Serum prostate-specific antigen decline as a marker of clinical outcome in hormone-refractory prostate cancer patients: association with progression-free survival, pain end points, and survival

The use of circulating biomarkers in early clinical trials in patients with cancer

The development of targeted therapies has changed the approach to early oncological clinical trial design. Identification of patient populations most likely to derive benefit and the biologically effective dose are now as important as determination of the maximum tolerated dose. Completion of the 'pharmacological audit trail' highlights drugs most likely to progress through to license, so resources can be allocated appropriately. Key to the success of this changing model is the validation/qualification of circulating biomarkers. These might provide a readily accessible and dynamic picture of drug effect, tumor response and toxicity with minimum risk to patients. This review article examines circulating biomarkers currently used in early oncological clinical trials. It considers the evidence for their employment, limitations and challenges for future development.

Effect of chronic Sildenafil treatment on the prostate of C57Bl/6 mice

Sildenafil is a potent and selective inhibitor of phosphodiesterase-5 (PDE5) and is considered first-line therapy for erectile dysfunction. Nowadays, Sildenafil is used extensively throughout the world on patients with pulmonary hypertension. However, few studies have evaluated the possible side effects of chronic Sildenafil treatment on the male reproductive system, specifically in the prostate. In the present study, it was demonstrated via morphological and ultrastructural analysis that chronic treatment with Sildenafil induced an enhancement of the glandular activity of the prostate. In addition, mice treated with Sildenafil showed a significant increase in testosterone serum levels. However, no statistically significant differences were observed in nitric oxide serum levels, or in sGC, eNOS, PSA and TGF-β prostatic expression. In conclusion, the present study suggests that chronic use of Sildenafil does not cause evident prostatic damage, and therefore, can be used pharmacologically to treat a variety of disorders.

Metastatic castration resistant prostate cancer: current strategies of management in the Middle East

Although most patients with prostate cancer respond to initial androgen-deprivation therapy, progression to castration-resistant prostate cancer (CRPC) is almost inevitable. In 2004, the docetaxel/prednisone regimen was approved for the management of patients with metastatic CRPC, becoming the standard first-line therapy. Recent advances have also led to an unprecedented number of approved new drugs; thus, providing several treatment options for patients with metastatic CRPC. Five new drugs have received US Food and Drug Administration-approval between 2010 and 2012: sipuleucel-T, an immunotherapeutic agent; cabazitaxel, a novel microtubule inhibitor; abiraterone acetate, a new androgen biosynthesis inhibitor; enzalutamide, a novel androgen receptor inhibitor; and denosumab, a bone-targeting agent. Such drugs are either already marketed or about to be marketed in the Middle East. Data supporting the approval of each of these agents are described in this review, as are recent approaches to the treatment of metastatic CRPC.

Metastatic prostate cancer in transsexual diagnosed after three decades of estrogen therapy

The incidence of prostate cancer in transsexual patients is very low with only few reported cases. Many years before presenting with prostate cancer, these patients receive hormone ablation as a part of their gender therapy. Their disease is already defined as castrate resistant, and the treatment and follow-up of such patients remains a challenge. We report a case of a male-to-female transgender woman who was diagnosed with metastatic prostate cancer, 31 years post-feminization.

Phase II Study of Pomalidomide in Patients with Castration-Resistant Prostate Cancer

Pomalidomide is a distinct immunomodulatory agent that also displays anti-proliferative and proapoptotic activity. The purpose of this study was to assess the efficacy and safety of pomalidomide for the treatment of chemotherapy-naïve patients with metastatic castration-resistant prostate cancer (CRPC). Methods: Pomalidomide was administered orally in doses of 1 or 2 mg/day without interruption. Follow ups were conducted every 4 weeks with evaluation of study outcomes at 12 weeks. The principal study outcomes were PSA response, time to progression (TTP) using RECIST, overall survival (OS), and safety. A total of 32 patients were enrolled: 15 in the 1 mg/day cohort (median baseline PSA level of 12.30 ng/mL [0.8–236.0]), and 17 in the 2 mg/day cohort (median baseline PSA level of 12.50 ng/mL [0.6–191.8]). Results: In the 1 mg cohort disease was stabilized for ≥28 days in eight patients, and median TTP was 2.90 months. In the 2 mg cohort, PSA decreased ≥50% in three patients, disease was stabilized for ≥28 days in seven patients, and median TTP was 5.87 months. Toxicity in both cohorts was predominantly grade 1 or 2; 2 grade 3 toxicity (fatigue) occurred in the 1 mg cohort, and 5 grade 3 toxicities (chest pain, diarrhea, epigastric pain, impaction, pain) occurred in the 2 mg cohort. One grade 4 toxicity of cardiac ischemia occurred. Conclusions: Pomalidomide shows promising activity in patients with CRPC and has an acceptable safety profile.

Prostate cancer

Prostate cancer is biologically and clinically a heterogeneous disease and its imaging evaluation will need to be tailored to the specific phases of the disease in a patient-specific, risk-adapted manner. We first present a brief overview of the natural history of prostate cancer before discussing the role of various imaging tools, including opportunities and challenges, for different clinical phases of this common disease in men. We then review the preclinical and clinical evidence on the potential and emerging role of positron emission tomography with various radiotracers in the imaging evaluation of men with prostate cancer.

Lycopene for advanced hormone refractory prostate cancer: a prospective, open phase II pilot study

PURPOSE

We investigated the influence of lycopene on the clinical and laboratory course in men with hormone refractory prostate cancer. To our knowledge this study represents the first time that subjective assessments of the course of therapy have been recorded.

MATERIAL AND METHODS

We performed a prospective, open phase II pilot study, in which patients with progressive hormone refractory prostate cancer were included. Lycopene supplementation (15 mg) was given daily for 6 months. Followup laboratory tests and clinical examinations were done monthly. Changes to analgesic use and quality of life (European Organisation for Research and Treatment of Cancer QLQ-C30) were measured. The study end point was a significant change in serum prostate specific antigen, clinical progression or the end of the 6-month observation period.

RESULTS

A total of 18 patients 64 to 85 years old (median age 73) were enrolled in the study during a 20-month period, of whom 17 could be analyzed. Five of the 17 patients (29%) withdrew from the study prematurely, including 4 of 5 because of prostate specific antigen progression and/or tumor associated complications, and 1 due to an allergic reaction to lycopene. Median prostate specific antigen doubled in 6 months from 42.7 ng/ml (range 13.8 to 521.6) in 17 patients to 96.4 ng/ml (range 13.5 to 1,240) in 12. Stable prostate specific antigen was observed in 5 of 17 patients (29%). None of the patients had a greater than 50% decrease in prostate specific antigen. Patients experienced a slight deterioration in mean health status at the end of the study compared to the outset. However, two-thirds of the patients experienced an improved or unchanged situation regardless of the clinical and biochemical course.

CONCLUSIONS

No clinically relevant benefits were shown for patients with advanced stages of the disease.

