Salvage therapy for locally recurrent prostate cancer after external beam radiotherapy

Combination of Abiraterone Acetate, Prostate Bed Radiotherapy, and Luteinizing Hormone-releasing Hormone Agonists in Biochemically Relapsing Patients After Prostatectomy (CARLHA): A Phase 2 Clinical Trial

BACKGROUND

The relevance of next-generation hormone therapies and circulating tumor cells (CTCs) are not elucidated in biochemical recurrence after prostatectomy.

OBJECTIVE

To evaluate the combination of abiraterone acetate plus prednisone (AAP), prostate bed radiotherapy (PBRT), and goserelin in biochemically relapsing men after prostatectomy, and to investigate the utility of CTCs.

DESIGN, SETTING, AND PARTICIPANTS

In this single-arm multicenter phase 2 trial, 46 biochemically relapsing men were enrolled between December 2012 and January 2019. The median follow-up was 47 mo.

INTERVENTION

All patients received AAP 1000 mg daily (but 750 mg during PBRT), salvage PBRT, and goserelin.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome was 3-yr biochemical recurrence-free survival (bRFS) when prostate-specific antigen (PSA) levels were ≥0.2 ng/ml. The secondary outcomes included alternative bRFS (alt-bRFS) when PSA levels were ≥0.5 ng/ml and safety assessment. CTC count was assessed.

RESULTS AND LIMITATIONS

The 3-yr bRFS and alt-bRFS were 81.5% (95% confidence interval or CI [66.4-90.3%]) and 95.6% (95% CI [83.5-98.9%]), respectively. The most common acute radiotherapy-related adverse effect (AE; all grades was pollakiuria (41.3%). The most common late AE (all grades) was urinary incontinence (15.2%). Grade 3-4 acute or late radiotherapy-related AEs were scarce. Most frequent AEs nonrelated to radiotherapy were hot flashes (76%), hypertension (63%), and hepatic cytolysis (50%, of which 20% were of grades 3-4). Of the patients, 11% had a CTC count of ≥5, which was correlated with poorer bRFS (p = 0.042) and alt-bRFS (p = 0.008). The association between CTC count and higher rates of relapse was independent of the baseline PSA level and PSA doubling time (p = 0.42 and p = 0.09, respectively). This study was nonrandomized with a limited number of patients, and few clinical events were reported.

CONCLUSIONS

Adding AAP to salvage radiation therapy and goserelin resulted in high bRFS and alt-bRFS. AEs remained manageable, although a close liver surveillance is advised. CTC count appears as a promising biomarker for prognosis and predicting response to treatment.

PATIENT SUMMARY

Our study was a phase 2 clinical trial that exhibited the efficacy and tolerance of a novel androgen-receptor targeting agent (abiraterone acetate plus prednisone) in patients with prostate cancer who experienced rising prostate-specific antigen after radical prostatectomy, in combination with prostate bed radiotherapy. The results also indicated the feasibility and potential value of circulating tumor cell detection, which constitutes a possible advance in managing prostate cancers.

Magnetic Resonance-Guided Prostate Ablation

In 2019, the American Cancer Society (ACS) estimates that 174,650 new cases of prostate cancer will be diagnosed and 31,620 will die due to the prostate cancer in the United States. Prostate cancer is often managed with aggressive curative intent standard therapies including radiotherapy or surgery. Regardless of how expertly done, these standard therapies often bring significant risk and morbidity to the patient's quality of life with potential impact on sexual, urinary, and bowel functions. Additionally, improved screening programs, using prostatic-specific antigen and transrectal ultrasound-guided systematic biopsy, have identified increasing numbers of low-risk, low-grade "localized" prostate cancer. The potential, localized, and indolent nature of many prostate cancers presents a difficult decision of when to intervene, especially within the context of the possible comorbidities of aggressive standard treatments. Active surveillance has been increasingly instituted to balance cancer control versus treatment side effects; however, many patients are not comfortable with this option. Although active debate continues on the suitability of either focal or regional therapy for the low- or intermediate-risk prostate cancer patients, no large consensus has been achieved on the adequate management approach. Some of the largest unresolved issues are prostate cancer multifocality, limitations of current biopsy strategies, suboptimal staging by accepted imaging modalities, less than robust prediction models for indolent prostate cancers, and safety and efficiency of the established curative therapies following focal therapy for prostate cancer. In spite of these restrictions, focal therapy continues to confront the current paradigm of therapy for low- and even intermediate-risk disease. It has been proposed that early detection and proper characterization may play a role in preventing the development of metastatic disease. There is level-1 evidence supporting detection and subsequent aggressive treatment of intermediate- and high-risk prostate cancer. Therefore, accurate assessment of cancer risk (i.e., grade and stage) using imaging and targeted biopsy is critical. Advances in prostate imaging with MRI and PET are changing the workup for these patients, and advances in MR-guided biopsy and therapy are propelling prostate treatment solutions forward faster than ever.

