Use of hormonal therapy in men with metastatic prostate cancer

Disparities With Systemic Therapies for Black Men Having Advanced Prostate Cancer: Where Do We Stand?

PURPOSE

Prostate cancer represents the most common cancer diagnosis in Black men and is the second leading cause of cancer death in this population. Multilevel disparities have been well-documented in Black men with prostate cancer and play a role in poorer survival outcomes when compared with White men with prostate cancer. In this review, we highlight the changing trend in disparities for systemic therapy outcomes in Black men diagnosed with metastatic prostate cancer.

METHODS

We reviewed data from real-world registries and prospective clinical trials with a particular focus on equal access settings to compare outcomes to systemic therapies between Black and White men with metastatic prostate cancer.

RESULTS

In metastatic prostate cancer, there is growing evidence to suggest that Black men may have similar, if not better, outcomes to systemic therapies than White men with advanced disease, as corroborated by prospective studies and clinical trials where health care delivery and follow-up are more likely to be standardized.

CONCLUSION

This review illustrates the importance of nonbiological drivers of racial disparities in Black men with advanced prostate cancer. Mitigating barriers to health care access and delivery as well as including participation in clinical trials will be pivotal to ongoing efforts to address disparities in systemic therapy outcomes for Black men with metastatic prostate cancer.

ESTRO-ACROP recommendations for evidence-based use of androgen deprivation therapy in combination with external-beam radiotherapy in prostate cancer

BACKGROUND AND PURPOSE

There is no consensus concerning the appropriate use of androgen deprivation therapy (ADT) during primary and postoperative external-beam radiotherapy (EBRT) in the management of prostate cancer (PCa). Thus, the European Society for Radiotherapy and Oncology (ESTRO) Advisory Committee for Radiation Oncology Practice (ACROP) guidelines seeks to present current recommendations for the clinical use of ADT in the various indications of EBRT.

MATERIAL AND METHODS

A literature search was conducted in MEDLINE PubMed that evaluated EBRT and ADT in prostate cancer. The search focused on randomized, Phase II and III trials published in English from January 2000 to May 2022. In case topics were addressed in the absence of Phase II or III trials, recommendations were labelled accordingly based on the limited body of evidence. Localized PCa was classified according to D'Amico et al. classification in low-, intermediate and high risk PCa. The ACROP clinical committee identified 13 European experts who discussed and analyzed the body of evidence concerning the use of ADT with EBRT for prostate cancer.

RESULTS

Key issues were identified and are discussed: It was concluded that no additional ADT is recommended for low-risk prostate cancer patients, whereas for intermediate- and high-risk patients four to six months and two to three years of ADT are recommended. Likewise, patients with locally advanced prostate cancer are recommended to receive ADT for two to three years and when ≥ 2 high-risk factors (cT3-4, ISUP grade ≥ 4 or PSA ≥ 40 ng/ml) or cN1 is present ADT for three years plus additional Abiraterone for two years is recommended. For postoperative patients no ADT is recommended for adjuvant EBRT in pN0 patients whereas for pN1 patients adjuvant EBRT with long-term ADT is performed for at least 24 to 36 months. In the setting of salvage EBRT ADT is performed in biochemically persistent PCa patients with no evidence of metastatic disease. Long-term ADT (24 months) is recommended in pN0 patients with high risk of further progression (PSA ≥ 0.7 ng/ml and ISUP grade group ≥ 4) and a life expectancy of over ten years, whereas short-term ADT (6 months) is recommended in pN0 patients with lower risk profile (PSA < 0.7 ng/ml and ISUP grade group 4). Patients considered for ultra-hypofractionated EBRT as well as patients with image based local recurrence within the prostatic fossa or lymph node recurrence should participate in appropriate clinical trials evaluating the role of additional ADT.

CONCLUSION

These ESTRO-ACROP recommendations are evidence-based and relevant to the use of ADT in combination with EBRT in PCa for the most common clinical settings.

