Update on cryotherapy for prostate cancer in 2006

Epigenetics as a Key Factor in Prostate Cancer

Nowadays, prostate cancer is one of the most common forms of malignant neoplasms in men all over the world. Against the background of increasing incidence, there is a high mortality rate from prostate cancer, which is associated with an inadequate treatment strategy. Such a high prevalence of prostate cancer requires the development of methods that can ensure early detection of the disease, improve the effectiveness of treatment, and predict the therapeutic effect. Under these circumstances, it becomes crucial to focus on the development of effective diagnostic and therapeutic approaches. Due to the development of molecular genetic methods, a large number of studies have been accumulated on the role of epigenetic regulation of gene activity in cancer development, since it is epigenetic changes that can be detected at the earliest stages of cancer development. The presence of epigenetic aberrations in tumor tissue and correlations with drug resistance suggest new therapeutic approaches. Detection of epigenetic alterations such as CpG island methylation, histone modification, and microRNAs as biomarkers will improve the diagnosis of the disease, and the use of these strategies as targets for therapy will allow for greater personalization of prostate cancer treatment.

Prostate Cancer Review: Genetics, Diagnosis, Treatment Options, and Alternative Approaches

Simple Summary

Prostate cancer affects men of all racial and ethnic groups and leads to higher rates of mortality in those belonging to a lower socioeconomic status due to late detection of the disease. There is growing evidence that suggests the contribution of an individual’s genetic profile to prostate cancer. Currently used prostate cancer treatments have serious adverse effects; therefore, new research is focusing on alternative treatment options such as the use of genetic biomarkers for targeted gene therapy, nanotechnology for controlled targeted treatment, and further exploring medicinal plants for new anticancer agents. In this review, we describe the recent advances in prostate cancer research.

Abstract

Prostate cancer is one of the malignancies that affects men and significantly contributes to increased mortality rates in men globally. Patients affected with prostate cancer present with either a localized or advanced disease. In this review, we aim to provide a holistic overview of prostate cancer, including the diagnosis of the disease, mutations leading to the onset and progression of the disease, and treatment options. Prostate cancer diagnoses include a digital rectal examination, prostate-specific antigen analysis, and prostate biopsies. Mutations in certain genes are linked to the onset, progression, and metastasis of the cancer. Treatment for localized prostate cancer encompasses active surveillance, ablative radiotherapy, and radical prostatectomy. Men who relapse or present metastatic prostate cancer receive androgen deprivation therapy (ADT), salvage radiotherapy, and chemotherapy. Currently, available treatment options are more effective when used as combination therapy; however, despite available treatment options, prostate cancer remains to be incurable. There has been ongoing research on finding and identifying other treatment approaches such as the use of traditional medicine, the application of nanotechnologies, and gene therapy to combat prostate cancer, drug resistance, as well as to reduce the adverse effects that come with current treatment options. In this article, we summarize the genes involved in prostate cancer, available treatment options, and current research on alternative treatment options.

A multicenter randomized controlled trial to assess the efficacy of cancer green therapy in treatment of stage IIIb/IV non-small cell lung cancer

BACKGROUND

Chemotherapy is the main therapy for stage IIIB/IV non-small cell lung cancer (NSCLC). However, the 5-year survival rate is 6%. Cancer Green Therapy is a novel therapy in China, which refers to cryoablation combined with traditional Chinese medicine (TCM) formula. Our previous retrospective analysis showed that patients with NSCLC had longer survival time and better quality of life after receiving cryoablation combined with TCM formula, compared with patients who received chemotherapy alone.

METHODS

This study is a multicenter, randomized, controlled clinical study. The experiment will be carried out in 6 hospitals at the same time, and a total of 450 cases of participants will be randomly assigned to the experimental group and the control group (n = 225). The experimental group will be given cryoablation and 28-days TCM formula, and the control group will be given 4 cycles chemotherapy. After 30 months of follow-up, the efficacy and safety of cryoablation combines with TCM formula in patients with stage IIIB/IV NSCLC will be observed. The primary outcome is overall survival. The secondary outcomes include progression-free survival, objective response rate, and quality of life. We will also conduct a safety evaluation of the treatment at the end of the trial.

DISCUSSION

This multicenter, randomized, controlled clinical study not only provides data on the efficacy and safety of cryoablation combined with TCM formula, but also provides a novel treatment strategy for clinicians and advanced NSCLC patients.

Metastatic retro-crural lymph nodes from transitional cell carcinoma of bladder successfully treated with single session cryoablation

Bladder cancer (BC) is a relatively common tumor, with a male preponderance. High-grade muscle invasive bladder cancer (MIBC) has a very high incidence of pelvic lymph node metastasis at presentation. Involvement of the retro-crural lymph nodes, although has been described in other pelvic tumors, is very uncommon for BC. Cryoablation in the retro-crural region is extremely challenging due to the proximity to the critical structures like inferior venacava and aorta and has not been extensively reported. We describe a 56-year old male patient with MIBC who underwent extensive treatments including radical cystoprostatectomy, chemoradiation and immunotherapy, ultimately with localized disease in the retro-crural region. Single session cryoablation of these lymph nodes was performed with a curative intent yielding a positive response that has persisted for more than 2 years.