Disease Control With Delayed Salvage Radiotherapy for Macroscopic Local Recurrence Following Radical Prostatectomy

Purpose: To retrospectively assess clinical outcomes and toxicity profile of prostate cancer patients treated with delayed dose-escalated image-guided salvage radiotherapy (SRT) for macroscopic local recurrence after radical prostatectomy (RP). Material and Methods: We report on a cohort of 69 consecutive patients with local recurrence after RP and no evidence of regional or distant metastasis who were referred for salvage radiotherapy between 2007 and 2016. SRT consisted of 64-66 Gy (2 Gy/fraction) to the prostatic bed followed by dose escalation to 72-74 Gy (2Gy/fraction) to the macroscopic disease. All patients received concurrent short-term androgen deprivation therapy (ADT). Biochemical recurrence-free survival (bRFS) and clinical progression-free-survival (cPFS) were depicted using Kaplan-Meier method. Multivariable Cox proportional hazards regression assessed predictors of survival outcomes. Baseline, acute, and late urinary and gastrointestinal (GI) toxicity rates were reported using CTCAE v4.03. Results: Median time from RP to SRT was 66 months (IQR: 32-124). Median pre-SRT prostate-specific antigen (PSA) was 2.7 ng/ml (IQR: 0.9-6.5). Median follow-up after SRT was 38 months (IQR: 24-66). The 3- and 5-year bRFS were 58 and 44%, respectively. The 3- and 5-year cPFS were 91 and 76%, respectively. Median time from SRT to clinical disease progression was 102 months (IQR 77.5-165). At baseline, 3 patients (4%) had grade 3 urinary symptoms. Six patients (9%) developed acute and six patients (9%) developed late grade 3 urinary toxicity. Five patients (7%) had acute grade 2 GI toxicity. No acute grade 3 GI toxicity was reported. Late grade 3 GI toxicity was reported in one patient (1.5%). Conclusions: Delayed dose-escalated SRT combined with short-course ADT for macroscopic LR after RP was associated with 44% bRFS and 76% cPFS at 5 years. Albeit improved patient stratification is warranted, these data suggest that delayed SRT provides inferior tumor control compared to early intervention.

MR-Guided Prostate Interventions

Prostate cancer is the most commonly diagnosed noncutaneous cancer and second leading cause of death in men. Many patients with clinically organ-confined prostate cancer undergo definitive treatment of the whole gland, including radical prostatectomy, radiation therapy, and cryosurgery. Active surveillance is a growing alternative option for patients with documented low-volume and low-grade prostate cancer. However, many patients are wanting a less morbid focal treatment alternative. With recent advances in software and hardware of magnetic resonance imaging (MRI), multiparametric MRI of the prostate has been shown to improve the accuracy in detecting and characterizing clinically significant prostate cancer. Targeted biopsy is increasingly utilized to improve the yield of MR detected, clinically significant prostate cancer and to decrease in detection of indolent prostate cancer. MR-guided targeted biopsy techniques include cognitive MR fusion transrectal ultrasound (TRUS) biopsy, in-bore transrectal targeted biopsy using robotic transrectal device, and in-bore direct MR-guided transperineal biopsy with a software based transperineal grid template. In addition, advances in MR-compatible thermal ablation technology allow accurate focal or regional delivery of thermal ablative energy to the biopsy-proved, MRI-detected tumor. MR-guided ablative treatment options include cryoablation, laser ablation, and high-intensity focused ultrasound with real-time or near simultaneous monitoring of the ablation zone. We present a contemporary review of MR-guided techniques for prostatic interventions.

Improving postoperative radiotherapy following radical prostatectomy

INTRODUCTION

Prostate cancer has one of the highest incidences in the world, with good curative treatment options like radiotherapy and radical prostatectomy. Unfortunately, about 30% of the patients initially treated with curative intent will develop a recurrence and need adjuvant treatment. Five randomized trials covered the role of postoperative radiotherapy after radical prostatectomy, but there is still a lot of debate about which patients should receive postoperative radiotherapy. Areas covered: This review will give an overview on the available literature concerning post-operative radiotherapy following radical prostatectomy with an emphasis on the five randomized trials. Also, new imaging techniques like prostate-specific membrane antigen positron emission tomography (PSMA-PET) and multiparametric magnetic resonance imaging (mp-MRI) and the development of biomarkers like genomic classifiers will be discussed in the search for an improved selection of patients who will benefit from postoperative radiotherapy following radical prostatectomy. With new treatment techniques like Intensity Modulated Radiotherapy, toxicity profiles will be kept low. Expert commentary: Patients with biochemical recurrence following radical prostatectomy with an early rise in prostate-specific antigen (PSA) will benefit most from postoperative radiotherapy. In this way, patients with only high risk pathological features can avoid unnecessary treatment and toxicity, and early intervention in progressing patients would not compromise the outcome.

