Predicting the 10-year risk of death from other causes in men with localized prostate cancer using patient-reported factors: Development of a tool

OBJECTIVE

To develop a tool for estimating the 10-year risk of death from other causes in men with localized prostate cancer.

SUBJECTS AND METHODS

We identified 2,425 patients from the Surveillance Epidemiology and End Results-Medicare Health Outcomes Survey database, age <80, newly diagnosed with clinical stage T1-T3a prostate cancer from 1/1/1998-12/31/2009, with follow-up through 2/28/2013. We developed a Fine and Gray competing-risks model for 10-year other cause mortality considering age, patient-reported comorbid medical conditions, component scores and items of the SF-36 Health Survey, activities of daily living, and sociodemographic characteristics. Model discrimination and calibration were compared to predictions from Social Security life table mortality risk estimates.

RESULTS

Over a median follow-up of 7.7 years, 76 men died of prostate-specific causes and 465 died of other causes. The strongest predictors of 10-year other cause mortality risk included increasing age at diagnosis, higher approximated Charlson Comorbidity Index score, worse patient-reported general health (fair or poor vs. excellent-good), smoking at diagnosis, and marital status (all other vs. married) (all p<0.05). Model discrimination improved over Social Security life tables (c-index of 0.70 vs. 0.59, respectively). Predictions were more accurate than predictions from the Social Security life tables, which overestimated risk in our population.

CONCLUSIONS

We provide a tool for estimating the 10-year risk of dying from other causes when making decisions about treating prostate cancer using pre-treatment patient-reported characteristics.

Prostate-specific antigen testing after the US Preventive Services Task Force recommendation: a population-based analysis of electronic health data

PURPOSE

This study describes longitudinal trends in the use of prostate-specific antigen (PSA)-based testing in two geographically distinct healthcare systems following the 2011 US Preventive Services Task Force (USPSTF) recommendations against routine PSA screening.

METHODS

We analyzed population-based health claims data from 253,139 men aged 40-80 who were enrolled at two US healthcare systems. We assessed trends in the percentage of eligible men receiving ≥ 1 PSA test per year by time period (2000-2008, 2009-2011, 2012-2014), age (40-54, 55-69, 70-80), and race (white, black, other, unknown), and conducted a joinpoint regression analysis.

RESULTS

Men aged 55-69 and 70-80 years of all races had similar use of PSA testing between 2000 and 2011, ranging between 47 and 56% of eligible men by year, while only 22-26% of men aged 40-54 had a PSA test per year during this period. Overall, the percentage of men receiving at least one PSA test per year decreased by 26% between 2009-2011 and 2012-2014, with similar trends across race and age groups. PSA testing declined significantly after 2011 (annual percent change = - 11.28).

CONCLUSIONS

Following the 2011 USPSTF recommendations against routine PSA screening, declines in PSA testing were observed among men of all races and across all age groups in two large US healthcare systems.

Transplantation of Renal Allograft After Removal of Renal Cell Carcinoma: Case Report and Review of the Literature

With the rising incidence of end-stage renal disease in the United States, patients needing renal transplants are waiting longer for increasingly scarce grafts. Formerly, the general practice was to avoid organs with tumors for transplant because of the risk of malignancy transmission to the recipient. However, with comprehensive donor selection and a small-sized primary tumor, the positive outcomes of transplant outweigh the risks of transmission after a partial nephrectomy. In our case, a 31-year-old woman, the daughter of the recipient, underwent a laparoscopic nephrectomy with an existing 8-mm tumor later confirmed as renal cell carcinoma. An ex vivo tumor enucleation was performed before the allograft was transplanted into the 69-year-old patient with endstage renal disease. At last follow-up, graft function has remained excellent with no evidence of local recurrence or metastasis in both the donor and recipient. Here, we describe our case and perform a literature review on the incidence and management of renal allografts with incidentally detected renal cell carcinoma during transplant.

Management of recurrent prostate cancer after radiotherapy: long-term results from CALGB 9687 (Alliance), a prospective multi-institutional salvage prostatectomy series

BACKGROUND

To evaluate efficacy and morbidity prospectively in a contemporary multi-institutional salvage radical prostatectomy (SRP) series.

METHODS

Forty-one men were enrolled between 1997 and 2006, who suffered biopsy-proven recurrent prostate cancer (CaP) after receiving ≥ 60c Gy radiation as primary treatment for cT_1-2N_XM₀ disease. Surgical morbidity, quality of life, biochemical progression-free survival (BPFS) and overall survival (OS) were evaluated.

RESULTS

Twenty-four men had undergone external beam radiotherapy, 11 brachytherapy, and six both. Median time between radiation and SRP was 64 months. Median age at SRP was 64 years. Pathologic staging revealed 44% pT2, 54% pT3, and 3% pT4. Surgical margins were positive in 17 and 88% were pN0. Twenty-two percent required intraoperative blood transfusion. Three rectal and one obturator nerve injuries occurred. Seventeen of 38 evaluable patients (45%) had urinary incontinence ( ≥ 3 pads/day) prior to SRP; 88% reported urinary incontinence at 6 months, 85% at 12 months, 63% at 24 months after SRP. Furthermore, 37% of men reported impotence prior to SRP; 78% reported impotence at 6 months, 82% at 12 months, and 44% at 24 months after SRP. The 2-, 5- and 10-year BPFS rates were 51, 39, and 33% respectively; the 2-, 5- and 10-year OS rates were 100, 89, and 52%, respectively, at median follow-up 91 months.

CONCLUSIONS

Modern surgical techniques continue to be associated with significant peri-operative complication rates. Nevertheless, SRP may benefit carefully selected patients through durable oncologic control.

Severe gangrene at the glans penis requiring penectomy as the first major complication of Buerger's disease

We report an interesting case of Buerger's disease that manifested at the glans penis in a 56 year-old former smoker. Penile involvement in Buerger's disease is rare. Our patient had no prior extremity or digit amputations in his 4-year history of Buerger's disease. However, our patient did suffer from recurrent penile ulcers over an 8-week timeframe that ultimately progressed to a gangrenous, unsalvageable glans penis. He underwent a partial penectomy and urethral reconstruction with excellent post-operative results.

