Control of prostate cancer with radiotherapy: long-term results

Comparative oncological outcomes after radical prostatectomy or external beam radiation therapy plus androgen deprivation therapy in men with clinical T3b prostate cancer

OBJECTIVE

To compare oncological outcomes in men with clinical T3b prostate cancer who underwent radical prostatectomy or a combination of radiation therapy plus androgen deprivation therapy.

METHODS

Men with clinical T3b prostate cancer who underwent radical prostatectomy or radiation therapy plus androgen deprivation therapy between 2007 and 2014 were evaluated. All patients were relatively healthy, with Eastern Cooperative Oncology Group performance status of 0 or 1 without nodal or distant metastasis. Cancer-specific survival was analyzed. Age, Charlson Comorbidity Index, biopsy Gleason score and pretreatment prostate-specific antigen were adjusted by propensity score matching. The Cox proportional hazards model was used to assess factors prognostic of cancer-specific survival.

RESULTS

Of the 152 patients with clinical T3b prostate cancer, 45 underwent radical prostatectomy, and 107 underwent radiation therapy plus androgen deprivation therapy between 2007 and 2014. The mean cancer-specific survival was significantly longer in the radical prostatectomy than in the radiation therapy plus androgen deprivation therapy group (P = 0.029). Age, Charlson Comorbidity Index and pretreatment prostate-specific antigen were significantly higher in the radiation therapy plus androgen deprivation therapy group. In the propensity score matched population of 24 patients each, the median cancer-specific survival remained significantly longer in the radical prostatectomy than in the radiation therapy plus androgen deprivation therapy group (not reached vs 112.93 ± 11.94 months, P = 0.026). Multivariate analysis showed that undergoing radiation therapy plus androgen deprivation therapy was the only significant poor prognostic factor for cancer-specific survival (hazard ratio 6.694, 95% confidence interval 1.642-27.592, P = 0.008).

CONCLUSION

Cancer-specific survival was significantly longer in men with clinical T3b prostate cancer who underwent radical prostatectomy than radiation therapy plus androgen deprivation therapy, suggesting that radical prostatectomy can be a better treatment option for the initial definitive treatment for these patients.

Inhibition of EZH2 by chemo- and radiotherapy agents and small molecule inhibitors induces cell death in castration-resistant prostate cancer

Androgen deprivation therapy is the mainstay of treatment of advanced prostate cancer (PCa). However, a significant portion of patients experience disease relapse and tumors ultimately evolve into castration resistant prostate cancer (CRPC), for which there is no cure in the clinic. The Polycomb protein enhancer of zeste homolog 2 (EZH2) is frequently overexpressed in CRPC. It is unclear whether EZH2 can be a therapeutic target in CRPC. Here, we demonstrated that chemo- and radiotherapy agents such as camptothecin (CPT) and γ irradiation decrease EZH2 expression in various PCa cell lines. We provided evidence that functional p53 and RB proteins are required for CPT- and irradiation-induced downregulation of EZH2 in CRPC cells. We demonstrated that EZH2-specific small molecule inhibitors mitigate CRPC cell growth. We further showed that the EZH2 inhibitor GSK126 inhibits both Polycomb-dependent and -independent functions of EZH2 in PCa cells. Importantly, we found that inhibition of EZH2 by genetic and pharmacological means sensitizes CRPC cells to CPT-induced apoptotic death and growth inhibition in culture and in mice. Our data suggest that concomitant administration of small molecule inhibitors of EZH2 may significantly increase the anti-tumor efficacy of conventional chemo- and radiotherapies in CRPC.

Retrospective comparison of external beam radiotherapy and radical prostatectomy in high-risk, clinically localized prostate cancer

PURPOSE

Because of the lack of conclusive and well-conducted randomized studies, the optimal therapy for prostate tumors remains controversial. The aim of this study was to retrospectively compare the results of radical surgery vs. a conservative approach such as external beam radiotherapy (EBRT) plus androgen deprivation therapy using an intent-to-treat analysis on two pretreatment defined, concurrently treated, high-risk patient populations.

METHODS AND MATERIALS

Between January 2003 and December 2007, 162 patients with high-risk prostate cancer underwent an EBRT plus androgen deprivation therapy program at the RT department of our institute. In the same period, 122 patients with the same high-risk disease underwent radical prostatectomy (RP) at the urologic department of our institute. Patients with adverse pathologic factors also underwent adjuvant EBRT with or without androgen deprivation therapy. The primary endpoint was freedom from biochemical failure.

RESULTS

The two groups of high-risk patients were homogeneous in terms of freedom from biochemical failure on the basis of the clinical T stage, biopsy Gleason score, and initial prostate-specific antigen level. The median follow-up was 38.6 and 33.8 months in the EBRT and RP groups, respectively. The actuarial analysis of the freedom from biochemical failure showed a 3-year rate of 86.8% and 69.8% in the EBRT and RP group, respectively (p = .001). Multivariate analysis of the whole group revealed the initial prostate-specific antigen level and treatment type (EBRT vs. RP) as significant covariates.

CONCLUSION

This retrospective intention-to-treat analysis showed a significantly better outcome after EBRT than after RP in patients with high-risk prostate cancer, although a well-conducted randomized comparison would be the best procedure to confirm these results.

Asians with localized prostate cancer treated with 3-dimensional conformal radiation therapy and adjuvant hormonal therapy: comparing Phoenix and American Society of Therapeutic Radiology and Oncology (ASTRO) definitions in an Asian population

OBJECTIVES

Conformal radiotherapy with adjuvant androgen suppression is used in our center to treat localized prostate cancer. We compare Phoenix as an alternative to American Society of Therapeutic Radiology and Oncology (ASTRO) for defining biochemical failure. Our primary aim was to assess the Phoenix and ASTRO definitions of biochemical failure in a population of mainly Asian men with early localized prostate cancer treated with conformal radiotherapy with and without androgen ablation.

METHODS

We retrospectively analyzed 141 patients who were treated for T1/T2 cancer of the prostate in our center from January 1997 to June 2002 with a mean duration of follow-up of 62 months. Outcomes were analyzed by using both Phoenix and ASTRO definitions of biochemical failure as well as clinical failure.