Single-institution comparative study on the outcomes of salvage cryotherapy versus salvage robotic prostatectomy for radio-resistant prostate cancer

BACKGROUND

Although primary treatment of localized prostate cancer provides excellent oncologic control, some men who chose radiotherapy experience a recurrence of disease. There is no consensus on the most appropriate management of these patients after radiotherapy failure. In this single-institution review, we compare our oncologic outcome and toxicity between salvage prostatectomy and cryotherapy treatments.

METHODS

From January 2004 to June 2013, a total of 23 salvage procedures were performed. Six of those patients underwent salvage prostatectomy while 17 underwent salvage cryotherapy by two high-volume fellowship-trained urologists. Patients being considered for salvage therapy had localized disease at presentation, a prostate-specific antigen (PSA) < 10 ng/mL at recurrence, life expectancy > 10 years at recurrence, and a negative metastatic workup. Patients were followed to observe cancer progression and toxicity of treatment.

RESULTS

Patients who underwent salvage cryotherapy were statistically older with a higher incidence of hypertension than our salvage prostatectomy cohort. With a mean follow up of 14.1 months and 7.2 months, the incidence of disease progression was 23.5% and 16.7% after salvage cryotherapy and prostatectomy, respectively. The overall complication rate was also 23.5% versus 16.7%, with the most frequent complication after salvage cryotherapy being urethral stricture and after salvage prostatectomy being severe urinary incontinence. There were no rectal injuries with salvage prostatectomy and one rectourethral fistula in the cohort after salvage cryotherapy.

CONCLUSION

While recurrences from primary radiotherapy for prostate cancer do occur, there is no consensus on its management. In our experience, salvage procedures were generally safe and effective. Both salvage cryotherapy and salvage prostatectomy allow for adequate cancer control with minimal toxicity.

Cryotherapy in prostate cancer

Review objectives:

Cryotherapy use has increased due to technological advances. A review of the literature was performed to evaluate the efficacy and outcomes of whole gland, salvage and targeted focal cryotherapy in the management of prostate cancer.

Review findings:

Cryotherapy use has increased significantly over the last 10 years with a trend towards focal ablation. Whole gland cryotherapy, salvage cryotherapy and focal cryotherapy biochemical recurrence rates appear to be comparable to other treatment modalities for low risk disease, however biochemical failure remains difficult to compare across studies due to a lack of consensus regarding appropriate end points for evaluation of cryotherapy. Short-term focal cryotherapy outcomes are encouraging. Side effect profiles for cryotherapy have significantly improved with fourth generation systems while salvage cryotherapy continues to carry a slightly higher risk of incontinence than primary whole gland cryotherapy. The incidence of erectile dysfunction after focal cryotherapy is dramatically lower than that for whole gland ablation.

Conclusions:

Cryotherapy continues to have an active role in the primary and salvage treatment of prostate cancer. Targeted focal cryotherapy is a promising treatment with minimal morbidity. Further long-term data is needed to support targeted therapy in addition to direct comparison with other treatment modalities.

The dilemma of a rising prostate-specific antigen level after local therapy: what are our options?

Prostate cancer is the most common solid tumor diagnosed in men in the United States and Western Europe. Primary treatment with radiation or surgery is largely successful at controlling localized disease. However, a significant number (up to one third of men) may develop biochemical recurrence (BR), defined as a rise in serum prostate-specific antigen (PSA) level. A general presumption is that BR will lead to overt progression in patients over subsequent years. There are a number of factors that a physician must consider when counseling and recommending treatment to a patient with a rising PSA. These include the following (1) various PSA-based definitions of BR; (2) source of PSA (ie, local or distant disease, residual benign prostate); (3) available modalities to treat the disease with the least morbidity; and (4) timing of therapy. In this article we review the current and future factors that clinicians should consider in the diagnosis and treatment of recurrent prostate cancer.

Early salvage radiotherapy following radical prostatectomy

CONTEXT

Depending on the pathologic tumour stage, up to 60% of prostate cancer patients who undergo radical prostatectomy will develop biochemical relapse and require further local treatment.

OBJECTIVES

We reviewed the results of early salvage radiation therapy (RT), defined as prostate-specific antigen (PSA) values prior to RT ≤ 0.5 ng/ml in the setting of lymph node-negative disease.

EVIDENCE ACQUISITION

Ten retrospective studies, including one multicentre analysis, were used for this analysis. Among them, we received previously unpublished patient characteristics and updated outcome data from five retrospective single-centre trials to perform a subgroup analysis for early salvage RT.

EVIDENCE SYNTHESIS

Patients treated with early salvage RT have a significantly improved biochemical recurrence-free survival (BRFS) rate compared with those receiving salvage RT initiated after PSA values are >0.5 ng/ml. Similarly, within the cohort of patients with pre-RT PSA values <0.5 ng/ml, improved BRFS rates were noted among those with lower rather higher pre-RT PSA levels. It is possible that higher RT dose levels and the use of adjunctive androgen-deprivation therapy improve biochemical control outcomes in the salvage setting.