Randomized, double-blind, placebo-controlled trial of polyphenon E in prostate cancer patients before prostatectomy: evaluation of potential chemopreventive activities

Compelling preclinical and pilot clinical data support the role of green tea polyphenols in prostate cancer prevention. We conducted a randomized, double-blind, placebo-controlled trial of polyphenon E (enriched green tea polyphenol extract) in men with prostate cancer scheduled to undergo radical prostatectomy. The study aimed to determine the bioavailability of green tea polyphenols in prostate tissue and to measure its effects on systemic and tissue biomarkers of prostate cancer carcinogenesis. Participants received either polyphenon E (containing 800 mg epigallocatechin gallate) or placebo daily for 3 to 6 weeks before surgery. Following the intervention, green tea polyphenol levels in the prostatectomy tissue were low to undetectable. Polyphenon E intervention resulted in favorable but not statistically significant changes in serum prostate-specific antigen, serum insulin-like growth factor axis, and oxidative DNA damage in blood leukocytes. Tissue biomarkers of cell proliferation, apoptosis, and angiogenesis in the prostatectomy tissue did not differ between the treatment arms. The proportion of subjects who had a decrease in Gleason score between biopsy and surgical specimens was greater in those on polyphenon E but was not statistically significant. The study's findings of low bioavailability and/or bioaccumulation of green tea polyphenols in prostate tissue and statistically insignificant changes in systemic and tissue biomarkers from 3 to 6 weeks of administration suggests that prostate cancer preventive activity of green tea polyphenols, if occurring, may be through indirect means and/or that the activity may need to be evaluated with longer intervention durations, repeated dosing, or in patients at earlier stages of the disease.

Testis cancer

PURPOSE

We quantified the burden of testis cancer in the United States by identifying trends in its incidence, its treatment and the use of health care resources to estimate the economic impact of the disease.

MATERIALS AND METHODS

The analytical methods used to generate these results were described previously.

RESULTS

The overall incidence of testis cancer in the United States increased 46% between 1975 and 2001. During the same period the ratio of seminoma to nonseminoma increased and there were fewer men presenting with stage II and III tumors. Survival rates increased successively, attaining the current level of 95.9%. Treatment patterns changed and active surveillance increased as a primary treatment modality. Overall hospitalization rates for men with testis cancer decreased from 1.8/100,000 in 1994 and 1.4/100,000 in 2000. Care for white men shifted to the outpatient setting, which did not occur for black men. The estimated annual expenditure for testis cancer for privately insured individuals between ages 18 and 54 years was $6,236. National estimates of annual medical expenditures placed the total cost of treatment at $21.8 million in 2000, representing an increase of 10% over the total in 1994. Of men with testis cancer 16% missed work for treatment of the disease with an average of 8.4 total hours of work missed.

CONCLUSIONS

The cost of testis cancer is estimated at almost $21.8 million annually. It appears to be increasing with time despite a shift to active surveillance treatments and less hospitalization.

Adjunctive therapy for men with high risk localized and locally advanced prostate cancer: targeting disseminated tumor cells

PURPOSE

Our research into the pathophysiology of micrometastatic dissemination and cancer recurrence has resulted in the initiation of a clinical trial for men with clinically localized and locally advanced disease.

MATERIALS AND METHODS

We describe the development of this trial, which exploits anti-angiogenesis therapy, and delineate how our understanding of prostate cancer metastasis influenced its design.

RESULTS

Prostate cancer is a heterogeneous disease. Although many men can be cured with local therapy, a large majority with clinically localized disease will experience a relapse usually at a distant site. This result is most likely due to micrometastatic dissemination early in the disease process. Therefore, successful contemporary treatment of many men with prostate cancer should include a combination of local and systemic therapies. Fortunately, cellular, molecular and genetic features that may predict which men are most in need of this therapeutic approach are being identified and characterized. This insight not only supports the rationale for a combination therapeutic approach to prostate cancer management, but will help identify the pathways and agents that provide the most promising targets for intervention.

CONCLUSIONS

Despite advances in prevention and early detection, refinements in surgical technique, and improvements in radiation and systemic therapies, the ability to cure all men with prostate cancer remains unattainable. The continuing challenge is the successful eradication of recurrent and metastatic disease.

Laparoscopic diagnosis and management of perinephric adipose-containing lesions

We describe two patients in whom imaging and percutaneous biopsy of perinephric masses were insufficient for diagnosis. Laparoscopic biopsy permitted the diagnosis of fibrosis with chronic inflammation in one case and liposarcoma in the other.

Post-Operative Changes Mimicking the Radiographic Appearance of Recurrent Renal Cell Carcinoma

Partial nephrectomy for small renal tumors is associated with excellent long-term outcomes. In the absence of positive surgical margins, local recurrence is uncommon. Although computed tomography is associated with good diagnostic accuracy, the radiographic evaluation of some renal lesions remains difficult. This difficulty can be greater in the period following surgery, when post-operative tissue changes can result in abnormal radiographic findings. We report a case of benign post-operative changes mimicking the radiographic appearance of recurrent renal cell carcinoma.

Well-differentiated papillary mesothelioma occurring in the tunica vaginalis of the testis with contralateral atypical mesothelial hyperplasia

Well-differentiated papillary mesothelioma (WDPM) occurs rarely in the paratesticular region, with only a handful of published case reports. Often presenting with recurrent hydrocele, WDPM is a multifocal mesothelial proliferation with a predominantly indolent clinical course. Accordingly, pathologic distinction of this lesion from true malignant mesothelioma is crucial, although it may be difficult because of the variability of associated histologic features. In addition, rare cases of WDPM have progressed to malignant mesothelioma, leading to its classification as a tumor of low malignant potential. Here, we report a case of multifocal WDPM occurring in the tunica vaginalis and tunica albuginea, with contralateral atypical mesothelial hyperplasia, a potentially premalignant lesion.

Current clinical trials in renal cell carcinoma

The treatment of renal cell carcinoma remains primarily surgical. Consequently, it is not surprising that urologists have been active in the design and operation of clinical trials for patients with kidney cancer. Currently, clinical trial efforts of the urologic community are focused on the adjuvant setting in patients undergoing nephrectomy at high risk for recurrence or metastasis. As newer agents become available and are applied earlier during the course of the disease, the involvement of urologists in clinical trials in renal cell carcinoma will increase. This review highlights several key trials currently available for patients with kidney cancer.