RESULTS

The Phoenix definition of biochemical failure was superior as measured by sensitivity, specificity, positive and negative predictive values, accuracy, and a greater concordance with clinical outcome as measured by Kappa analysis.

CONCLUSIONS

The ASTRO definition helped to standardize reporting of biochemical failures post-radiotherapy but inadequacies have been identified especially when adjuvant hormone therapy has been given. The Phoenix definition has been noted to be a more accurate and precise description of biochemical failure in international series, and we find this to be true in our Asian population as well.

Update in systemic therapy of prostate cancer: improvement in quality and duration of life

Overall survival benefit with a docetaxel and prednisone regimen in metastatic androgen-independent prostate cancer marked a major advance in the management of prostate cancer. Immunotherapy, antiangiogenic therapies and targeted agents are areas of active research interest. Simultaneous progress in palliative and supportive care has enabled us to improve the quality of life of advanced prostate cancer patients. Multiple predictors of outcome have been reported, and systemic therapy is being actively explored in localized disease. This review attempts to summarize the risk profiling strategy in prostate cancer and the existing therapies in high-risk prostate cancer, including some of the novel agents under investigation.

Long-term effectiveness of luteinizing hormone-releasing hormone agonist or antiandrogen monotherapy in elderly men with localized prostate cancer (T1-2) : a retrospective study

AIM

To evaluate the long-term effectiveness, side effects and compliance rates of two types of drugs (luteinizing hormone-releasing hormone [LHRH] agonist and antiandrogen) that were used individually to treat patients with localized prostate cancer (T1-2) at our institution.

METHODS

Ninety-seven patients who were diagnosed in the period from April 1997 to January 2000 as having clinically localized prostate cancer (T1-2) received either LHRH agonist (leuprolide acetate 7.5 mg/month) monotherapy (group 1, n = 62) or antiandrogen monotherapy (group 2, n = 35; 18 received bicalutamide 50 mg q.d., 13 received nilutamide 150 mg t.i.d. and 4 received flutamide 250 mg t.i.d.). The mean age in both groups was 76 years.

RESULTS

The mean follow-up time was (50.8 +/- 8.5) months in group 1 and (43.1 +/- 2.2) months in group 2. Prostate-specific antigen (PSA) levels rose in only 1 of the 62 patients (1.6%) in group 1, and in 20 of the 35 patients (57.1%) in group 2. In group 2, 10 of the 20 patients (50%) with increasing PSA levels were treated with LHRH salvage therapy, and eight (80%) responded. Hot flashes (54.8%) and lethargy (41.9%) were the most common side effects in group 1. In contrast, nipple-tenderness (40%) and light-dark adaptation (17.1%) were more often seen in group 2. Only 1 of the 62 patients (1.6%) in group 1 switched to another medication because of adverse side effects; whereas 8 of the 35 patients (22.9%) in group 2 did so.

CONCLUSION

Unlike antiandrogen monotherapy, LHRH agonist monotherapy provided long-term durable control of localized prostate cancer (T1-2). It can also be an effective treatment option for patients whose disease failed to respond to antiandrogen monotherapy. The limitations of our study are the lack of health outcomes analysis and a small sample size.

A Randomized Trial Comparing Radical Prostatectomy Plus Endocrine Therapy versus External Beam Radiotherapy Plus Endocrine Therapy for Locally Advanced Prostate Cancer: Results at Median Follow-up of 102 Months

BACKGROUND

To investigate the optimal treatment of locally advanced prostate cancer, a prospective randomized trial was conducted to compare radical prostatectomy plus endocrine therapy versus external beam radiotherapy plus endocrine therapy.

METHODS

One hundred patients with T2b-3N0M0 prostate cancer were enrolled and 95 were evaluated. Of 95 cases, 46 underwent radical prostatectomy with pelvic lymph node dissection and 49 were treated with external beam radiation by linear accelerator with 40-50 Gy to the whole pelvis and 20-Gy boost to the prostatic area. For all patients, endocrine therapy was initiated 8 weeks before surgery or radiotherapy and continued thereafter. The long-term outcome and morbidity were examined.

RESULTS

Median follow-up period was 102 months. At 10 years overall survival rates in the surgery group were better than the radiation group (76.2% versus 71.1% for biochemical progression-free rates; P=0.25, 83.5% versus 66.1% for clinical progression-free rates; P=0.14, 85.7% versus 77.1% for cause-specific survival rates; P=0.06, and 67.9% versus 60.9% for overall survival rates; P=0.30), although none of them reached statistical significance. Erectile dysfunction was recognized in almost all patients as a result of continuous endocrine therapy. Incontinence requiring more than one pad per day was observed more frequently in the surgery group than the radiation group (P<0.01).

CONCLUSIONS

For the treatment of patients with locally advanced prostate cancer, when combined with endocrine therapy, either radical prostatectomy or external beam radiotherapy demonstrated favorable long-term outcomes. The radiation dose of 60-70 Gy might not be enough for the local treatment of locally advanced prostate cancer.

An image contrast agent selectively activated by prostate specific antigen

A family of image contrast agent conjugates designed to undergo enzymatic activation has been synthesized. The agents underwent activation both with enzymatically active prostate specific antigen (PSA) and alpha-chymotrypsin, releasing free fluorophore via cleavage of a three-component system. A hexapeptide derivative showed exclusive activation by PSA and constitutes a method for tracking PSA activity in vitro.

Individualized planning target volumes for intrafraction motion during hypofractionated intensity-modulated radiotherapy boost for prostate cancer

PURPOSE

The objective of the study was to access toxicities of delivering a hypofractionated intensity-modulated radiotherapy (IMRT) boost with individualized intrafraction planning target volume (PTV) margins and daily online correction for prostate position.

