Emerging minimally invasive techniques for treating localized prostate cancer

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.

Targeting single-walled carbon nanotubes for the treatment of breast cancer using photothermal therapy

This paper focuses on the targeting of single-walled carbon nanotubes (SWNTs) for the treatment of breast cancer with minimal side effects using photothermal therapy. The human protein annexin V (AV) binds specifically to anionic phospholipids expressed externally on the surface of tumour cells and endothelial cells that line the tumour vasculature. A 2 h incubation of the SWNT-AV conjugate with proliferating endothelial cells followed by washing and near-infrared (NIR) irradiation at a wavelength of 980 nm was enough to induce significant cell death; there was no significant cell death with irradiation or the conjugate alone. Administration of the same conjugate i.v. in BALB/c female mice with implanted 4T1 murine mammary at a dose of 0.8 mg SWNT kg(-1) and followed one day later by NIR irradiation of the tumour at a wavelength of 980 nm led to complete disappearance of implanted 4T1 mouse mammary tumours for the majority of the animals by 11 days since the irradiation. The combination of the photothermal therapy with the immunoadjuvant cyclophosphamide resulted in increased survival. The in vivo results suggest the SWNT-AV/NIR treatment is a promising approach to treat breast cancer.

Antitumour effect of electrochemotherapy with bleomycin on human prostate cancer xenograft

OBJECTIVE

To investigate the antitumour effect of electroporation (EP), a drug delivery system that has been shown to be effective synergistically with antitumour drugs, with bleomycin on the growth of prostate cancer xenografts in nude mice.

MATERIALS AND METHODS

PC-3 cells were implanted subcutaneously into nude mice. After determination of the optimal conditions of electric pulse voltage and bleomycin dose, tumour growth in mice treated with EP plus bleomycin was compared with that in mice receiving EP alone, bleomycin alone or no treatment. In all four groups, apoptosis in the tumours was assessed.

RESULTS

There was a significant reduction in tumour growth in mice that received EP with bleomycin. Apoptotic cells in tumours at 24 h after treatment with EP plus bleomycin showed a significant difference compared with the other three groups, but not at 12 h after treatment.

CONCLUSIONS

These results indicate the possibility that EP with bleomycin could be effective as an ablation therapy for prostate cancer, especially androgen-independent cancer.

Role of 5 alpha-reductase inhibitors in the management of prostate cancer

Prostate cancer is one of the most complex and enigmatic oncologic problems in medicine. It is highly prevalent, particularly in elderly males. Unfortunately, its generally protracted and variable clinical course and high association with treatment-related morbidity raise serious questions about the ideal treatment strategy for the individual patient. 5 alpha-reductase (5AR) inhibitors have a dramatic effect on benign prostatic disease with low toxicity. Thus, there is much interest in the potential role of 5AR inhibitors in the prevention and treatment of prostate cancer. Finasteride is the only agent that has been shown in a randomized clinical trial to decrease the risk of prostate cancer with a reduction of almost 25%. Additionally, a recent analysis of the Prostate Cancer Prevention Trial (PCPT) has found that finasteride improves the performance characteristics of prostate-specific antigen (PSA) blood test as a screening tool for prostate cancer, for both cancer detection as well as for detection of high risk disease. Finally, 5AR inhibitors have been studied as a component of multimodal therapy for all stages of prostate cancer, with the goal of improving oncologic outcomes while avoiding the toxicity of medical and surgical castration.

New Modality for Maximizing Cryosurgical Killing Scope While Minimizing Mechanical Incision Trauma Using Combined Freezing-Heating System

