Fifteen-year survival outcomes following primary androgen-deprivation therapy for localized prostate cancer

Disparities in Treatment of Patients With High-risk Prostate Cancer: Results From a Population-based Cohort

OBJECTIVE

To assess the variation in primary treatment of high-risk prostate cancer (PCa) by different hospital characteristics in the United States.

MATERIALS AND METHODS

We used the National Cancer Data Base to identify patients diagnosed with pretreatment high-risk PCa from 2004 to 2011. The primary outcomes were different forms of primary therapy or watchful waiting (WW) across different types of hospitals (community, comprehensive cancer community, and academic hospitals). Multivariable logistic regression analyses were used to test for differences in treatment by hospital type.

RESULTS

During the study period, we identified 102,701 men diagnosed with high-risk PCa. Overall, the most common treatment was radical prostatectomy (37.0%) followed by radiation therapy (33.2%) and WW (8.5%). Compared with white men with high-risk PCa, black men had lower adjusted odds ratios (OR) for surgery at comprehensive community (OR: 0.64; P <.001) and academic (OR: 0.62; P <.001) hospitals. Similarly, black men were also more likely to be managed with WW at community (OR: 1.49; P <.001), comprehensive cancer community (OR: 1.24; P <.001), and academic (OR: 1.55; P <.001) hospitals, as well as with radiation therapy at comprehensive cancer community (OR: 1.27; P <.001) and academic hospitals (OR: 1.23; P <.001).

CONCLUSION

Disparities in the use of WW and different primary treatments among patients with high-risk PCa persisted across different types of hospitals and over time. Our findings highlight a significant racial disparity in the use of curative therapy for high-risk PCa that should be urgently addressed to ensure that all men with PCa receive appropriate care across all racial groups and cancer care facilities.

The comparative oncologic effectiveness of available management strategies for clinically localized prostate cancer

The primary goal of modern prostate cancer treatment paradigms is to optimize the balance of predicted benefits associated with prostate cancer treatment against the predicted harms of therapy. However, given the limitations in the existing evidence as well as the significant tradeoffs posed by each treatment, there remain myriad challenges associated with individualized prostate cancer treatment decision-making. In this review, we summarize the existing comparative effectiveness evidence of treatments for localized prostate cancer with an emphasis on oncologic control. While we focus on the major treatment categories of radical prostatectomy, radiation therapy, and observation, we also provide a review of emerging therapies such as cryotherapy and high-intensity frequency ultrasound (HIFU).

[Cardiovascular risks of androgen deprivation therapy for prostate cancer]

Androgen deprivation therapy (ADT) is the standard treatment for metastatic prostate cancer. It has increasingly been used in other stages of the disease as well. Besides well-known side effects caused by the lack of testosterone (impotency, osteoporosis, fatigue, loss of muscle mass), an increase of cardiovascular (CV) morbidity and mortality has recently been discussed in association with ADT. Cardiovascular side effects cannot be sufficiently explained by low testosterone levels. This review gives an overview of the recent literature, interprets the results, and offers clinical consequences.

The Quantitative Criteria Based on the Fractal Dimensions, Entropy, and Lacunarity for the Spatial Distribution of Cancer Cell Nuclei Enable Identification of Low or High Aggressive Prostate Carcinomas

Background: Tumor grading, PSA concentration, and stage determine a risk of prostate cancer patients with accuracy of about 70%. An approach based on the fractal geometrical model was proposed to eliminate subjectivity from the evaluation of tumor aggressiveness and to improve the prediction. This study was undertaken to validate classes of equivalence for the spatial distribution of cancer cell nuclei in a larger, independent set of prostate carcinomas.

Methods: The global fractal capacity D₀, information D₁ and correlation D₂ dimension, the local fractal dimension (LFD) and the local connected fractal dimension (LCFD), Shannon entropy H and lacunarity λ were measured using computer algorithms in digitalized images of both the reference set (n = 60) and the test set (n = 208) of prostate carcinomas.

Results: Prostate carcinomas were re-stratified into seven classes of equivalence. The cut-off D₀-values 1.5450, 1.5820, 1.6270, 1.6490, 1.6980, 1.7640 defined the classes from C1 to C7, respectively. The other measures but the D₁ failed to define the same classes of equivalence. The pairs (D₀, LFD), (D₀, H), (D₀, λ), (D₁, LFD), (D₁, H), (D₁, λ) characterized the spatial distribution of cancer cell nuclei in each class. The co-application of those measures enabled the subordination of prostate carcinomas to one out of three clusters associated with different tumor aggressiveness. For D₀ < 1.5820, LFD < 1.3, LCFD > 1.5, H < 0.7, and λ > 0.8, the class C1 or C2 contains low complexity low aggressive carcinomas exclusively. For D₀ > 1.6980, LFD > 1.7644, LCFD > 1.7051, H > 0.9, and λ < 0.7, the class C6 or C7 contains high complexity high aggressive carcinomas.

