Androgen suppression adjuvant to definitive radiotherapy in prostate carcinoma--long-term results of phase III RTOG 85-31

Duration of androgen suppression in the treatment of prostate cancer

BACKGROUND

The combination of radiotherapy plus long-term medical suppression of androgens (> or = 2 years) improves overall survival in patients with locally advanced prostate cancer. We compared the use of radiotherapy plus short-term androgen suppression with the use of radiotherapy plus long-term androgen suppression in the treatment of locally advanced prostate cancer.

METHODS

We randomly assigned patients with locally advanced prostate cancer who had received external-beam radiotherapy plus 6 months of androgen suppression to two groups, one to receive no further treatment (short-term suppression) and the other to receive 2.5 years of further treatment with a luteinizing hormone-releasing hormone agonist (long-term suppression). An outcome of noninferiority of short-term androgen suppression as compared with long-term suppression required a hazard ratio of more than 1.35 for overall survival, with a one-sided alpha level of 0.05. An interim analysis showed futility, and the results are presented with an adjusted one-sided alpha level of 0.0429.

RESULTS

A total of 1113 men were registered, of whom 970 were randomly assigned, 483 to short-term suppression and 487 to long-term suppression. After a median follow-up of 6.4 years, 132 patients in the short-term group and 98 in the long-term group had died; the number of deaths due to prostate cancer was 47 in the short-term group and 29 in the long-term group. The 5-year overall mortality for short-term and long-term suppression was 19.0% and 15.2%, respectively; the observed hazard ratio was 1.42 (upper 95.71% confidence limit, 1.79; P=0.65 for noninferiority). Adverse events in both groups included fatigue, diminished sexual function, and hot flushes.

CONCLUSIONS

The combination of radiotherapy plus 6 months of androgen suppression provides inferior survival as compared with radiotherapy plus 3 years of androgen suppression in the treatment of locally advanced prostate cancer. (ClinicalTrials.gov number, NCT00003026.)

Six-month depot formulation of leuprorelin acetate in the treatment of prostate cancer

Hormonal deprivation therapy is well established for the treatment of locally advanced and metastatic prostate cancer, as well as the adjuvant treatment of some patients with localized disease. Long-acting gonadotropin releasing hormone (GnRH) agonists have become a mainstay of androgen deprivation therapy, due to their efficacy, tolerability, and convenience of use. One-month, 3-month, and 4-month depot leuprorelin formulations are well established and widely used to this end. Recently, a 6-month depot leuprorelin has been approved for use in advanced and metastatic prostate cancer patients. With similar efficacy and side effect profiles to earlier formulations, 6-month depot leuprorelin is a convenient treatment option for these patients. This review will highlight the role of GnRH agonists in the treatment of prostate cancer with a focus on the clinical efficacy, pharmacology, and patient-focused outcomes of the newer 6-month 45 mg depot leuprorelin formulation in comparison to available shorter-acting products.

Outcomes for patients with high-grade prostate cancer treated with a combination of brachytherapy, external beam radiotherapy and hormonal therapy

OBJECTIVE

To assess the outcomes for patients with Gleason score 8-10 prostate cancer treated with brachytherapy, external beam radiotherapy (EBRT) and hormonal therapy (HT).

PATIENTS AND METHODS

In all, 181 patients with Gleason scores 8-10 prostate cancer were treated from 1994 to 2006 with a (103)Pd implant (prescription dose 100 Gy), 45 Gy of EBRT and 9 months of HT. The median (range) follow-up was 65 (24-150) months; freedom from biochemical failure (FBF) rates were calculated using the Phoenix definition.

RESULTS

The 8-year actuarial FBF, freedom from distant metastases, prostate-cancer specific survival and overall survival were 73%, 80%, 87% and 79%, respectively. The pretreatment prostate-specific antigen (PSA) level significantly affected FBF, with 8-year rates of 72%, 82% and 58% for patients with PSA level of <or=10, >10-20 and >20 ng/mL, respectively (P = 0.006). The PSA level had no significant effect on rates of distant metastases. The Gleason score had the most significant affect on FBF in a multivariate analysis, and was the only factor to significantly affect rates of distant metastases; the 8-year FBF rates were 84%, 55% and 30% for scores of 8, 9 and 10, respectively (P = 0.003). The corresponding freedom from distant metastases and prostate-cancer specific survival rates were 86%, 76%, 30% (P < 0.001) and 92%, 80%, 62.5% (P = 0.003), respectively.

CONCLUSIONS

The 8-year outcomes after this regimen showed favourable biochemical and distant control, as well disease-specific survival rates for patients with Gleason scores of 8-10. This treatment approach should be considered as a viable option for this subset of patients with high-risk disease.

RTOG GU Radiation oncology specialists reach consensus on pelvic lymph node volumes for high-risk prostate cancer

PURPOSE

Radiation therapy to the pelvic lymph nodes in high-risk prostate cancer is required on several Radiation Therapy Oncology Group (RTOG) clinical trials. Based on a prior lymph node contouring project, we have shown significant disagreement in the definition of pelvic lymph node volumes among genitourinary radiation oncology specialists involved in developing and executing current RTOG trials.

MATERIALS AND METHODS

A consensus meeting was held on October 3, 2007, to reach agreement on pelvic lymph node volumes. Data were presented to address the lymph node drainage of the prostate. Extensive discussion ensued to develop clinical target volume (CTV) pelvic lymph node consensus.

RESULTS

Consensus was obtained resulting in computed tomography image-based pelvic lymph node CTVs. Based on this consensus, the pelvic lymph node volumes to be irradiated include: distal common iliac, presacral lymph nodes (S(1)-S(3)), external iliac lymph nodes, internal iliac lymph nodes, and obturator lymph nodes. Lymph node CTVs include the vessels (artery and vein) and a 7-mm radial margin being careful to "carve out" bowel, bladder, bone, and muscle. Volumes begin at the L5/S1 interspace and end at the superior aspect of the pubic bone. Consensus on dose-volume histogram constraints for OARs was also attained.