Technical considerations for laparoscopic right renal surgery in presence of Riedel's lobe of the liver

Riedel's lobe of the liver is an anatomic variant, described as a caudal extension of the right lobe of the liver, that presents a challenge in laparoscopic right renal surgery. A 52-year-old woman with a Riedel's lobe of the liver and a large right renal mass underwent laparoscopic right radical nephrectomy. Transperitoneal access with the Veress needle through a right lateral port was initially unsuccessful. After a supraumbilical approach, pneumoperitoneum was eventually achieved. The right lateral liver attachments were freed, and the lobe was retracted medially to expose the right kidney and its hilum. The surgery was then performed successfully. Riedel's lobe presents two special technical concerns: intraperitoneal access and hilar exposure. For access, an initial supraumbilical approach, or possibly an open approach, decreases the risk of liver injury. For renal and hilar exposure, the right lateral liver attachments can be taken down so that the hepatic lobe can be retracted medially instead of in the conventional cephalad direction. Retroperitoneal access, if feasible, may also circumvent these problems. Surgery can then be performed safely and effectively.

Modified clipless antegrade nerve preservation in robotic-assisted laparoscopic radical prostatectomy with validated sexual function evaluation

INTRODUCTION

We present our technique for clipless antegrade neurovascular bundle preservation during robotic laparoscopic radical prostatectomy, along with short-term follow-up of our patients' sexual function.

TECHNICAL CONSIDERATIONS

Using the da Vinci three-arm robotic system, we performed robotic laparoscopic radical prostatectomy using a transperitoneal approach in an antegrade fashion. After division of the bladder neck, the posterior plane of the prostate was developed distally toward the apex of the prostate in the midline. This plane was then developed completely, releasing the vascular pedicles and neurovascular bundles in a medial to lateral direction, with occasional use of bipolar cautery and without the use of clips or monopolar cautery. Patients with a minimal follow-up of 3 months who did not require open conversion were included in this study. A total of 56 patients met these inclusion criteria between February 2003 and May 2004, with a mean follow-up of 6 months. Patients were given the validated Rand Medical Outcomes Study 36-Item Health Survey, version 2, with the University of California, Los Angeles, Prostate Cancer Index preoperatively and at 1, 3, 6, and 12 months postoperatively. The overall score for both unilateral and bilateral nerve-sparing groups was 35.0, 39.7, 49.4, and 49.6 at 1, 3, 6, and 12 months postoperatively, respectively. These coincided with a return to baseline potency rate of 47%, 54%, 66%, and 69% at 1, 3, 6, and 12 months, respectively.

CONCLUSIONS

Antegrade dissection of the neurovascular bundle, avoiding the use of clips or monopolar cautery during robotic laparoscopic radical prostatectomy, may result in early return of sexual function and overall outcome similar to that after radical retropubic prostatectomy.

Use of Suspension Traction System for Renal Positioning during Laparoscopic Partial Nephrectomy

BACKGROUND AND PURPOSE

The technical difficulty of laparoscopic partial nephrectomy (LPN) lies mainly in the steps required during warm ischemia time (WIT), which includes tumor excision and renal reconstruction. We present a renal-suspension traction system to place the tumor in stable optimal view during the critical steps of LPN.

PATIENTS AND METHODS

Thirty-three patients underwent LPN from October 2002 through December 2003. Eight had a renal sling placed intraoperatively because of difficult access to the tumor. Perioperative parameters were assessed. The renal hilum was dissected and the tumor exposed. To keep the tumor oriented perfectly toward the camera and the working ports, a 2-0 braided polyglactin (Vicryl) traction suture was passed through Gerota's fascia, catching the renal capsule; brought out through the abdominal wall; and secured to the skin with a clamp.

RESULTS

All surgical margins were negative. For the traction and nontraction groups, the mean sizes of the tumor were 2.5 cm and 2.2 cm, respectively (P = 0.426). The estimated blood loss was 125 mL and 246 mL respectively (P = 0.041). The WIT average 27.4 minutes and 30.12 minutes (P = 0.470). The surgical time was 192 minutes and 235 minutes respectively, (P = 0.062). Based on our findings, we have devised a renal suspension traction algorithm for specific tumor locations during LPN.

CONCLUSIONS

The renal suspension traction system allows precision in tumor excision and renal reconstruction during the critical steps of LPN. With the renal suspension system we devised, we are able to simplify LPN for tumors located away from optimal port access.

Primary malignant melanoma of the urethra

Primary malignant melanoma of the urethra is an aggressive neoplasm associated with a poor prognosis. The outcome is dependent on early diagnosis and surgical intervention. However, the diagnosis is often delayed as a result of difficulties related to differentiating this lesion from other disorders. Such difficulties result from the variety of clinical and pathologic presentations that are common to melanoma. We report a case of primary malignant melanoma of the urethra with subsequent retrograde seeding of the bladder initially diagnosed and managed as invasive urothelial carcinoma.

ELIMINATING KNOT TYING DURING WARM ISCHEMIA TIME FOR LAPAROSCOPIC PARTIAL NEPHRECTOMY

PURPOSE

Rapid intracorporeal suturing represents a challenge when performing laparoscopic partial nephrectomy (LPN). During warm ischemia time (WIT) knot tying is a major time-consuming step. We present our technique of eliminating knot tying during LPN and the outcomes of our initial series.

MATERIALS AND METHODS

Between October 2002 and October 2003, 32 patients underwent LPN for clinical T1a renal tumors. Our technique includes initial placement of a 5Fr ureteral catheter for collecting system irrigation. The renal hilum is clamped, the tumor is sharply excised and freehand suturing of the collecting system and renal parenchyma is performed using 2-zero and zero polyglactin sutures prepared with an absorbable clip (LapraTy, Ethicon Endosurgery Inc., Piscataway, New Jersey) at the terminal end. Once the suture is passed an additional clip is used to cinch it down, obviating the need for knot tying. This technique is used for closure of the collecting system as well as for placement of parenchymal compressive sutures over bolsters. Subsequent testing for watertightness with methylene blue solution is performed.

RESULTS

Pathological mean tumor size was 2.1 cm (range 0.3 to 4.2). Mean operative time was 224.2 minutes (range 105 to 396). In 21 cases (65.6%) the collecting system was entered, necessitating further suturing. Mean WIT was 33.1 minutes (range 13 to 55) and mean estimated blood loss was 222.7 cc (range 5 to 600). No postoperative bleeding or urine leaks were encountered in this series.