Cryoablation of cardiophrenic angle lymph node metastases: a case report

Background

Cardiophrenic angle lymph node metastases are relatively rare. Surgical resection is the main treatment for cardiophrenic angle lymph node metastasis, but it is not always possible.

Case presentation

Here, we report our initial experience with cryoablation of a cardiophrenic angle lymph node metastasis from liver cancer. As the cardiophrenic angle lymph node metastasis was located close to the heart, about 200 mL of 0.9% saline was injected into the pericardium to separate the heart from the target area. The cardiophrenic angle lymph node metastasis was successfully ablated, without any complications.

Conclusions

Cryoablation may be a suitable alternative treatment for cardiophrenic angle lymph node metastasis.

Cryoablation Combined with Iodine-125 Implantation in the Treatment of Cardiac Metastasis from Alveolar Soft Part Sarcoma: A Case Report

Objectives

A 36-year-old Asian man was referred to our hospital with cardiac metastasis. He had a history of alveolar soft part sarcoma and initially underwent resection in 2005.

Methods

After exposing the tumor by thoracotomy, cryoablation was performed under ultrasound guidance. This treatment was combined with iodine-125 seed implantation to treat the cardiac metastasis.

Results

The patient had an uneventful recovery, and his cardiac function shows no obvious abnormalities. Imaging techniques suggest that cardiac metastasis was well controlled, and the patient is still alive 12 months after treatment.

Conclusions

Tumor cryoablation, combined with iodine seed implantations, may be regarded as a means of palliative treatment.

Advances in cryoablation for pancreatic cancer

Pancreatic carcinoma is a common cancer of the digestive system with a poor prognosis. It is characterized by insidious onset, rapid progression, a high degree of malignancy and early metastasis. At present, radical surgery is considered the only curative option for treatment, however, the majority of patients with pancreatic cancer are diagnosed too late to undergo surgery. The sensitivity of pancreatic cancer to chemotherapy or radiotherapy is also poor. As a result, there is no standard treatment for patients with advanced pancreatic cancer. Cryoablation is generally considered to be an effective palliative treatment for pancreatic cancer. It has the advantages of minimal invasion and improved targeting, and is potentially safe with less pain to the patients. It is especially suitable in patients with unresectable pancreatic cancer. However, our initial findings suggest that cryotherapy combined with 125-iodine seed implantation, immunotherapy or various other treatments for advanced pancreatic cancer can improve survival in patients with unresectable or metastatic pancreatic cancer. Although these findings require further in-depth study, the initial results are encouraging. This paper reviews the safety and efficacy of cryoablation, including combined approaches, in the treatment of pancreatic cancer.

Adenoviral-based immunotherapy provides local disease control in an orthotopic murine model of esophageal cancer

Despite recent advances in the development of novel therapies, esophageal carcinoma remains an aggressive cancer associated with a poor prognosis. The lack of a high throughput, reproducible syngeneic animal model that replicates human disease is partly responsible for the paucity of novel therapeutic approaches. In this report, we present the first successful syngeneic, orthotopic model for esophageal cancer. This model was used to test an established adenoviral-based tumor vaccine. We utilized a murine esophageal cancer cell line established from the ED-L2-cyclin D1;p53 mouse that was transduced to express a viral tumor antigen, the Human Papilloma Virus (HPV) E7 protein. The tumor was established in its natural microenvironment at the gastroesophageal junction. Tumor growth was consistent and reproducible. An adenoviral vaccine to E7 (Ad.E7) induced an E7-specific population of functionally active CD8 T cells that trafficked into the tumors and retained cytotoxicity. Ad.E7 vaccination reduced local tumor growth and prolonged overall survival. These findings suggest that orthotopic tumor growth is a reasonable preclinical model to validate novel therapies.

Current status of cryotherapy for prostate and kidney cancer

In terms of treating diseases, minimally invasive treatment has become a key element in reducing perioperative complications. Among the various minimally invasive treatments, cryotherapy is often used in urology to treat various types of cancers, especially prostate cancer and renal cancer. In prostate cancer, the increased incidence of low-risk, localized prostate cancer has made minimally invasive treatment modalities an attractive option. Focal cryotherapy for localized unilateral disease offers the added benefit of minimal morbidities. In renal cancer, owing to the increasing utilization of cross-sectional imaging, nearly 70% of newly detected renal masses are stage T1a, making them more susceptible to minimally invasive nephron-sparing therapies including laparoscopic and robotic partial nephrectomy and ablative therapies. This article reviews the various outcomes of cryotherapy compared with other treatments and the possible uses of cryotherapy in surgery.

