Gene and immune therapy for renal cell carcinoma

Conventional therapy for metastatic renal cell carcinoma is associated with a poor response rate and few patients are long-term survivors. The occurrence of spontaneous regression and the prolonged latency period between primary tumor removal and the appearance of metastases in some patients suggest the existence of important host immune responses to autologous tumor cells. With the advent of molecular gene transfer techniques and increased knowledge of the basic pathways of immune activation, the field of cancer immunotherapy has finally begun to develop novel and effective approaches for harnessing the immune system as a therapeutic agent. Current immunotherapy and gene therapy strategies, including methods of cytokine delivery and tumor-cell-based vaccines, are presented.

Glucose toxicity and the development of diabetes in mice with muscle-specific inactivation of GLUT4

Using cre/loxP gene targeting, transgenic mice with muscle-specific inactivation of the GLUT4 gene (muscle GLUT4 KO) were generated and shown to develop a diabetes phenotype. To determine the mechanism, we examined insulin-stimulated glucose uptake and metabolism during hyperinsulinemic-euglycemic clamp in control and muscle GLUT4 KO mice before and after development of diabetes. Insulin-stimulated whole body glucose uptake was decreased by 55% in muscle GLUT4 KO mice, an effect that could be attributed to a 92% decrease in insulin-stimulated muscle glucose uptake. Surprisingly, insulin's ability to stimulate adipose tissue glucose uptake and suppress hepatic glucose production was significantly impaired in muscle GLUT4 KO mice. To address whether these latter changes were caused by glucose toxicity, we treated muscle GLUT4 KO mice with phloridzin to prevent hyperglycemia and found that insulin-stimulated whole body and skeletal muscle glucose uptake were decreased substantially, whereas insulin-stimulated glucose uptake in adipose tissue and suppression of hepatic glucose production were normal after phloridzin treatment. In conclusion, these findings demonstrate that a primary defect in muscle glucose transport can lead to secondary defects in insulin action in adipose tissue and liver due to glucose toxicity. These secondary defects contribute to insulin resistance and to the development of diabetes.

Reevaluation of the 1997 TNM classification for renal cell carcinoma: T1 and T2 cutoff point at 4.5 rather than 7 cm. better correlates with clinical outcome

PURPOSE

We analyzed the effects of the change in TNM classification from the 1987 to the 1997 version and suggest a modified tumor size cutoff point between T stages 1 and 2 for renal cell carcinoma.

MATERIALS AND METHODS

We evaluated a database containing the records of 661 patients who underwent nephrectomy between 1989 and 1999. The effect of the change in TNM classification on the distribution of patients between stages, the rates of M+ and N+ disease, and the local and distant recurrence rates were outlined for 280 patients with T stages 1 and 2 disease. The Cox model was used to identify the optimal cutoff point between T1 and T2 disease, and the resulting effect of adopting this cutoff was outlined.

RESULTS

A total of 174 and 128 cases were down staged from 1987 version stage T2 to 1997 version stage T1 and from 1987 TNM stage II to 1997 TNM stage I, respectively. Survival was not significantly different in patients with 1997 TNM stages I and II disease due to a lack of survival difference during the first 2 years of followup. Stage shift also caused an increase in average tumor size, the proportion of patients with high grade cancer, and M+ and N+ disease at diagnosis in 1997 stages T1 and T2 as well as an increase in the proportion of 1997 stage T2N0M0 cases at diagnosis with systemic failure. Analysis of 11 potential cutoff points between 1 and 10 cm. revealed that 4.5 cm. was most predictive of patients survival (hazards ratio 4.99, p = 0.0001). Using this cutoff resulted in improved discriminatory power of the TNM classification and a moderating effect on the distribution of patients, average tumor size, high grade disease, M+ and N+ disease at diagnosis, and systemic failure between T(14.5) and T(24.5) compared with 1997 T1 and T2.