CONCLUSIONS

Consensus on pelvic lymph node CTVs for radiation therapy to address high-risk prostate cancer was attained and is available as web-based computed tomography images as well as a descriptive format through the RTOG. This will allow for uniformity in evaluating the benefit and risk of such treatment.

Suppression of NF-kappaB activity by parthenolide induces X-ray sensitivity through inhibition of split-dose repair in TP53 null prostate cancer cells

We have shown that parthenolide, a sesquiterpene lactone, is a radiation sensitizer for human CGL1 hybrid cells that have constitutively activated NF-kappaB and wild-type p53. Since many malignant cells have nonfunctional p53, we investigated whether parthenolide could alter the X-ray sensitivity of PC-3 prostate cancer cells, a p53 null cell line with constitutively activated NF-kappaB. The addition of 5 microM parthenolide induced non-apoptotic cell death, inhibited PC-3 proliferation, and increased the population doubling time from 23+/-1 h to 49+/-4 h. Parthenolide also inhibited constitutive and radiation-induced NF-kappaB binding activity and enhanced the X-ray sensitivity of these p53 null PC-3 cells by a dose modification factor of 1.7. Cell cycle analysis of PC-3 cells treated with parthenolide showed only small alterations in G1 and G2/M cells, and these appeared to be insufficient to explain the observed radiosensitization. Split-dose studies using clinically relevant 2- and 4-Gy fractions demonstrated that parthenolide completely inhibited split-dose repair in PC-3 cells. We hypothesized that inhibition of NF-kappaB activity by parthenolide was responsible for the observed X-ray sensitization and inhibition of split-dose repair. To test this hypothesis, we knocked down the expression of NF-kappaB p65 protein, an active component of NF-kappaB in both PC-3 and CGL1 cells, by siRNA. Inhibition of NF-kappaB activity by knockdown of p65 increased radiation sensitivity and completely inhibited split-dose repair in both cell lines in a nearly identical manner as parthenolide treatment alone. Treating p65-depleted PC-3 cells with 5 microM parthenolide did not further increase their radiation sensitivity or the inhibition of split-dose repair. We propose that the suppression of radiation-induced NF-kappaB activity by parthenolide leads to X-ray sensitization through inhibition of split-dose repair in p53 null PC-3 prostate cancer cells.

[Medical castration in the treatment of locally advanced or metastatic prostate cancer: an update]

Indications for hormonotherapy in prostate cancer are in deep mutation and are constantly evolving. Used initially (1941) in metastatic stages, hormone therapy is used nowadays in locally advanced prostate cancer and aggressive localized disease. Its prescription in association with radiotherapy or surgery has provided a benefit regarding survival free progression. The place of hormone therapy in localized prostate cancer is not well defined and the debate is still ongoing, especially in case of biochemical recurrence after irradiation or radical prostatectomy and even in neoadjuvant cases. Additional and further studies are ongoing and are strongly needed to establish new guidelines. Nevertheless, hormone therapy is not restricted any more to palliative cases and is part of the current therapeutic arsenal of the urologist for high risk localized and/or locally advanced prostate cancers.

Non-surgical treatment of localised prostate cancer

The non-surgical treatment of localised prostate cancer depends on a number of factors including: PSA, stage, Gleason score, age, fitness for treatment and life expectancy, and is individualised depending on risk. Patients who present with early localised (stage T1 or T2) tumours with low risk features (PSA <10 ng/ml, Gleason score 3+4 or below) and who have a life expectancy of more than 10 years may consider radiotherapy or active surveillance. Permanent brachytherapy seed implantation is suitable for low risk patients who have minimal lower urinary tract symptoms, with equivalent results to external beam radiotherapy Conformal high-dose external beam radiotherapy is effective for patients with high risk disease, and consideration should be given to the use of neoadjuvant and adjuvant anti-androgens. Prophylactic pelvic nodal irradiation is indicated for patients with high risk of lymph node disease, followed by a boost to the prostate using either a smaller external beam volume, or brachytherapy. The definitive treatment depends on both clinical parameters such as the clinical staging, prognostic risk, and the likelihood of acute and late toxicity and the patient's personal choice based on their life style.

The clinical significance and therapeutic implications of extraprostatic invasion

Invasion of the prostatic margin by cancer establishes a higher risk of disease progression and treatment failure depending upon its extent and other clinical factors. Pathological stage is the most important single prognostic indicator, but determined reliably only in patients having radical prostatectomy. Tumour beyond the prostatic margin or its invasion into the seminal vesicle defines the local stage category as T3, and when confirmed by pathological examination the extent of prostatic margin involvement has prognostic significance. Prediction of extraprostatic invasion may influence therapeutic decisions, but can be difficult to determine for the individual patient prior to treatment. In some individuals having radical prostatectomy, the finding of extraprostatic invasion is unsuspected, and fortunately for the majority of these men the treatment remains curative. On the other hand, when extraprostatic invasion is suspected prior to or at surgery, wide excision may be necessary to achieve negative surgical margins, with other factors contributing independently to the likelihood of subsequent progression. Radiotherapy is an effective alternative treatment for clinical stage T3 and high-risk clinically localized cancer. Recent technological advances and use of combination modality treatment with radiation and hormone manipulation have improved survival outcomes and reduced side-effects. Radiation also has its place as adjuvant treatment following radical prostatectomy in high-risk disease, or as salvage following PSA recurrence, with ongoing trials evaluating potential benefit and toxicity. For clinically localised stage T3 prostate cancer, treatment with surgery or radiotherapy may be highly effective, but multimodality interventions are increasingly being used for primary treatment where clinical assessment indicates that there would otherwise be a high risk for disease progression and therapeutic failure.