CONCLUSIONS

Based on a literature review, improved 5-yr BRFS rates are observed for patients who receive early salvage RT compared with patients treated with salvage RT with a pre-RT PSA value >0.5 ng/ml. Whether the routine application of early salvage RT in patients with initially undetectable PSA levels will be associated with demonstrable clinical benefit awaits the results of ongoing prospective trials.

Management of biochemical recurrence after primary treatment of prostate cancer: a systematic review of the literature

CONTEXT

Despite excellent cancer control with the treatment of localized prostate cancer (PCa), some men will experience a recurrence of disease. The optimal management of recurrent disease remains uncertain.

OBJECTIVE

To systematically review recent literature regarding management of biochemical recurrence after primary treatment for localized PCa.

EVIDENCE ACQUISITION

A comprehensive systematic review of the literature was performed from 2000 to 2012 to identify articles pertaining to management after recurrent PCa. Search terms included prostate cancer recurrence, salvage therapy, radiorecurrent prostate cancer, post HIFU, post cryoablation, postradiation, and postprostatectomy salvage. Studies were selected according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines and required to provide a comprehensive description of primary and secondary treatments along with outcomes.

EVIDENCE SYNTHESIS

The data from 32 original publications were reviewed. The most common option for local salvage therapy after radical prostatectomy (RP) was radiation. Options for local salvage therapy after primary radiation included RP, brachytherapy, and cryotherapy. Different definitions of recurrence and risk profiles among patients make comparative assessment among salvage treatment modalities difficult. Triggers for intervention and factors predicting response to salvage therapy vary.

CONCLUSIONS

Radiation therapy (RT) after RP can provide durable prostate-specific antigen (PSA) responses in a sizeable percentage of men, especially when given early (ie, PSA <1 ng/ml). Though a few studies suggest improvements in mortality, prospective randomized trials are needed and underway. The role of salvage treatment after RT is less clear.

Management of biochemical recurrence after primary localized therapy for prostate cancer

Clinically localized prostate cancer is typically managed by well established therapies like radical prostatectomy, brachytherapy, and external beam radiation therapy. While many patients can be cured with definitive local therapy, some will have biochemical recurrence (BCR) of disease detected by a rising serum prostate-specific antigen (PSA). Management of these patients is nuanced and controversial. The natural history indicates that a majority of patients with BCR will not die from prostate cancer but from other causes. Despite this, a vast majority of patients with BCR are empirically treated with non-curable systemic androgen deprivation therapy (ADT), with its myriad of real and potential side effects. In this review article, we examined the very definition of BCR after definitive local therapy, the current status of imaging studies in its evaluation, the need for additional therapies, and the factors involved in the decision making in the choice of additional therapies. This review aims to help clinicians with the management of patients with BCR. The assessment of prognostic factors including absolute PSA level, time to recurrence, PSA kinetics, multivariable nomograms, imaging, and biopsy of the prostatic bed may help stratify the patients into localized or systemic recurrence. Patients with low-risk of systemic disease may be cured by a salvage local therapy, while those with higher risk of systemic disease may be offered the option of ADT or a clinical trial. An algorithm incorporating these factors is presented.

Brachytherapy for the treatment of recurrent prostate cancer after radiotherapy or radical prostatectomy

What's known on the subject? and What does the study add? The curative treatment of prostate cancer includes surgery, external beam radiation or interstitial radiation. However, a high percentage of patients may develop recurrent disease, which is often localised. The possibilities of treatment in these cases, including surgery or adjuvant radiotherapy, are not well defined. Brachytherapy is a well established first-line treatment option. We review and update the use of brachytherapy in the treatment of recurrences post-radiotherapy, brachytherapy or radical prostatectomy as an alternative to surgery and radiotherapy, with a focus on functional and oncological outcomes. Salvage therapeutic options following radical prostatectomy or radiotherapy for patients with local relapse of prostate cancer include radical prostatectomy, radiotherapy, brachytherapy or cryotherapy. Salvage radical prostatectomy following radiotherapy failure is associated with a 5-year PSA relapse-free rate of 30-40%. Biochemical relapse-free survival rates after salvage radiotherapy following radical prostatectomy failure range from 10% to 77% after a follow-up of 22-60 months. A number of studies have evaluated salvage brachytherapy for radiotherapy failure and 5-year biochemical disease-free survival (bDFS) rate results reported are of the order of 20-87%; one study reported a 10-year bDFS rate of 54%. Fewer studies in small numbers of patients and with shorter follow-up have been conducted on brachytherapy for radical prostatectomy failure and bDFS rates reported include 25.8% at a median of 29 months to 70% at a median of 20 months. The side-effects were as expected for brachytherapy. A newer initiative conducted in Spain in a larger series of 42 patients with failure following radical prostatectomy involves brachytherapy with RAPID Strand™(125) I seeds and real-time placement. The 5-year bDFS rate was 88.6% and cancer-specific survival was 97%; complication rates were low. Optimization of salvage brachytherapy is under way and involves accurate placement of seeds, dose optimization and optimal patient selection.