CONCLUSIONS

Our data imply that the current cutoff point of 7 cm. between stages T1 and T2 tumors is too high. Lowering the cutoff to 4.5 cm. resulted in better discriminatory power of the TNM classification in our dataset. This observation should be further validated by external data.

Cryosurgical ablation for prostate cancer: preliminary results of a new advanced technique

BACKGROUND

Cryosurgery is a minimally invasive treatment option for prostate cancer.

OBJECTIVES

To report on the first series of cryosurgical ablation for prostate cancer performed in Israel.

METHODS

Cryosurgical ablation of the prostate was undertaken in 12 patients aged 53-72 diagnosed with adenocarcinoma of the prostate. The procedures were performed percutaneously and were monitored by real-time trans-rectal ultrasound. The CRYOHIT machine applying Argon gas was used with standard or ultra-thin cryoprobes. The average follow-up was 12.8 months postsurgery (range 1-24 months).

RESULTS

No rectal or urethral injuries occurred and all patients were discharged from hospital within 24-48 hours. The duration of suprapubic drainage was 14 days in 10 patients and prolonged in 2. Early complications included penoscrotal edema in four patients, perineal hematoma in three, hemorrhoids in two and epidydimitis in one. Long-term complications included extensive prostatic sloughing in one patient and a perineal fistula in another, both of whom required prolonged suprapubic drainage. Minimal stress incontinence was noted in two patients for the first 8 weeks after surgery. None of the patients has yet regained spontaneous potency. A prostate-specific antigen nadir of less than 0.5 ng/ml was achieved in eight patients and an undetectable PSA level below 0.1 ng/ml in five patients.

CONCLUSION

Cryoablation for prostate cancer is safe and feasible, and the preliminary results are encouraging. Further study is needed to elucidate the efficacy of the procedure.

Immunotherapy of prostate cancer

The realization that prostate cancer is an immunogenic tumor, in conjunction with the discovery of novel methods for priming the immune system to generate an antitumor response, has resulted in several new approaches for prostate cancer immunotherapy. Based on these various approaches, several human clinical trials have begun using immune-based therapies for prostate cancer. These approaches can be divided into cytokine-based therapies, tumor-associated antigen-based therapies, tumor vaccines, and dendritic cell-based therapies. This review summarizes the latest findings from each of these approaches and gives results from the few completed human clinical trials.

Interleukin 2 gene therapy for prostate cancer: phase I clinical trial and basic biology

Twenty-four patients with locally advanced prostate cancer (CaP) were enrolled in a phase I clinical trial using gene-based immunotherapy. A functional DNA-lipid complex encoding the interleukin 2 (IL-2) gene (Leuvectin; Vical, San Diego, CA) was administered intraprostatically into the hypoecogenic tumor lesion, using transrectal ultrasound guidance. Two groups of patients having locally advanced tumors were enrolled to receive a treatment regimen composed of two serial intraprostatic injections of the IL-2 gene agent administered 1 week apart. The first groups of patients included radical prostatectomy candidates who subsequently underwent surgery after the completion of the treatment regimen. The second group consisted of patients who had failed a prior therapy. Prostate specimens of the treated areas were attained after treatment and compared with the transrectal biopsies performed at baseline to assess for any responses. IL-2 gene therapy was well tolerated, with no grade 3 or 4 toxic reactions occurring. The most commonly reported symptoms were mild hematuria, transient rectal bleeding, and perineal discomfort that are likely attributable to the injection itself. During the entire course of treatment, there were no significant changes in American Urologic Association (AUA) symptom scores, in hematologic disturbances, electrolyte imbalances, or hepatic functions. Evidence of systemic immune activation was observed after IL-2 gene therapy, based on an increase in the intensity of T cell infiltration seen on immunohistochemical analysis of tissue samples from the injected tumor sites, and based on increased proliferation rates of peripheral blood lymphocytes that were cocultured with patient serum collected after treatment. Furthermore, transient decreases in serum prostate-specific antigen (PSA) (responders) were seen in 16 of 24 patients (67%) on day 1. Fourteen of the patients persisted in this decrease to day 8 (58%). In eight patients the PSA level rose (nonresponders). More patients (9 to 10) in the group that failed prior therapy responded to the IL-2 gene injections (chi-square test, p = 0.04), and 6 of the 9 also had lower than baseline PSA levels at week 10 after treatment. To the best of our knowledge, this is the first clinical study of its kind aimed at exploring the role of IL-2-based gene therapy in CaP patients. This phase I trial demonstrated the safety of intraprostatic Leuvectin injection, with transient PSA-based responses seen after therapy.