Radiation therapy approaches to the treatment of high-risk prostate cancer

Radiation therapy modalities have been shown to offer patients a nonoperative option for definitive treatment of localized prostate cancer as well as options for adjuvant or salvage therapy in high-risk prostate cancer patients. In patients with high-risk, localized disease, radiation therapy with or without adjuvant hormonal therapy is considered an excellent treatment option because of its efficacy within the prostate and among local periprostatic structures, addressing micrometastatic disease. Following radical prostatectomy in patients with high-risk or recurrent disease, radiotherapy can increase oncologic efficacy in both the adjuvant and salvage setting. Continued studies are underway to address ongoing concerns of sparing surrounding tissues unnecessary radiation while administering high-dose radiation to the prostate and targeted periprostatic structures. Newer technologies are using real-time imaging and computer-simulated motion calculation to adjust for physiological organ motion with respect to bony landmarks classically used to map areas of radiation administration.

Radioterapia externa conformada 3D para o carcinoma de próstata: experiência do Instituto do Radium de Campinas com 285 pacientes

OBJETIVO: Reportar resultados de tratamentos do câncer de próstata com radioterapia conformada 3D realizados em uma única instituição. MATERIAIS E MÉTODOS: De julho de 1997 a janeiro de 2002, 285 pacientes consecutivos com câncer de próstata foram submetidos a radioterapia conformada 3D com dose mediana de 7.920 cGy na próstata e analisados retrospectivamente. A distribuição segundo o grupo de risco foi a seguinte: baixo risco - 95 (33,7%); risco intermediário - 66 (23,4%); alto risco - 121 (42,9%) pacientes. RESULTADOS: Em seguimento mediano de 53,6 meses (3,6-95,3 meses), sobrevidas atuariais global, causa específica, livre de metástases a distância e livre de recidiva bioquímica em cinco anos foram de 85,1%, 97,0%, 94,2% e 75,8%, respectivamente. Sobrevidas atuariais livre de toxicidade retal e urinária tardias em cinco anos foram de 96,4% e 91,1%, respectivamente. Ressecção transuretral pré-radioterapia conformada 3D e doses > 70 Gy em 30% do volume da bexiga implicaram maior toxicidade urinária tardia grau 2-3 em cinco anos (p = 0,0002 e p = 0,0264, respectivamente). CONCLUSÃO: A primeira experiência relatada de radioterapia conformada 3D no Brasil permitiu altas doses de radiação, com toxicidades retal e urinária aceitáveis. A existência de ressecção transuretral de próstata pré-radioterapia conformada 3D pode sinalizar maior risco de toxicidade urinária tardia grau 2-3 após irradiação. Restrição da dose < 70 Gy em 30% do volume da bexiga à tomografia de planejamento pode reduzir complicações urinárias tardias.

Impact of the duration of adjuvant hormonal therapy in patients with locally advanced prostate cancer treated with radiotherapy: a secondary analysis of RTOG 85-31

PURPOSE

Radiation Therapy Oncology Group 85-31 was a randomized trial of androgen suppression for life for patients with locally advanced prostate cancer. However, not all patients continued on the protocol-mandated long-term hormonal therapy despite no evidence of recurrence. We correlated duration of adjuvant hormonal therapy and outcomes among patients who prematurely discontinued hormonal therapy.

PATIENTS AND METHODS

The protocol mandated pelvic radiotherapy followed by goserelin given indefinitely or until disease progression. There were 189 analyzable patients. Patients were divided in groups based on the tertile of hormonal therapy duration (HTD) as follows: < or = 1 year, more than 1 year and < or = 5 years, and more than 5 years. Overall survival (OS), disease-free survival (DFS), cause-specific mortality, local failure (LF), and distant metastasis (DM) were studied. Kaplan-Meier estimation and Cox proportional hazards regression model were used for OS and DFS, and Fine and Gray's regression model was used for the other outcomes.

RESULTS

The median follow-up for surviving patients is 9.6 years. The median duration of adjuvant hormonal therapy was 2.2 years. The HTD more than 5 years group is significantly associated with an improved survival and DFS and fewer DMs than other HTD groups. After adjustment for age, radical prostatectomy, nodal status, Gleason score, and stage variables, the HTD more than 5 years group remains significantly associated with better OS and DFS than other HTD groups.

CONCLUSION

In this hypothesis-generating analysis, prolonged HTD of more than 5 years seems significantly associated with improvements in most outcomes. Given these data, decreasing HTD to < or = 5 years may have a detrimental effect on patients with locally advanced prostate cancer. Only a randomized trial will conclusively clarify this issue.

Metabolic complications of androgen deprivation therapy for prostate cancer

PURPOSE

Androgen deprivation therapy has a variety of well recognized adverse effects including vasomotor flushing, loss of libido, fatigue, gynecomastia, anemia and osteoporosis. This review focuses on the more recently described metabolic complications of androgen deprivation therapy including obesity, insulin resistance and lipid alterations as well as the association of androgen deprivation therapy with diabetes and cardiovascular disease.

MATERIALS AND METHODS

We reviewed the medical literature using the PubMed(R) search terms prostate cancer, androgen deprivation therapy, gonadotropin-releasing hormone agonists, obesity, insulin resistance, lipids, diabetes, cardiovascular disease and myocardial infarction. We provide a focused review and our perspective on the relevant literature.

RESULTS

Androgen deprivation therapy decreases lean mass and increases fat mass. It also decreases insulin sensitivity while increasing low density lipoprotein cholesterol, high density lipoprotein cholesterol and triglycerides. Consistent with these adverse metabolic effects, androgen deprivation therapy may be associated with a greater incidence of diabetes and cardiovascular disease. Some of these androgen deprivation therapy related metabolic changes (obesity, insulin resistance and increased triglycerides) overlap with features of the metabolic syndrome. However, in contrast to the metabolic syndrome, androgen deprivation therapy increases subcutaneous fat and high density lipoprotein cholesterol.