Dendritic-cell vaccination for prostate cancer

Vaccination with tumor antigen-loaded dendritic cells has been one of the most frequently applied immunotherapeutic strategies in prostate cancer. Immunological effects have been observed in a majority of patients, while clinical effects have been modest and transient. Advances in the understanding of the interplay between cancer and the immune system have generated new concepts in tumor immunology and immunotherapy that might aid in the improvement of vaccine effectiveness. The combination of immunotherapy with conventional treatment modalities and targeting of immunosuppressive mechanisms has demonstrated improved immunological and clinical results that warrant further investigation.

[PSA and follow-up after treatment of prostate cancer]

A first serum total PSA assay is recommended during the first three months after treatment. When PSA is detectable, PSA assay should be repeated three months later to confirm this elevation and to estimate the PSA doubling time (PSADT). In the absence of residual cancer, PSA becomes undetectable by the first month after total prostatectomy: less than 0.1 ng/ml (or less than 0.07 ng/ml) for the ultrasensitive assay method and less than 0.2 ng/ml for the other methods. In the presence of residual cancer, PSA either does not become undetectable or increases after an initial undetectable period. A consensus has been reached to define recurrence as PSA greater than 0.2 ng/ml confirmed on two successive assays. After external beam radiotherapy, PSA can decrease after a mean interval of one to two years to a value less than 1 ng/ml (predictive of recurrence-free survival). Biochemical recurrence after radiotherapy is defined by an increase of PSA by 2 ng or more above the PSA nadir, whether or not it is associated with endocrine therapy. After endocrine therapy, the PSA nadir is correlated with recurrence-free survival. PSA is decreased for a mean of 18 to 24 months followed by a rise in PSA, corresponding to hormone-independence. The time to recurrence or the time to reach the nadir and the PSA doubling time after local therapy with surgery or radiotherapy have a diagnostic value in terms of the site of recurrence, local or metastatic and a prognostic value for survival and response to complementary radiotherapy or endocrine therapy. A PSADT less than eight to 12 months is correlated with a high risk of metastatic recurrence and 10-year mortality. The histological and biochemical characteristics in favour of local recurrence are Gleason score less or equal to seven (3+4), elevation of PSA after a period greater than 12 months and PSADT greater than 10 months. In other cases, recurrence is predominantly metastatic. The risk of demonstrating metastasis in the case of biochemical recurrence after total prostatectomy and before endocrine therapy depends on the PSA level and the PSADT. No consensus has been reached concerning the indication for complementary investigations by bone scan and abdominopelvic CT in patients with biochemical recurrence after treatment of localized cancer without endocrine therapy. However, when PSADT greater than six months, the risk of metastasis is less than 3% even for PSA greater than 30 ng/ml. When PSADT less than six months and PSA greater than 10 ng/ml, the risk of metastasis is close to 50%.

Current perspectives in the treatment of advanced prostate cancer

Prostate cancer (PC) continues to be an important world health problem for men. Patients with locally confined PC are treated with either radiotherapy or surgery. However, treatment of more advanced stages of the disease is problematic. Initially, androgen deprivation offers a period of clinical stability, which is however invariably followed by progression to non-responsiveness to hormonal manipulation. Current management of patients with androgen-independent prostate cancer (AIPC) displays modest response rates and achieves only short-term benefit. Recently, knowledge in the complex pathophysiology of advanced PC has led to the identification of mechanisms and target molecules permitting the introduction of new therapies. Consequently, many investigational treatments are ongoing for AIPC in Phase-II and Phase-III trials aiming at the combination of chemotherapeutic regimens along with immunotherapy targeting PC-associated antigens. Other attractive options are gene therapy, as well as the targeting of survival signaling, differentiation, and apoptosis of the malignant PC cells. Further treatment modalities are directed against the tumor microenvironment, bone metastasis, or both. Collectively, the aforementioned efforts introduce a new era in the management of advanced PC. Novel pharmaceutical compounds and innovative approaches, integrated into the concept of individualized therapy will hopefully, during the next decade, improve the outcome and survival for hundreds of thousands of men worldwide.

[Active immunotherapy of prostate cancer with a focus on dendritic cells]

Recurrent or metastatic prostate cancer is generally considered an incurable disease. Given the transient benefit from hormone deprivation therapy and limited successes of systemic chemotherapy, alternative treatment modalities are needed both in the situation of PSA recurrence and in hormone-refractory disease. Prostate cancer cells express several tumor associated antigens which are currently being evaluated as targets for active and specific immunotherapy approaches. Dendritic cells (DC) are the most powerful antigen-presenting cells (APC), able to prime naive T cells and to break peripheral tolerance and thus induce tumor immune responses. Close to 1000 prostate cancer patients have been treated with DC-based or other forms of active immunotherapy to date. Vaccination-induced immune responses have been reported in two thirds of DC trials, and favorable changes in the clinical course of the disease in almost half of the patients treated. Most responses, however, were modest and transient. Therefore, mechanisms of treatment failure and possibilities to improve vaccination efficacy are being discussed.

Serum PSA half-life as a predictor of survival for hormone-refractory prostate cancer patients: modelization using a standardized set of response criteria

OBJECTIVE

Changes of serum prostate-specific antigen (PSA) during chemotherapy have been validated as a marker of response for hormone-refractory prostate cancer (HRPC) patients. We retrospectively established new response criteria to assess the risk of death.

METHODS

Two hundred fifty-six chemonaive HRPC patients treated with chemotherapy were included in the analysis. According to PSA half-life (HL) dynamics, three response categories were defined: responders (R), late-progressors (LP) and initial-progressors (IP), that were compared with Working Group (WG) criteria. PSA HL time to failure (TTF) and overall survival (OS) were estimated and compared between HT categories. Multivariate regression analysis was performed to isolate the impact on OS of these response categories. A new predictor of survival, delta-time PSA interval (DeltaT) was described.

RESULTS

PSA HL categories were strongly related with WG criteria (P = 0.0001). PSA HL TTF differed among PSA HL categories: 4.2, 2.3, and 0.9 months for R, LP, and IP patients, respectively, and their respective median OS were 27, 19.7, and 12.3 months (P = 0.0001). For DeltaT > or = 3 versus <3 months, median OS significantly differed: 24.9 months versus 13.2 months (P = 0.0001).

CONCLUSIONS

PSA HL dynamics during chemotherapy were able to accurately predict survival, earlier than WG-defined progression criteria. This criterion should be prospectively evaluated in randomized trials for HRPC patients in order to better estimate the risk of death.

Successful Treatment of Metastatic Androgen-Independent Prostate Carcinoma in a Transsexual Patient

The occurrence of prostate carcinoma in transsexual patients has rarely been reported. These cases present a unique challenge in that such patients are effectively receiving androgen deprivation therapy. By definition, their disease is androgen-independent prostate cancer, and the role of local therapy is undefined. We report on a male-to-female transsexual patient with metastatic prostate cancer treated successfully with combination chemotherapy after previous standard therapy failed.