Prostate cancer in men of African origin

Men of African origin are disproportionately affected by prostate cancer: prostate cancer incidence is highest among men of African origin in the USA, prostate cancer mortality is highest among men of African origin in the Caribbean, and tumour stage and grade at diagnosis are highest among men in sub-Saharan Africa. Socioeconomic, educational, cultural, and genetic factors, as well as variations in care delivery and treatment selection, contribute to this cancer disparity. Emerging data on single-nucleotide-polymorphism patterns, epigenetic changes, and variations in fusion-gene products among men of African origin add to the understanding of genetic differences underlying this disease. On the diagnosis of prostate cancer, when all treatment options are available, men of African origin are more likely to choose radiation therapy or to receive no definitive treatment than white men. Among men of African origin undergoing surgery, increased rates of biochemical recurrence have been identified. Understanding differences in the cancer-survivorship experience and quality-of-life outcomes among men of African origin are critical to appropriately counsel patients and improve cultural sensitivity. Efforts to curtail prostate cancer screening will likely affect men of African origin disproportionately and widen the racial disparity of disease.

Reducing bias in the assessment of treatment effectiveness: androgen deprivation therapy for prostate cancer

BACKGROUND

Indication bias is the major challenge in assessing treatment effectiveness in observational studies. We explored the potential advantages of using an instrumental variable approach in the context of primary androgen deprivation therapy (ADT) for prostate cancer.

METHODS

We identified 31,930 men in the linked Surveillance, Epidemiology, and End Results-Medicare database with a diagnosis of prostate cancer who were not treated definitively with radical prostatectomy or radiation in the years 1992 through 2002, with follow-up through 2005. The association between use of primary ADT and overall, prostate cancer-specific, and nonprostate cancer survival was assessed using multivariable regression and instrumental variable methods. Two instrumental variables, based on region and urologist prescribing preference, were constructed and analyzed using exogenous probit models. Prespecified subgroup analyses in patients with lower-risk and higher-risk prostate tumors were also carried out.

RESULTS

In the overall cohort, standard multivariable regression analyses showed a significantly increased risk of prostate cancer-related death, whereas the instrumental variable approaches showed a protective effect of primary ADT, which was significant for the urologist preference instrument (hazard ratio: 0.74; 95% confidence interval, 0.60-0.93). In the high-risk subgroup, using urologist preference for primary ADT as the instrument, there was a significant reduction in overall mortality (hazard ratio: 0.75; 95% confidence interval, 0.57-0.99), driven by a large reduction in prostate cancer-specific mortality.

CONCLUSIONS

Instrumental variable analysis appears to provide better control of bias when assessing the effectiveness of primary ADT for prostate cancer, although the results may be more applicable to policy rather than to clinical decisions.

Disparities at presentation, diagnosis, treatment, and survival in African American men, affected by prostate cancer

BACKGROUND

Prostate cancer (PCa) remains the most common malignancy and the second leading cause of cancer death among men in the United States. PCa exhibits the most striking racial disparity, as African American men are at 1.4 times higher risk of being diagnosed, and 2-3 times higher risk of dying of PCa, compared to Caucasian men. The etiology of the disparity has not been clearly elucidated. The objective of this article is to critically review the literature and summarize the most prominent PCa racial disparities accompanied by proposed explanations.

METHODS

The present literature on disparities at presentation, diagnosis, treatment, and survival of African American men affected by PCa was systematically reviewed. Original research as well as relevant review articles were included.

RESULTS

African American men persistently present with more advanced disease than Caucasian men, are administered different treatment regimens than Caucasian men, and have shorter progression-free survival following treatment. In addition, African American men report more treatment-related side-effects that translates to the diminished quality of life (QOL).

CONCLUSIONS

PCa racial disparity exists at stages of presentation, diagnosis, treatment regimens, and subsequent survival, and the QOL. The disparities are complex involving biological, socio-economic, and socio-cultural determinants. These mounting results highlight an urgent need for future clinical, scientific, and socio-cultural research involving transdisciplinary teams to elucidate the causes for PCa racial disparities.

Risk of colorectal cancer in men on long-term androgen deprivation therapy for prostate cancer

BACKGROUND

Androgen deprivation with gonadotropin-releasing hormone (GnRH) agonists or orchiectomy is a common but controversial treatment for prostate cancer. Uncertainties remain about its use, particularly with increasing recognition of serious side effects. In animal studies, androgens protect against colonic carcinogenesis, suggesting that androgen deprivation may increase the risk of colorectal cancer.