Sonablate®-500: transrectal high-intensity focused ultrasound for the treatment of prostate cancer

Prostate cancer (PCa) is the most common cancer in men and the second leading cause of death from malignancy in the UK. The number of men diagnosed with PCa is increasing, due in part to an increased willingness of men to visit their family doctors with lower urinary tract symptoms, and also a willingness of physicians to test for it. As the demographic of men diagnosed with PCa becomes younger and better informed, so the demand for a less-invasive alternative to standard therapies becomes greater. The Sonablate-500 is one of only two high-intensity focused ultrasound (HIFU) devices commercially available to treat PCa. HIFU is an attractive treatment option as it is the only form of therapy that neither involves direct instrumentation of the prostate nor ionizing radiation. This article describes the unique features of both the Sonablate-500 system hardware and software, and the outcome data from this device in the context of current standard therapies. Finally, a view into the future attempts to outline where this technology is heading and how a paradigm shift in the way that PCa is considered may make HIFU even more relevant.

A report on major complications and biochemical recurrence after primary and salvage cryosurgery for prostate cancer in patients with prior resection for benign prostatic hyperplasia: a single-center experience

OBJECTIVE

To report on biochemical recurrence (BCR) and major complications in patients with prior prostate resection that underwent cryosurgery (CS) for prostate cancer.

METHODS

The Columbia University Urologic Oncology database identified patients that underwent CS after resection. Patient demographics, surgical details, prostate volume, prostate-specific antigen (PSA) levels, biopsy results, major complications, and BCR were recorded.

RESULTS

Prior resection for benign prostatic hyperplasia was identified in 32 patients who underwent CS. Median age was 70.7 years (range 54.9-83.1 years). Median prostate volume before and after resection was 40 (range 30-90) and 20 cm(3) (range 9-54), respectively. Median time from resection to CS was 50.4 months (range 0-178.1 months). Twenty-one (16 full and 5 focal gland ablations) and 11 patients underwent primary and salvage CS, respectively. Median prostate-specific antigen at CS was 5.9 ng/mL (range 0.1-18.4 ng/mL), with a median nadir post-CS of 0.1 ng/mL (range 0.04-12.2 ng/mL). Median follow-up was 41.2 months (range 8.9-154.2 months). According to Stuttgart and Phoenix definitions, 11 and 10 patients, respectively, experienced BCR. Three patients underwent further CS for disease recurrence. Overall complications were rare and minor. Patients with smaller glands postresection (<20 cc(3)) experienced a similar incidence of BCR as those with larger glands after CS in all the settings.

CONCLUSION

Although no patients experienced major complications after primary CS, 18% (2/11) had grade III or higher complications in the salvage setting. Postresection gland volume was not associated with BCR. Further research is needed to evaluate functional and oncological outcomes in postresection patients after CS because they are considered high-risk for major complications.

The efficacy evaluation of cryosurgery in pancreatic cancer patients with the expression of CD44v6, integrin-β1, CA199, and CEA

Increased expression of cell adhesion molecule CD44v6, integrin-β1, carbohydrate antigen 199 (CA199), and carcinoembryonic antigen (CEA) are closely associated with the progression and metastasis of numerous cancers. In this study, peripheral blood mononuclear cell (PBMC) and serum samples were collected from 37 pancreatic cancer patients and 12 healthy people. A novel triplex TaqMan real-time reverse transcription polymerase chain reaction assay was used to measure the expression levels of CD44v6 and integrin-β1 gene in PBMCs, while chemiluminescence and enzyme-linked immunosorbent assay were used to measure the levels of CA199 and CEA expression in serum. The results showed that both the levels of CD44v6 and integrin-β1 expression had significant correlation with clinical stage, lymph node, and liver metastasis of pancreatic cancer (P < 0.05). Age, tumor size, tumor differentiation, clinical stage, lymph nodes, and liver metastasis were significantly associated with the levels of CA199 and CEA expression (P < 0.05). The levels of CD44v6, integrin-β1, CA199, and CEA expression in the patients prior cryosurgery and chemotherapy were significantly higher than those in the control group (P < 0.05), whereas no significant difference was found between the patients 1 month post cryosurgery and control group (P > 0.05). The expression levels of CD44v6, integrin-β1, CA199, and CEA in the patients 1 month post cryosurgery were significantly lower than those in the patients prior cryosurgery (P < 0.05). Interestingly, no significant difference was found for the CD44v6, integrin-β1, CA199, and CEA levels between the patients prior and post-chemotherapy (P > 0.05). The higher expression of CD44v6, integrin-β1, CA199, and CEA are closely related to the progression and metastasis of pancreatic cancer and may play a important role in the curative evaluation of cryosurgery of pancreatic cancer.