CONCLUSIONS

The use of LapraTy clips as an alternative to knot tying in LPN is safe and efficient. It simplifies the procedure and allows completion of the necessary suturing tasks during an acceptable WIT.

Relationship of erythrocyte membrane polyunsaturated fatty acids and prostate-specific antigen levels in Jamaican men

OBJECTIVE

To investigate the relationship between erythrocyte membrane polyunsaturated fatty acid (PUFA) and serum prostate- specific antigen (PSA) levels in Jamaican men, as there may be an association between prostate cancer incidence and dietary fatty acids, and prostate cancer incidence in Jamaica is among the highest in the world.

PATIENTS AND METHODS

Blood from 107 Jamaican men was analysed for 32 individual fatty acids and PSA levels. Special attention was given to correlations between Omega3 and Omega6 PUFAs and PSA. Data were analysed using standard linear regression methods.

RESULTS

The mean PSA was 18.6 ng/mL (normal 0-4.0); for age groups of 51-60, 61-70 and 71-80 years the levels were 14, 26 and 23 ng/mL, respectively. Eicosapentaenoic acid (Omega3) levels decreased as PSA exceeded 10 ng/mL (P = 0.02). Arachidonic acid (Omega6) levels decreased as PSA was < 2 ng/mL (P = 0.02). Linoleic acid (Omega6) levels decreased in men with PSA levels of 2-10 ng/mL (P = 0.04). In men with a PSA of > 10 ng/mL there was a positive correlation between the ratio of Omega6 to Omega3 PUFAs and PSA (P = 0.036); there was also a negative correlation between the ratio of Omega3 to Omega6 PUFAs and PSA (P = 0.08). When the ratio of Omega3 PUFAs over the products of Omega6 PUFAs were used, this trend was significant (P= 0.03).

CONCLUSIONS

Increased levels of Omega6 PUFAs and the ratio of Omega6/Omega3 PUFAs in Jamaican men are associated with an increased mean PSA level and risk of prostate cancer. Additional studies are needed to establish a causal link between dietary fatty acid intake and the development of prostate cancer in Jamaican men.

Ex vivo partial nephrectomy and autotransplantation for renal cell cancer after laparoscopic renal harvest

Laparoscopic partial nephrectomy is an alternative to the open approach. For centrally located tumors, open extracorporeal partial nephrectomy has been used. We report 2 cases of laparoscopic nephrectomy for the purpose of extracorporeal partial nephrectomy and autotransplantation for renal cell cancer.

Use of Biopsy Sheath to Improve Standardization of Renal Mass Biopsy in Tissue-Ablative Procedures

PURPOSE

We used a biopsy sheath to standardize and improve biopsy specimens obtained during laparoscopic cryoablation.

MATERIALS AND METHOD

Tru-Cut biopsy was performed using a resized sheath in three patients undergoing laparoscopic cryoablation of renal masses.

RESULTS

All three biopsy specimens were sufficient for pathologic evaluation and representative of the tissue mass.

CONCLUSIONS

The application of a biopsy sheath to standardize the depth of needle penetration during Tru-Cut biopsy provides better results and minimizes false-negative studies.

Characterizing prostatic adenocarcinomas in men with a serum prostate specific antigen level of <4.0 ng/mL

OBJECTIVE

To characterize prostate cancer in men undergoing radical prostatectomy who have a prostate-specific antigen (PSA) level of < 4.0 ng/mL, hypothesizing that a low PSA is not caused by diminished tumour production of PSA, nor does it signify clinically insignificant disease.

PATIENTS AND METHODS

Seventy-nine men (mean age 59.3 years, range 43-77) with a PSA level of < 4.0 ng/mL were identified from 702 who had a radical prostatectomy between 1994 and 2000. Demographic and clinical data were analysed; pathological specimens were evaluated by routine haematoxylin and eosin staining and immunohistochemistry with anti-PSA antibody, for both pathological staging and grading, and for the presence of PSA production. Tumours were classified as 'clinically insignificant' if the tumour volume was < 0.5 mL and the Gleason score < 7.

RESULTS

The mean (SD, range) preoperative PSA level was 3.04 (0.85, 0.8-3.8) ng/mL Indications for biopsy included an abnormal digital rectal examination (61%), a PSA velocity of > 0.75 ng/mL/year (12%), a strong family history of prostate cancer (3%), obstructive urinary symptoms (2%), or no obvious indication (23%). Thirty-eight (48%) tumours were clinically insignificant. Of 41 clinically significant cancers, 13 had a final Gleason score of > or = 7, 20 had extraprostatic extension and 11 had a tumour volume of > or = 10 mL Of the 79 prostate cancer specimens 78 stained strongly for PSA; the exception was a Gleason 9 tumour. With a mean (range) follow-up of 3.5 (0.18-6) years only one patient had a biochemical recurrence (PSA > or = 0.1 ng/mL).

CONCLUSIONS

Most prostate cancers in men with a PSA level of < 4.0 ng/mL are clinically significant and PSA-producing. Many of these tumours are high-grade, high-volume and extraprostatic. We are currently exploring factors to explain why serum PSA is not elevated in these men, including tumour location, pattern of invasion and microvessel density.

Inhibition of prostate cancer metastatic colonization by approximately 4.2 Mb of human chromosome 12

Our previous studies demonstrate that introduction of a approximately 70 cM region (now estimated at 63.75 Mb by the Human Genome Project) of human chromosome 12 into the highly metastatic Dunning rat prostate cancer cell line AT6.1 results in >30-fold (>/=90%) reduction in the number of overt metastases in spontaneous metastasis assays. We report the further localization and biological characterization of the metastasis-suppressor activity encoded by a reduced region of chromosome 12. To localize this metastasis-suppressor activity, a panel of AT6.1 microcell hybrids that retain varying portions of human chromosome 12 was constructed and subjected to sequence-tagged site (STS)-based PCR analysis and assessment of in vivo metastatic ability. Data from these complementary approaches localized the metastasis-suppressor activity to a approximately 4.2 Mb portion of human chromosome 12q24.3 comprised of 3 separate regions. Reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblotting were used for differential expression analyses to identify which characterized genes, predicted gene sequences and expressed sequence tags (ESTs) within this region could be responsible for the observed metastasis suppression. Comprehensive in vivo studies showed that suppressed AT6.1-12 hybrids that retain the metastasis-suppressor region on 12q24.3 are capable of arriving at the secondary site, but are not able to persist there. Thus, unlike other metastasis-suppressor genes characterized to date, the metastasis-suppressor gene encoded by this region appears to utilize a different biologic mechanism to suppress the growth of overt metastases at the secondary site.