CONCLUSIONS

Androgen deprivation therapy increases obesity, decreases insulin sensitivity and adversely alters lipid profiles. It may be associated with a greater incidence of diabetes and cardiovascular disease. The benefits of androgen deprivation therapy should be weighed against these and other potential harms. Little is known about the optimal strategy to mitigate the adverse metabolic effects of androgen deprivation therapy. Thus, we recommend an emphasis on existing strategies for screening and treatment that have been documented to reduce the risk of diabetes and cardiovascular disease in the general population.

Neoadjuvant hormonal therapy and external-beam radiotherapy versus external-beam irradiation alone for prostate cancer. A quality-of-life analysis

PURPOSE

To evaluate the impact of neoadjuvant hormonal therapy (NHT) on quality of life after external-beam radiotherapy (EBRT) for prostate cancer.

PATIENTS AND METHODS

A group of 170 patients (85 with and 85 without NHT) has been surveyed prospectively before EBRT (70.2-72 Gy), at the last day of EBRT, a median time of 2 months and 15 months after EBRT using a validated questionnaire (Expanded Prostate Cancer Index Composite). Pairs with and without NHT (median treatment time of 3.5 months before EBRT) were matched according to the respective planning target volume and prostate volume.

RESULTS

Before EBRT, significantly lower urinary function/bother, sexual function and hormonal function/bother scores were found for patients with NHT. More than 1 year after EBRT, only sexual function scores remained lower. In a multivariate analysis, NHT and adjuvant hormonal therapy (HT) versus NHT only (hazard ratio 14; 95% confidence interval 2.7-183; p = 0.02) and luteinizing hormone-releasing hormone (LHRH) agonists versus antiandrogens (hazard ratio 3.6; 95% confidence interval 1.1-12; p = 0.04) proved to be independent risk factors for long-term erectile dysfunction (no or very poor ability to have an erection).

CONCLUSION

With the exception of sexual function (additional adjuvant HT and application of LHRH analog independently adverse), short-term NHT was not found to decrease quality of life after EBRT for prostate cancer.

Causes of death in men undergoing androgen suppression therapy for newly diagnosed localized or recurrent prostate cancer

BACKGROUND

The authors estimated and characterized mortality after androgen suppression therapy (AST) use in men with newly diagnosed localized and recurrent prostate cancer.

METHODS

The study cohorts comprised 102 men who were randomized to radiation therapy (RT) and AST and 46 men who underwent salvage AST for recurrence from a randomized trial that compared external beam RT and 6 months of AST to RT. Cox regression multivariable analyses were performed to estimate the mortality hazard ratio (HR) in men with moderate to severe as compared with no or minimal comorbidity, adjusting for age and known prostate cancer prognostic factors.

RESULTS

After a median follow-up of 8.4 years (interquartile range: 7.2-9.6 years), prostate cancer-specific mortality (PCSM) comprised 13% and 75% of all mortality in men with newly diagnosed localized and recurrent prostate cancer, respectively. There was an increased risk of death in men with moderate to severe as compared with no or minimal comorbidity (adjusted HR [AHR], 11.5; 95% confidence interval [CI], 5.2-25.6; P < .001) in men with newly diagnosed localized prostate cancer but not in men with recurrent prostate cancer (AHR, 2.5; 95% CI, 0.2-37.8; P = .51).

CONCLUSIONS

The ability to measure an increase in the risk of death in men with moderate to severe as compared with no or minimal comorbidity undergoing AST decreases as the risk of PCSM increases, which may explain the discordance in the literature regarding the risk of cardiovascular death and AST use.

Endocrine treatment, with or without radiotherapy, in locally advanced prostate cancer (SPCG-7/SFUO-3): an open randomised phase III trial

BACKGROUND

Several studies have shown the efficacy of endocrine therapy in combination with radiotherapy in high-risk prostate cancer. To assess the effect of radiotherapy, we did an open phase III study comparing endocrine therapy with and without local radiotherapy, followed by castration on progression.

METHODS

This randomised trial included men from 47 centres in Norway, Sweden, and Denmark. Between February, 1996, and December, 2002, 875 patients with locally advanced prostate cancer (T3; 78%; PSA<70; N0; M0) were centrally randomly assigned by computer to endocrine treatment alone (3 months of total androgen blockade followed by continuous endocrine treatment using flutamide; 439 patients), or to the same endocrine treatment combined with radiotherapy (436 patients). The primary endpoint was prostate-cancer-specific survival, and analysis was by intention to treat. This study is registered as an international standard randomised controlled trial, number ISRCTN01534787.

FINDINGS

After a median follow-up of 7.6 years, 79 men in the endocrine alone group and 37 men in the endocrine plus radiotherapy group had died of prostate cancer. The cumulative incidence at 10 years for prostate-cancer-specific mortality was 23.9% in the endocrine alone group and 11.9% in the endocrine plus radiotherapy group (difference 12.0%, 95% CI 4.9-19.1%), for a relative risk of 0.44 (0.30-0.66). At 10 years, the cumulative incidence for overall mortality was 39.4% in the endocrine alone group and 29.6% in the endocrine plus radiotherapy group (difference 9.8%, 0.8-18.8%), for a relative risk of 0.68 (0.52-0.89). Cumulative incidence at 10 years for PSA recurrence was substantially higher in men in the endocrine-alone group (74.7%vs 25.9%, p<0.0001; HR 0.16; 0.12-0.20). After 5 years, urinary, rectal, and sexual problems were slightly more frequent in the endocrine plus radiotherapy group.