METHODS AND MATERIALS

Phase I involved delivering 42 Gy in 21 fractions using three-dimensional conformal radiotherapy, followed by a Phase II IMRT boost of 30 Gy in 10 fractions. Digital fluoroscopy was used to measure respiratory-induced motion of implanted fiducial markers within the prostate. Electronic portal images were taken of fiducial marker positions before and after each fraction of radiotherapy during the first 9 days of treatment to calculate intrafraction motion. A uniform 10-mm PTV margin was used for the first phase of treatment. PTV margins for Phase II were patient-specific and were calculated from the respiratory and intrafraction motion data obtained from Phase I. The IMRT boost was delivered with daily online correction of fiducial marker position. Acute toxicity was measured using National Cancer Institute Common Toxicity Criteria, version 2.0.

RESULTS

In 33 patients who had completed treatment, the average PTV margin used during the hypofractionated IMRT boost was 3 mm in the lateral direction, 3 mm in the superior-inferior direction, and 4 mm in the anteroposterior direction. No patients developed acute Grade 3 rectal toxicity. Three patients developed acute Grade 3 urinary frequency and urgency.

CONCLUSIONS

PTV margins can be reduced significantly with daily online correction of prostate position. Delivering a hypofractionated boost with this high-precision IMRT technique resulted in acceptable acute toxicity.

The efficacy of conventional external beam, three-dimensional conformal, intensity-modulated, particle beam radiation, and brachytherapy for localized prostate cancer

Technologic advances in radiation treatment planning and delivery have generated popular interest in the different radiation therapy techniques used in treating patients with localized prostate cancer. Throughout the past decade, high-energy (> 4 MV) linear accelerators have largely replaced Cobalt machines in external beam radiation therapy (EBRT) delivery. Conventional EBRT has been used to treat prostate cancer successfully since the 1950s. By switching to computed tomography-based planning, three-dimensional conformal radiation therapy provides better relative conformality of dose than does conventional EBRT. Intensity-modulated radiation therapy (IMRT) has further refined dose conformality by spreading the low-dose region to a larger volume. However, the potential long-term risks of larger volumes of normal tissues receiving low doses of radiation in IMRT are unknown. Particle-beam radiation therapy offers unique dose distributions and characteristics with higher relative biologic effect and linear energy transfer. Transperineal prostate brachytherapy offers the shortest treatment time with equivalent efficacy without significant risk of radiation exposure. The addition of hormonal therapy to radiation therapy has been shown to improve the outcome of radiation therapy.

Image contrast agents activated by prostate specific antigen (PSA)

A family of image contrast agent conjugates designed to undergo enzymatic activation has been synthesized. The agents underwent activation both with enzymatically active prostate specific antigen and alpha-chymotrypsin, releasing free fluorophore via cleavage of a three-component system.

Long-term follow-up of radiotherapy for prostate cancer

PURPOSE

To determine the long-term outcome of radiotherapy for prostate cancer.

METHODS AND MATERIALS

A total of 136 consecutive patients with prostate cancer underwent primary radiotherapy. All but 4 patients received 6000 cGy to the prostate. The minimal follow-up was 22.9 years.

RESULTS

Of the 136 patients, 93 had Stage B (T2), 9 Stage A (T1), and 34 Stage C (T3). Sixty-nine percent of the patients developed recurrence, and 51% of all patients died of prostate cancer. The recurrences developed at a steady state throughout the length of follow-up. One half the recurrences occurred after 10 years, and recurrence was still observed >20 years after treatment. The survival rate at 5, 10, 15, 20, and 25 years was 81%, 59%, 37%, 16%, and 10%, respectively. The recurrence-free survival rate at 25 years was 17%. The median survival for Grade 3-4 patients was 6.3 years and for Grade 1-2 patients was 13.0 years. The median survival for those with T1 tumors was 12.9 years; T2 tumors, 12.4 years; and T3 tumors, 9.5 years.

CONCLUSION

Despite favorable early results, with long-term follow-up, patients continued to experience prostate cancer recurrence. Unless they died an intercurrent death, they were highly likely to develop recurrence and die of prostate cancer. The conclusions from treatment studies with <15 years of follow-up should be viewed as preliminary.

Phase I/II clinical trials of carbon ion therapy for prostate cancer

BACKGROUND

Heavy ion beams possess high linear energy transfer components and a prominent Bragg peak in the human body, resulting in higher relative biological effectiveness and improved dose distribution. To establish heavy ion therapy techniques for the treatment of prostate cancer, phase I/II clinical trials were initiated.

METHODS

For 96 patients with T1b-T3 prostate cancer, three carbon ion beams were used to irradiate the prostate and seminal vesicles (20 times/5 weeks) with or without endocrine therapy. Radiation dose was expressed in GyE which was initially thought to be equivalent to photon dose. Total dose was gradually increased from 54 to 72 GyE.

RESULTS

Carbon ion therapy was completed in 20 cases of T1b/T1c/T2aN0M0 as monotherapy, in 8 cases of T2b/T3pN0M0 with neoadjuvant endocrine therapy, and in 68 cases of T2b/T3N0/pN1M0 with neoadjuvant and adjuvant endocrine therapy. Median observation period was 47 months. Grade 3 late radiation morbidity of rectum and/or bladder/urethra developed in one and five cases who received 66 and 72 GyE of radiation, respectively. After these adverse effects were observed, total dose was decreased to 66 GyE and the radiation field was coned down during the treatment course. At 5 years, overall, cause-specific, clinical recurrence-free, and biochemical recurrence-free survival rates were 87.7, 94.9, 90.0, and 82.6%, respectively. Local control was achieved in all patients except one patient who received 54 GyE of radiation.

CONCLUSIONS

The therapeutic techniques of carbon ion therapy have been established for patients with prostate cancer. Carbon ion therapy may exert excellent effect to the tissues of prostate cancer.