Biology of renal cell carcinoma: changing concepts in classification and staging

Advances in our understanding of the pathogenesis, behavior, and importance of prognostic factors for renal cell carcinoma (RCC) have paved the way for increased sophistication in its classification and staging. In the past, lack of consistent classification and terminology for RCC histology and staging has complicated comparability of clinical studies looking at patient prognosis and response to treatment. In this review, the results of international consensus efforts to achieve uniform classification systems for RCC are outlined and some future directions are considered.

Laparoscopic radical nephrectomy

Most of the open renal procedures have been duplicated or approximated by laparoscopy. Past concerns about increased operative time, cost, resection completeness, and port site metastases are being overruled or put into perspective as experience with laparoscopic radical nephrectomy (LRN) is gained: necessary skills can be acquired, operative times are approaching those for open procedure, and a 14% difference in cost is counterbalanced by reduced postoperative expenditures. Moreover, LRN is acknowledged by its quality-of-life advantages-reduced morbidity and improved cosmetic outcome. Disease-free rate with LRN at last follow-up is 100% for TNM stage I and 89% +/- 6.6 for stage II (1997 classification). Complications are acceptable with an 8% to 35% incidence of minor complications and a 3% to 19% incidence of severe complications. Conversion to an open procedure occurs in 0% to 10% of cases. The procedure's limitations and the appropriate criteria for patient selection are evident. The learning process is believed to last for approximately 20 procedures and patient selection is based on both clinical criteria and one's insight on his location on the learning curve. Therefore, LRN is becoming the treatment of choice for most TNM stages I and II renal tumors. Moreover, recent data advocating pre-immunotherapy nephrectomy in metastatic patients may permit laparoscopic nephrectomy to further benefit selected metastatic patients by potentially shortening the time interval from nephrectomy to immunotherapy and improving immune responsiveness.

Improved prognostication of renal cell carcinoma using an integrated staging system

PURPOSE

To integrate stage, grade, and Eastern Cooperative Oncology Group (ECOG) performance status (PS) into a clinically useful tool capable of stratifying the survival of renal cell carcinoma (RCC) patients.

PATIENTS AND METHODS

The medical records of 661 patients undergoing nephrectomy at University of California Los Angeles between 1989 and 1999 were evaluated. Median age was 61 years, male-to-female ratio was 2.2:1, and median follow-up was 37 months. Survival time was the primary end point assessed. Sixty-four possible combinations of stage, grade, and ECOG PS were analyzed and collapsed into distinct groups. The internal validity of the categorized was challenged by a univariate analysis and a multivariate analysis testing for the accountability of each UCLA Integrated Staging System (UISS) category against independent variables shown to have impact on survival.

RESULTS

Combining and stratifying 1997 tumor-node-metastasis stage, Fuhrman's grade and ECOG PS resulted in five survival stratification groups designated UISS, and numbered I to V. The projected 2- and 5-year survival for the UISS groups are as follows for the groups: I, 96% and 94%; II, 89% and 67%; III, 66% and 39%; IV, 42% and 23%; and V, 9% and 0%, respectively. UISS accounted for the significant variables in the variate analysis.