Immunotherapy for prostate cancer

Whereas androgen deprivation and chemotherapy have become the cornerstone of therapy for advanced prostate cancer, novel therapies are being developed that may expand upon currently available treatments. The identification of antigens expressed by prostate tissue and/or prostate cancer that are recognized by T cells or antibodies creates opportunities to develop novel immunotherapeutic approaches including tumor vaccines. Proteins expressed in prostate cancer-including prostate-specific antigen, prostatic acid phosphatase, and prostate membrane antigen-have been used as immunologic targets for immunotherapy. Moreover, innovations in cancer genomics and proteomics also will aid in the identification of immunologic targets. Emerging trials have demonstrated that immunotherapy may generate not only immune responses in patients but also clinical responses. Future studies will be directed at capitalizing on these findings.

Immunotherapy with dendritic cells for prostate cancer

Radical prostatectomy for prostate cancer is followed by PSA recurrence in up to 40% of patients. One third of patients with biochemical relapse progress to uncurable metastatic disease. Therefore, alternative treatment modalities are needed both in the situation of PSA recurrence and in hormone-refractory disease. Dendritic cells (DC) are the most powerful antigen-presenting cells, able to prime naïve T-cells and to break peripheral tolerance and thus induce tumor immune responses. More than 400 prostate cancer patients have been treated with DC-based immunotherapy to date, and immune responses have been reported in two-thirds of these, resulting in clinical responses in almost half of the patients treated. Most responses, however, were modest and transient. Therefore, mechanisms of treatment failure and possibilities to improve vaccination efficacy are being discussed.

Current Indications for Chemotherapy in Prostate Cancer Patients

Recently, data from two randomized studies, TAX327 and SWOG 9916, which compared docetaxel-based chemotherapy to mitoxantrone-based therapy, have demonstrated that treatment with docetaxel can prolong life in a statistically significant way in patients with hormone refractory prostate cancer (HRPC). In the TAX237 trial the median overall survival rates for patients treated with docetaxel every 3 wk was 18.9 mo, compared with 16.4 mo for the patients in the control arm (p=0.009). Patients treated with the combination of docetaxel and estramustine in the SWOG trial had a significant improvement in median survival (18 mo vs 16 mo, p=0.01), longer progression-free survival (6 mo compared with 3 mo, p<0.0001), and a 20% reduction in the risk of death. The optimal timing of docetaxel-based chemotherapy is still unknown because there are no prospective clinical trials indicating whether earlier treatment is more effective than delayed treatment. There are now increasing options also for second-line therapies in the palliative treatment of HRPC, and ongoing studies on new drugs such as satraplatin and ixabepilone will define the role of these agents in this setting. Preliminary neoadjuvant and adjuvant chemotherapy studies in high-risk prostate cancer patients have demonstrated that these approaches are feasible and do not add morbidity to surgery or radiotherapy, but their impact on survival still needs to be proven in randomized studies.

Immunotherapy for prostate cancer

Whereas androgen deprivation and chemotherapy have become the cornerstone of therapy for advanced prostate cancer, novel therapies are being developed that may expand upon currently available treatments. The identification of antigens expressed by prostate tissue and/or prostate cancer that are recognized by T cells or antibodies creates opportunities to develop novel immunotherapeutic approaches including tumor vaccines. Proteins expressed in prostate cancer including prostate-specific antigen, prostatic acid phosphatase, and prostate membrane antigen have been used as immunologic targets for immunotherapy. Moreover, innovations in cancer genomics and proteomics also will aid in the identification of immunologic targets. Emerging trials have demonstrated that immunotherapy may not only generate immune responses in patients, but also clinical responses. Future studies will be directed at capitalizing on these findings.

Evaluation of prostate-specific antigen declines for surrogacy in patients treated on SWOG 99-16

BACKGROUND

The identification of surrogate endpoints that can replace true outcome endpoints is crucial to the rapid evaluation of new cancer drugs. Retrospective analyses of phase II and III trials in metastatic androgen-independent prostate cancer have shown associations between declines in serum prostate-specific antigen (PSA) levels and survival. We evaluated PSA changes as potential surrogate markers for survival by using data from a clinical trial.

METHODS

Men with androgen-independent prostate cancer were randomly assigned to either docetaxel/estramustine (D/E) or mitoxantrone/prednisone (M/P) treatment on Southwest Oncology Group Protocol 99-16. Of 674 eligible patients, 551 had a baseline PSA measurement and at least one PSA measurement during the first 3 months on protocol. PSA level declines of 5%-90% and PSA velocity at 1, 2, and 3 months were tested for surrogacy by using three statistical criteria: Prentice's criteria, the proportion of treatment effect explained, and the proportion of variation explained. All statistical tests were two-sided.

RESULTS

Three-month PSA level declines of 20%-40%, a 2-month PSA decline of 30%, and PSA velocity at 2 and 3 months met all three surrogacy criteria. For example, a 3-month PSA decline of at least 30% was associated with a more than 50% decrease in the risk of death compared with the lack of such a decline (hazard ratio [HR] = 0.43, 95% confidence interval [CI] = 0.34 to 0.55; P < .001), and the increased risk of death for men treated with M/P compared with D/E (HR = 1.24, 95% CI = 1.02 to 1.51; P = .032) lost statistical significance after adjustment for this surrogate, whereas the decrease in risk of death associated with a 3-month 30% PSA decline remained statistically significant after adjustment for treatment. PSA level declines of 50%, commonly reported in clinical trials, did not meet the criteria for surrogacy.

CONCLUSIONS

Several PSA measures satisfied the surrogacy criteria for survival in a retrospective analysis of data from SWOG 99-16. However, these measures await prospective validation in future clinical trials of chemotherapy in men with androgen-independent prostate cancer.

Therapeutic Vaccines for Prostate Cancer

Prostate cancer is the most common, noncutaneous cancer for men in the U.S., leading to more than 30,000 deaths a year. Vaccines for prostate cancer, which for several years have been shown to generate immunologic responses, are beginning to show significant clinical promise. At present, numerous therapeutic options are being investigated, including autologous and allogeneic whole-tumor cell vaccines, dendritic cell vaccines, and poxvirus-based vaccines. Advances in basic immunology have translated into new, more complex therapeutic strategies. The findings from current trials and the demonstrated potential to combine vaccines with conventional therapies herald a promising future for the treatment of prostate cancer. This review highlights recent advances and clinical trials in immunotherapy for prostate cancer, along with current thoughts on immunologic and clinical monitoring of these trials.