Use of nomograms to predict the risk of disease recurrence after definitive local therapy for prostate cancer

The generally indolent nature of prostate cancer, as well as the impact that treatment can have on quality of life (QOL) and cancer control, makes the decision analysis difficult for patients facing the task of selecting a treatment for clinically localized disease. Instruments to aid patients and their physicians in this decision analysis are needed. Nomograms are instruments that predict outcomes using specific clinical parameters. Nomograms use algorithms that incorporate several variables to calculate the predicted probability that a patient will achieve a particular clinical end point. Nomograms tend to outperform both clinical experts and predictive models using methods of risk grouping. We briefly outline the uses and limitations of nomograms, principles of nomogram construction, and the available models for predicting the progression-free probability after local definitive therapy with radical prostatectomy, external-beam radiotherapy, or brachytherapy. There is a need for additional nomograms that predict outcomes after salvage therapy, as well other clinical end points, including QOL-adjusted survival.

External beam radiotherapy in elderly patients with clinically localized prostate adenocarcinoma: age is not a problem

The files of 183 elderly patients aged >70 years, with localized prostate cancer (T1-3, N0-X, M0), treated with radical external radiation therapy (ERT) from January 1992 to December 2001 at the Radiotherapy Department of the Istituto Nazionale Tumori of Milan, were reviewed. Median age was 75 years. ERT represented the sole treatment for 73 patients (39.9%); in 110 cases (60.1%) hormonal therapy (HT) was associated with neoadjuvant intent. Five-year overall, disease-specific and biochemical NED (bNED) survival rates were 90.2, 93.7 and 63.2%, respectively. A subset of 23 patients aged 80 years and over were analyzed and compared to 160 men aged 70-79 years. Acute toxicity and late complications were analyzed in the two groups of patients according to the RTOG scoring system. Only 10 patients (5.4%) showed grades 2-3 (G2-3) late sequelae. The results obtained in this single-institute series highlight the pivotal role of ERT in the management of clinically localized prostate cancer in the elderly.

Early prostate cancer: clinical decision-making

Prostate cancer is one of the most common malignant diseases for which health-care intervention is sought worldwide, and in many developed countries it is the most common. Some patients with early-stage prostate cancer, especially those who are elderly and have comorbidities, can be observed without treatment. Surgery (radical prostatectomy) and radiotherapy (external-beam radiotherapy, brachytherapy, or both) are the most widely accepted curative options for patients with early-stage disease who need intervention. All these local treatments have been refined, resulting in comparable cure rates; however, they all have different side-effect profiles. Adjuvant systemic treatments (hormones or chemotherapy), which are effective for advanced-stage disease, might have a greater role in early-stage disease. Selecting the best option for individuals from the available options is challenging--the decision on whether and how to treat is based on many disease and patient factors. Here, we review the major treatment options, discuss their relative advantages and disadvantages, and provide a general approach to management of patients with early-stage prostate cancer.

A population-based study on management of prostate cancer in four regions of France

In France, as in other European countries, management of prostate cancer in the population is rather variable. The objective was to analyse diagnosis and treatment modalities of prostate cancer in patients from French cancer registries.A sample of 803 patients with prostate cancer diagnosed in 1995 was drawn at random from cases recorded in four cancer registries in the geographical regions of Bas-Rhin, Calvados, Isère and Tarn. Diagnosis, clinical staging and treatment were analysed by questionnaire. Multivariate analysis by logistic regression was used to describe medical determinants (age, PSA, clinical staging) of the various treatment choices.The mean age of the patients was 71.6 y (range 46-94 y). Clinical staging showed 60% T(1-2) tumours, 15% T(3-4) and 17% N+or metastases. PSA rate (median 18.2 ng/ml) was assessed in 92.4% of patients. Prostate cancer was diagnosed by prostate biopsy in 63% and by transurethral resection of the prostate (TURP) in 32% of patients. The main treatments were radical prostatectomy 22%, radiotherapy 19.4%, hormonal therapy 33%, TURP alone 17.7% and expectant management 6%. The method of treatment was unknown in 5.7% of cases. Adjuvant radiotherapy or hormonal therapy had been used in 31% of cases. Logistic regression analysis showed that radical prostatectomy was most often performed in patients aged <60 y, three times more frequently for T(2) tumour and for PSA between 4 and 20 ng/ml. Radiotherapy was the most frequently applied treatment for patients aged between 65 and 75 y, especially in T(3) tumours.Approximately 75% of the patients in the study underwent a specific treatment for prostate cancer with a curative intention in 40%. This study provides a baseline to clinicians and public health authorities on the management of prostate cancer in France with recent data. This survey will be useful to compare future descriptive analysis and to provide data regarding changing clinical practice.Prostate Cancer and Prostatic Diseases (2001) 4, 154-160.

Primary radiation therapy for localized prostate cancer

Prostate cancer in men is similar to breast cancer in women; both cancers rank first, respectively, in incidence and are normally responsive to radiation therapy. In addition, advances in mammography help detect earlier breast cancers, and the development and refinement of prostatic specific antigen (PSA) has resulted in early detection of low-stage localized prostate cancers. This has generated debate over the proper management of localized prostate cancer. While there have not been any controlled, prospective, randomized trials of sufficient power to compare the various local therapies, based on the current available data, the three commonly used local modalities, surgery, and external beam radiation therapy and brachytherapy (radioactive seed implant), have similar efficacy controlling the disease up to 10 years in many patients. Technological advances in treatment delivery and planning have improved the treatment of prostate cancer with external-beam radiotherapy using three-dimensional conformal radiotherapy (3DCRT), ultrasound-guided transperineal implant, or intensity-modulated radiotherapy (IMRT), as well as proton or neutron beam based therapies.