Locally recurrent prostate cancer after high-dose-rate brachytherapy: the value of diffusion-weighted imaging, dynamic contrast-enhanced MRI, and T2-weighted imaging in localizing tumors

OBJECTIVE

The purpose of this article is to retrospectively evaluate the utility of prostate MRI for detecting locally recurrent prostate cancer after high-dose-rate (HDR) brachytherapy.

MATERIALS AND METHODS

Sixteen men with biochemical failure after HDR brachytherapy for prostate cancer underwent prostate MRI, including T2-weighted imaging, dynamic contrast-enhanced MRI (DCE-MRI), and diffusion-weighted imaging (DWI), using a 1.5-T MRI unit before 12-core-specimen biopsy. Two radiologists in consensus assessed the presence of tumor on each sequence within eight regions of the prostate (six from the peripheral zone [PZ] and two from the transition zone [TZ]) on the basis of biopsy.

RESULTS

Biopsy revealed locally recurrent prostate cancer in 22 (17 in PZ and five in TZ) of 128 regions (17.2%). The sensitivity, specificity, and accuracy of each MRI method in the detection of recurrent tumor were 27%, 99%, and 87%, respectively, for T2-weighted imaging; 50%, 98%, and 90%, respectively, for DCE-MRI; and 68%, 95%, and 91%, respectively, for DWI. The sensitivity of DWI in detecting recurrent tumor was significantly higher than that of T2-weighted imaging (p = 0.004). Multiparametric MRI achieved the highest sensitivity (77%) but with slightly decreased specificity (92%).

CONCLUSION

These results indicate that a multiparametric MRI protocol that includes DWI provides a sensitive method to detect local recurrence after HDR brachytherapy.

Incremental value of diffusion weighted and dynamic contrast enhanced MRI in the detection of locally recurrent prostate cancer after radiation treatment: preliminary results

OBJECTIVES

To assess the incremental value of diffusion-weighted (DW-MRI) and dynamic contrast-enhanced MRI (DCE-MRI) to T2-weighted MRI (T2WI) in detecting locally recurrent prostate cancer after radiotherapy.

METHODS

Twenty-four patients (median age, 70 years) with a history of radiotherapy-treated prostate cancer underwent multi-parametric MRI (MP-MRI) and transrectal prostate biopsy. Two readers independently scored the likelihood of cancer on a 1-5 scale, using T2WI alone and then adding DW-MRI and DCE-MRI. Areas under receiver operating characteristic curves (AUCs) were estimated at the patient and prostate-side levels. The apparent diffusion coefficient (ADC) from DW-MRI and the K(trans), k(ep), v(e), AUGC90 and AUGC180 from DCE-MRI were recorded.

RESULTS

Biopsy was positive in 16/24 (67%) and negative in 8/24 (33%) patients. AUCs for readers 1 and 2 increased from 0.64 and 0.53 to 0.95 and 0.86 with MP-MRI, at the patient level, and from 0.73 and 0.66 to 0.90 and 0.79 with MP-MRI, at the prostate-side level (p values < 0.05). Biopsy-positive and biopsy-negative prostate sides differed significantly in median ADC [1.44 vs. 1.68 (×10(-3) mm(2)/s)], median K(trans) [1.07 vs. 0.34 (1/min)], and k(ep) [2.06 vs 1.0 (1/min)] (p values < 0.05).

CONCLUSIONS

MP-MRI was significantly more accurate than T2WI alone in detecting locally recurrent prostate cancer after radiotherapy.

Feasibility of 3T dynamic contrast-enhanced magnetic resonance-guided biopsy in localizing local recurrence of prostate cancer after external beam radiation therapy

OBJECTIVES

The objective of this study was to assess the feasibility of the combination of magnetic resonance (MR)-guided biopsy (MRGB) and diagnostic 3T MR imaging in the localization of local recurrence of prostate cancer (PCa) after external beam radiation therapy (EBRT).

MATERIALS AND METHODS

Twenty-four consecutive men with biochemical failure suspected of local recurrence after initial EBRT were enrolled prospectively in this study. All patients underwent a diagnostic 3T MR examination of the prostate. T2-weighted and dynamic contrast-enhanced MR images (DCE-MRI) were acquired. Two radiologists evaluated the MR images in consensus for tumor suspicious regions (TSRs) for local recurrence. Subsequently, these TSRs were biopsied under MR-guidance and histopathologically evaluated for the presence of recurrent PCa. Descriptive statistical analysis was applied.