Metastasis suppression: the evolving role of metastasis suppressor genes for regulating cancer cell growth at the secondary site

PURPOSE

The prevention and treatment of prostate cancer metastasis continue to provide a significant clinical challenge. Identification of the rate limiting steps of metastasis and their underlying molecular mechanisms may lead to new therapeutic targets and also allow more accurate risk stratification for clinical metastases. We review the literature supporting growth of disseminated tumor cells at the secondary site as a key rate limiting step in metastasis. We also reviewed the definition, identification and characterization of metastasis suppressor genes, and discuss their evolving role in regulating this step.

MATERIALS AND METHODS

We performed MEDLINE searches and manual bibliographic reviews on the specific steps of metastasis, including growth at the secondary site. In addition, we performed a comprehensive literature review to identify genes fitting the classic definition of a metastasis suppressor gene. The literature was also searched to assess the status of each gene in clinical cancer and evaluate functional support for the potential involvement of each gene in regulating growth at the secondary site.

RESULTS

Clinical studies in prostate cancer and other cancer types suggest that dissemination to the secondary site is often an early clinical event. However, not all patients with tumor cells at the secondary site have overt metastatic lesions even in the absence of therapy, suggesting that growth at the secondary site may be highly inefficient. Complimentary approaches have allowed researchers to document and quantify the inefficiency of cancer cell growth at the secondary site. Regarding the mechanism of growth control, many studies support a role for the interaction of a cancer cell and the microenvironment at the secondary site influencing whether growth into metastasis may occur. The 7 genes that suppress metastasis without affecting primary tumor growth that have been identified are KAI1, CD44, mitogen activated protein kinase (MAPK) kinase 4, nm23-H1, nm23-H2, KiSS1 and BrMS1. Three of these genes (KAI1, CD44 and MAPK kinase 4) act as metastasis suppressor genes of prostate cancer, while the remainder have yet to be tested in this cancer type. Loss of expression has been demonstrated for most of these genes during the clinical progression of prostate cancer to metastasis. MAPK kinase 4 and KiSS1 appear to suppress metastasis by inhibiting cancer cell growth at the secondary site. Interestingly many metastasis suppressor genes have common roles in growth control, adhesion and cytoskeletal reorganization, suggesting a common mechanism of metastasis suppression. Proposed candidate pathways include signaling through Src kinase and Rac GTPase.

CONCLUSIONS

The findings discussed support growth at the secondary site as a clinical target for metastasis treatment and prevention. Metastasis suppressor genes may offer valuable mechanistic insight for guiding specific therapeutic strategies, which may include drug induced reactivation of metastasis suppressor genes and their signaling pathways. Clinical assessment of metastasis suppressor gene product status in disseminated cancer cells may improve the accuracy of predicting the prognosis in patients with clinically localized disease.

Indications and contraindications for nerve-sparing radical prostatectomy

Nerve-sparing radical prostatectomy can be performed safely in most men undergoing radical prostatectomy. As is true in many aspects of prostate cancer diagnosis and therapy, the key element is patient selection. With many prostate tumors diagnosed at an earlier stage, the authors have seen a shift toward more favorable pathologic findings at the time of surgery. Concomitant with the success of early detection of prostate cancer is the realization that men are younger at the time of diagnosis and more interested in preserving sexual function. This article has described factors associated with an increased risk for extraprostatic tumor and, subsequently, an increased possibility of postprostatectomy cancer recurrence. Except for the previously mentioned absolute contraindications, none of these factors, by themselves, should be used to exclude a patient from nerve-sparing prostatectomy. Instead, meticulous attention must be given to the surgical dissection. If any doubt remains regarding residual tumor, the surgeon should err on the side of caution and remove the neurovascular bundle. The use of standardized intraoperative frozen-section analysis can help guide these decisions. The patient must be informed before surgery regarding the risks of nerve-sparing surgery, the potency rates of the surgeon, and the possibility that, to ensure adequate cancer control, the nerves may be sacrificed despite any preoperative optimism favoring the potential for their salvage.

Mitogen-activated protein kinase kinase 4 metastasis suppressor gene expression is inversely related to histological pattern in advancing human prostatic cancers

We have shown recently (B. A. Yoshida et al., Cancer Res., 59: 5483-5487) that mitogen-activated protein kinase kinase 4 (MKK4) can suppress AT6.1 rat prostate cancer metastases in vivo. Evaluation of the expression of components of the MKK4 signaling cascade showed a loss or down-regulation of expression of MKK4 or c-Jun, a downstream mediator of MKK4, in six of eight human prostate cancer cell lines. Given these findings, we next assessed whether MKK4 dysregulation occurs during the development of clinical prostate cancer. Immunohistochemical studies showed high levels of MKK4 expression in the epithelial but not the stromal compartment of normal prostatic tissues. In neoplastic tissues, a statistically significant, direct, inverse relationship between Gleason pattern and MKK4 was established. These results demonstrate that MKK4 protein is consistently down-regulated during prostate cancer progression and support a role for dysregulation of its signaling cascade in clinical disease. To test the possibility that down-regulation of MKK4 protein is the result of allelic loss, metastatic prostate cancer lesions were examined for loss of heterozygosity (LOH) within the MKK4 locus (D17S969). These studies showed a 31% (5 of 16) LOH of MKK4 that is not associated with coding region mutations, which suggests that the nucleotide sequence of the gene in the remaining allele is infrequently mutated.

Targeting of cancer cells with monoclonal antibodies specific for C3b(i)

PURPOSE

The goal of this research is to determine the feasibility of an immunotherapeutic approach based on the use of monoclonal antibodies (mAb) to target complement activation fragments on opsonized cancer cells.