Current status and perspective of antiangiogenic therapy for cancer: urinary cancer

Angiogenesis is considered a prerequisite for solid tumor growth. Antiangiogenic therapy reduces tumor size and extends host survival in a number of preclinical animal models. However, in humans antiangiogenic therapy is a poor promoter of tumor regression and has shown minimal effect on patient survival. In urinary cancers, such as renal cell cancer, prostate cancer, and bladder cancer, advanced refractory disease is a good candidate for antiangiogenic therapy because of its resistance to ordinary chemotherapy, radiotherapy, and hormonal therapy. Unique characteristics of molecular mechanisms underlie the induction of angiogenesis in urinary cancers. In this review, we summarize these unique mechanisms and review the results of clinical trials of antiangiogenic therapy for these cancers, discussing prospects and problems relating to antiangiogenic therapy.

Prostate-specific antigen velocity and survival for patients with hormone-refractory metastatic prostate carcinoma

BACKGROUND

The authors investigated whether prostate-specific antigen (PSA) velocity was associated significantly with the time to death after randomization among patients with hormone-refractory metastatic prostate carcinoma (HRMPC) who were treated with cytotoxic, cytotatic, or combination therapy.

METHODS

The study cohort included 213 men with HRMPC who were treated on 3 prospective, randomized Phase II studies between February 1996 and October 2001. Cox regression analysis was used to evaluate whether there was a significant association between PSA velocity and the time to death after randomization, controlling for treatment and known prognostic factors.

RESULTS

Increasing PSA velocity was associated significantly with shorter survival after randomization (P = 0.005) controlling for treatment and known prognostic factors. The adjusted hazard ratio for death was 1.8 (95% confidence interval [95% CI], 1.3-2.5; P = 0.0004) for men who had a PSA velocity > 0.0 ng/mL per month compared with men who had a PSA velocity < or = 0.0 ng/mL per month. Estimates of survival 2 years after randomization for these men were 16% (95% CI, 7-25%) and 44% (95% CI, 35-53%), respectively.

CONCLUSIONS

PSA velocity was associated significantly with the length of survival among men with HRMPC who received cytotoxic, cytostatic, or combination therapy.

[Treatment options for hormone-refractory prostate cancer]

Surgical or medical androgen deprivation therapy in its multiple variants represents the standard therapeutic approach in the management of metastatic prostate cancer resulting in a primary response rate of about 90%. However, about 90% of the men treated will develop PSA progression within 3-4 years resulting in androgen-independent and later on hormone-refractory prostate cancer. Management of AIPCA and HRPCA still represents a therapeutic challenge despite the development of new and effective treatment options. PSA progression following primary ADT defines an androgen-refractory but still hormone-sensitive PCA which might respond to secondary hormonal manipulations such as antiandrogen withdrawal, addition of nonsteroidal antiandrogens, and administration of estrogens, ketoconazole and hydrocortisone, and somatostatin analogues. Secondary hormonal manipulations will result in a PSA decline >50% in about 60-80% of the patients with a mean duration of 7-17 months depending on the type of treatment. PSA progression following secondary endocrine treatment defines hormone-refractory prostate cancer (HRPCA) which might be treated by systemic chemotherapy. Based on the results of two prospective, randomized clinical phase III trials comparing docetaxel and mitoxantrone, docetaxel results in a statistically significant survival benefit of 2.5 months, a significantly higher PSA and pain response, and represents the treatment of choice in the management of HRPCA. Bisphosphonates such as zoledronate represent another cornerstone in the management of PSA-progressive PCA demonstrating a significant benefit with regard to the prevention of skeletal-related events. Furthermore, bisphosphonates might be indicated in the treatment of symptomatic bone pain as has been demonstrated for ibandronate and zoledronate. The current article critically reflects on the various therapeutic options in the management of PSA progression following primary androgen deprivation for advanced prostate cancer. The development, rationale, and results of systemic chemotherapy are discussed critically and a therapeutic algorithm is demonstrated.

Therapie des hormonrefraktären Prostatakarzinoms

PSA-progression following primary ADT defines an androgen-refractory but still hormone sensitive PCA which might respond to secondary hormonal manipulations. Secondary hormonal manipulations will result in a PSA decline >50% in about 60-80% of the patients with a mean duration of 7-17 months depending on the type of treatment. PSA-progression following secondary endocrine treatment defines hormone-refractory prostate cancer (HRPCA) which might be treated by systemic chemotherapy. Based on the results of 2 prospective, randomized clinical phase-III trials comparing docetaxel and mitoxantrone, docetaxel results in a statistically significant survival benefit of 2.5 months, a significantly higher PSA- and pain response and represents the treatment of choice in the management of HRPCA. Bisphosphonates such as zoledronate represent another cornerstone in the management of PSA-progressive PCA demonstrating a significant benefit with regard to the prevention of skeletal related events. Furthermore, bisphosphonates might be indicated in the treatment of symptomatic bone pain. The current article critically reflects the various therapeutic options in the management of PSA progression following primary androgen deprivation for advanced prostate cancer.

Prognostic model of event-free survival for patients with androgen-independent prostate carcinoma

BACKGROUND

The current study was conducted to develop a prognostic model of event-free survival (EFS) in men with androgen-independent prostate carcinoma (AIPC).

METHODS

Data from 160 patients diagnosed with AIPC between 1989-2002 were reviewed. No patient had received cytotoxic chemotherapy. A univariate Cox proportional hazards model identified significant predictors of EFS. Recursive partitioning analysis divided these significant variables into prognostic risk groups. The final prognostic model was tested with a Cox proportional hazards model.

RESULTS

The final prognostic risk model included the presence of metastatic disease at the time of androgen-independent disease progression (P = 0.040), time to prostate-specific antigen (PSA) recurrence (P = 0.043), and PSA doubling time (P < 0.01). Three highly independent risk groups were identified. The observed median EFSs were 6.1 months (95% confidence interval [95= CI], 3.4-8.8 months), 33.6 months (95= CI, 25.3-41.9 months), and 96.1 months (95= CI, 57.9-134.3 months) for the low-risk, intermediate-risk, and high-risk groups, respectively. Each risk group was found to be independently predictive of EFS (P < 0.01). Patients who died of prostate carcinoma experienced significantly more clinical events than those who died of other causes (P < 0.01).

CONCLUSIONS

The prognostic model in the current study stratified patients into three highly significant and independent risk groups for EFS. A detailed PSA history and knowledge of metastatic disease are sufficient to risk-stratify patients with AIPC. One very unique aspect of this model was that it was developed from a patient cohort that never received chemotherapy.

Long-term outcome for men with androgen independent prostate cancer treated with ketoconazole and hydrocortisone

PURPOSE

The combination of high dose ketoconazole and hydrocortisone (HDK) is active against androgen independent prostate cancer (AIPC). Median response times with HDK tend to be brief but a significant minority of AIPC patients benefit with extended responses. Well characterized response and survival information, especially in the cohort of patients who experience these longer, more durable, responses has not been previously reported. Characterization of this subgroup is of particular interest since men with long-term responses derive the greatest benefit from HDK therapy.

MATERIALS AND METHODS

The medical records of 78 patients with AIPC treated with HDK between March 1991 and February 1999 were retrospectively reviewed. Baseline clinical and laboratory factors predictive of prolonged response and survival were identified.