Cryosurgery is a minimally invasive surgical technique using extremely low temperature to destroy undesired tissues. A surgical freezing margin of at least 1 cm is often recommended to avoid local tumor recurrence after surgery. For treating slender or elongated solid tumors in a conventional cryosurgery, simultaneous insertion of multiple cryoprobes is a necessity to guarantee an adequate killing scope. However, the risk of mechanical incision trauma may outweigh the benefits of such therapy. To resolve this difficulty, we proposed a new cryosurgical treatment modality, which can significantly maximize the killing scope while minimize the incision trauma, using the recently developed combined cryosurgical-hyperthermia treatment system (CCHTS). The method, named as one time’s percutaneous insertion while multiple times’ freezing∕heating ablation, is rather flexible in administrating a complex cryosurgical process and avoids certain shortcomings of conventional freezing strategies. Owing to the powerful heating function, the present probe can be easily moved back along its original incision tract to the desired positions immediately after initiating the heating. Then, a new iceball can be formed there while the iceballs generated before still remain unmelted in the following cycles. Consequently, a slender iceball could be generated to embrace the whole elongated tumor. This is, however, rather hard to achieve for a conventional cryosurgery with only one single freezing function or using only one probe. To visually demonstrate the feasibility and potential advantage of the present method, proof of concept in vitro gel experiments were performed. In addition, tests and corresponding theoretical simulations were performed on pork tissues. All the results indicate that the elongated iceball could be easily generated by using only one CCHTS probe owing to its strong freezing∕heating capability. In this way, a large number of incisions with multiple probes, commonly adopted in a conventional cryosurgery, can be avoided and the serious mechanical trauma including potential dangers can thus be significantly reduced. Meanwhile, the cost for the operation and postmedical care will be lowered. The present strategies are expected to be valuable in administrating a highly efficient and minimally invasive cryosurgery in the near future.

Physical mechanisms and methods employed in drug delivery to tumors

In addition to several well-known drug delivery strategies developed to facilitate effective chemotherapy with anticancer agents, some new approaches have been recently established, based on specific effects arising from the applications of ultrasound, magnetic and electric fields on drug delivery systems. This paper gives an overview of newly developed methods of drug delivery to tumors and of the related anticancer therapies based on the combined use of different physical methods and specific drug carriers. The conventional strategies and new approaches have been put into perspective to revisit the existing and to propose new directions to overcome the threatening problem of cancer diseases.

Prospective evaluation of short-term impact and recovery of health related quality of life in men undergoing robotic assisted laparoscopic radical prostatectomy versus open radical prostatectomy

PURPOSE

In the last few years there have been increasing claims that robotic assisted laparoscopic radical prostatectomy decreases short-term morbidity in patients undergoing surgical treatment for prostate cancer. However, there is surprisingly little objective evidence to support this point, which is often used to market the procedure to patients. To address this issue we prospectively evaluated patients undergoing open and robotic assisted laparoscopic radical prostatectomy at baseline and weekly through the postoperative period using a validated questionnaire.

MATERIALS AND METHODS

A total of 162 men undergoing radical prostatectomy, including open radical prostatectomy in 120 and robotic assisted laparoscopic radical prostatectomy in 42, for clinically localized prostate cancer completed the SF-12, version 2 Physical and Mental Health Survey Acute Form preoperatively and each week postoperatively for 6 weeks. Physical and Mental Component Scores were calculated from the questionnaires at each time point. Comparisons between the 2 surgical approaches were made at each time point.

RESULTS

No significant differences were seen between the open and robotic assisted laparoscopic radical prostatectomy groups with regard to patient age, clinical stage or preoperative prostate specific antigen. Mean surgical blood loss was significantly higher in the open group compared to that in the robotic assisted laparoscopic group. Physical Component Scores in the robotic assisted laparoscopic group were significantly higher than those in the open cohort beginning postoperative week 1 and extending through week 6. On statistical extrapolation Physical Component Scores returned to baseline between weeks 5 and 6 postoperatively in the robotic assisted laparoscopic group and between weeks 6 and 7 in the open group. Mental Component Score scores were not statistically different between the groups except preoperatively.

CONCLUSIONS

This study helps prospectively define short-term health related quality of life in patients undergoing robotic assisted laparoscopic vs open radical prostatectomy. Higher physical scores were seen in the robotic assisted laparoscopic group than the open group beginning postoperative week 1 and continuing weekly throughout the 6-week study period. Physical Component Score scores returned to baseline sooner in the robotic assisted laparoscopic group than in the open group.

A prospective evaluation of the short-term impact and recovery of health-related quality of life in men undergoing radical prostatectomy

OBJECTIVE

To prospectively evaluate the acute and short-term effects of radical retropubic prostatectomy (RRP) on health-related quality of life (HRQoL) using a validated generic HRQoL instrument that measures overall health status, as although there is increasing interest in the HRQoL of patients being treated for prostate cancer, most studies have focused on long-term outcomes.

PATIENTS AND METHODS

In all, 121 men undergoing RRP for clinically localized prostate cancer were prospectively evaluated for short-term HRQoL using an acute Short Form-12 version-2 Physical and Mental Health Survey Acute Form before and serially each week from 1 to 6 weeks after RRP. The physical (PCS) and mental component score (MCS) were calculated from the questionnaires at each time and the data analysed by random coefficient modelling. Separate models were fitted for MCS and PCS using covariates of race, age, estimated blood loss (EBL), time after RRP, and their interaction terms.