METHODS

We investigated whether treatment of LNCaP and C4-2 human prostate cancer cell lines with normal human serum would allow for deposition of sufficient amounts of the complement-activation protein C3b and its fragments [collectively referred to as C3b(i)] such that these proteins could serve as cancer-cell-associated antigens for targeting by mAb. Radioimmunoassays, flow cytometry, and magnetic purging with specific immunomagnetic beads were used for the analyses.

RESULTS

In vitro opsonization of human prostate cancer cells with normal human serum resulted in deposition of C3b(i) in sufficient quantity (approx. 100,000 molecules/cell) for the cells to be targeted in a variety of protocols. We found that 51Cr-labeled and C3b(i)-opsonized cancer cells could be specifically purged at high efficiency (95%-99%) using anti-C3b(i) mAb covalently coupled to magnetic beads. Flow-cytometry experiments indicated that most normal white cells were not removed under similar conditions. Opsonization of cancer cells with sera from men with prostate cancer led to lower levels of cell-associated IgM and, subsequently, lower amounts of C3b(i) deposited than in normal subjects. Prototype experiments suggested that this deficiency could be corrected by addition of IgM from normal donor plasma.

CONCLUSION

mAb directed against complement-activation products may provide new opportunities to deliver diagnostic and therapeutic agents selectively to cancer cells and tumor deposits. These opportunities may include ex vivo purging of C3b(i)-opsonized cancer cells prior to autologous bone marrow or stem cell transplantation.

Surgical and postoperative factors affecting length of hospital stay after radical prostatectomy

BACKGROUND

Radical prostatectomy continues to comprise the mainstay of therapy for localized prostate carcinoma. However, caring for radical prostatectomy patients accounts for approximately half of the $1.7 billion annual cost of prostate carcinoma treatment. Length of stay (LOS) after surgery appears to be one of the main components of this cost. The first step in reducing cost is to identify those variables associated with LOS. Radical prostatectomy can be performed using two very different surgical techniques and with each technique different costs are incurred. The objective of the current study was to identify factors associated with LOS as a function of surgical approach. To reduce potential biases due to patient requests for longer hospitalization or physician preferences in that regard, secondary objectives were to identify factors associated with time to fluid intake (TTF) and time to consume solid foods (TTS).

METHODS

An institutional-based, retrospective chart review of 313 men with clinically localized prostate carcinoma who underwent either a perineal (RPP) or retropubic (RRP) prostatectomy at a single university center from March 1988 to October 1996 was undertaken. Information regarding LOS was available for 311 patients. Linear regression models were used to assess the association between covariables and LOS. Poisson regression models for count data were used to assess associations between covariables and the secondary endpoints of TTF and TTS. Covariables included: preoperative (age, race, prostate specific antigen, Gleason score, clinical stage, lymph node resection, comorbidity, and admission time), intraoperative (surgical approach, surgeon, operative time, estimated blood loss, transfusion requirement, anesthetic approach, and American Society of Anesthesiologists score), and postoperative (pain management complications and transfusions) parameters.

RESULTS

The median LOS was 4 days (range, 1-19 days) for RPP and 5 days (range, 3-16 days) for RRP approaches. The final model included six main effects and three interaction terms. Overall, LOS decreased over time with LOS decreasing at a faster rate in patients who underwent RPP. In general, patients who underwent RRP had an increased LOS compared with patients who underwent RPP. Complications from surgery and age increased the LOS for all patients; however, the increase was greater in patients who underwent RPP. In addition, the use of intraoperative epidural anesthesia and the increased use of postoperative narcotics were associated with increased LOS for patients undergoing both surgical approaches. TTF and TTS were significantly longer for patients who underwent the retropubic approach compared with those patients who underwent the perineal approach. After adjustment for surgical approach no other covariables were found to be associated with TTF. After adjustment for surgical approach, the occurrence of complications was found to be associated with TTS, indicating that patients who experienced complications took longer before they could tolerate solid foods.

CONCLUSIONS

In view of the importance of clinical care pathways in reducing medical expenditures from radical prostatectomy, the results of the current study may contribute to the further refining of these pathways by highlighting the differences and similarities among the variables affecting LOS as a function of surgical approach.

Targeting angiogenic pathways involving tumor-stromal interaction to treat advanced human prostate cancer

Interfering with and preventing tumor angiogenesis is an attractive therapeutic approach for treating cancer metastases. This commentary presents treatment strategies that may enhance the effectiveness of anti-angiogenic therapy by selectively targeting newly sprouting and immature vessels, inhibiting the production of angiogenic factors, and disrupting extracellular matrices. We propose several clinical paradigms, including hormonal ablation, intermittent androgen suppression, chemotherapy, and radiation therapy, that 'injure' nascent vasculature and interrupt the cancer cell-stromal relationship, thereby potentiating the efficacy of experimental anti-angiogenic agents. These stromal-epithelial interactions play an important role in the development, proliferation and dissemination of prostate cancer, as well as guiding the processes of tumor neovascularization. Successful utilization and targeting of tumor angiogenesis requires an increased understanding of tumor cell-stromal cell-endothelial cell relationships, most notably the intricate intracellular signalling cascades mediated by growth factors and the extracellular matrix.

Quantitative polymerase chain reaction does not improve preoperative prostate cancer staging: a clinicopathological molecular analysis of 121 patients

PURPOSE

To improve on current staging and monitoring methods for prostate cancer, we applied the technique of quantitative polymerase chain reaction to measure the degree of tumor burden in the circulation and correlate this with pathological tumor stage. A reproducible, highly sensitive and specific, reverse transcriptase-polymerase chain reaction amplification technique to quantify prostate specific antigen (PSA) and prostate specific membrane antigen gene expression in the peripheral circulation was developed. Using a 32phosphorus-gamma-adenosine triphosphate-5'PSA and prostate specific membrane antigen primer incorporation assay, the ribonucleic acid signal extracted from a single neoplastic cell (LNCaP) premixed in 10 cc normal whole blood could be amplified. PSA and prostate specific membrane antigen polymerase chain reaction indexes have been created for clinical application.

MATERIALS AND METHODS

From September 1994 through July 1995 specimens from 121 patients were prospectively analyzed for PSA and prostate specific membrane antigen signals.