METHODS

We identified 107 859 men in the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database who were diagnosed with prostate cancer in 1993 through 2002, with follow-up available through 2004. The primary outcome was development of colorectal cancer, determined from SEER files on second primary cancers. Cox proportional hazards regression was used to assess the influence of androgen deprivation on the outcome, adjusted for patient and prostate cancer characteristics. All statistical tests were two-sided.

RESULTS

Men who had orchiectomies had the highest unadjusted incidence rate of colorectal cancer (6.3 per 1000 person-years; 95% confidence interval [CI] = 5.3 to 7.5), followed by men who had GnRH agonist therapy (4.4 per 1000 person-years; 95% CI = 4.0 to 4.9), and men who had no androgen deprivation (3.7 per 1000 person-years; 95% CI = 3.5 to 3.9). After adjustment for patient and prostate cancer characteristics, there was a statistically significant dose-response effect (P(trend) = .010) with an increasing risk of colorectal cancer associated with increasing duration of androgen deprivation. Compared with the absence of these treatments, there was an increased risk of colorectal cancer associated with use of GnRH agonist therapy for 25 months or longer (hazard ratio [HR] = 1.31, 95% CI = 1.12 to 1.53) or with orchiectomy (HR = 1.37, 95% CI = 1.14 to 1.66).

CONCLUSION

Long-term androgen deprivation therapy for prostate cancer is associated with an increased risk of colorectal cancer.

Reimbursement policy and androgen-deprivation therapy for prostate cancer

BACKGROUND

The Medicare Modernization Act led to moderate reductions in reimbursement for androgen-deprivation therapy (ADT) for prostate cancer, starting in 2004 and followed by substantial changes in 2005. We hypothesized that these reductions would lead to decreases in the use of ADT for indications that were not evidence based.

METHODS

Using the Surveillance, Epidemiology, and End Results (SEER) Medicare database, we identified 54,925 men who received a diagnosis of incident prostate cancer from 2003 through 2005. We divided these men into groups according to the strength of the indication for ADT use. The use of ADT was deemed to be inappropriate as primary therapy for men with localized cancers of a low-to-moderate grade (for whom a survival benefit of such therapy was improbable), appropriate as adjuvant therapy with radiation therapy for men with locally advanced cancers (for whom a survival benefit was established), and discretionary for men receiving either primary or adjuvant therapy for localized but high-grade tumors. The proportion of men receiving ADT was calculated according to the year of diagnosis for each group. We used modified Poisson regression models to calculate the effect of the year of diagnosis on the use of ADT.

RESULTS

The rate of inappropriate use of ADT declined substantially during the study period, from 38.7% in 2003 to 30.6% in 2004 to 25.7% in 2005 (odds ratio for ADT use in 2005 vs. 2003, 0.72; 95% confidence interval [CI], 0.65 to 0.79). There was no decrease in the appropriate use of adjuvant ADT (odds ratio, 1.01; 95% CI, 0.86 to 1.19). In cases involving discretionary use, there was a significant decline in use in 2005 but not in 2004.

CONCLUSIONS

Changes in the Medicare reimbursement policy in 2004 and 2005 were associated with reductions in ADT use, particularly among men for whom the benefits of such therapy were unclear. (Funded by the American Cancer Society.).

Trends and racial differences in the use of androgen deprivation therapy for metastatic prostate cancer

CONTEXT

Androgen deprivation therapy (ADT) is widely used to manage the symptoms of advanced prostate cancer and has been shown to slow the progression of the disease. Previous research investigating racial differences in the use of ADT has reported inconsistent findings.

OBJECTIVES

The purpose of this study was to assess use trends for ADT overall and by type (orchiectomy and luteinizing hormone-releasing hormone [LHRH] agonists) and the factors associated with time to receipt for metastatic prostate cancer.

METHODS

Data from the Surveillance, Epidemiology, and End Results (SEER) cancer registry and Medicare claims database were obtained for 5,273 men, aged 65 years and older and diagnosed with Stage IV prostate cancer during 1991-1999 from seven SEER regions. An accelerated failure time regression model with log-normal distribution was used to examine factors associated with mean time to receipt of ADT.