RESULTS

The median baseline prostate specific antigen (PSA) before the initiation of HDK was 25.1. The number of patients with zero, 1 to 3, and more than 3 lesions on bone scan were 25, 35 and 18, respectively. Median and mean time to PSA progression was 6.7 and 14.5 months. Median and mean survival time was 38.0 and 42.4 months, respectively. Response time and survival were highly correlated (r = 0.799). A total of 34 (44%) men had a greater than 75% decrease in PSA. The median survival times in men with more vs less than a 75% decrease were 60 vs 24 months, respectively. In a Cox proportional hazard regression, prolonged survival was predicted by percent PSA decrease, extent of disease on bone scan and baseline PSA.

CONCLUSIONS

Ketoconazole can induce prolonged responses, occasionally lasting for years. Long responses are more likely to occur in men initiating HDK earlier in the course of disease before the cancer burden becomes excessive.

Combination chemotherapy with docetaxel, estramustine and suramin for hormone refractory prostate cancer

PURPOSE

To investigate more effective chemotherapy against hormone refractory prostate cancer (HRPC) with the combination of estramustine (EM), docetaxel, and suramin.

PATIENTS AND METHODS

A total of 42 patients with symptomatic, progressive HRPC were included in this study. We evaluated the activity of the following schedule: EM 10 mg/kg orally daily on Days 1 to 21 every 28 days, docetaxel 70 mg/m(2) IV on Day 2 every 28 days and a total doses of 2150 mg of suramin in every cycle. Treatment was continued until disease progression or excessive toxicity.

RESULTS

Median follow-up was 23.4 months. A median of 8.8 consecutive cycles was administered per patient. In the 25 patients with lymphadenopathy, there were three (12%) complete and 18 (72%) partial responses for a measurable disease response rate of 84%. Levels of prostatic specific antigen (PSA) decreased by greater than 50% in 100% of patients and by greater than 90% in 76.2%. The median time to progression was 57 weeks and median overall survival was 132 weeks. A decline in PSA of > or =50% lasting > or =30 days was significantly associated with a prolonged median time to progression and median overall survival. Tumor volume reduction and/or antitumor treatment effects were observed in 88% of patients. A significant decrease in mean pain score from 7.8 (range, 6-10) to 2.2 (range, 0-4) (P < 0.001) was achieved in 78%. Of patients with bone metastasis, 30.5% demonstrated a partial response. The mean Eastern Cooperative Oncology Group (ECOG) performance score improved from 2.8 to 1.5 at the end of treatment period. There was no therapy-related death. The predominant toxicities were Grade 3 or 4 leukopenia in 33.3%, anemia in 21%, thrombocytopenia in 21.4%, cardiac ischemia in 4.7%, and rash in 4.7%.

CONCLUSION

The combination of docetaxel, EM, and suramin is a highly effective regimen for HRPC. Although hematologic and gastrointestinal toxicities were modest, these were easily managed medically.

Phase III trial of satraplatin, an oral platinum plus prednisone vs. prednisone alone in patients with hormone-refractory prostate cancer

Satraplatin is a novel oral platinum (IV) complex that shows activity against hormone-refractory prostate cancer (HRPC) in cisplatin-resistant human tumor lines in phase I and phase II trials. A randomized multicenter phase III trial with a target sample size of 380 patients was initiated in men with HRPC. After 50 randomized patients, the trial was closed to further accrual by the sponsoring company. An ad hoc analysis of all available data is reported here. Eligibility criteria included pathological proof of prostate cancer, documented progression despite prior hormonal manipulation, WHO PS 0-2, and no daily intake of narcotic analgesics. Patients were randomized between satraplatin 100 mg/m(2) for 5 days plus prednisone 10 mg orally BID or prednisone alone. Compliance was excellent. 48/50 patients have progressed and 42 have died, mostly due to prostate cancer. Median overall survival was 14.9 months (95% CI: 13.7-28.4) on the satraplatin plus prednisone arm and 11.9 months (95% CI: 8.4-23.1) on prednisone alone (hazard ratio, HR = 0.84, 95% CI: 0.46-1.55). A >50% decrease in prostrate specific antigen (PSA) was seen in 9/27 (33.3%) in the satraplatin plus prednisone arm vs. 2/23 (8.7%) on the prednisone alone arm. Progression-free survival was 5.2 months (95% CI: 2.8-13.7) on the satraplatin plus prednisone arm as compared to 2.5 months (95% CI: 2.1- 4.7) on the prednisone alone arm (HR = 0.50, 95% CI: 0.28-0.92). This difference is statistically significant (p = 0.023). Toxicity was generally minimal in both arms. This randomized comparison of a combination of satraplatin and prednisone versus prednisone alone supports the antitumor activity of the combination. Its role in the treatment of HPRC remains to be elucidated in an appropriate phase III setting.

Management of patients with hormone refractory prostate cancer

Prostate cancer is the second most common cancer in men in the UK, and the incidence of prostate cancer has increased dramatically over the past two decades. Although most men are diagnosed at early stage, more than 50% develop locally advanced or metastatic disease. Androgen ablation with luteinising hormone-releasing hormone (LHRH) agonists alone, or in combination with anti-androgens, is the standard treatment for men with metastatic prostate cancer. Unfortunately, almost all men develop progressive disease after a variable time period, despite the maximal androgen blockade. The management of hormone refractory prostate cancer (HRPC) is challenging, as there is no uniformly accepted strategy. Various treatment options, including second-line hormone therapy, are discussed. Chemotherapy is being increasingly used and, importantly, docetaxel and estramustine may play an important role in the near future. The role of radiotherapy, strontium-89, bisphosphonates, novel agents and future therapies are also outlined.

Oral low-dose cyclophosphamide in metastatic hormone refractory prostate cancer (MHRPC)

The chemotherapeutic approach to hormone-refractory metastatic prostate cancer (MHRPC) for a long time included only estramustine. Then, attempts have been made with other various agents as cyclophosphamide, vinblastine, etoposide, taxanes and carboplatinum. Although the new drugs and combinations have increased the response rate of MHRPC, they have had no impact on the natural history of MHRPC, which is about 1 year as median time of survival. After an occasional observation of prolonged response in a patient with MHRPC treated with a very well tolerated oral low-dose of cyclophosphamide, from February 1996 to October 2002, seven more patients with MHRPC and progressive disease were consecutively recruited. Response to treatment was evaluated by conventional radiological procedures and/or serial serum PSA measurements. The decline of PSA value was considered to assess the response consistent with the response guidelines from the prostate specific antigen-working group. All eight studied patients continuously received oral low dose cyclophosphamide until progression or the occurrence of significant toxicity. So far three patients (37.5%) progressed (PD), two (25%) showed PR and the three remaining SD. Response rate was 25%, and clinical benefit occurred in 62.5% of the studied patients. In the five patients with clinical benefit on cyclophosphamide median duration of clinical benefit, PR and SD were 9, 24+ and 8 months, respectively. In these five patients median overall survival times from cyclophosphamide and from the first regimen of chemotherapy were 17 and 33+ months respectively, while in the three patients with PD they were 4 and 13 months. The same interval times in patients with > or =50% decline of serum PSA were 29 and 50.5 months, while in those with <50% decline of the same marker, they were 13 and 32 months, respectively. Grade 2 or 3 neutropenia were observed in all the studied patients. In four (50%) of them pulmonary and urinary infections that were easily cured by the common antibiotics occurred. These data suggest that the metronomic use of cyclophosphamide, given alone, has similar or higher activity with lower toxicity than when administered with other active drugs. So it can be an useful option before or after the use of other single or combined potentially active chemotherapeutic agents.