The efficacy evaluation of cryosurgery in pancreatic cancer patients with the expression of CD44v6, integrin-β1, CA199, and CEA

Increased expression of cell adhesion molecule CD44v6, integrin-β1, carbohydrate antigen 199 (CA199), and carcinoembryonic antigen (CEA) are closely associated with the progression and metastasis of numerous cancers. In this study, peripheral blood mononuclear cell (PBMC) and serum samples were collected from 37 pancreatic cancer patients and 12 healthy people. A novel triplex TaqMan real-time reverse transcription polymerase chain reaction assay was used to measure the expression levels of CD44v6 and integrin-β1 gene in PBMCs, while chemiluminescence and enzyme-linked immunosorbent assay were used to measure the levels of CA199 and CEA expression in serum. The results showed that both the levels of CD44v6 and integrin-β1 expression had significant correlation with clinical stage, lymph node, and liver metastasis of pancreatic cancer (P < 0.05). Age, tumor size, tumor differentiation, clinical stage, lymph nodes, and liver metastasis were significantly associated with the levels of CA199 and CEA expression (P < 0.05). The levels of CD44v6, integrin-β1, CA199, and CEA expression in the patients prior cryosurgery and chemotherapy were significantly higher than those in the control group (P < 0.05), whereas no significant difference was found between the patients 1 month post cryosurgery and control group (P > 0.05). The expression levels of CD44v6, integrin-β1, CA199, and CEA in the patients 1 month post cryosurgery were significantly lower than those in the patients prior cryosurgery (P < 0.05). Interestingly, no significant difference was found for the CD44v6, integrin-β1, CA199, and CEA levels between the patients prior and post-chemotherapy (P > 0.05). The higher expression of CD44v6, integrin-β1, CA199, and CEA are closely related to the progression and metastasis of pancreatic cancer and may play a important role in the curative evaluation of cryosurgery of pancreatic cancer.

Cryosurgery for lung cancer

Cryosurgery is suited for patients with lung cancer who are not considered for lung resection because of the advanced stage of the disease or the patient's poor general condition or poor respiratory function and with tumor recurrence following radiotherapy, chemotherapy or lung resection, and those patients who have localized lung cancer but refuse to receive operative therapy. Procedures of cryosurgery for lung cancer can be performed through endobronchial, direct intrathoracic (at exploratory thoracotomy) or percutaneous routes depending upon location and size of tumor. Six hundred and twenty-five patients with Non-small cell lung cancer (NSCLC) received percutaneous cryoablation in Fuda Cancer Hospital Guangzhou, China. One hundred and fifty patients were followed-up for 12 to 38 months. Results showed that 1-, 2-, and 3-year survival rates were 64%, 45% and 32%, respectively. The adverse effects after cryosurgery of lung cancer include haemoptysis, pneumothorax, bloody thorax, pleural effusion and pulmonary infection which are generally mild, transient, and recovery with symptomatic management. In vitro studies have shown cryotherapy of lung cancer cells can improve the immune system to trigger the specific anti-tumor response. In the future, comparative studies between this modality and other therapies should be conducted for the treatment of lung cancer. In addition, more attention needs to be put on the immunomodulators that enhance the cryoimmunology.

Changes in the expression of serum markers CA242, CA199, CA125, CEA, TNF-α and TSGF after cryosurgery in pancreatic cancer patients

The presence of serum tumor markers, carbohydrate antigen 242 (CA242), carbohydrate antigen 199 (CA199), carbohydrate antigen 125 (CA125), carcinoembryonic antigen (CEA), tumor-supplied group of factors (TSGF) and tumor necrosis factor-α (TNF-α), is closely associated with invasion and metastasis of many malignancies. The expression of these markers were measured in serum taken from 37 pancreatic cancer patients prior to treatment. Levels of CA242, CA199, CA125, CEA and TNF-α expression correlated with tumor size, clinical stage, tumor differentiation, lymph node and liver metastasis (P < 0.05). One month after cryosurgery, serum levels of these markers were significantly reduced compared with levels prior to cryosurgery (P < 0.05), whereas there was no significant difference was found between serum levels before and after chemotherapy (P > 0.05). Thus, cryosurgery is more effective than chemotherapy for decreasing CA242, CA199, CA125, CEA, TSGF and TNF-α serum levels in these patients.

Vitamin D(3) cryosensitization increases prostate cancer susceptibility to cryoablation via mitochondrial-mediated apoptosis and necrosis

OBJECTIVES

To investigate the effect and molecular mechanisms of action of Vitamin D(3) (VD(3) ) as a neo-adjunctive agent before cryosurgery in an effort to increase treatment efficacy for prostate cancer (CaP). To eliminate the potential for disease recurrence that exists at the periphery of the freeze lesion, where temperatures may be insufficient to destroy both androgen-sensitive (AS) and androgen-insensitive (AI) CaP.

METHODS

Human CaP cells, LNCaP, were each genetically altered to express the AS and AI phenotypes and subjected to VD(3) treatment and freezing in an in vitro and tissue-engineered model. Cell viability, caspase inhibitor and western blot studies were used to determine the basis of the different responses of AI and AS cells to VD(3) cryosensitization.