INTERPRETATION

In patients with locally advanced or high-risk local prostate cancer, addition of local radiotherapy to endocrine treatment halved the 10-year prostate-cancer-specific mortality, and substantially decreased overall mortality with fully acceptable risk of side-effects compared with endocrine treatment alone. In the light of these data, endocrine treatment plus radiotherapy should be the new standard.

Management of locally advanced prostate cancer

The management of all stages of prostate cancer is an increasingly complex process and involves a variety of available treatments and many disciplines. Despite prostate-specific antigen (PSA) testing, the presentation of prostate cancer at a locally advanced stage is common in the UK, accounting for one-third of all new cases. There is no universally accepted definition of locally advanced prostate cancer; the term is loosely used to encompass a spectrum of disease profiles that show high-risk features. Men with high-risk prostate cancer generally have a significant risk of disease progression and cancer-related death if left untreated. High-risk patients, including those with locally advanced disease, present two specific challenges. There is a need for local control as well as a need to treat any microscopic metastases likely to be present but undetectable until disease progression. The optimal treatment approach will therefore often necessitate multiple modalities. The exact combinations, timing and intensity of treatment continue to be strongly debated. Management decisions should be made after all treatments have been discussed by a multidisciplinary team (including urologists, oncologists, radiologists, pathologists and nurse specialists) and after the balance of benefits and side effects of each therapy modality has been considered by the patient with regard to his own individual circumstances. This article reviews the current therapy options.

Giant organ confined prostatic adenocarcinoma: a case report

Introduction

Giant prostatic adenocarcinoma represents a rare and challenging treatment dilemma.

Case presentation

We describe a case of an otherwise healthy 71-year-old African male who presented with a PSA of 5800 ng/ml and a prostate volume of over 1000cc. Unique aspects of this case include the size of the prostate, the apparent absence of distant metastases, and the safe usage of transabdominal biopsy of this mass.

Conclusion

We present this case report and review of literature to generate further discussion amongst readers as to management options for this difficult case.

Cardiovascular mortality after androgen deprivation therapy for locally advanced prostate cancer: RTOG 85-31

PURPOSE

Gonadotropin-releasing hormone (GnRH) agonists are associated with greater risk of coronary heart disease and myocardial infarction in men with prostate cancer, but little is known about potential impact on cardiovascular mortality. We assessed the relationship between GnRH agonists and cardiovascular mortality in a large randomized phase III trial of men treated with or without adjuvant goserelin after radiation therapy (RT) for locally advanced prostate cancer.

PATIENTS AND METHODS

Between 1987 and 1992, 945 men with locally advanced prostate cancer were randomly assigned to RT and adjuvant goserelin or RT alone. Fine and Gray's regression was used to evaluate treatment effect on cardiovascular mortality. Covariates included age, prevalent cardiovascular disease (CVD), hypertension, diabetes mellitus (DM), body mass index, race, Gleason score, stage, acid phosphatase level, prostatectomy history, and nodal involvement.

RESULTS

After a median follow-up of 8.1 years, there were 117 cardiovascular-related deaths but no treatment-related increase in cardiovascular mortality. At 9 years, cardiovascular mortality for men receiving adjuvant goserelin was 8.4% v 11.4% for men treated without adjuvant goserelin (Gray's P = .17). In multiple regression analyses, treatment arm was not significantly associated with increased risk of cardiovascular mortality (adjusted hazard ratio [HR] = 0.73; 95% CI, 0.47 to 1.15; P = .16; when censoring at time of salvage goserelin therapy, HR = 0.99; 95% CI, 0.58 to 1.69; P = .97). Traditional cardiac risk factors, including prevalent CVD and DM, were significantly associated with greater cardiovascular mortality.

CONCLUSION

GnRH agonists do not seem to increase cardiovascular mortality in men with locally advanced prostate cancer. Further studies are warranted to evaluate adverse effects of GnRH agonists in men with lower cancer-specific mortality.

Adjuvant and salvage radiotherapy after prostatectomy for prostate cancer: a literature review

PURPOSE

Given that postprostatectomy recurrence of prostate cancer occurs in 10-40% of patients, the best use of immediate postoperative radiotherapy (RT) in high-risk patients and salvage RT for biochemical recurrence remains a topic of debate. We assessed the levels of evidence (in terms of efficacy, prognostic factors, and toxicity) for the following treatment strategies: immediate postoperative RT alone, salvage RT alone, and the addition of androgen deprivation therapy to the two RT strategies.

METHODS AND MATERIALS

A systematic literature search for controlled randomized trials, noncontrolled trials, and retrospective studies between 1990 and 2008 was performed on PubMed, CancerLit, and MEDLINE. Only relevant articles that had appeared in peer-reviewed journals were selected. We report on the levels of evidence (according to the National Cancer Institute guidelines) supporting the various treatment strategies.

RESULTS

Immediate postoperative RT improves biochemical and clinical progression-free survival (Level of evidence, 1.ii) but has no significant effect on metastasis-free survival or overall survival. A pathologic review is of particular importance for correctly analyzing the treatment strategies. Low-grade morbidity has been significantly greater in the postoperative groups, but no severe toxicity has been observed. The influence of immediate postoperative RT on postprostatectomy continence appears to be slight; therefore, immediate postoperative RT should be considered in patients with major risk factors for local relapse (Level of evidence, 1.ii). On the basis of extensive retrospective data, salvage RT is effective in biochemical relapse after prostatectomy; some patients with few adverse prognostic factors might also benefit from salvage RT (Level of evidence, 3.ii). The addition of androgen deprivation therapy to immediate postoperative or salvage RT has only been supported by weak, retrospective data (Level of evidence, 3.ii).

CONCLUSION

Prospective randomized trials are needed to compare immediate postoperative RT with salvage RT and to assess the value of androgen deprivation therapy in this setting.