9-Nitrocamptothecin as second line chemotherapy for men with progressive, metastatic, hormone refractory prostate cancer: Results of the CALGB 99901

BACKGROUND

Institution of early hormone therapy in the PSA era coupled with demonstration of clinical benefit with chemotherapy in hormone refractory prostate cancer (HRPC) and acceptance of PSA decline as a surrogate for response has resulted in introduction of chemotherapy earlier in the natural history of disease. There now exists a need to identify, effective agents for second line chemotherapy. 9-nitrocamptothecin (9-NC) a novel, oral camptothecin analogue was tested as second line chemotherapy for patients with progressive hormone refractory prostate cancer.

PATIENTS AND METHODS

Eligible patients had metastatic hormone refractory prostate cancer with performance status (0-1) following progression on at least 1 prior cytotoxic chemotherapy. 9-NC was administered orally at the dose of 1.5 mg/m2/d for 5 days each week for 3 weeks, followed by rest for 1 week. Response was evaluated after 2 cycles according to the guidelines set forth for Phase II trials in HRPC by the PSA working group.

RESULTS

Thirty-five patients were recruited to the study within a period of 6 months; 33 were evaluable for analysis. No patients had a >50% decline in PSA levels. Two out of 8 (25%) patients with measurable disease and 5/25 (20%) patients with nonmeasurable disease showed stable disease. The median time to disease and PSA progression was 2 months [95% confidence interval (CI), 0.9-2.8]. The median overall survival was 10 months (95% CI = 5-12). Seven patients are alive after a median follow-up of 23 months.

CONCLUSIONS

9-nitrocamptothecin failed to elicit clinical or PSA responses. Further study in pretreated HRPC patients is not warranted.

THE NATURAL HISTORY OF ANDROGEN INDEPENDENT PROSTATE CANCER

PURPOSE

We describe the natural history of androgen independent prostate cancer (AIPC) in the modern prostate specific antigen (PSA) era.

MATERIALS AND METHODS

Data from 160 patients diagnosed with AIPC between 1989 and 2002 were reviewed. No patient had received cytotoxic chemotherapy. Univariate and multivariate proportional hazards models were constructed to identify significant risk factors for cancer specific survival. Recursive partitioning analysis stratified patients into prognostic risk groupings. The types and frequencies of cancer specific complications per risk grouping were compared.

RESULTS

The final prognostic risk model included nadir PSA on androgen deprivation therapy (p = 0.023), time to PSA recurrence (p = 0.006) and prostate specific antigen doubling time (p <0.01). Three highly independent risk groupings were identified. The observed median cancer specific survivals were 14.0 months (95% CI, 8.3-19.8), 38.4 months (95% CI, 26.9-49.9) and 89.1 months (95% CI, 69.0-109.2) for low, intermediate and high risk groupings, respectively (p <0.001). Patients in the low risk grouping experienced significantly fewer cancer specific complications (p = 0.003).

CONCLUSIONS

This prognostic model stratified patients into 3 highly significant and independent risk groupings. A detailed PSA history alone is sufficient to risk stratify patients with AIPC.

Update on hormone-refractory prostate cancer

PURPOSE OF REVIEW

Androgen deprivation therapy is the cornerstone treatment for men with de novo or recurrent metastatic prostate cancer. Unfortunately, androgen deprivation therapy is primarily palliative, with nearly all men progressing to an androgen-independent state. Hormone-refractory prostate cancer presents significant management challenges and is the focus of this review.

RECENT FINDINGS

Investigations into the pathophysiology of hormone-refractory prostate cancer, the exploration of chemotherapeutic combinations, novel biological targets, skeletal protectants, and radiopharmaceuticals, as well as new prognostic tools are expanding the clinician's armamentarium and improving patient outcomes.

SUMMARY

Bisphosphonates and chemotherapy are providing effective palliative approaches. Phase II trials of taxane-based regimens show higher response rates and longer survival than has typically been achieved with existing standards. Two completed randomized phase III studies to be reported in mid-2004 will more definitively answer the question of whether currently available chemotherapy can improve survival.

Antiandrogen withdrawal alone or in combination with ketoconazole in androgen-independent prostate cancer patients: a phase III trial (CALGB 9583)

PURPOSE

Antiandrogen withdrawal (AAWD) results in a prostate-specific antigen (PSA) response (decline in PSA level of > or =50%) in 15% to 30% of androgen-independent prostate cancer (AiPCa) patients. Thereafter, adrenal androgen ablation with agents such as ketoconazole (K) is commonly utilized. The therapeutic effect of AAWD alone was compared with simultaneous AAWD and K therapy.

PATIENTS AND METHODS

AiPCa patients were randomized to undergo AAWD alone (n=132), or together with K (400 mg orally [p.o.] tid) and hydrocortisone (30 mg p.o. each morning, 10 mg p.o. each evening; n=128). Patients who developed progressive disease after AAWD alone were eligible for deferred treatment with K.

RESULTS

Eleven percent of patients undergoing AAWD alone had a PSA response, compared to 27% of patients who underwent AAWD and simultaneous K (P=.0002). Objective responses were observed in 2% of patients treated with AAWD alone compared to 20% in patients treated with AAWD/K (P=.02). There was no difference in survival. PSA and objective responses were observed in 32% and 7%, respectively, of patients receiving deferred K, and were more common in patients with prior AAWD response. Treatment with K was well tolerated, and resulted in a decline in adrenal androgen levels, which rose at the time of disease progression.

CONCLUSION

K has modest activity in AiPCa patients, while AAWD alone has minimal activity. Adrenal androgen levels fall with treatment with K and then climb at the time of progression, suggesting that progressive disease while on K may be due to tachyphylaxis to the adrenolytic properties of K.

[Chemotherapy of hormone refractory prostate carcinoma]

An increasing life expectancy and the growing number of largely healthy older men have lead to more patients with hormone insensitive relapses after palliative hormone or curative therapy for prostate cancer. After 10 years without therapeutic improvement for hormone refractory prostate cancer, the introduction of new substances has led to a revival of chemotherapy. Although a definitive cure is still not possible, such chemotherapy fulfils important palliative criteria-good toleration and an improvement in quality of life-in addition to distinct long-term remission. For example, taxane as a monotherapy or in combination with estramustine is effective and well tolerated while mitoxantrone in combination with prednisolone, although of limited effectiveness, leads to a substantial reduction in symptoms. Although evidence for increased longevity through modern chemotherapy is available, this has still not been definitively demonstrated. The substantial reduction in pain and therapy related morbidity frequently makes chemotherapy for hormone refractive prostate cancer a superior alternative to simple pain and complication management.