RESULTS

VD(3) was found to be a highly effective cryosensitizer, resulting in a >50% overall increase in cell death after -15 °C freezing. Fluorescence microscopy, western blot analysis and caspase protease assays confirmed that the increased activation of apoptosis was modulated through a mitochondrial-mediated pathway. Caspase inhibition studies showed that apoptosis played an integral role in cell death, with VD(3) cryosensitivation-induced apoptotic events responsible for >30% of the overall cell death after -15 °C freezing.

CONCLUSIONS

The present study suggests that the use of VD(3) as a cryosensitizer increases cryoablation efficacy through the increased activity of apoptosis as well as through necrosis. The data show that through VD(3) treatment the overall level of AI CaP cell tolerance to freezing is reduced to a level similar to that of AS CaP. VD(3) pre-treatment in conjunction with cryoablation may increase treatment efficacy and reduce disease recurrence for CaP patients.

Prostate cancer overview

OBJECTIVES

To review prostate anatomy, epidemiology and risk factors, presentation and diagnosis, staging and treatment, emerging therapies, and patient education.

DATA SOURCES

Review of current and classic literature.

CONCLUSION

Patients must be educated regarding screening recommendations and offered evidence-based guidance regarding the risks, benefits, and alternatives to treatment. Adverse effects of treatment may impact quality of life.

IMPLICATIONS FOR NURSING PRACTICE

As the incidence of prostate cancer continues to rise, nurses will play an essential role in the treatment and counseling of men facing this malignancy. Nursing research will also be necessary to further investigate quality-of-life concerns and evidence-based practice regarding symptom management.

Microsecond and nanosecond electric pulses in cancer treatments

New local treatments based on electromagnetic fields have been developed as non-surgical and minimally invasive treatments of tumors. In particular, short electric pulses can induce important non-thermal changes in cell physiology, especially the permeabilization of the cell membrane. The aim of this review is to summarize the present data on the electroporation-based techniques: electrochemotherapy (ECT), nanosecond pulsed electric fields (nsPEFs), and irreversible electroporation (IRE). ECT is a safe, easy, and efficient technique for the treatment of solid tumors that uses cell-permeabilizing electrical pulses to enhance the activity of a non-permeant (bleomycin) or low permeant (cisplatin) anticancer drug with a very high intrinsic cytotoxicity. The most interesting feature of ECT is its unique ability to selectively kill tumor cells without harming normal surrounding tissue. ECT is already used widely in the clinics in Europe. nsPEFs could represent a drug free, purely electrical cancer therapy. They allow the inhibition of tumor growth, and interestingly, nsPEF can target intracellular organelles. However, many questions remain on the mechanism of action of these pulses. Finally, IRE is a new ablation procedure using pulses that provoke the permanent permeabilization of the cells resulting in their death. This technique does not result in any thermal effect, which is its main advantage in current physical ablation technologies. For both the nsPEF and the IRE, the preservation of the normal tissue, which is characteristic of ECT, has not yet been shown and their safety and efficacy still have to be investigated thoroughly in vivo and in the clinics.

Cryosurgery as primary treatment for localized prostate cancer

OBJECTIVE

To present the early results of the use of third-generation cryotherapy as primary treatment for localized prostate cancer in China.

PATIENTS AND METHODS

From January 2006 to December 2009, 102 patients underwent primary cryosurgery for clinically localized prostate cancer. All patients underwent a dual freeze-thaw cycle using third-generation cryotechnology with ultrathin 17-gauge cryoneedles.

RESULTS

The prostate-specific antigen (PSA) level for all patients at the last follow-up visit was less than 0.5 ng/ml in 94 patients (92.2%) and 0.5 ng/ml or more in 8 (7.8%). One patient (1.0%) had recurrent prostate cancer confirmed by prostate biopsy and was treated with salvage cryotherapy. Seven other patients (6.9%) had an elevated PSA level after cryotherapy despite negative posttreatment biopsies and a metastatic evaluation. Of 102 patients, 1 patient was incontinent preoperatively. Of the remaining 101 patients, 4 patients (4.0%) developed mild incontinence requiring 1 to 2 pads per day. Urethral sloughing occurred in 5 of the 102 patients (4.9%) and in 1 of these patients (1.0%) required transurethral resection of sloughing. The rates of erectile dysfunction were 64.1%. No urethral strictures, rectourethral fistulas, urinary retention, or chronic pelvic pain was reported. The median inpatient stay after cryoablation was 3.2 days.

CONCLUSION

Early results suggest that cryotherapy offers a safe and effective alternative for the primary treatment of localized prostate cancer. Additional studies with longer follow-up are necessary to determine the sustained efficacy of this procedure.