Definitive radiotherapy for prostate cancer

The probability of extraprostatic disease may be estimated based on clinical T-stage, pretreatment prostatic-specific antigen, Gleason score, and percent positive core biopsies. Patients with disease confined to the prostate may be treated with either prostatectomy or radiotherapy (RT). Patients with extraprostatic disease without evidence of distant metastases are best managed with RT. RT consisting of either external beam and/or brachytherapy results in a relatively high likelihood of cure, particularly for those with low- and intermediate-risk disease. The impact of elective nodal RT on survival is unclear. Dose escalation results in improved biochemical relapse-free survival compared with standard dose RT. Androgen deprivation therapy likely improves the probability of disease control in patients with high-risk cancers.

Phase III multi-institutional trial of adjuvant chemotherapy with paclitaxel, estramustine, and oral etoposide combined with long-term androgen suppression therapy and radiotherapy versus long-term androgen suppression plus radiotherapy alone for high-risk prostate cancer: preliminary toxicity analysis of RTOG 99-02

PURPOSE

Long-term androgen suppression plus radiotherapy (AS+RT) is standard treatment of high-risk prostate cancer. A randomized trial, Radiation Therapy Oncology Group trial 9902, was undertaken to determine whether adjuvant chemotherapy with paclitaxel, estramustine, and etoposide (TEE) plus AS+RT would improve disease outcomes with acceptable toxicity.

METHODS AND MATERIALS

High-risk (prostate-specific antigen 20-100 ng/mL and Gleason score >or=7; or Stage T2 or greater, Gleason score 8, prostate-specific antigen level <100 ng/mL) nonmetastatic prostate cancer patients were randomized to AS+RT (Arm 1) vs. AS+RT plus four cycles of TEE (Arm 2). TEE was delivered 4 weeks after RT. AS continued for 2 years for both treatment arms. RT began after 8 weeks of AS began.

RESULTS

The Radiation Therapy Oncology Group 9902 trial opened January 11, 2000. Excess thromboembolic toxicity was noted, leading to study closure October 4, 2004. A total of 397 patients were accrued, and the data for 381 were analyzable. An acute and long-term toxicity analysis was performed. The worst overall toxicities during treatment were increased for Arm 2. Of the 192 patients, 136 (71%) on Arm 2 had RTOG Grade 3 or greater toxicity compared with 70 (37%) of 189 patients on Arm 1. Statistically significant increases in hematologic toxicity (p < 0.0001) and gastrointestinal toxicity (p = 0.017) but not genitourinary toxicity (p = 0.07) were noted during treatment. Two Grade 5 complications related to neutropenic infection occurred in Arm 2. Three cases of myelodysplasia/acute myelogenous leukemia were noted in Arm 2. At 2 and 3 years after therapy completion, excess long-term toxicity was not observed in Arm 2.

CONCLUSION

TEE was associated with significantly increased toxicity during treatment. The toxicity profiles did not differ at 2 and 3 years after therapy. Toxicity is an important consideration in the design of trials using adjuvant chemotherapy for prostate cancer.

Variation in the definition of clinical target volumes for pelvic nodal conformal radiation therapy for prostate cancer

PURPOSE

We conducted a comparative study of clinical target volume (CTV) definition of pelvic lymph nodes by multiple genitourinary (GU) radiation oncologists looking at the levels of discrepancies amongst this group.

METHODS AND MATERIALS

Pelvic computed tomography (CT) scans from 2 men were distributed to 14 Radiation Therapy Oncology Group GU radiation oncologists with instructions to define CTVs for the iliac and presacral lymph nodes. The CT data with contours were then returned for analysis. In addition, a questionnaire was completed that described the physicians' method for target volume definition.

RESULTS

Significant variation in the definition of the iliac and presacral CTVs was seen among the physicians. The minimum, maximum, mean (SD) iliac volumes (mL) were 81.8, 876.6, 337.6 +/- 203 for case 1 and 60.3, 627.7, 251.8 +/- 159.3 for case 2. The volume of 100% agreement was 30.6 and 17.4 for case 1 and 2 and the volume of the union of all contours was 1,012.0 and 807.4 for case 1 and 2, respectively. The overall agreement was judged to be moderate in both cases (kappa = 0.53 (p < 0.0001) and kappa = 0.48 (p < 0.0001). There was no volume of 100% agreement for either of the two presacral volumes. These variations were confirmed in the responses to the associated questionnaire.

CONCLUSIONS

Significant disagreement exists in the definition of the CTV for pelvic nodal radiation therapy among GU radiation oncology specialists. A consensus needs to be developed so as to accurately assess the merit and safety of such treatment.

Changes of prostate gland volume with and without androgen deprivation after intensity modulated radiotherapy - A follow-up study

BACKGROUND AND PURPOSE

The shrinking effect of androgen deprivation therapy (ADT) on prostate volume is a known finding, but data on volume changes during radiotherapy are inconsistent. We examined patients with and without ADT undergoing intensity modulated radiotherapy (IMRT) and performed follow-up examinations to study volume changes before and after radiotherapy.

METHODS AND MATERIALS

Prostate volumes between planning magnetic resonance imaging (MRI) and last available follow-up MRI were retrospectively determined in 39 patients. Median time interval between first and last MRI was 233days (range 126-813). Two observers performed volume measurements in consensus and were blind to the timing of MRI. Volume changes over MRI were determined using the ellipsoid formula. Data of patients with and without ADT were compared by a linear mixed model.

RESULTS

Of 39 patients, 22 had ADT with a median duration of 5months (range 1-24). ADT patients showed lower prostate volume throughout the study period (-28% to 38%). Although individual shrinking effect was highly variable, patients treated with IMRT but without ADT showed a significantly larger volume reduction (26.1%) than patients with ADT (12.9%, p<0.05).

CONCLUSIONS

Patients undergoing IMRT show definite prostate shrinkage. The rate is slowed down after 6months in both groups, whereas the volume reduction is significantly larger in patients without ADT. Nevertheless there is no adding effect of ADT+IMRT vs. IMRT alone.