RESULTS

Tissue sampling was successful in all patients and all TSRs. The positive predictive value on a per patient basis was 75% (15/20) and on a per TSR basis 68% (26/38). The median number of biopsies taken per patient was 3, and the duration of an MRGB session was 31 minutes. No intervention-related complications occurred.

CONCLUSIONS

The combination of MRGB and diagnostic MR imaging of the prostate was a feasible technique to localize PCa recurrence after EBRT using a low number of cores in a clinically acceptable time.

Current salvage methods for recurrent prostate cancer after failure of primary radiotherapy

We reviewed the current salvage methods for patients with local recurrent prostate cancer after primary radiotherapy (RT), using a search of relevant Medline/PubMed articles published from 1982 to 2008, with the following search terms: 'radiorecurrent prostate cancer, local salvage treatment, salvage radical prostatectomy (RP), salvage cryoablation, salvage brachytherapy, salvage high-intensity focused ultrasound (HIFU)', and permutations of the above. Only articles written in English were included. The objectives of this review were to analyse the eligibility criteria for careful selection of appropriate patients and to evaluate the oncological results and complications for each method. There are four whole-gland re-treatment options (salvage RP, salvage cryoablation, salvage brachytherapy, salvage HIFU) for RT failure, although others might be in development or investigations. Salvage RP has the longest follow-up with acceptable oncological results, but it is a challenging technique with a high complication rate. Salvage cryoablation is a feasible option, especially using third-generation technology, whereby the average biochemical disease-free survival rate is 50-70% and there are fewer occurrences of severe complications such as recto-urethral fistula. Salvage brachytherapy, with short-term cancer control, is comparable to other salvage methods but depends on cumulative dosage limitation to target tissues. HIFU is a relatively recent option in the salvage setting. Both salvage brachytherapy and HIFU require more detailed studies with intermediate and long-term follow-up. As these are not prospective, randomized studies and the definitions of biochemical failure varied, there are limited comparisons among these different salvage methods, including efficacy. In the focal therapy salvage setting, the increased use of thermoablative methods for eligible patients might contribute to reducing complications and maintaining quality of life. The problem to effectively salvage patients with locally recurrent disease after RT is the lack of diagnostic examinations with sufficient sensitivity and specificity to detect local recurrence at an early curable stage. Therefore, a more strict definition of biochemical failure, improved imaging techniques, and accurate specimen mapping are needed as diagnostic tools. Furthermore, universal selection criteria and an integrated definition of biochemical failure for all salvage methods are required to determine which provides the best oncological efficacy and least comorbidity.

Prostate MR imaging at 3T using a phased-arrayed coil in predicting locally recurrent prostate cancer after radiation therapy: preliminary experience

The purpose of this study was to retrospectively assess the diagnostic performance of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced imaging (DCEI) at 3T in predicting locally recurrent prostate cancer after radiation therapy. Twenty-four patients with a rising prostate-specific antigen level after treatment with radiation therapy underwent prostate MR imaging at 3T, followed by transrectal ultrasound-guided biopsy. MRI findings and biopsy results were correlated in six prostate sectors of both peripheral zones. Two radiologists in consensus reviewed the MR images and rated the likelihood of recurrent cancer on a 5-point scale. Out of the 144 prostate sectors, 37 (26%) sectors were positive for cancer in ten patients. For predicting locally recurrent cancer, the sensitivity and specificity of DWI, DCEI, and combined DCEI and DWI were higher than those for T2-weighted imaging (T2WI). The accuracy of DWI, DCEI and combined DCEI and DWI was greater than that of T2WI. A significantly greater Az was determined for combined DCEI and DWI (Az = 0.863, P < 0.05) as compared with T2WI, DCEI, and DWI. For predicting locally recurrent prostate cancer after radiation therapy, our preliminary results suggest that the use of either DWI or DCEI is superior to the use of T2WI.

National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for Use of Tumor Markers in Testicular, Prostate, Colorectal, Breast, and Ovarian Cancers

Background: Updated National Academy of Clinical Biochemistry (NACB) Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed.

Methods: Published reports relevant to use of tumor markers for 5 cancer sites—testicular, prostate, colorectal, breast, and ovarian—were critically reviewed.