Integrin involvement in freeze resistance of androgen-insensitive prostate cancer

Cryoablation has emerged as a primary therapy to treat prostate cancer. While effective, the assumption that freezing serves as a ubiquitous lethal stress is challenged by clinical experience and experimental evidence demonstrating time-temperature related cell death dependence. The age-related transformation from an androgen-sensitive (AS) to an androgen-insensitive (AI) phenotype is a major challenge in the management of prostate cancer. AI cells exhibit morphological changes and treatment resistance to many therapies. Since this resistance has been linked with α6β4 integrin overexpression as a result of androgen receptor (AR) loss, we investigated whether α6β4 integrin expression, as a result AR loss, contributes to the reported increased freeze tolerance of AI prostate cancer. A series of studies using AS (LNCaP LP and PC-3 AR) and AI (LNCaP HP and PC-3) cell lines were designed to investigate the cellular mechanisms contributing to variations in freezing response. Investigation into α6β4 integrin expression revealed that AI cell lines overexpressed this protein, thereby altering morphological characteristics and increasing adhesion characteristics. Molecular investigations revealed a significant decrease in caspase 8, 9, and 3 levels AI cells following freezing. Inhibition of α6β4 integrin resulted in increased caspase activity following freezing (similar to AS cells) and enhanced cell death. These data demonstrate that AI cells show an increase in post-freeze susceptibility following inhibition of α6β4 integrin function. Further understanding the role of androgen-receptor related α6β4 integrin expression in prostate cancer cells responses to freezing might lead to novel options for neo-adjunctive treatments targeting the AR signaling pathway.

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 cryotherapy monitoring using vibroacoustography: preliminary results of an ex vivo study and technical feasibility

The objective of this research is to prospectively evaluate the feasibility of vibroacoustography (VA) imaging in monitoring prostate cryotherapy in an ex vivo model. Baseline scanning of an excised human prostate is accomplished by a VA system apparatus in a tank of degassed water. Alcohol and dry ice mixture are used to freeze two prostate tissue samples. The frozen prostates are subsequently placed within the water tank at 27 degrees C and rescanned. VA images were acquired at prescribed time intervals to characterize the acoustic properties of the partially frozen tissue. The frozen prostate tissue appears in the images as hypoemitting signal. Once the tissue thaws, previously frozen regions show coarser texture than prior to freezing. The margin of the frozen tissue is delineated with a well-defined rim. The thawed cryolesions show a different contrast compared with normal unfrozen prostate. In conclusion, this pilot study shows that VA produces clear images of a frozen prostate at different temperature stages. The frozen tissue appears as a uniform region with well-defined borders that are readily identified. These characteristic images should allow safer and more efficient application of prostatic cryosurgery. These results provide substantial motivation to further investigate VA as a potential modality to monitor prostate cryotherapy intraoperatively.

Pathologic stage T2a and T2b prostate cancer in the recent prostate-specific antigen era: implications for unilateral ablative therapy

BACKGROUND

Early detection of small volume prostate cancer (PCa) has led to the concept of focal therapy to treat in an organ-sparing manner. We evaluated trends in pathologic staging among patients with localized PCa undergoing radical prostatectomy (RP), defining the frequency of unilateral cancers during 1988-1995, 1996-2000 and 2001-2006.

METHODS

Data were abstracted from the Duke Prostate Cancer Outcome database selecting 3,676 men with available pathology treated with RP. Based on surgical pathology, trends in as pathological T (pT) stage, pathological Gleason Score (pGS), and percent tumor involvement (PTI) were evaluated.

RESULTS

pT2a increased from 2.8% of men undergoing RP in 1988-1995 to 13.0% during 2001-2006 (P < 0.0005). PTI analysis shifted towards low volume disease, e.g. PTI <or= 5% increased from 10% during 1988-1995, to 37% in 2001-2006 (P < 0.005). Of all pT2a disease throughout 1988-2006, an increase in proportion of pT2a tumors from 10% during 1988-1995 to 69.4% during 2001-2006 was identified. Over three eras, pT2a had minimal (65% had PTI <or= 5%) or small volume (14% had PTI 5.01-10.00) disease, and 59% were low grade (pGS <or= 6). Using a Cox Hazard model, pT2a versus pT2b disease, surgical margins, PTI, and PSA statistically contributed to PSA disease-free survival in the contemporary era 2001-2006.

CONCLUSIONS

The increasing prevalence of unilateral pT2a/T2b PCa characterizes a growing proportion of men recently electing RP. These tumors are associated with lower PTI, pGS <or= 7, and demonstrated better PSA-free survival in the 2001-2006 era. These low risk pathologic characteristics may allow for unilateral focal therapy in carefully selected patients.

A pilot study on combination of cryosurgery and 125iodine seed implantation for treatment of locally advanced pancreatic cancer

AIM: To study the therapeutic value of combination of cryosurgery and ¹²⁵iodine seed implantation for locally advanced pancreatic cancer.