CONCLUSION

A novel system for staging and predicting survival for RCC integrating clinical variables is offered. UISS is simple to use and is superior to stage alone in differentiating patients' survival. Our data suggests that UISS is an important prognostic tool for counseling patients with various stages of kidney cancer. Further prospective large-scale validation with external data is awaited.

New biologicals for prostate cancer prevention: Genes, vaccines, and immune-based interventions

For at least 100 years, immunologists have proposed activating the immune system to specifically target and eradicate autologous tumor cells. The idea that tumor cells can be recognized as foreign to the host's immune system is an essential concept of tumor immunology that was first postulated by Paul Ehrlich at the turn of the century. Anecdotal reports of spontaneous tumor regression have been presumed to be immunologically mediated. With the advent of molecular gene transfer techniques and increased knowledge of the regulation of the immune response, effective methods for harnessing the immune system as a therapeutic agent are finally being realized. Current results of clinical immune/gene therapy protocols will be reviewed with consideration towards the concept of cancer prevention.

Improved prognostication of renal cell carcinoma using an integrated staging system

PURPOSE

To integrate stage, grade, and Eastern Cooperative Oncology Group (ECOG) performance status (PS) into a clinically useful tool capable of stratifying the survival of renal cell carcinoma (RCC) patients.

PATIENTS AND METHODS

The medical records of 661 patients undergoing nephrectomy at University of California Los Angeles between 1989 and 1999 were evaluated. Median age was 61 years, male-to-female ratio was 2.2:1, and median follow-up was 37 months. Survival time was the primary end point assessed. Sixty-four possible combinations of stage, grade, and ECOG PS were analyzed and collapsed into distinct groups. The internal validity of the categorized was challenged by a univariate analysis and a multivariate analysis testing for the accountability of each UCLA Integrated Staging System (UISS) category against independent variables shown to have impact on survival.

RESULTS

Combining and stratifying 1997 tumor-node-metastasis stage, Fuhrman's grade and ECOG PS resulted in five survival stratification groups designated UISS, and numbered I to V. The projected 2- and 5-year survival for the UISS groups are as follows for the groups: I, 96% and 94%; II, 89% and 67%; III, 66% and 39%; IV, 42% and 23%; and V, 9% and 0%, respectively. UISS accounted for the significant variables in the variate analysis.

CONCLUSION

A novel system for staging and predicting survival for RCC integrating clinical variables is offered. UISS is simple to use and is superior to stage alone in differentiating patients' survival. Our data suggests that UISS is an important prognostic tool for counseling patients with various stages of kidney cancer. Further prospective large-scale validation with external data is awaited.

The impact of prostate biopsy on patient well-being: a prospective study of pain, anxiety and erectile dysfunction

PURPOSE

We prospectively studied the impact of transrectal ultrasound guided prostate biopsy on patient well-being.

MATERIALS AND METHODS

We enrolled 211 consecutive men who underwent a total of 218 biopsy events in a questionnaire based survey focusing on pain, anxiety and erectile dysfunction risk factors. Surveys were administered before, and immediately, 1 week and 1 month after biopsy. Quantitative information on the intensity of symptoms and signs was obtained using a uniform grading system.

RESULTS

Intraoperative pain considered severe in 20% of the biopsy events was associated with pain in the first 24 hours postoperatively, leading to analgesic use in 10%. Inflammatory infiltrate in the biopsy core and younger patient age correlated with persistent pain on days 2 and 7 after biopsy, respectively. Preoperative anxiety was reported in 64% of biopsy events and predictive of intraoperative pain. Anxiety peaked before result disclosure. Erectile dysfunction attributed to anxiety in anticipation of biopsy was reported in 7% of cases. At days 7 and 30, 15% of previously potent patients reported erectile dysfunction.

CONCLUSIONS

The impact of prostate biopsy on patient well-being begins while waiting for the scheduled procedure. Shortening the anticipation period before results are disclosed and administering pre-biopsy anxiety decreasing measures may benefit patients. Analgesic therapy is recommended in younger patients, those reporting moderate to severe intraoperative pain and those with known prostatic inflammatory infiltrate. The risk of acute erectile dysfunction should be discussed cautiously with patients who are potent before biopsy.