RESULTS

Circulating PSA producing cells were present in 29 of 33 patients (88%) with metastatic prostate cancer. Two of 19 patients (11%) with no known prostate cancer exhibited positive signals (1 later had prostate cancer), establishing a sensitivity of 88% and specificity of 94% for our assay. Positive PSA polymerase chain reaction signals were detected in 30 of 51 patients (59%) with stages pT1 and pT2 disease and in 13 of 18 (72%) with stage pT3 cancer. No statistically significant relationship of a positive PSA polymerase chain reaction signal to pathological stage, tumor grade, apical involvement or positive surgical margins was found, and no benefit was derived by measuring the quantity of circulating PSA polymerase chain reaction signals. Circulating prostate specific membrane antigen polymerase chain reaction signals were identified mostly in patients with advanced prostate cancer and offered no benefit to preoperative staging.

CONCLUSIONS

Given the high incidence of false positive signals in patients with pathologically determined localized disease, in our experience polymerase chain reaction based assays offer no immediate benefit for preoperative prostate cancer staging. The prognostic significance of detecting circulating prostate specific signals awaits longer followup in this cohort of patients, which is currently under study.

Current management of renal cell carcinoma

Renal cell carcinoma is the most common malignancy of the kidney and accounts for about three percent of all adult neoplasms. This article reviews the clinical presentation, diagnosis, staging, and treatment of this disease.

In vitro modulation of tumor progression-associated properties of hormone refractory prostate carcinoma cell lines by cytokines

BACKGROUND

Cytokines exert cytostatic and immunomodulatory effects on carcinoma cells. Growth inhibition of human prostate carcinoma by cytokines has been demonstrated both in vitro and in vivo, whereas the cellular and molecular changes in prostate carcinoma properties after cytokine treatment have never been characterized. We have thus investigated whether the intrinsic properties of prostate carcinoma cells that are associated with tumor development and progression can be altered by direct cytokine treatment.

METHODS

LNCaP, DU-145, and PC-3 cell lines were treated with tumor necrosis factor-alpha (TNF-alpha) (200 U/mL), interferon-gamma (IFN-gamma) (500 U/mL), human leukocyte interferon (IFN-alpha) (500 U/mL), and interleukin-2 (IL-2) (400 U/mL). The expression of (prostate-specific antigen [PSA] and prostate-specific membrane [PSM]), androgen receptor (AR), growth factors, oncogenes, collagenase, cell adhesion molecules, HLA antigens, cell adhesion to human bone marrow stroma, and cell growth were determined by quantitative polymerase chain reaction (PCR) analysis, fluorescence-activated cell sorter (FACS) analysis, and cell attachment and proliferation assays, and were compared with non-treated cells.

RESULTS

PCR analysis indicated that only LNCaP cells expressed PSA, PSM, and AR mRNA. Cytokine treatment did not alter PSM mRNA expression, whereas a 15-fold decrease in PSA and a 5-fold reduction in AR mRNA expression was detected in TNF-alpha-treated cells. The down regulation of PSA production was also demonstrated at the protein level in a dose-dependent fashion. A fivefold decrease in PSA mRNA was also detected in IL-2-treated LNCaP cells but without a reduction in AR. Down regulated epidermal growth factor receptor (EGF-R) and basic fibroblast growth factor (b-FGF) mRNA expressions were detected in TNF-alpha- and IFN-alpha-treated DU-145 and PC-3 cells, whereas, only reduced EGF-R expression was observed in LNCaP cells. IFN-gamma and IL-2 treatment down regulated the expression of collagenase Type IV mRNA in DU-145 and PC-3 cells, whereas tumor transforming growth factor-beta (TGF-beta) and IL-6 mRNA expressions did not exhibit any essential changes after cytokine treatment. A reduction in c-myc mRNA expression was observed in TNF-alpha- and IFN-alpha-treated cells, whereas no change in HER-2 expression was noted in any cytokine treated cells. Up regulated P-cadherin, but not E-cadherin, mRNA expression was detected in TNF-alpha- and IFN-gamma-treated PC-3 cells. FACS analysis revealed that all but IL-2-treated cells had enhanced HLA Class I expression, with the maximum effect seen in TNF-alpha-treated LNCaP cells (threefold increase). Up regulated HLA Class II expression was seen only in IFN-gamma-treated cells. All cytokine-treated DU-145 and PC-3 cells expressed reduced levels of alpha3, but not beta1, integrin. Up regulated of ICAM-1 expression was seen in all cytokine treated DU-145 and PC-3 cells, whereas no change in CD44 occurred. Cytokine treatment reduced the binding affinity of LNCaP and DU-145, but not of PC-3 cells, to human bone marrow stromal cells, and all cytokines but IL-2 showed a mild to moderate growth inhibition to prostate cancer cells, with a marked inhibition only observed in TNF-alpha-treated LNCaP cells.

CONCLUSIONS

Cytokine treatment can effectively alter several prostate carcinoma properties that are closely associated with tumor invasion and a metastatic phenotype, suggesting that immunotherapy via the local delivery of cytokines may have a potentially therapeutic role in the treatment of hormone-refractory prostate cancer through both direct and indirect antitumor mechanisms.

Dose response of fish oil versus safflower oil on graft arteriosclerosis in rabbit heterotopic cardiac allografts