Patterns and trends in prostate cancer incidence, survival, prevalence and mortality. Part I: international comparisons

The international patterns and trends in prostate cancer incidence, survival, prevalence and mortality were examined. Age-standardized incidence and death rates among men in a variety of countries worldwide were obtained from various sources, survival rates from European sources and elsewhere, and prevalence estimates from the EUROPREVAL study. Results from many published studies were summarized. The incidence of prostate cancer varies widely around the world, with by far the highest rates in the USA and Canada. There has been a gradual increase in the incidence of prostate cancer since the 1960s in many countries and in most continents; there were large increases in the late 1980s and early 1990s in the USA, but increases have also occurred in countries with comparatively low incidence, e.g. India. Survival from prostate cancer improved during the 1970s and 1980s; further increases in the 1990s may be largely a result of earlier diagnosis. There were wide differences in survival across Europe, with rates in the UK well below the average, but all European rates were far below those in the USA. There was wide variation in the prevalence of prostate cancer in Europe; in some countries with high incidence and high life-expectancy, prostate cancers formed approximately 15% of all prevalent cancers in men. Mortality from prostate cancer has also increased in many countries, but to a lesser extent than incidence; this is consistent with the observed trends in survival. Mortality decreased slightly in the mid to late 1990s in several countries, including the USA, Canada, England, France and Austria. Part of the apparent increases in the incidence of prostate cancer has been associated with diagnostic artefacts (particularly detecting preclinical tumours through the increased use of transurethral resection) which may also have had an effect on death certification through the incorrect attribution of prostate cancer as the underlying cause of death. However, the greatest effect on the registration of new cases of prostate cancer has been the increased availability of prostate specific antigen testing during the early- to mid-1990s. Possibly, in addition to the effect of attribution bias, the earlier diagnosis of prostate cancers has contributed to the recent slight decreases in mortality. However, this is unlikely to account for much of the reduction, given the slow development of the disease from onset to death. Changes in disease management are probably more important. There are many strong arguments against introducing population-based screening for prostate cancer.

Neoadjuvant androgen withdrawal prior to external radiotherapy for locally advanced adenocarcinoma of the prostate

BACKGROUND

It is unclear whether positive interactions between radiation and androgen withdrawal for patients with locally advanced prostate cancer is synergistic or additive. The present study aimed to clarify the significance of neoadjuvant androgen ablation prior to external radiotherapy in a human prostate LNCaP tumor model and in patients with locally advanced prostate cancer.

METHODS

Comparisons were made between the effect of castration prior to radiation on the growth of subcutaneous LNCaP tumors implanted into male nude mice and their serum prostate-specific antigen (PSA) levels, and the results of castration or radiation alone. Twenty-nine patients with histologically proven and locally advanced adenocarcinoma of the prostate were treated with luteinizing hormone-releasing hormone analog at least 3 months before, during, and after external radiation therapy with a total dose of 70 Gy. The toxicity and response to this therapy were evaluated.

RESULTS

Treatment combining castration and radiation resulted in synergistic inhibition of LNCaP tumor growth and a significant delay in the emergence of androgen-independent recurrence as opposed to either treatment alone. The external radiotherapy was completed in 28 patients (96.6%), resulting in a reduction of serum PSA levels in all 28 patients to below 1.0 ng/mL. All patients were alive after a mean follow-up period of 34 months (range 11-53) with a 3-year PSA relapse-free survival rate of 83.7%. Among several factors examined, only the Gleason score was significantly associated with PSA relapse-free survival in univariate analysis, but not in multivariate analysis. Thirteen of 28 patients (46%) and 7 of 28 (25%) also showed at least one form of gastrointestinal or genitourinary toxicity, respectively. Of these patients, 8 with gastrointestinal toxicities, and 1 with genitourinary toxicity, experienced acute complications higher than grade 3.

CONCLUSION

The experimental findings objectively suggested the use of neoadjuvant androgen withdrawal prior to radiation therapy. Although our clinical experience is preliminary, combined androgen ablation and radiation therapy may also be effective in controlling locally advanced prostate cancer, with tolerable side-effects.

The evolving role of systemic therapy in high risk prostate cancer: strategies for cure in the 21st century

High-risk prostate cancer is a heterogeneous group that includes patients with clinically locally advanced stage disease at diagnosis. Unlike overt locally advanced disease, prediction of risk in clinically localized disease at an individual patient level, is not always easy or accurate with present knowledge. Gleason score, pretreatment prostate specific antigen (PSA), and stage (capsular invasion, seminal vesicle and nodal involvement) are the universally recognized criteria used to define risk. Overall, this group of patients have a greater than 50% risk of relapse. Historically, local treatment modalities with radical prostatectomy or radiation therapy constituted the mainstay of therapy in the majority of localized prostate cancer patients. However, the primary cause of failure and disease mortality stems from the development of systemic metastases. As we continue to witness stage migration towards earlier stage disease (presumably PSA related) and mortality reduction, devising better strategies for cure is a must. Recently completed randomized trials indicate a benefit from the use of hormonal therapy in patients with locally advanced prostate cancer treated with radiation therapy or node positive patients, post radical prostatectomy. While hormone-based combined modality trials have consistently shown improvements in local and systemic disease control, only two of these demonstrated improvements in overall survival. The palliative benefit of chemotherapy in hormone refractory disease and the promising response rates with newer agents has evoked interest in the use of chemotherapy in high-risk prostate cancer in the adjuvant and neoadjuvant settings. Several phase II and III trials are ongoing. Novel avenues of therapy such as tyrosine kinase inhibitors, gene therapy and angiogenesis inhibitors incorporated in a multimodality treatment strategy are likely to impact the course of this disease in the future.

[Clinical and biological surveillance after radiotherapy for localized prostate cancer]

Serum PSA is an excellent marker of disease status after external beam radiotherapy or brachytherapy for patients with prostate carcinoma. A low PSA nadir < or = 1 even < or = 0.5 ng/mL has been shown to be as a surrogate end point for disease control. Three successive increases of this marker after achieving the nadir defines recurrence as recommended by the American Society for Therapeutic Radiology and Oncology. The biochemical relapse or PSA failure after treatment precedes clinical disease relapse by several months. PSA profile or kinetics may have implications for patterns of failure and prognosis. Prostate post-radiotherapy biopsies should not be part of routine follow-up as its interpretation is frequently problematic. Other exams should not be performed unless clinical symptoms are present. Post-radiotherapy relapse treatment has generally no curative intent.

Endoscopic therapy for radiation proctitis-induced hemorrhage in patients with prostatic carcinoma using argon plasma coagulator application

BACKGROUND

Recurrent hemorrhage in patients with severe radiation proctitis is very common. It is often refractory to medical therapy. Endoscopic and surgical treatment may be required when conservative medical therapy fails. The aim of this study was to assess the therapeutic results of the Argon Plasma Coagulator (APC) (ERBE USA, Inc., Marietta, GA, USA) application in patients with radiation proctitis-induced hemorrhage.

