult height has been positively associated with prostate cancer risk. However, the exposure window of importance is currently unknown and assessments of height during earlier growth periods are scarce. In addition, the association between birth weight and prostate cancer remains undetermined. We assessed these relationships in a cohort of the Copenhagen School Health Records Register (CSHRR).

METHODS

The CSHRR comprises 372,636 school children. For boys born between the 1930s and 1969, birth weight and annual childhood heights-measured between ages 7 and 13 years-were analyzed in relation to prostate cancer risk. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI).

RESULTS

There were 125,211 males for analysis, 2,987 of who were subsequently diagnosed with prostate cancer during 2.57 million person-years of follow-up. Height z-score was significantly associated with prostate cancer risk at all ages (HRs, 1.13 to 1.14). Height at age 13 years was more important than height change (P = 0.024) and height at age 7 years (P = 0.024), when estimates from mutually adjusted models were compared. Adjustment of birth weight did not alter the estimates. Birth weight was not associated with prostate cancer risk.

CONCLUSIONS

The association between childhood height and prostate cancer risk was driven by height at age 13 years.

IMPACT

Our findings implicate late childhood, adolescence, and adulthood growth periods as containing the exposure window(s) of interest that underlies the association between height and prostate cancer. The causal factor may not be singular given the complexity of both human growth and carcinogenesis.