With the advent of cyclosporin A, accelerated coronary arteriosclerosis has become the major impediment to the long-term survival of heart transplant recipients. Due to epidemiologic reports suggesting a salutary effect of fish oil, the dose response of fish oil on graft coronary arteriosclerosis in a rabbit heterotopic cardiac allograft model was assessed using safflower oil as a caloric control. Seven groups of New Zealand White rabbits (n = 10/group) received heterotropic heart transplants from Dutch-Belted donors and were immunosuppressed with low-dose cyclosporin A (7.5 mg/kg/day). Group 1 animals were fed a normal diet and served as control. Group 2, 3, and 4 animals received a daily supplement of low- (0.25 mL/kg/day), medium- (0.75 mL/kg/day), and high- (1.5 mL/kg/day) dose fish oil (116 mg n-3 polyunsaturated fatty acid/mL), respectively. Group 5, 6, and 7 animals were supplemented with equivalent dose of safflower oil (i.e., 0.25, 0.75, and 1.5 mL/kg/day). Oil-supplemented rabbits were pretreated for 3 weeks before transplantation and maintained on the same diet for 6 weeks after operation. The extent of graft coronary arteriosclerosis was quantified using computer-assisted, morphometric planimetry. When the animals were killed, cyclosporin A was associated with elevated plasma total cholesterol and triglyceride levels in the control group. While safflower oil prevented the increase in plasma lipids at all dosages, fish oil ameliorated the cyclosporin-induced increase in total cholesterol only with high doses. Compared to control animals, there was a trend for more graft vessel disease with increasing fish oil dose, as assessed by mean luminal occlusion and intimal thickness. A steeper trend was observed for increasing doses of safflower oil; compared to the high-dose safflower oil group, animals supplemented with low-dose safflower oil had less mean luminal occlusion (16.3% +/- 5.9% versus 41.4% +/- 7.6%, p less than 0.017) and intimal thickness (7.9 +/- 1.9 microns versus 34.0 +/- 13.0 microns, analysis of variance: p = 0.054). Low-dose safflower oil also had a slight, but nonsignificant, beneficial effect on graft vessel disease when compared to control rabbits. The same trends were observed in the degree of histologic rejection (0 = none to 3 = severe) in fish oil- and safflower oil-treated animals. Rejection score correlated weakly but significantly (p = 0.0001) with mean luminal occlusion (r = 0.52) and intimal thickness (r = 0.46). Therefore allograft coronary disease in this model appeared to exhibit an unfavorable, direct-dose response to fish oil and safflower oil, independent of effects on plasma lipids.(ABSTRACT TRUNCATED AT 400 WORDS)

The reversibility of canine vein-graft arterialization

We assessed the reversibility of functional and morphological changes of arterialized vein segments by returning them to the venous circulation. Thirteen dogs underwent right carotid and femoral veno-arterial grafting. After 12 weeks, veno-arterial grafts were removed for contractility (norepinephrine [NE] and 5-hydroxytryptamine [5-HT]), luminal prostacyclin (PGI2), and morphometric analyses; the remaining segments were used as left jugular and femoral veno-venous grafts. After another 12 weeks, the veno-venous grafts were harvested. To NE, veno-arterial grafts (ED50, 5.4 +/- 0.1 [-log M]) were less sensitive than control veins (ED50, 6.0 +/- 0.2) or veno-venous grafts (ED50, 6.4 +/- 0.2) but were more sensitive than control arteries (ED50, 4.0 +/- 0.1); the maximum tension of veno-arterial grafts (6.2 +/- 0.6 g) was greater than that of veins, less than that of arteries (9.8 +/- 1.0 g), and comparable with that of veno-venous grafts (5.1 +/- 1.1 g). To 5-HT, veno-arterial (ED50, 7.5 +/- 0.1) and veno-venous (ED50, 7.3 +/- 0.2) grafts were more sensitive than arteries (ED50, 6.0 +/- 0.3), while the vein was unresponsive; the maximum tension of veno-arterial grafts (5.0 +/- 0.7 g) was less than that of arteries (6.9 +/- 0.9 g) and greater than that of veno-venous grafts (1.4 +/- 0.3 g). PGI2 production in veins (3.6 +/- 0.8 ng/ml), veno-arterial grafts (3.9 +/- 0.8 ng/ml), and veno-venous grafts (3.3 +/- 0.9 ng/ml) was comparable and less than that of arteries (6.4 +/- 0.9 ng/ml). Veno-arterial graft intimal thickness (127 +/- 8 microns) and intimal area (15.6 +/- 1.8 x 10(3) microns 2) tended to be greater than that in the veno-venous graft (113 +/- 9 microns and 12.4 +/- 1.8 x 10(3) microns 2); also, the veno-arterial graft medial area (103.0 +/- 7.3 x 10(3) microns 2) was greater than that of the veno-venous graft (80.3 +/- 6.9 x 10(3) microns 2), thereby resulting in a similar relative intimal area (13 +/- 1%). Therefore, some changes associated with arterialization, for example, adrenergic sensitivity, maximum tension to 5-HT, medial thickening, and perhaps intimal hyperplasia, reverted toward venous values when replaced in the venous environment, possibly due to variations in pressure, flow, shear stress, and/or graft preparation techniques. Luminal PGI2 was unchanged in the grafts, implying that graft contractility was not modulated by luminal PGI2.

Mechanisms responsible for inhibition of vein-graft arteriosclerosis by fish oil

Favorable changes in lipoproteins, inhibition of platelet aggregation, reduction of serum thromboxane (TX), altered plasma-membrane fluidity, and reduced production of growth factors (mitogens) have all been implicated as possibly being involved in the inhibition of arteriosclerosis by fish oil (FO), which is rich in omega 3 fatty acids; however, causal relations are mostly lacking. Several putative mechanisms responsible for the salutary effects of FO were investigated in a canine model of accelerated vein-graft arteriosclerosis. Venoarterial autografts (N = 192) were implanted in 48 hypercholesterolemic dogs divided into six groups: group A, control; B, FO (as MaxEPA, 200 mg/kg/day eicosapentaenoic acid); C, aspirin (ASA, 50 mg/kg/day); D, TX synthetase inhibitor (TXSI [CGS-12970], 10 mg/kg/day); E, FO + ASA; and F, FO + TXSI. At sacrifice 3 months later, there was no significant difference in plasma lipoproteins, hepatic low density lipoprotein-receptor concentration, red blood cell fragility, bleeding time, or platelet count compared with controls; the decrease in platelet aggregation (30 +/- 5% [mean +/- SEM]) was similar in all treatment groups. Arterialized vein-graft intimal thickening was significantly inhibited by FO (with or without ASA), while ASA alone was ineffective. Conversely, serum TX was significantly lower only in the ASA and FO + ASA groups. Serum mitogenic activity was higher at 3 months in the control group versus all treatment groups. Compared with baseline values, serum mitogenic activity rose significantly over time in the control and the TXSI groups, and an increase or rising trend was present in all other treatment groups except for the FO-treated animals. Thus, the salutary biologic effect of FO in this hypercholesterolemic model of arterialized vein grafts may have been more related to in vivo inhibition of platelet-mitogen growth factor release than to changes in lipoproteins, low density lipoprotein receptors, platelet function, or eicosanoid metabolism. These observations underscore the need for further studies to clarify the interactions between FO (omega 3 fatty acids) and paracrine cellular mitogenic factors in the context of atherosclerosis prevention.