RESULTS

African-American men were less likely than white men to receive any ADT after diagnosis (P<0.001). Differences were noted in the time to receipt of ADT, with African-American men having a longer mean time to receipt of orchiectomy (time ratio [TR]=1.50; 95% confidence interval [CI]=1.03, 2.17) or LHRH agonist (TR=1.42; 95% CI=1.06, 1.89) than white men.

CONCLUSION

African-American men with metastatic prostate cancer were significantly less likely to receive ADT and, when treated, had a slightly longer time to receipt than white men, which has implications for patients and physicians involved in the palliative management of metastatic prostate cancer.

Hormonal therapy of prostate cancer

Of all cancers, prostate cancer is the most sensitive to hormones: it is thus very important to take advantage of this unique property and to always use optimal androgen blockade when hormone therapy is the appropriate treatment. A fundamental observation is that the serum testosterone concentration only reflects the amount of testosterone of testicular origin which is released in the blood from which it reaches all tissues. Recent data show, however, that an approximately equal amount of testosterone is made from dehydroepiandrosterone (DHEA) directly in the peripheral tissues, including the prostate, and does not appear in the blood. Consequently, after castration, the 95-97% fall in serum testosterone does not reflect the 40-50% testosterone (testo) and dihydrotestosterone (DHT) made locally in the prostate from DHEA of adrenal origin. In fact, while elimination of testicular androgens by castration alone has never been shown to prolong life in metastatic prostate cancer, combination of castration (surgical or medical with a gonadotropin-releasing hormone (GnRH) agonist) with a pure anti-androgen has been the first treatment shown to prolong life. Most importantly, when applied at the localized stage, the same combined androgen blockade (CAB) can provide long-term control or cure of the disease in more than 90% of cases. Obviously, since prostate cancer usually grows and metastasizes without signs or symptoms, screening with prostate-specific antigen (PSA) is absolutely needed to diagnose prostate cancer at an 'early' stage before metastasis occurs and the cancer becomes non-curable. While the role of androgens was believed to have become non-significant in cancer progressing under any form of androgen blockade, recent data have shown increased expression of the androgen receptor (AR) in treatment-resistant disease with a benefit of further androgen blockade. Since the available anti-androgens have low affinity for AR and cannot block androgen action completely, especially in the presence of increased AR levels, it becomes important to discover more potent and purely antagonistic blockers of AR. The data obtained with compounds under development are promising. While waiting for this (these) new anti-androgen(s), combined treatment with castration and a pure anti-androgen (bicalutamide, flutamide or nilutamide) is the only available and the best scientifically based means of treating prostate cancer by hormone therapy at any stage of the disease with the optimal chance of success and even cure in localized disease.

Gonadotropin-releasing hormone agonist use in men without a cancer registry diagnosis of prostate cancer

Background

Use of gonadotropin-releasing hormone (GnRH) agonists has become popular for virtually all stages of prostate cancer. We hypothesized that some men receive these agents after only a limited work-up for their cancer. Such cases may be missed by tumor registries, leading to underestimates of the total extent of GnRH agonist use.

Methods

We used linked Surveillance, Epidemiology and End-Results (SEER)-Medicare data from 1993 through 2001 to identify GnRH agonist use in men with either a diagnosis of prostate cancer registered in SEER, or with a diagnosis of prostate cancer based only on Medicare claims (from the 5% control sample of Medicare beneficiaries residing in SEER areas without a registered diagnosis of cancer). The proportion of incident GnRH agonist users without a registry diagnosis of prostate cancer was calculated. Factors associated with lack of a registry diagnosis were examined in multivariable analyses.

Results

Of incident GnRH agonist users, 8.9% had no diagnosis of prostate cancer registered in SEER. In a multivariable logistic regression model, lack of a registry diagnosis of prostate cancer in GnRH agonist users was significantly more likely with increasing comorbidity, whereas it was less likely in men who had undergone either inpatient admission or procedures such as radical prostatectomy, prostate biopsy, or transurethral resection of the prostate.

Conclusion

Reliance solely on tumor registry data may underestimate the rate of GnRH agonist use in men with prostate cancer.

Use of androgen deprivation therapy for metastatic prostate cancer in older men

OBJECTIVE

To assess factors associated with early or delayed androgen deprivation therapy (ADT) among men diagnosed with metastatic prostate cancer, and to assess the relationship between ADT and overall survival, as there is uncertainty about the ideal timing for initiating ADT in men with metastatic prostate cancer.