A Phase II trial of suramin monthly × 3 for hormone-refractory prostate carcinoma

BACKGROUND

The goal of the current study was to determine the prostate-specific antigen (PSA) and objective response rates and the pharmacokinetics associated with a monthly x 3 one-hour infusion of suramin in 58 patients with hormone-refractory prostate carcinoma.

METHODS

A PSA response was defined as a > 50% reduction in the PSA level from baseline for at least 3 consecutive evaluations over a minimum of 6 weeks. The suramin dose was 2400 mg/m(2) taken intravenously on Day 1, 1620 mg/m(2) on Day 29, and 1292 mg/m(2) on Day 57. All patients received 0.5 mg dexamethasone twice daily.

RESULTS

Among 56 evaluable patients (median entry PSA level, 229.5 ng/mL), there were 21 PSA responders (37.5%). Among 27 patients with measurable disease, there were 5 responders (4 partial and 1 complete). The median overall survival time was 15.3 months. Grade III fatigue (14.1%) was the predominant toxicity observed. Suramin plasma levels remained high even 3 months after treatment was discontinued. Among the 12 evaluable patients who previously had received chemotherapy, the PSA response rate was 42%; one response was observed among 4 patients with measurable disease, and the median survival was 12 months.

CONCLUSIONS

Monthly bolus suramin was well tolerated, reduced PSA levels, and induced objective responses, even in patients who previously had received chemotherapy.

Current strategies in the management of hormone refractory prostate cancer

Prostate cancer is the most common cancer diagnosed in American males, and is the second leading cause of cancer-related deaths. Most patients who develop metastatic disease will initially respond to androgen deprivation, but response is invariably temporary. Most patients will develop androgen-independent ("hormone-refractory") disease that results in progressive clinical deterioration and ultimately death. This progression to androgen independence is accompanied by increasingly evident DNA instability and alterations in genes and gene expression, including mutations in p53, over-expression of Bcl2, and mutations in the androgen receptor gene, among others. Treatment options for hormone refractory disease include intensive supportive care, radiotherapy, bisphosphonates, second-line hormonal manipulations, cytotoxic chemotherapy and investigational agents. A post-treatment reduction in the level of prostate specific antigen (PSA) by 50% has been shown to correlate with survival and has been accepted by consensus as a valid endpoint in clinical trials. Chemotherapeutic agents such as mitoxantrone, estramustine, and the taxanes have yielded improved response rates and palliative benefit, but not improved survival. Therefore, current efforts must be focused on enrolling patients onto clinical trials of investigational agents with novel mechanisms of action, and on using survival, time to progression, and quality of life as end points in routine clinical practice.

Pretreatment CA 19-9 level as a prognostic factor in patients with advanced pancreatic cancer treated with gemcitabine

BACKGROUND

Serum levels of CA 19-9 correlate with survival among patients with pancreatic cancer treated with surgery or radiation therapy. In addition, CA 19-9 responses have been shown to predict for a better prognosis among patients with advanced disease treated with chemotherapy. The present study evaluates the predictive role of CA 19-9 pretreatment levels and response among patients treated with gemcitabine.

METHODS

We retrospectively identified 28 patients with advanced pancreatic cancer and baseline elevations of CA 19-9 (> 37 U/mL) who were treated with single agent gemcitabine. CA 19-9 response was defined as a > or = 50% decline at any time after treatment. Survival was estimated with the Kaplan-Meier method, and curves were compared with the log-rank test.

RESULTS

Eleven patients (39%) had a CA 19-9 response. The median survival of responding patients was longer than that of non-responding patients (13.8 vs 8 mo, p = .0272). When pretreatment CA 19-9 levels were analyzed, patients who had CA 19-9 below the median for the entire sample (1212 U/mL) lived significantly longer than patients with a CA 19-9 above the median (14.9 vs 7.4 mo, p = .0013). On multivariable analysis, pretreatment CA 19-9 level was an independent, and stronger predictor of survival (p = .0005) than CA 19-9 response (p = .0497). Other variables were not associated with survival.

CONCLUSIONS

CA 19-9 may be a useful adjunct to response evaluation is this setting. In addition to CA 19-9 responses, prechemotherapy levels of this marker seem to have strong prognostic significance.

Nilutamide as second line hormone therapy for prostate cancer after androgen ablation fails

PURPOSE

We investigate the prostate specific antigen (PSA) response rate with nilutamide as a second line hormonal agent in patients with advanced prostate cancer in whom androgen ablation failed.

MATERIALS AND METHODS

From 1998 to 2001, 28 patients with hormone resistant prostate cancer were treated with nilutamide as second line hormonal therapy. Average patient age +/- SD was 72.9 +/- 9.1 years. Median time from diagnosis of cancer to hormone failure was 48 months (range 2 to 120). Median followup from initiation of nilutamide therapy was 26 months (range 15 to 44). All patients had previously received at least 1 antiandrogen (flutamide or bicalutamide) in addition to medical or surgical castration, which failed.

RESULTS

Upon initiation of nilutamide therapy 18 of the 28 patients (64%) had an initial reduction in PSA and 8 (29%) sustained a PSA response (greater than 50% decrease) beyond 3 months (range 3 to 21). PSA response to nilutamide in patients with a previous antiandrogen withdrawal response versus nonresponse was 100% and 18%, respectively. In 10 of the 28 patients, (36%) PSA continued to increase. Interstitial pneumonitis developed, in 1 patient and 5 had nonspecific complaints (headaches, nausea, dizziness). During followup 6 of the 28 patients died 1 of whom was a nilutamide responder. No patient died while on nilutamide.

CONCLUSIONS

Nilutamide can achieve a significant sustained PSA response with a favorable toxicity profile. Patients with a previous antiandrogen withdrawal response have a significantly greater chance of responding to nilutamide.

Phase II trial of cyclophosphamide, vincristine, and dexamethasone in the treatment of androgen-independent prostate carcinoma

BACKGROUND

In this Phase II study, the authors assessed the toxicity and anti-tumor activity of a combination of oral cyclophosphamide, oral low-dose dexamethasone, and intravenous vincristine (CVD) in patients with metastatic androgen-independent prostate carcinoma (AI-PCa).

METHODS

Patients with histologic proof of adenocarcinoma of the prostate progressing despite adequate hormonal therapy and adequate organ function were treated with oral cyclophosphamide, 250 mg/daily (Days 1-14); intravenous vincristine, 1 mg daily (Days 1, 8, 15); and oral dexamethasone, 0.75 mg twice a day (Days 1-14) in 28-day cycles. Study endpoints were toxicity, rate of prostate specific antigen (PSA) decline > 50%, and/or measurable disease response.