Conclusions: The cut-off D₀-values defining the classes of equivalence were validated in this study. The cluster analysis suggested that the number of the subjective Gleason grades and the number of the objective classes of equivalence could be decreased from seven to three without a loss of clinically relevant information. Two novel quantitative criteria based on the complexity and the diversity measures enabled the identification of low or high aggressive prostate carcinomas and should be verified in the future multicenter, randomized studies.

Relationship between androgen deprivation therapy and community-acquired respiratory infections in patients with prostate cancer

OBJECTIVES

To investigate the dose-dependent effect of androgen deprivation therapy on community-acquired respiratory infections in patients with localized prostate cancer.

METHODS

We identified 52 905 men diagnosed with localized prostate cancer within the Surveillance, Epidemiology and End Results-Medicare database between 1991 and 2006. We compared those who did not receive androgen deprivation therapy with those who received androgen deprivation therapy within 2 years of diagnosis, calculated as monthly equivalent doses (<7, 7-11, >11 doses), or orchiectomy. Adjusted Cox hazard models were fitted to predict the risk of community-acquired respiratory infections (acute sinusitis, acute bronchitis, [severe] pneumonia) in patients treated with medical androgen deprivation therapy versus orchiectomy versus none.

RESULTS

Overall, 43.4% received medical androgen deprivation therapy. These patients more likely experienced respiratory events compared with those who did not receive androgen deprivation therapy or who underwent orchiectomy (62.2% vs 54.5% vs 47.8%, P < 0.001). The risk of experiencing any respiratory event increased with the number of doses received. For example, men receiving >11 doses of androgen deprivation therapy were at greatest risk of acute sinusitis, acute bronchitis and pneumonia (HR 1.13, 1.26 and 1.15, respectively, all P < 0.001), except severe pneumonia. Furthermore, we did not detect any relationship between orchiectomy and respiratory events. Study limitations include the utilization of a retrospective population-based dataset.

CONCLUSIONS

Increased exposure to medical androgen deprivation therapy for men with localized prostate cancer is associated with a higher risk of community-acquired respiratory infections. Our results suggest that respiratory complications represent potentially underreported complications of medical androgen deprivation therapy.

Degarelix therapy for prostate cancer in a real-world setting: experience from the German IQUO (Association for Uro-Oncological Quality Assurance) Firmagon® registry

Background

We investigated the use of the gonadotropin-releasing hormone (GnRH) antagonist degarelix in everyday clinical practice using registry data from uro-oncology practices in Germany.

Methods

Data were analysed retrospectively from the IQUO (Association for uro-oncological quality assurance) patient registry. Data were prospectively collected from all consecutive PCa patients treated with degarelix (n = 1010) in 138 uro-oncology practices in Germany between May 2009 and December 2013.

Results

Median overall survival had not yet been reached in the all-patient group or in subgroups who had or had not received prior hormonal therapy (HT). Cox regression analysis showed that patients who had received prior HT (n = 542) had a 58 % increased mortality risk (hazard ratio 1.58, 95 % CI 1.20–2.09) versus patients who had not (n = 468) (p = 0.001). Also, in patients who had received prior luteinizing hormone-releasing hormone (LHRH) analogue therapy (LHRH agonists or GnRH antagonists), median time to PSA progression was shorter (209 weeks) than in those who had not received prior LHRH analogues (n = 555; median PSA progression-free survival not yet reached). Degarelix was generally well tolerated.

Conclusions

Degarelix was effective and well tolerated in everyday clinical practice, confirming observations from clinical studies. Patients who received prior HT appeared to have a significantly higher mortality risk.

Survival after initiation of androgen deprivation therapy for prostate cancer of Australian men

OBJECTIVE

To examine duration of use and survival rates of Australian males who initiated androgen deprivation therapy for prostate cancer, including survival rates stratified by the type of the initial androgen deprivation therapy and age at initiation.

METHOD

Cohort study using Australian Government Department of Veterans' Affairs (DVA) data. Males aged 50 and over initiating androgen deprivation therapy (2008-2010) were included in the cohort. Time to death or end of study (31 Dec 2012), duration of therapy and 1 to 5-year relative survival rates stratified by type of initial therapy and age were presented.

RESULTS

Of the androgen deprivation therapy initiators (n=3,611, mean age 84), 92% survived 1 year with the relative survival rate decreasing to 79% at 3 years and to 57% at 5 years. Survival outcomes stratified by the type of initial therapy showed slightly higher rates amongst those initiated on gonadotropin releasing hormone analogues or on combined androgen blockage compared to those initiated on anti-androgens. Age specific rates were similar amongst the younger groups (under 80 years old) at each single point of time and were slightly higher than in those aged 80 years and over for some points of time. Fifty percent of patients received androgen deprivation therapy for extended periods (30 months).