PATIENTS AND METHODS

We studied a population-based cohort of American men aged >or=66 years diagnosed with metastatic prostate cancer during 1992-2002 and followed to 2003. We assessed the receipt of ADT early (4 months), or not at all, using multinomial logistic regression to identify factors associated with treatment, and Cox proportional-hazard models to assess whether treatment was associated with survival.

RESULTS

Overall, 69.5% of men received early ADT and 7.3% delayed. Adjusted rates of early ADT were lower for black than white men (58.3% vs 71.0%), and of delayed ADT were higher for black than white men (12.7% vs 6.2%). Receipt of ADT was associated with improved survival (adjusted hazard ratio 0.69, 95% confidence interval 0.66-0.73). The benefit of early treatment did not differ from delayed treatment (P = 0.58).

CONCLUSIONS

A large minority of men with metastatic prostate cancer, particularly black men, receive delayed or no ADT. Early or delayed ADT was associated with similarly prolonged survival. After controlling for patient and tumour characteristics, survival did not differ by race, and receipt of ADT did not contribute to racial differences in survival.

Etude randomisée multicentrique comparant la castration médicale par triptoréline à la castration chirurgicale dans le traitement du cancer de la prostate localement avancé ou métastatique

OBJECTIVE

To report the results of a trial comparing the efficacy of triptorelin and surgical castration in the treatment of locally advanced or metastatic prostate cancer.

MATERIALS AND METHODS

80 patients with previously untreated locally advanced or metastatic prostate cancer prostate cancer were included in a one-year multicentre, randomized, prospective, open-label therapeutic trial. Patients either received a monthly injection of triptorelin (group 1; n = 40), or were treated by pulpectomy (group 2; n = 40). Patients were reviewed every 3 months, then every 6 months.

RESULTS

The mean age of the patients was 71.22 +/- 8.25 years. At 1 month, 38 patients were castrated (plasma testosterone < 0.5 mg/ml) in the pulpectomy group versus 35 in the triptorelin group. The mean follow-up was 38.8 +/- 26 months in the triptorelin group and 36.3 +/- 25 months in the pulpectomy group. On multivariate analysis, age, impaired performance status and PAP level (> 3.2 ng/ml) were predictive factors of a poor outcome. The median survival was 37.5 +/- 9 months in the triptorelin group and 33 +/- 3 months in the pulpectomy group. At 3 years, no significant difference in specific survival was observed between the 2 groups. At 8 years of follow-up, 63 patients had died.

CONCLUSION

This study demonstrates an equivalent specific survival between patients treated by triptorelin or surgical castration. Castration is rapidly obtained with triptorelin (< 2 months) and is maintained over time throughout the duration of treatment.

Population Based Study of Hormonal Therapy and Survival in Men With Metastatic Prostate Cancer

PURPOSE

Although the palliative benefits of hormonal therapy for metastatic prostate cancer are widely recognized, little information is available regarding the effect of hormonal therapy on cancer specific and overall survival, and the types of patients who might benefit the most or least from hormonal therapy.

MATERIALS AND METHODS

Prostate cancer specific and overall survival according to hormonal therapy use was determined by the Kaplan-Meier method in 6,098 men 65 years or older diagnosed with metastatic prostate cancer in 1991 to 1999 who were identified through the population based Surveillance, Epidemiology, and End Results, and Medicare linked database. Cox proportional hazards and propensity score methods were used to adjust for potential confounders, such as disease status and patient comorbidity.

RESULTS

Propensity score adjusted median overall survival was 26 months in men who received hormonal therapy compared with 13 months in those who did not (HR 0.66, 95% CI 0.17-0.70, p <0.0001). The benefit of hormonal therapy was observed across all comorbidity strata and races. Effects were most evident in patients with poorly differentiated cancer (cancer specific mortality in favor of treatment HR 0.60, 95% CI 0.53-0.69, p <0.001). Benefit was not found in patients with well differentiated cancer (cancer specific mortality in favor of no treatment HR 1.92, 95% CI 0.90-4.10, p = 0.09).

CONCLUSIONS

Hormonal therapy is associated with improved prostate cancer specific and overall survival in men with poorly differentiated cancer. Improved survival does not appear evident in men with well differentiated disease.