RESULTS

Fifty-two (95%) of 55 registered patients were evaluable. The majority (65%) of patients had received prior chemotherapy. The median number of treatment cycles given was two (range, one-seven cycles). Twenty-nine percent of the patients were found to have a > 50% decline in PSA level compared with baseline levels, and 25% of the patients with bidimensionally measurable soft-tissue or visceral disease were found to have a partial response. The median progression-free survival duration was 10 weeks, and the median overall survival duration was 10.6 months. There were no thromboembolic events, and hematologic and nonhematologic toxicity was minimal.

CONCLUSIONS

CVD was found to be an active and well-tolerated regimen for AI-PCa. The low toxicity profile makes CVD a useful treatment option for patients with significant comorbidities and high risk for treatment-related toxicity, especially thromboembolic events and myelotoxicity.

Using splines to detect changes in PSA doubling times

BACKGROUND

PSA doubling time (PSADT) can predict the likelihood of clinical progression in patients with biochemical relapse after surgery or radiation for prostate cancer. Changes in PSA doubling time in response to therapy may be of clinical or investigational significance. How does one estimate PSADT before and after the initiation of therapy and determine if any change is statistically significant or simply the result of random variation? These are the type of questions addressed.

METHODS

Our technique uses a best-fitting spline (i.e., a broken-line approximation) to a graph of log PSA on time to estimate PSADTs before and after treatment initiation. A linear regression program is used to produce the fit and to evaluate the statistical significance of any change in PSADT. This method differs from previous methods in that it uses all the data, exploits the continuity of PSA at the time of treatment initiation, and allows one to make statistical significance statements about specific individuals.

RESULTS

Our technique is illustrated with data from a pilot clinical trial using a nutritional supplement in 12 men with prostate cancer. A detailed analysis of the first patient shows how the data are handled, how two lines of computer code are sufficient to fit the spline model, and how the doubling times and statistical significance of a change are read from the computer output. In the study, 9 of 12 patients had a statistically significant increase in doubling time. Because the study is preliminary and used only to illustrate our method, no medical discussion of the study is included. The last section of the study, in part expository, is devoted to explaining the underlying principles for those who may want to know not only what to do, but why it works.

CONCLUSIONS

The method presented here for determining changes in PSADT is both simple and broadly applicable. It allows the evaluation of the size and statistical significance of an observed change or increase in PSADT in response to therapy for prostate cancer. It can be done using essentially any statistical software and widely accepted statistical methods.

Bloodborne biomolecular markers in prostate cancer development and progression

Prostate cancer is notoriously difficult to treat, which makes its early detection a priority. Biomarkers have been used to diagnose and monitor prostate cancer for more than 50 years, and the discovery of the serum marker prostate-specific antigen (PSA) significantly altered the detection and management of prostate cancer. But imperfect correlation with cancer hinders the usefulness of PSA. The elucidation and validation of new biological markers of prostate cancer should aid detection, and improve the application of the available therapeutics.

"PSA-itis": knowledge of serum prostate specific antigen and other causes of anxiety in men with metaststic prostate cancer

PURPOSE

High or increasing prostatic specific antigen (PSA) levels may be a source of anxiety in patients with metastatic prostate cancer.

MATERIALS AND METHODS

Patients with metastatic prostate cancer completed questionnaires, including the Prostate Cancer Specific Quality of Life Instrument, Hospital Anxiety and Depression Scale, and a questionnaire to assess the impact of the knowledge of PSA levels on anxiety. These were completed at home more than 3 days before or after a clinic appointment and returned by mail. Patient medical history was obtained from the record.

RESULTS

Of the 65 patients who consented to the study 52 returned the completed questionnaires. Median age was 70 years (range 55 to 86) and median time since diagnosis was 53 months. Of the patients 81% had hormone resistant disease. Most reported good overall quality of life with a median Prostate Cancer Specific Quality of Life Instrument score of 93 (maximum 100). Of the patients 77% indicated that PSA levels were one of the ways and 44% indicated they were the only way that they knew whether disease was progressing. When asked to rate preferences for treatment outcome, 25% of the men rated decreasing PSA and worse physical symptoms above increasing PSA and better physical symptoms. If measurement of PSA levels ceased, 52% of patients would believe that their doctor was giving up on them and only 1 would be relieved. Before receiving PSA results 76% reported some level of anxiety and 15% reported extreme anxiety.

CONCLUSIONS

PSA related anxiety represents a substantial problem in patients with metastatic prostate cancer.

Hormone-refractory Prostate Cancer

For more than five decades, the preferred treatment for advanced prostate cancer has been suppression of androgen production by medical or surgical castration. However, all patients treated with androgen deprivation eventually develop resistant disease as manifested by increasing prostate-specific antigen levels, progressive disease on imaging studies, and ultimately worsening symptoms. The treatment of patients with hormone-refractory prostate cancer (HRPC), once thought to represent a relatively futile endeavor, has changed significantly in the past several years with the development of new therapeutics. One of the most important new treatment strategies involves secondary hormonal manipulation after the failure of primary androgen deprivation; this approach is predicated on the recognition that HRPC is a heterogenous disease. Some patients may respond to alternative hormonal interventions despite the presence of castrate levels of testosterone. Furthermore, the application of chemotherapeutic regimens has provided viable treatment options for patients with HRPC.

Nomogram for overall survival of patients with progressive metastatic prostate cancer after castration

PURPOSE

To develop a pretreatment prognostic model for survival of patients with progressive metastatic prostate cancer after castration using parameters that are measured during routine clinical management.

PATIENTS AND METHODS

Pretreatment clinical and biochemical determinants from 409 patients enrolled onto 19 consecutive therapeutic protocols from June 1989 through January 2000 were evaluated. The factors selected were age, Karnofsky performance status (KPS), hemoglobin (HGB), prostate-specific antigen (PSA), lactate dehydrogenase (LDH), alkaline phosphatase (ALK), and albumin. These factors were combined in an accelerated failure time regression model to produce a nomogram to predict median, 1-year, and 2-year survival. The nomogram was validated internally and externally using data from a multicenter randomized trial of suramin plus hydrocortisone versus hydrocortisone alone.

RESULTS

The median survival of the entire group was 15.8 months (range, 0.9 to 77.8 months); 87% have died. In multivariable analysis, KPS, HGB, ALK, albumin, and LDH were significantly associated with survival (P <.05), whereas age and PSA were not. All seven factors were included in the nomogram. When applied to the external validation data set, the nomogram achieved a concordance index of 0.67. Calibration plots suggested that the nomogram was well calibrated for all predictions.

CONCLUSION

A nomogram derived from pretreatment parameters that are measured on a routine basis was constructed. It can be used to predict the median, 1-year, and 2-year survival of patients with progressive castrate metastatic disease with reasonable accuracy. The information is useful to assess prognosis, guide treatment selection, and design clinical trials.