RESULTS

The PCS initially declined and improved linearly. and the baseline level was not achieved by 6 weeks, but modelling lines showed an expected return to baseline at 7-8 weeks for all patients. Age had a significant relationship with the PCS; older men (>60 years) scored higher, and their PCS remained significantly higher after RRP than younger men (< or =60 years) until 5 weeks. EBL also had a significant relationship with PCS; men with an EBL of >500 mL had a significantly lower PCS at 1 week and this remained significantly lower than for men with an EBL of < or = 500 mL until approximately 7 weeks. The MCS improved immediately after RRP and remained higher throughout the study than at baseline. Race was the only covariate for which there were significant differences in the MCS. The MCS was significantly lower at baseline for African-Americans than for Caucasian Americans, and remained lower until 6 weeks after RRP.

CONCLUSIONS

There were significant changes in HRQoL during in the short-term after RRP. Younger men and those with a higher EBL might have a slower recovery of the PCS after RRP. African-Americans had a slower increase in MCS and might have a different initial emotional or mental health response to RRP than have Caucasians.

An update on localised prostate cancer

Prostate cancer remains a most intriguing condition, which poses unique challenges. On reviewing recent literature on localised disease (confined within the capsule T1 or T2, N0, M0), it would seem that it is over treated, resulting in significant morbidity. We now have strong evidence, however, that there can be mortality associated with 'watchful waiting'. Clinicians should, therefore, aim to identify men at risk of progression in order that they should be treated effectively with minimal adverse effects. In this paper, we report on recent developments in the expanding array of management options available.

Diagnostic performance of a random versus lesion-directed biopsy of the prostate from transrectal ultrasound: results of a 5-year consecutive clinical study in 1 institution in South Taiwan

OBJECTIVE

The purpose of this study was to compare cancer detection rates of sonographically suspicious lesion-directed biopsies and random biopsies through transverse examination of prostate halves in 518 patients over 5 years.

METHODS

From 1998 to 2002, 518 patients were referred for prostate biopsies because of either elevated prostate-specific antigen (PSA) levels or abnormal digital rectal examination findings. On the basis of transverse examination of prostate halves by transrectal ultrasound, we performed lesion-directed biopsy of 3 to 5 cores if morphologically suspicious lesions existed on sonography or random biopsy of 3 cores if no obvious suspicious lesions existed. Biopsy specimens were put into 2 labeled containers. Pathologic results were correlated with random and lesion-directed guided locations.

RESULTS

Nine-hundred fifty-nine results were obtained from 439 random and 520 lesion-directed biopsies in 518 patients. Cancer was detected in 207 patients (40.7%). Patients with cancer who had PSA levels of 10.0 ng/mL or greater had higher proportions of bilateral cancer lesions than those with PSA levels of less than 10 ng/mL (P = 0.03). One hundred ten (25.1%) of 439 normal-appearing halves taken by random biopsy were tumor-positive compared with 200 (38.5 %) of 520 biopsies from halves with sonographically suspicious lesions. Regardless of having random or lesion-directed biopsies, patients with PSA levels of 10 ng/mL or greater had higher positive malignancy rates than those with PSA levels of less than 10.0 ng/mL (P < .001). In about 40 patients, a diagnosis was made by random biopsy from halves that were morphologically normal on sonography, not by lesion-directed biopsy from tumor-suspicious contralateral halves.

CONCLUSIONS

Cancer detection rates of lesion-directed biopsies are superior to those of random biopsies regardless of PSA level.

Visually directed high-intensity focused ultrasound for organ-confined prostate cancer: a proposed standard for the conduct of therapy

OBJECTIVE

To propose a standard for the conduct of visually directed transrectal high-intensity focused ultrasound (HIFU) and to offer a formal description of the changes observed on B-mode ultrasonography (US) during this procedure. We describe our early experience of using two different treatment methods; algorithm-based HIFU and visually directed HIFU for the treatment of organ-confined prostate cancer.