METHODS

Forty patients with radiation-induced proctitis causing severe bleeding, who had failed conservative medical management were treated endoscopically. Twenty-one patients in this group required blood transfusions.

RESULTS

APC application was used in 40 patients with only one failure. The failed patient underwent formalin application using 4% formalin solution with resolution of the bleeding.

CONCLUSION

Argon plasma coagulation application is a safe, well-tolerated treatment option and, historically, has been superior to Nd:YAG laser ablation.

Endocrine therapy for recurrence after definitive radiotherapy in patients with prostate cancer

BACKGROUND

Long-term results were analyzed to evaluate the role of endocrine therapy in the management of local and distant recurrence of prostate cancer following external radiation therapy.

METHODS

Between 1976 and 1994, 92 patients with untreated prostate cancer underwent external beam radiation therapy alone. Endocrine therapy had been started when relapse was evident.

RESULTS

Failure was seen in 35 of 92 patients: 10 local, 19 distant and six biochemical failures. Endocrine treatment was performed in 28 patients with nine local and 19 distant failures. The cancer-specific survival rate from the endocrine treatment was 54.5% at 5 years. Prostate-specific antigen level in 20 of 20 patients (100%) decreased to below the normal limit 3 months after the start of endocrine therapy. In univariate analysis, T classification was the most significant variable for cancer-specific survival from the initial treatment.

CONCLUSIONS

A favorable outcome was achieved by endocrine therapy in patients who had relapsed after external beam radiation monotherapy. Even the recurrent tumor had a sensitivity to androgen. Patients with locally advanced disease (T2b and T3) had poorer prognosis than those with minimally extended disease (T1b and T2a).

Incidence rate and management of prostate carcinoma

The age-standardised incidence of prostate cancer varies more than one hundredfold between the areas with the highest and lowest incidences in the world. In certain areas, in particular the Western countries, the incidence has increased rapidly over the last 20 years. There are several environmental and genetic factors which partly explain these variations, although the incidence probably depends most of all on the extent to which small latent tumours are detected. As the clinical significance of small tumours is uncertain, the value of early diagnosis and early aggressive treatment is controversial. Randomised trials addressing this question have been initiated and will hopefully provide more evidence-based data in a decade from now. Small localised tumours are managed by radical surgery or radiation therapy. In elderly men or men unfit for operation or radiation therapy surveillance is often preferred. For advanced or metastatic prostate cancers androgen deprivation has been the mainstay of treatment since the early 1940s. Recently, several new treatment strategies have evolved but have not yet been introduced into clinical routine.

The role of active treatment in early prostate cancer

The dramatic increase in the number of patients diagnosed with localized prostate cancer in the last decade presents a difficult challenge for physicians. Because the window of opportunity for cure is short it is vital to begin treatment before the cancer cells invade neighbouring tissues and organs or metastasise to other sites. This pressure of increased patient numbers provided clinicians with the opportunity to investigate other treatment options. New surgical techniques including laparoscopic radical prostatectomy, improving therapeutic radiation by the introduction of conformal radiotherapy, neutron radiation, cryosurgery, high intensity focussed ultrasound (HIF) and the revival of brachytherapy with or without external beam radiation are currently being investigated. The goal of these techniques is to treat localized prostate cancer based on the endpoints of disease specific mortality, no evidence of disease, absent or low levels of prostate-specific antigen (PSA), reduced side-effects, improved quality of life and importantly increased cost-efficacy. It is important to remember however, that watchful waiting and endocrine therapy are still valid therapy options in certain patient groups. The lack of randomized, prospective trials on local treatment of prostate cancer, makes it difficult to compare the efficacy of the different treatments, especially in terms of disease-specific survival. Trials are now in progress but it will be several years before results are available. In the meantime, we need to focus on surrogate endpoints, side effects, quality of life and the cost-efficacy of each treatment. It is also important to ensure that patients are kept informed and up-to-date with any new therapeutic developments.

Long-term survival in a Swedish population-based cohort of men with prostate cancer

OBJECTIVES

To study the long-term survival of patients with prostate cancer, determine the risk factors for prostate cancer death, and investigate the outcome of initially untreated localized prostate cancer and incidentally detected tumors.

METHODS

The survival of 813 patients in a population-based cohort of patients with prostate cancer in Linköping, Sweden, diagnosed from 1974 to 1986, was analyzed.

RESULTS

At 10, 15, and 20 years after diagnosis, the prostate cancer-specific survival rate of men with localized, initially untreated, prostate cancer was 85.0% (95% confidence interval [CI], 79.0% to 91.0%), 80.0% (95% CI, 72.5% to 87.5%), and 62.6% (95% CI, 43.0% to 82.2%). Age 70 years or older, advanced stage, and poor differentiation were risk factors associated with an increased risk of prostate cancer death. At 10 years, the prostate cancer-specific survival rate among men with localized tumors treated by expectancy was 90% (95% CI, 84% to 97%) for grade 1 tumors, 74% (95% CI, 60% to 89%) for grade 2 tumors, and 59% (95% CI, 29% to 90%) for grade 3 tumors. For patients with incidentally detected tumors, the grade of malignancy was a more important risk factor than tumor volume.

CONCLUSIONS

Patients with localized tumors have a favorable prognosis, even without initial treatment. However, when deciding on therapy, the grade of malignancy should be taken into account, as it has a great influence on survival. We did not see a tendency toward increased mortality when the patients were followed up for longer than 10 years after diagnosis.