Androgen deprivation therapy for the treatment of prostate cancer: consider both benefits and risks

CONTEXT

Androgen deprivation therapy (ADT) is increasingly used for the treatment of prostate cancer (PCa), even in clinical settings in which there is no evidence-based proof of prolonged overall survival (OS). ADT, however, may be associated with numerous side effects, including an increased therapy-related cardiovascular mortality.

OBJECTIVE

To discuss different clinical settings in which ADT is currently used and to critically weigh the benefits of ADT against its possible side effects.

EVIDENCE ACQUISITION

A MEDLINE search was conducted to identify original articles and review articles addressing the efficacy and side effects of ADT for the treatment of PCa. Keywords consisted of prostate cancer, hormonal therapy, adverse effects, radical prostatectomy, and radiotherapy. The articles with the highest level of evidence for the various examined end points were identified with the consensus of all authors and were reviewed.

EVIDENCE SYNTHESIS

Even short-term use of ADT may lead to numerous side effects, such as osteoporosis, obesity, sarcopenia, lipid alterations, insulin resistance, and increased risk for diabetes and cardiovascular morbidity. Despite these side effects, ADT is commonly used in various clinical settings in which a clear effect on improved OS has not been shown.

CONCLUSIONS

ADT is associated with an increased risk of multiple side effects that may reduce quality of life and/or OS. Consequently, these issues should be discussed in detail with patients and their families before initiation of ADT. ADT should be used with knowledge of its potential long-term side effects and with possible lifestyle interventions, especially in settings with the highest risk-benefit ratio, to alleviate comorbidities.

Safety and immunologic response of a viral vaccine to prostate-specific antigen in combination with radiation therapy when metronomic-dose interleukin 2 is used as an adjuvant

PURPOSE

We have previously reported on the safety and immunologic response of a poxvirus-based vaccine encoding prostate-specific antigen (PSA) used in combination with radiation therapy in patients with localized prostate cancer. We hypothesized that a "metronomic" dose of interleukin 2 (IL-2) as a biological adjuvant would cause less toxicity while maintaining immunologic response.

EXPERIMENTAL DESIGN

Eighteen patients with localized prostate cancer were treated in a single-arm trial using previously established doses of vaccine and radiation therapy. The vaccine used was a recombinant vaccinia virus engineered to encode PSA admixed with a recombinant vaccinia encoding the costimulatory molecule B7.1, followed by booster vaccinations with a recombinant fowlpox vector expressing PSA. Patients received a total of eight planned vaccination cycles, once every 4 weeks, with granulocyte-macrophage colony-stimulating factor given on days 1 to 4 and interleukin 2 (IL-2) at a dose of 0.6 MIU/M2 given from days 8 to 21 after each vaccination. Definitive external beam radiation therapy was initiated after the third vaccination cycle. Patients were evaluated for safety and immunologic response. Toxicity and immunologic activity were compared with the previously reported regimen containing a higher dose of IL-2.

RESULTS

Seventeen of 18 patients received all eight cycles of vaccine with IL-2. Five of eight HLA-A2+ patients evaluated had an increase in PSA-specific T cells of > or =3-fold. Toxicities were generally mild, with only seven vaccination cycles of 140 given resulting in grade 3 toxicities possibly attributable to IL-2.

CONCLUSIONS

Metronomic-dose IL-2 in combination with vaccine and radiation therapy is safe, can induce prostate-specific immune responses, and has immunologic activity similar to low-dose IL-2, with markedly reduced toxicities.

[Adjuvant and neoadjuvant drug therapy for prostate cancer]

Neoadjuvant and adjuvant therapeutic strategies are widely employed for a variety of cancer entities. The basic aim and the potential benefit for the patient are to eradicate micrometastases, with the downside being side effects and overtreatment. Neoadjuvant and adjuvant hormone therapy for prostate cancer have been investigated in a number of clinical studies. Based on these studies, the following recommendations can be given: there is currently no indication for neoadjuvant therapy prior to radical prostatectomy. Adjuvant therapy using LHRH analogs for patients with lymph node-positive tumors following radical prostatectomy can be considered but should be weighed against early"biochemical progression triggered" treatment. For locally advanced tumors the same is true (bicalutamide): adjuvant treatment has shown an advantage in clinically progression-free survival; however, no systematic comparison is available with early"biochemical progression triggered" treatment. Before radiotherapy 2 months of neoadjuvant LHRH analog treatment has shown a survival advantage in patients with locally advanced tumors and a low risk of systemic spread (Gleason <7). For high-risk patients, long-term (2-3 years) adjuvant LHRH analog treatment is indicated.

[Radiotherapy for locally advanced prostate cancer]

Technical developments in radiation oncology have led to major improvements in the treatment of locally advanced prostate cancer. This article summarizes the publications on dose escalation, including the side effects. The effect of additional hormonal therapy and irradiation of the pelvic lymphatics is also discussed.

Final report of multicenter Canadian Phase III randomized trial of 3 versus 8 months of neoadjuvant androgen deprivation therapy before conventional-dose radiotherapy for clinically localized prostate cancer

PURPOSE

To evaluate the effect of 3 vs. 8 months of neoadjuvant hormonal therapy before conventional-dose radiotherapy (RT) on disease-free survival for localized prostate cancer.

METHODS AND MATERIALS

Between February 1995 and June 2001, 378 men were randomized to either 3 or 8 months of flutamide and goserelin before 66 Gy RT at four participating centers. The median baseline prostate-specific antigen level was 9.7 ng/mL (range, 1.3-189). Of the 378 men, 26% had low-, 43% intermediate-, and 31% high-risk disease. The two arms were balanced in terms of age, Gleason score, clinical T category, risk group, and presenting prostate-specific antigen level. The median follow-up for living patients was 6.6 years (range, 1.6-10.1). Of the 378 patients, 361 were evaluable, and 290 were still living.