PATIENTS AND METHODS

Between November 2004 and October 2005, 34 men were treated using the Sonablate-500 (Focus Surgery, Indianapolis, IN, USA) as primary therapy for T1 or T2 prostate cancer. None had had previous hormone therapy and all had > or = 3-month PSA nadirs recorded at the follow-up. Nine men were treated using an algorithm-based protocol (group 1) and 25 using visually directed therapy (group 2). The conduct of visually directed treatment was described and changes seen using B-mode US were categorized using three 'Uchida' grades. RESULTS The mean PSA nadir achieved in group 2 was 0.15 ng/mL, vs 1.51 ng/mL in group 1 (P < 0.005). In group 2, 21 of 25 men achieved PSA nadirs of < or = 0.2 ng/mL 3 months after treatment. Seven men achieved undetectable PSA values. The occurrence rate of treatment-related toxicity was similar in both groups.

CONCLUSION

Visually directed, transrectal HIFU enables clinically important and statistically significantly lower PSA nadirs to be achieved than algorithm-based HIFU. This is the first reported experience of visually directed HIFU for the treatment of organ-confined prostate cancer. We think that this is the first attempt to standardize the conduct of therapy; such standardization facilitates teaching it, and makes it possible to derive quality standards. The standardization of the conduct of therapy is a key step in the process of health technology assessment.

The effect of neoadjuvant androgen suppression on prostate cancer-related outcomes after high-intensity focused ultrasound therapy

OBJECTIVE

To explore the effect of neoadjuvant androgen suppression (AS) compared to no AS on cancer-related outcomes after radical high-intensity focused ultrasound (HIFU) therapy for men with presumed organ-confined prostate cancer.

PATIENTS AND METHODS

Between January 1999 and January 2005, 250 patients underwent HIFU for presumed localized adenocarcinoma of the prostate; 154 had received neoadjuvant hormonal therapy and 96 had not. The primary outcome measure was treatment failure, as defined by the presence of prostate cancer on the biopsy taken 6 months after HIFU. Multiple logistic regression was used to examine relationships between the use of HIFU with and with no neoadjuvant AS and treatment failure.

RESULTS

The treatment failure rate was slightly lower in patients receiving neoadjuvant AS (31% vs 34%), but this was not statistically significant (P = 0.119).

CONCLUSION

In this unrandomized comparison between neoadjuvant or no AS before HIFU for men with presumed organ-confined prostate cancer, there appeared to be little if any benefit associated with the previous administration of AS.

To what extent does the prostate-specific antigen nadir predict subsequent treatment failure after transrectal high-intensity focused ultrasound therapy for presumed localized adenocarcinoma of the prostate?

OBJECTIVE

To explore the association between the prostate-specific antigen (PSA) nadir after transrectal high-intensity focused ultrasound (HIFU) therapy for organ-confined prostate cancer and subsequent treatment failure, as defined by the presence of residual disease at biopsy 6 months after treatment.

PATIENTS AND METHODS

Between January 1999 and January 2005, 115 patients in a Japanese hospital were treated using a transrectal HIFU system (Sonablate, Focus Surgery, IN, USA) for presumed localized adenocarcinoma of the prostate. All treatments were primary and none of the patients had received hormone therapy. The PSA level was measured at 2-monthly intervals and all patients had a transrectal prostate biopsy taken at 6 months. Multiple logistic regression was used to examine the relationship between PSA nadir and treatment failure, as defined by the presence of disease at biopsy.

RESULTS

The PSA nadir was strongly associated with treatment failure (P < 0.001). Patients with a PSA nadir of 0.0-0.2 ng/mL had a treatment failure rate of only 11% (four of 36), compared to 46% (17 of 37) in patients with a PSA nadir of 0.21-1.00 ng/mL and 48% (20 of 42) with a PSA nadir of >1.0 ng/mL. In addition, the PSA nadir was strongly associated with both preoperative PSA level and residual prostate volume.

CONCLUSION

There is a clear and intuitive association between the PSA nadir and the risk of treatment failure after HIFU. These data can be used to predict the risk of residual disease in patients with prostate cancer undergoing HIFU therapy. They can also be used to inform where the target PSA nadir should be set for this novel therapy.

Management of prostate cancer. Part 2: localized and locally advanced disease

Prostate cancer is the most prevalent nondermatological malignancy affecting men in the Western world. An increase in public awareness has led to earlier detection. Accepted treatments for localized prostate cancer include active surveillance, radical prostatectomy, interstitial brachytherapy, external beam radiotherapy and watchful waiting. The authors discuss the rationale for the different approaches together with outcomes including toxicity. Novel approaches are also explored. The management of locally advanced disease has long been a challenge and the evolving evidence is reviewed.