METHODS: Forty-nine patients with locally advanced pancreatic cancer (males 36, females 13), with a median age of 59 years, were enrolled in the study. Twelve patients had liver metastases. In all cases the tumors were considered unresectable after a comprehensive evaluation. Patients were treated with cryosurgery, which was performed intraoperatively or percutaneously under guidance of ultrasound and/or computed tomography (CT), and ¹²⁵iodine seed implantation, which was performed during cryosurgery or post-cryosurgery under guidance of ultrasound and/or CT. A few patients received regional celiac artery chemotherapy.

RESULTS: Thirteen patients received intraoperative cryosurgery and 36 received percutaneous cryosurgery. Some patients underwent repeat cryosurgery. ¹²⁵Iodine seed implantation was performed during freezing procedure in 35 patients and 3-9 d after cryosurgery in 14 cases. Twenty patients, 10 of whom had hepatic metastases received regional chemotherapy. At 3 mo after therapy, CT was repeated to estimate tumor response to therapy. Most patients showed varying degrees of tumor necrosis. Complete response (CR) of tumor was seen in 20.4% patients, partial response (PR), in 38.8%, stable disease (SD), in 30.6%, and progressive disease (PD), in 10.2%. Adverse effects associated with cryosurgery included upper abdomen pain and increased serum amylase. Acute pancreatitis was seen in 6 patients one of whom developed severe pancreatitis. All adverse effects were controlled by medical management with no poor outcome. There was no therapy-related mortality. During a median follow-up of 18 mo (range of 5-40), the median survival was 16.2 mo, with 26 patients (53.1%) surviving for 12 mo or more. Overall, the 6-, 12-, 24- and 36-mo survival rates were 94.9%, 63.1%, 22.8% and 9.5%, respectively. Eight patients had survival of 24 mo or more. The patient with the longest survival (40 mo) is still living without evidence of tumor recurrence.

CONCLUSION: Cryosurgery, which is far less invasive than conventional pancreatic resection, and is associated with a low rate of adverse effects, should be the treatment of choice for patients with locally advanced pancreatic cancer. ¹²⁵Iodine seed implantation can destroy the residual surviving cancer cells after cryosurgery. Hence, a combination of both modalities has a complementary effect.

Cryosurgery with combination of (125)iodine seed implantation for the treatment of locally advanced pancreatic cancer

OBJECTIVE

To study the therapeutic value of cryosurgery with combination of (125)iodine seed implantation for locally advanced pancreatic cancer.

METHODS

Thirty-eight patients with locally advanced pancreatic cancer were enrolled in this study. The diagnosis was confirmed by pathology in 31 patients. Ten patients had metastases of the peripancreatic lymph node and eight had liver metastases. The therapy included cryosurgery, which was performed intra-operatively or percutaneously under guidance of ultrasound and/or computed tomography (CT), and (125)iodine seed implantation, which was performed during cryosurgery process or post-cryosurgery under the guidance of ultrasound and/or CT.

RESULTS

Eleven patients received intra-operative cryosurgery and 27 received percutaneous cryosurgery. Fourteen patients underwent two procedures of cryosurgery and three underwent three procedures of cryosurgery. (125)Iodine seed implantation was performed during the freezing procedure in 29 patients and within 3-7 days after cryosurgery in nine patients under ultrasound and CT guidance. Fifteen patients, of whom 13 had metastases of peripancreatic lymph nodes or liver received regional chemotherapy. At 3 months after therapy, a CT follow-up was performed to estimate the tumor response to therapy. Most of the patients had varying degrees of tumor necrosis. A complete response of the tumor was seen in 23.6% of patients, a partial response in 42.1%, stable disease in 26.3% and progressive disease in 7.9%. The adverse effects associated with cryosurgery mainly included pain of the upper abdomen and increased serum amylase activity. Acute pancreatitis was seen in five patients, one of whom presented a severe type of pancreatitis. During the followed-up of a median of 16 months (range of 5-37) median overall survival was 12 months, 19 patients (50.0%) survived for 12 months or longer and four survived for 24 months or longer.

CONCLUSION

As it is far less invasive than conventional pancreas resection and entails a low rate of adverse effects, cryosurgery should be the choice modality for most patients with locally advanced pancreatic cancer. (125)Iodine seed implantation can destroy residue survival cancer cells after cryosurgery. Hence, combination of both modalities has a complementary effect.

Tumor ablation with irreversible electroporation

We report the first successful use of irreversible electroporation for the minimally invasive treatment of aggressive cutaneous tumors implanted in mice. Irreversible electroporation is a newly developed non-thermal tissue ablation technique in which certain short duration electrical fields are used to permanently permeabilize the cell membrane, presumably through the formation of nanoscale defects in the cell membrane. Mathematical models of the electrical and thermal fields that develop during the application of the pulses were used to design an efficient treatment protocol with minimal heating of the tissue. Tumor regression was confirmed by histological studies which also revealed that it occurred as a direct result of irreversible cell membrane permeabilization. Parametric studies show that the successful outcome of the procedure is related to the applied electric field strength, the total pulse duration as well as the temporal mode of delivery of the pulses. Our best results were obtained using plate electrodes to deliver across the tumor 80 pulses of 100 µs at 0.3 Hz with an electrical field magnitude of 2500 V/cm. These conditions induced complete regression in 12 out of 13 treated tumors, (92%), in the absence of tissue heating. Irreversible electroporation is thus a new effective modality for non-thermal tumor ablation.