Results: For testicular cancer, α-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase are recommended for diagnosis/case finding, staging, prognosis determination, recurrence detection, and therapy monitoring. α-Fetoprotein is also recommended for differential diagnosis of nonseminomatous and seminomatous germ cell tumors. Prostate-specific antigen (PSA) is not recommended for prostate cancer screening, but may be used for detecting disease recurrence and monitoring therapy. Free PSA measurement data are useful for distinguishing malignant from benign prostatic disease when total PSA is &lt;10 μg/L. In colorectal cancer, carcinoembryonic antigen is recommended (with some caveats) for prognosis determination, postoperative surveillance, and therapy monitoring in advanced disease. Fecal occult blood testing may be used for screening asymptomatic adults 50 years or older. For breast cancer, estrogen and progesterone receptors are mandatory for predicting response to hormone therapy, human epidermal growth factor receptor-2 measurement is mandatory for predicting response to trastuzumab, and urokinase plasminogen activator/plasminogen activator inhibitor 1 may be used for determining prognosis in lymph node–negative patients. CA15-3/BR27–29 or carcinoembryonic antigen may be used for therapy monitoring in advanced disease. CA125 is recommended (with transvaginal ultrasound) for early detection of ovarian cancer in women at high risk for this disease. CA125 is also recommended for differential diagnosis of suspicious pelvic masses in postmenopausal women, as well as for detection of recurrence, monitoring of therapy, and determination of prognosis in women with ovarian cancer.

Conclusions: Implementation of these recommendations should encourage optimal use of tumor markers.

Certainty in an Uncertain World - A Clinicians' Viewpoint of Sensitivity and Precision

Clinical practice is evolving as research evolves from the bench to the bedside. Similarly, analytical technologies are improving on an annual basis. Rightly or wrongly, increased emphasis is now placed by clinicians on such investigations to the detriment of clinical history and examination. As people live longer, the prevalence of long-term conditions such as thyroid disease, cardiovascular disease and malignancies is increasing. Clinical biochemistry assays play an important part in the management (screening, diagnosis, prognosis and monitoring) of such conditions. This is reflected in the UK since 2004 by the primary care contract where over 100 of the 550 clinical points depend on clinical biochemistry assay results. Inter-assay results may differ due to bias, precision, assay specificity and assay sensitivity. To date, little emphasis has been placed on the potential clinical effect of precision. This presentation will explore the effect that assay precision can have on the management of important long-term conditions such as thyroid disease, cardiovascular disease and malignancies.

A prostate-specific antigen-activated channel-forming toxin as therapy for prostatic disease

BACKGROUND

Most men will develop prostatic abnormalities, such as benign prostatic hyperplasia (BPH) or prostate cancer, as they age. Prostate-specific antigen (PSA) is a serine protease that is secreted at high levels by the normal and diseased prostate. Therapies that are activated by PSA may prove effective in treating prostatic malignancies.

METHODS

We modified proaerolysin (PA), the inactive precursor of a bacterial cytolytic pore-forming protein, to produce a PSA-activated protoxin (PRX302). The viability of the prostate adenocarcinoma cell lines LNCaP, PC-3, CWR22H, and DU145 and the bladder cancer cell line TSU after treatment with PA or PRX302 in the presence or absence of purified PSA was assayed. Mice carrying xenograft tumors derived from LNCaP, CWR22H, or TSU cells were treated with intratumoral injection of PA or PRX302, and tumor size was monitored. To test the safety of PRX302, we administered it into the PSA-secreting prostate glands of cynomolgus monkeys. All statistical tests were two-sided.

RESULTS

Native PA was highly toxic in vitro but had no tumor-specific effects in vitro or in vivo. Picomolar concentrations of PRX302 led to PSA-dependent decreases in cell viability in vitro (PRX302 versus PRX302 + PSA: DU145 cells, mean viability = 78.7% versus mean = 1.6%, difference = 77.1%, 95% confidence interval [CI] = 70.6% to 86.1%; P<.001; TSU cells, mean = 100.2% versus mean = 1.4%, difference = 98.8%, 95% CI = 96.4% to 104.0%; P<.001). Single intratumoral injections of PRX302 produced substantial and often complete regression of PSA-secreting human prostate cancer xenografts (5 microg dose, complete regression in 6 of 26 mice bearing LNCap or CWR22H xenografts [23%]; 10 microg dose, complete regression in 10 of 26 mice [38.5%]) but not PSA-null bladder cancer xenografts. The prostates of cynomolgus monkeys injected with a single dose of PRX302 displayed extensive but organ-confined damage, with no toxicity to neighboring organs or general morbidity.

CONCLUSIONS

Our observations demonstrate the potential safe and effective intraprostatic application of this engineered protoxin.

Quality of life 2 years after salvage cryosurgery for the treatment of local recurrence of prostate cancer after radiotherapy

PURPOSE

Previous research has raised concerns that although salvage cryosurgery may be an effective treatment to prevent the progression of prostate cancer after radiotherapy failure, the quality of life cost many be so severe as to prevent its acceptance as a viable treatment. The present study's purpose was to further the understanding of the quality of life outcomes of salvage cryosurgery.

MATERIALS AND METHODS

A total of 46 men with locally recurrent prostate cancer after radiotherapy were recruited to participate in a prospective Phase II clinical trial using salvage cryosurgery. There were 2 questionnaires (i.e., the European Organization of Research and Treatment of Cancer QLQ C30 and the Prostate Cancer Index) administered before cryosurgery, and at 1.5, 3, 6, 12, 18, and 24 months after treatment.