CONCLUSIONS

The 1-year relative survival of veterans was high and similar to that of the general Australian population with prostate cancer. Factors such as tumour stage and grade (not available in the data) could explain differences in survival based on the type of the initial therapy.

Primary radiotherapy vs conservative management for localized prostate cancer--a population-based study

BACKGROUND

Radiotherapy is the most common curative cancer therapy used for elderly patients with localized prostate cancer. However, the effectiveness of this approach has not been established. The purpose of this study is to evaluate the long-term outcomes of primary radiotherapy compared with conservative management in order to facilitate treatment decisions.

METHOD

This population-based study consisted of 57,749 patients with T1-T2 prostate cancers diagnosed during 1992-2007. We utilized an instrumental variable (IV) analytical approach with competing risk models to evaluate the outcomes of primary radiotherapy vs conservative management. The IV was comprised of combined health service areas with high- and low-use areas corresponding to the top and bottom tertile in radiotherapy usage rates.

RESULTS

In patients with low-/intermediate-risk prostate cancer, 10-year prostate cancer-specific and overall survival was similar in high- and low-radiotherapy use areas (96.1 vs 95.4% and 56.6 vs 56.3%, respectively). In patients with high-risk disease, however, areas with high-radiotherapy use had a higher 10-year cancer-specific survival (90.2 vs 88.1%, difference 2.1%; 95% CI 0.3-4.0%) and 10-year overall survival (53.3 vs 50.2%, difference 3.1%; 95% CI 1.3-6.3%). Results were similar irrespective of the type of radiotherapy used. To assess the robustness of our choice of IV, we repeated the IV analytical approach using different IVs (using the median utilization rate as the cutoff) and found the results to be similar.

CONCLUSIONS

Among men >65 years of age, the benefit of primary radiotherapy for localized disease is largely confined to patients with high-risk prostate cancer (Gleason scores 7-10).

Androgen receptor and prostate cancer stem cells: biological mechanisms and clinical implications

Prostate cancer (PCa) contains phenotypically and functionally distinct cells, and this cellular heterogeneity poses clinical challenges as the distinct cell types likely respond differently to various therapies. Clonal evolution, driven by genetic instability, and intraclonal cancer cell diversification, driven by cancer stem cells (CSCs), together create tumor cell heterogeneity. In this review, we first discuss PCa stem cells (PCSCs) and heterogeneity of androgen receptor (AR) expression in primary, metastatic, and treatment-failed PCa. Based on literature reports and our own studies, we hypothesize that, whereas PCSCs in primary and untreated tumors and models are mainly AR(-), PCSCs in CRPCs could be either AR(+) or AR(-/lo). We illustrate the potential mechanisms AR(+) and AR(-) PCSCs may employ to propagate PCa at the population level, mediate therapy resistance, and metastasize. As a result, targeting AR alone may not achieve long-lasting therapeutic efficacy. Elucidating the roles of AR and PCSCs should provide important clues to designing novel personalized combinatorial therapeutic protocols targeting both AR(+) and AR(-) PCa cells.

[Comparative oncologic and functional outcomes of prostate cancer surgery with other curative treatments]

OBJECTIVE

Review of the comparative results of different treatment strategies (surgery, radiotherapy, ultrasound, surveillance) of prostate cancer, in which the main goal is the local control and the second target is the tolerance of the side effects of those treatments.

MATERIALS AND METHODS

Review of literature using Medline databases selected based on scientific relevance. Clinical keys centered on the oncological and functional outcomes of comparative series between different curative treatments.

RESULTS

The numerous comparative series between surgery and other therapeutic modalities are essentially retrospective with significant methodological bias that is difficult to overcome in order to formulate the optimal thesis. However, there is a clear tendency toward surgery usually with young patients who have intermediate risk tumors without important comorbidity.

CONCLUSION

In the absence of randomized comparative series with significant power, the oncological and functional results of the radical prostatectomy with or without adjuvant treatment seem at least the same, in a selected population of patients, compared with the combination of radiotherapy-hormonotherapy in terms of survival, without biochemical recurrence, disease-specific survival and overall survival, for the aggressive tumors necessitating curative local treatments.

Contemporary Systemic Therapy for Urologic Malignancies in Geriatric Patients

Current data on systemic therapy in geriatric populations with genitourinary malignancies are largely derived from retrospective analyses of prospectively conducted trials or retrospective reviews. Although extrapolation of these data to real-world patients should be cautious, patients aged 65 years or older with good functional status and minimal comorbidities seem to enjoy similar survival benefit from therapy as their younger counterparts. Chronologic age alone should generally not be used to guide management decisions. Comprehensive geriatric assessment tools and prospective studies in older adults integrating comprehensive geriatric assessment can shed light on the optimal management of urologic malignancies in this population.