Short-term cancer control after primary cryosurgical ablation for clinically localized prostate cancer using third-generation cryotechnology

OBJECTIVES

Percutaneous perineal cryoablation of the prostate is a promising technique in the treatment armamentarium for clinically localized prostate carcinoma. We report our initial experience using a transrectal ultrasound-guided, third-generation, argon/helium cryosurgical system.

METHODS

From January 2002 to July 2005, 50 men underwent primary cryosurgery for clinically localized prostate carcinoma. The median patient age was 68 years (range 50 to 83), and the median follow-up period was 18 months (range 3 to 43). According to the D'Amico risk stratification system, 36 patients (72%) had low-risk, 9 (18%) had intermediate-risk, and 5 (10%) had high-risk prostate cancer. All patients underwent a dual freeze-thaw cycle using third-generation cryotechnology with ultrathin 17-gauge cryoneedles.

RESULTS

The prostate-specific antigen (PSA) level for all patients at the last follow-up visit was less than 0.5 ng/mL in 45 patients (90%) and 0.5 ng/mL or more in 5 (10%). Two patients had persistent prostate cancer confirmed by prostate biopsy and were treated with salvage cryotherapy or external beam radiotherapy. Three other patients had an elevated PSA level after cryotherapy despite negative posttreatment biopsies and a metastatic evaluation. Of these 3 patients, 2 had their postcryotherapy PSA level normalize, and 1 patient, with intermediate-risk disease preoperatively, had a consistent increase in PSA up to 1.2 ng/mL. The overall survival rate was 100%.

CONCLUSIONS

Cryoablation of the prostate is a feasible and safe treatment option in patients with organ-confined prostate cancer. Additional studies with longer follow-up are necessary to determine the sustained efficacy of this procedure.

Novel techniques for the treatment of localized prostate cancer: Evidence of efficacy?

Radical retropubic prostatectomy and radiation therapy remain the mainstay of treatment for localized prostate cancer. However, with the advent of the Internet, more patients are arriving in physicians' offices questioning novel techniques for their treatment that they otherwise would not have discovered. This paper discusses several of these techniques, including focal cryotherapy, high-intensity focused ultrasound, robotic-assisted laparoscopic prostatectomy, diets, supplements, and hormonal therapy. We also render our opinion on their efficacy for treatment based on the available published studies.

Locally ablative therapies for primary radiation failures: a review and critical assessment of the efficacy

A significant number of men with prostate cancer will experience biochemical failure following treatment with primary radiation therapy. For patients with biopsy-proven recurrent cancer confined to the prostate, local salvage therapy may be a potentially curative treatment option. Most men, however, do not undergo local salvage therapy owing to difficulties in diagnosis as well as concerns over treatment-related complications in the salvage setting. Recently, improvements in technique and technology have substantially reduced the morbidity associated with locally ablative therapies, resulting in an increased interest in the use of minimally invasive therapies such as brachytherapy, cryotherapy, and high-intensity focused ultrasound in the salvage setting. Although these treatments are well tolerated, concerns remain over incomplete and inadequate treatment with locally ablative therapies. Future studies are required to appropriately select candidates for salvage ablative therapies and to determine the long-term oncologic efficacy of these treatments.

Energy-based ablative therapy of prostate cancer: high-intensity focused ultrasound and cryoablation

PURPOSE OF REVIEW

This review is an update on the role of the two minimally invasive techniques in primary therapy of organ-confined prostate cancer: as a salvage option after standard-therapy failure and for focal ablation of index tumors.

RECENT FINDINGS

Energy-based ablative techniques are of growing interest for today's heterogeneous spectrum of prostate cancer. At present, primary high-intensity focused ultrasound appears to be a valid alternative to active surveillance protocols in low-risk cancers and, in older patients, to standard therapy. Morbidity is low, although postoperative impotence occurs frequently. Cryoablation has higher morbidity, even with third-generation conformal technology. With radiorecurrent cancer the potential radiation damage of the rectal wall renders transrectal high-intensity focused ultrasound more hazardous. Third-generation cryoablation seems to give better cancer control with lower morbidity in this situation. Unfortunately, long-term outcome data from controlled trials are not available.

SUMMARY

These minimally invasive techniques are not magic bullets, and patients must be informed accordingly. Focal ablation of the prostate segment with the index cancer would minimize morbidity and therefore appears highly appealing. Its success depends on correct localization of the lesion. Until this is achieved with sufficient reliability by appropriate biopsy or imaging techniques it remains strictly experimental.