RESULTS

Quality of life returned to preoperative levels by 24 months after cryosurgery in all domains, with the exception of urinary and sexual functioning. At 24 months, 29% of men reported urinary bother as a moderate-to-big problem, and 56% reported sexual bother as a moderate-to-big problem.

CONCLUSIONS

To our knowledge, this is the first study to evaluate prospectively men's quality of life for 2 years after salvage cryosurgery for locally recurrent prostate cancer after radiotherapy. Long-term impairments in quality of life appear to be limited to the sexual and urinary function domains. Overall quality of life appears to be high. These results support salvage cryosurgery as a viable treatment option.

Use of different definitions of biochemical failure after external beam radiotherapy changes conclusions about relative treatment efficacy for localized prostate cancer

OBJECTIVES

To report biochemical relapse-free survival (bRFS) after radiotherapy (RT) for localized prostate cancer with two separate failure definitions and compare the results with those after radical prostatectomy (RP).

METHODS

The study sample comprised 2516 patients with a median follow-up of 78 months. Biochemical relapse after RT was defined as either the American Society for Therapeutic Radiology Oncology definition (definition A [DefA]) or a prostate-specific antigen elevation of more than 2 ng/mL greater than the nadir prostate-specific antigen level (definition N [DefN]). Failure after RP was defined as a prostate-specific antigen level greater than 0.2 ng/mL.

RESULTS

Compared with DefA, DefN resulted in a 13% greater bRFS rate at 5 years and a 12% lower bRFS rate at 10 years. On multivariate analysis, the treatment modality (RP versus RT) was a significant predictor of bRFS using DefA in favor of RP (P <0.001), but was not with DefN (P = 0.87). Higher radiation doses were independently associated with a better outcome with either definition.

CONCLUSIONS

Compared with DefA, DefN resulted in better outcomes for up to 7 years after RT, but worse outcomes thereafter. The use of DefA versus DefN resulted in opposite conclusions about the relative efficacies of RT and RP, with DefN suggesting RT is equivalent to RP and DefA that it is worse than RP. Different definitions of biochemical failure after RT can result in differences in the conclusions about treatment efficacy in men with localized prostate cancer, thereby potentially affecting clinical decisions.

Radiotherapy in the management of common genitourinary malignancies

A continued role for radiation therapy in the multidisciplinary management of genitourinary malignancies seems certain. Treatment outcomes continue to improve, accompanied by diminishing rates of toxicity. With continued technologic advances in the delivery of radiation, including the use of adaptive radiotherapy, the discovery and application of novel treatment agents, and the combined efforts of urologists, medical oncologists, and radiation oncologists, patients who have genitourinary malignancies have an excellent chance of cure.

Endorectal MR Imaging before Salvage Prostatectomy: Tumor Localization and Staging

PURPOSE

To evaluate retrospectively the accuracy of endorectal magnetic resonance (MR) imaging for the depiction of tumor, extracapsular extension (ECE), and seminal vesicle invasion (SVI) before salvage prostatectomy in patients with locally recurrent prostate cancer after radiation therapy, by using pathologic analysis as the reference standard.

MATERIALS AND METHODS

The Institutional Review Board granted exempt status for this HIPAA-compliant study, with a waiver of informed consent. Forty-five consecutive patients (age range, 43-76 years) were identified who underwent salvage radical prostatectomy for prostate cancer at Memorial Sloan-Kettering Cancer Center between December 1, 1998, and October 31, 2004, and who underwent endorectal MR imaging prior to surgery. Tumor localization and determination of local stage with MR imaging were performed independently by two radiologists. Interpretations were compared to pathologic findings from surgical specimens. Interrater variability was estimated with the kappa statistic. Areas under the receiver operating characteristic curve (AUCs) were used to assess the accuracy of endorectal MR imaging in tumor detection and determination of ECE and SVI.

RESULTS

Findings of histologic examination showed that tumor was present in all patients. For tumor detection, the AUC value for reader 1 was 0.75 (95% confidence interval [CI]: 0.67, 0.84), whereas the AUC value for reader 2 was 0.61 (95% CI: 0.52, 0.71). The AUC values for prediction of ECE were 0.87 (95% CI: 0.80, 0.94) for reader 1 and 0.76 (95% CI: 0.67, 0.85) for reader 2. The AUC values for prediction of SVI were 0.76 (95% CI: 0.62, 0.90) for reader 1 and 0.70 (95% CI: 0.56, 0.85) for reader 2. For all variables, the kappa statistics used to assess interrater agreement between readers were fair (0.45, 0.52, and 0.47 for tumor location, ECE, and SVI, respectively).

CONCLUSION

Endorectal MR imaging following radiation therapy can help identify tumor sites and depict ECE and SVI with reasonable accuracy in patients with recurrent prostate cancer.