Adjuvant chemo-/hormonal therapy trials for locally advanced prostate cancer

Patients with clinical or pathologic locally advanced prostate cancer (LAPC) are at risk for systemic and local disease progression or relapse. Pre- and post-therapy predictors of risk include prostate-specific antigen (PSA) levels, clinical and pathologic stage, Gleason's score (GS) of the biopsy and prostatectomy specimens, positive margins, and post-therapy PSA kinetics. Combined modality trials have been done predominantly in LAPC patients treated with radiation. The data indicate a local control and disease-free survival advantage to the use of androgen deprivation. Neoadjuvant hormonal therapy with radical prostatectomy (RP) has no proven role thus far; however, recent data on adjuvant hormonal therapy in patients with pathologic D1 disease treated with radical prostatectomy suggest a potential benefit. Chemotherapy trials are still in their infancy but present exciting opportunities for future research. The heterogeneity in the hormone responsiveness of prostate cancer, the availability of several active chemotherapy combinations, and the refinement in risk prediction have stimulated a series of adjuvant therapy trials which constitute the subject of this discussion. Emphasis on enrollment in clinical trials is thus imperative in LAPC.

Cryosurgery for prostate cancer: new technology and indications

Patients diagnosed with prostate cancer who elect to pursue active treatment of their disease must choose among the many available treatment alternatives. Several treatment options now exist for similar-stage disease (clinical T1-3N0M0), including radical prostatectomy, external beam radiation, prostate brachytherapy (PB), and cryosurgical ablation of the prostate (CSAP). This article reviews the current role of CSAP in the treatment of clinically localized prostate cancer. CSAP has a role in the primary treatment of men with high-risk, clinically localized prostate cancer (defined as PSA >10, Gleason score >or=7, or clinical stage >or= cT2B). CSAP (occasionally followed by external beam radiotherapy) appears to offer improved rates of cancer control over other types of single or combination therapies for this high-risk prostate cancer, and it is associated with an acceptable side-effect profile. CSAP should also be the treatment of choice for men with recurrent local disease who have undergone external beam radiotherapy or PB.

External beam radiation monotherapy for prostate cancer

BACKGROUND

To clarify the implications and limitations of external beam radiation monotherapy for localized prostate cancer, the long-term outcomes and prognostic factors were investigated.

METHODS

Between 1976 and 1994, 91 patients with untreated prostate cancer were treated with external beam radiation therapy alone. Thirty-two were classified as T1b, eight were T2a, four were T2b and 47 were T3. Pelvic lymphadenectomy was carried out in 69 cases; 57 were staged as pN0, eight were pN1, four were pN2 and 22 were pNX. Linac X-rays were used in 55 cases, fast neutron in 15 and a combination of the two in 21. No other therapy was given until relapse and when relapse was evident endocrine therapy was started.

RESULTS

The observation period ranged from 3 to 206 months with a median of 78 months. Local control rate and disease-free, cause-specific and overall survivals at 10 years were 74.0, 49.6, 74.2 and 39.2%, respectively. By univariate analysis, T category, pN category and histologic grade were significant prognostic indicators for disease-free survival. Multivariate analysis revealed that T category was an independent prognostic factor. In T2b and T3 diseases, pN0/1 patients demonstrated significantly better disease-free survival than pNX.

CONCLUSIONS

A favorable long-term outcome was achieved by external beam radiation monotherapy in patients with minimally extended prostate cancer (T1b and T2a). For locally advanced disease (T2b and T3), staging pelvic lymphadenectomy would be useful for the selection of patients.

The role of volume-weighted mean nuclear volume in predicting disease outcome in patients with prostate cancer treated with radical prostatectomy

BACKGROUND

Estimates of volume-weighted mean nuclear volume (MNV) are the only means by which unbiased estimates of three-dimensional parameters can be obtained from single two-dimensional sections without any assumptions. We have reported that for prostate cancer estimates of MNV are prognostically equal or superior to morphological grading of malignancy, such as Gleason score (GS), and in particular, that MNV proved to be a meaningful predictor of prognosis for patients with clinically localized tumors. However, all previous studies were conducted on patients treated conservatively, and no authors have tested whether estimates of MNV can predict the prognosis of patients treated with radical prostatectomy.

MATERIALS AND METHODS

A retrospective prognostic study of 52 patients with clinically localized prostate cancer diagnosed at three Hospitals in Shizuoka Prefecture, Japan (Shizuoka City Hospital, Shizuoka Prefectural Hospital and Shimada Municipal Hospital) and treated by radical prostatectomy was performed. Twenty of these patients were treated with hormone therapy before radical prostatectomy. Unbiased estimates of MNV were compared with clinical stage, histological grading according to GS and neo-adjuvant hormone therapy with regard to the prognostic value.

RESULTS

MNV was significantly correlated with pathological T stage, but was not significantly correlated with the presence or absence of lymph node metastasis. Univariate analysis revealed that MNV correlated significantly with progression-free survival (p = 0.0116). Multivariate analysis revealed that MNV (p = 0.0115) and GS (p = 0.0275) were two significant independent predictors of progression-free survival.

CONCLUSIONS

The results of the present study suggest that MNV and GS are powerful independent predictors of prognosis for prostate cancer treated with radical prostatectomy. We recommend estimates of MNV as a supportive method to the histological grading for patients with prostate cancer.

Long-term results of a randomized trial for the treatment of Stages B2 and C prostate cancer: radical prostatectomy versus external beam radiation therapy with a common endocrine therapy in both modalities

OBJECTIVES

To improve the treatment of locally advanced prostate cancer (Stages B2 and C), a prospective randomized trial was conducted to compare radical prostatectomy versus external beam radiotherapy with the combination of endocrine therapy in both modalities.

METHODS

One hundred patients were enrolled and 95 were evaluated. Forty-six patients underwent radical prostatectomy with pelvic lymph node dissection, and 49 were treated with radiation by linear accelerator with 40 to 50 Gy to the whole pelvis and a 20-Gy boost to the prostatic area. For all patients, endocrine therapy was initiated 8 weeks before surgery or radiation, and continued thereafter. The living patients were asked to respond to a quality-of-life questionnaire.

RESULTS

The follow-up period ranged from 6.0 to 94.4 months (median 58.5). The progression-free and cause-specific survival rates at 5 years were 90.5% and 96.6% in the surgery group and 81.2% and 84.6% in the radiation group, respectively. The surgery group had better progression-free and cause-specific survival rates (P = 0.044 and 0.024, respectively). More patients in the surgery group complained of urinary incontinence. The questionnaire revealed that quality of life was less disturbed in the radiation group.