RESULTS

The 5-year actuarial freedom from failure rate for the 3- vs. 8-month arms was 72% vs. 75%, respectively (p = 0.18). No difference was found in the failure types between the two arms. The median prostate-specific antigen level at the last follow-up visit for patients without treatment failure was 0.6 ng/mL in the 3-month arm vs. 0.50 ng/mL in the 8-month arm. The disease-free survival rate at 5 years was improved for the high-risk patients in the 8-month arm (71% vs. 42%, p = 0.01).

CONCLUSION

A longer period of NHT before standard-dose RT did not alter the patterns of failure when combined with 66-Gy RT. High-risk patients in the 8-month arm had significant improvement in the 5-year disease-free survival rate.

Predicting prostate cancer mortality among men with intermediate to high-risk disease and multiple unfavorable risk factors

PURPOSE

To determine whether the number of unfavorable risk factors could be used to predict the risk of prostate cancer-specific mortality (PCSM) among men with intermediate- to high-risk prostate cancer.

METHODS AND MATERIALS

We studied 1,063 men who underwent radical prostatectomy (n = 559), external beam radiotherapy (n = 288), or radiotherapy plus androgen suppression therapy (n = 116) for prostate cancer between 1965 and 2002. Fine and Gray's regression analysis was used to determine whether an increasing number of unfavorable risk factors (prostate-specific antigen level >10 ng/mL, Gleason score of >or=7, clinical Stage T2b or greater, or pretreatment prostate-specific antigen velocity >2.0 ng/mL/y) was associated with the interval to PCSM and all-cause mortality.

RESULTS

Median follow-up was 5.6 years. Compared with those with one risk factor, the adjusted hazard ratio for PCSM was 2.3 (95% confidence interval 1.1-4.8; p = 0.03) for two risk factors, 5.4 (95% confidence interval 2.7-10.7; p < 0.0001) for three risk factors, and 13.6 (95% confidence interval 6.3-29.2; p < 0.0001) for all four risk factors. The 5-year cumulative incidence of PCSM was 2.4% for one factor, 2.4% for two factors, 7.0% for three factors, and 14.7% for all four factors. Prostate cancer deaths as a proportion of all deaths was 19% for one factor, 33% for two factors, 53% for three factors, and 80% for four factors.

CONCLUSION

The number of unfavorable risk factors was significantly associated with PCSM. Prostate cancer was the major cause of death in men with at least three risk factors. Therefore, these men should be considered for clinical trials designed to assess whether survival is prolonged with the addition of novel agents to current standards of practice.

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.

[Androgen deprivation for advanced prostate cancer]

Androgen deprivation (ADT) by medical or surgical castration represents the standard therapeutic approach for managing prostate cancer (PCA) with systemic or locoregional metastases. Although ADT has been successfully used for more than 60 years, there are still major controversies with regard to the initiation (early versus delayed), type (complete versus monotherapy), and duration (continuous versus intermittent) of treatment. It is the purpose of this review to critically present the results of the various ADT options. Bilateral orchiectomy and subcutaneous application of luteinising hormone-releasing hormone (LHRH) analogues represent the guideline-recommended standard treatment for metastatic PCA, whereas estrogens are no longer recommended because of significant cardiovascular side effects despite comparable therapeutic efficacy. Antiandrogen monotherapy with bicalutamide is comparable to LHRH analogues in men with minimal tumour burden. However, survival rates are inferior in patients with extensive metastatic disease, in whom medical or surgical castration should be favoured. Complete ADT results in a median survival benefit of about 5% in men with low metastatic tumour burden, and it cannot be recommended for routine use. Early ADT is associated with a significant advantage in terms of symptom-free survival and prevention of metastasis-associated complications, but it does not result in a prolonged progression-free and overall survival when compared with delayed ADT. Despite encouraging results, intermittent ADT remains an experimental therapeutic approach that should be considered on an individual basis in carefully selected patients. Adjuvant ADT is still discussed controversially for men after radical prostatectomy, whereas it has become the standard approach in patients who undergo external beam radiation for locally advanced PCA.

Risk of prostate cancer recurrence in men treated with radiation alone or in conjunction with combined or less than combined androgen suppression therapy

PURPOSE

We determined the risk of recurrence in men enrolled on a randomized trial for prostate cancer who were treated with radiation therapy (RT) alone or in conjunction with combined or less than combined androgen suppression therapy (AST).

PATIENTS AND METHODS

Between 1995 and 2001, 206 men with localized but unfavorable-risk adenocarcinoma of the prostate were randomly assigned to receive RT or RT and AST, which was defined as 6 months of both a luteinizing hormone-releasing hormone agonist and an antiandrogen. A post-random assignment hypothesis that was generated by multivariable Cox regression analyses was used to evaluate whether the risk of prostate-specific antigen (PSA) recurrence was significantly associated with months of antiandrogen use; regression analysis adjusted for known prognostic factors, comorbidity score, and medications that can elevate liver function tests sufficiently to necessitate discontinuation of the antiandrogen.

RESULTS

After a median follow-up of 8.2 years (interquartile range,7.0 to 9.5 years), 81 men sustained PSA recurrence. An increasing PSA level (P < .001); Gleason score of 8, 9, or 10 (P < .001); and clinical category T2 disease (P = .005) were significantly associated with an increased risk of recurrence. However, recurrence risk was significantly decreased (adjusted hazard ratio, 0.81; 95% CI, 0.72 to 0.92; P = .001) with each additional month of antiandrogen use after analysis was adjusted for these known prognostic factors.

CONCLUSION

Men with localized but unfavorable-risk prostate cancer who were treated with RT and 6 months of planned combined AST appear to have an increased risk of recurrence when treated with less than as compared with 6 months of the antiandrogen.