CONCLUSIONS

Radical prostatectomy combined with endocrine therapy may contribute to the survival benefit of patients with locally advanced prostate cancer. External beam radiotherapy in combination with endocrine therapy can be used in selected patients because of its low morbidity.

Conventional external-beam radiation therapy alone or with androgen ablation for clinical stage III (T3, NX/N0, M0) adenocarcinoma of the prostate

PURPOSE

To evaluate the outcome of clinical Stage III (T3, N0/NX, M0) prostate cancer treated by conventional radiation alone or with adjuvant androgen ablation.

METHODS AND MATERIALS

Three hundred forty-four men with T3, N0/NX, M0 adenocarcinoma of the prostate who received conventional radiation alone (260) or with androgen ablation (84) were analyzed for relapse or rising prostate-specific antigen (PSA), using univariate and multivariate techniques.

RESULTS

With a median follow-up of 68 months, the 260 men treated with radiation alone had a 10-year actuarial rate of relapse or rising PSA of 76%. Pretreatment PSA level (< or = 10 ng/ml vs. > 10 < or = 20 ng/ml vs. > 20 ng/ml) and radiation dose (< 68 Gy vs. > or = 68 Gy) were the only independently significant determinants of biochemical failure; Gleason score (2-7 vs. 8-10) was an additional determinant of metastatic relapse. Patients treated to doses < 68 Gy experienced 6-year failure rates exceeding 50% regardless of PSA level. Patients with PSA < or = 10 ng/ml and receiving 68-70 Gy had a 6-year failure of 24%, but those with PSA > 10 ng/ml had relapse rates exceeding 50% even at doses of 70 Gy. At a median follow-up of 44 months, the 84 patients treated with radiation and androgen ablation had a 6-year biochemical failure rate of 22%. The only significant determinant of outcome in this group was pretreatment PSA; patients with PSA < or = 80 ng/ml had a 6-year failure rate of only 12% compared to a failure rate of 53% for those with PSA > 80 ng/ml. The outcome for those treated with combined modalities was significantly better than for those treated with radiation alone in all PSA strata.

CONCLUSION

Conventional radiation alone has little curative potential for Stage III disease. Doses < 68 Gy are particularly ineffective. Patients with PSA < or = 10 ng/ml may be candidates for conventional radiation to a dose of 70 Gy. Other patients are probably best served by combined radiation-androgen ablation or high-dose conformal radiation.

Fractionated radiotherapy of rat prostatic adenocarcinoma (Dunning R3327-PAP) in nonanesthetized animals

BACKGROUND

The dose-response effect of fractionated external beam radiotherapy on nonanesthetized rats bearing the androgen-sensitive prostatic adenocarcinoma Dunning R3327-PAP was studied.

METHODS

The radiation was given with a photon beam from a 4-MeV linear accelerator in doses from 4 to 11 Gray per fraction during 5 consecutive days. When the tumors with low and intermediate radiation doses relapsed into regrowth, the rats were castrated. Tumor volumes and rat weights were followed, and at the end of the study a morphometric analysis of the tumors was done.

RESULTS

Fractionated irradiation induced a dose-dependent delay in tumor growth in hormonally intact rats. Castration stopped the tumor regrowth, showing that some of the tumor cells were still hormone-sensitive. The study was facilitated by the nonanesthesia procedure.

CONCLUSIONS

The Dunning R3327-PAP hormone-sensitive rat tumor is sensitive to radiotherapy in a dose-dependent way. Regrowing, irradiated tumors contain hormone-sensitive cells. This work provided basic knowledge for further experimental studies of the effects of radiation on prostatic adenocarcinoma.

Variation in survival of patients with prostate cancer in Europe since 1978. EUROCARE Working Group

Since the incidence of prostate cancer has increased considerably over the past two decades in most European countries, knowledge of the variation in survival is pertinent. The collaboration across Europe in the EUROCARE study has now been extended to 45 registries in 17 countries. We report on variation in relative survival according to age of 65,728 patients diagnosed with prostate cancer between 1985 and 1989 and also explore time trends since 1978 for most countries. Considerable variation in survival was found within and between countries, with the highest survival in Switzerland (5-year relative survival 72%), followed by Germany (67%) and the Nordic countries (except Denmark). The lowest survival was found in Estonia (39%), preceded by Slovenia (40%), Denmark (41%) and England (45%). Between 1978 and 1986, relative survival barely changed over time, but it improved from 55% (95% confidence interval [CI] 53-57) during 1984-1986 to 59% (CI 56-61) during 1987-1989. A small but unexpected deterioration of survival for patients aged between 45 and 54 years from 61% to 56% was observed in the early 1980s. It is likely that variation in both detection methods and treatment plays a role in the observed variation in survival, but more information is needed to assess each contribution.

The Role of Radiotherapy in the Treatment of Carcinoma of the Prostate: A Survey of Clinical Practices in Lombardy, Italy, by the Airo-Lombardia Cooperative Group

Aims and background

We report the results of a survey performed in 1994 by the AIRO-Lombardia Cooperative Group, on the clinical patterns of radiation treatment for prostatic carcinoma in Lombardy, Italy, involving all radiotherapy centers serving an overall local population of about 8,800,000 people.

Methods

A questionnaire was sent to all 13 radiotherapy centers throughout Lombardy, asking for demographic and treatment details concerning the local population of patients with a localized (T1-4, N0-1, M0) carcinoma of the prostate treated with radiotherapy; 12 centers responded, making the basis for the present report.

Results

Analysis of collected data showed that in Lombardy: a) approximately 400 patients per year are irradiated for a localized carcinoma of the prostate, accounting for less than 30% of the total expected number of patients with this disease presentation; b) a complete staging (with PSA, transrectal ultrasonography, abdomino-pelvic CT or MRI scan and total-body bone scan) is performed in over 95% of patients before initiating radiotherapy; c) significant differences exist between radiotherapy centers as regards treatment planning and delivery.

Conclusions

An urgent need exists for implementing procedures aimed at standardizing radiotherapy procedures within Lombardy.