Molecular-based therapies for renal cell carcinoma

The incidence of renal cell carcinoma (RCC) is rising steadily, but the ability to cure patients with metastatic RCC unfortunately remains limited. Emerging interest in gene therapy performance and safety is expressed by patients, medical institutes, and other agencies. It has become evident that better understanding of the genetic impairments and immune pathophysiology in RCC is essential for future improvement in patient care. Clinical trials now underway that are focusing on genetic and immune impairments will hopefully lead to future breakthroughs in RCC therapy. This paper reviews available gene therapies and other related therapeutic approaches for RCC and lists some of the current clinical trials focused on molecular-based therapies.

Bladder cancer 2000: molecular markers for the diagnosis of transitional cell carcinoma

The search continues for better tumor markers to improve the rate of detection of transitional cell carcinoma (TCC) more quickly in larger populations and to predict the possibility of disease recurrence. Among several new tests currently being screened, telomerase and hyaluronic acid/hyaluronidase (HA/HAase) have shown sensitivity and specificity equal to or better than cytology, and other promising tumor markers are being investigated. Although no marker has yet replaced the need to perform cystoscopy and cytology, the new tests can minimize the cost and difficulty of screening and long-term surveillance of patients who have or are at risk for bladder cancer.

Diabetic ketoacidosis and hyperglycemic hyperosmolar nonketotic syndrome

Diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar nonketotic syndrome (HHNS) are life-threatening acute metabolic complications of diabetes mellitus. Although there are some important differences, the pathophysiology, the presenting clinical challenge, and the treatment of these metabolic derangements are similar. Each of these complications can be seen in type 1 or type 2 diabetes, although DKA is usually seen in patients with type 1 diabetes and HHNS in patients with type 2 disease. The clinical management of these syndromes involves careful evaluation and correction of the metabolic and volume status of the patient, identification and treatment of precipitating and comorbid conditions, a smooth transition to a long-term treatment regimen, and a plan to prevent recurrence.

Predicting CAP in patients with intermediate PSA using modified PSA indices

OBJECTIVES

To test a new PSA index: peripheral zone fraction PSA (PSA-PZ) and evaluate its' predictive value in patients with intermediate PSA.

METHODS

Fifty seven of 273 patients with serum PSA 4-10 ng/ml had CAP (21%). Total prostate volume and transition zone volume were calculated. Different cut-off points were used to calculate specificity, sensitivity, efficacy, positive and negative predictive values for PSA, PSAD, PSA-TZ and PSA-PZ (PSA-PZ= serum PSA((Total gland volume-TZ volume)/(Total gland volume))

RESULTS

The distribution of PSA-PZ is presented. PSA-PZ is shown to be effective in DRE negative patients with serum PSA 4-10 ng/ml. For patients with PSA-PZ (1.5 ng/ml the biopsy may be spared with no cancer being missed.

CONCLUSIONS

The mathematical formula for PSA-PZ is straightforward and easy to use. Its application is convenient in the clinical setting. We suggest the use of PSA-PZ mainly in DRE negative patients having large glands and serum PSA between 4-10.

A model to explore the interaction between muscle insulin resistance and beta-cell dysfunction in the development of type 2 diabetes

Type 2 diabetes is a polygenic disease characterized by defects in both insulin secretion and insulin action. We have previously reported that isolated insulin resistance in muscle by a tissue-specific insulin receptor knockout (MIRKO mouse) is not sufficient to alter glucose homeostasis, whereas beta-cell-specific insulin receptor knockout (betaIRKO) mice manifest severe progressive glucose intolerance due to loss of glucose-stimulated acute-phase insulin release. To explore the interaction between insulin resistance in muscle and altered insulin secretion, we created a double tissue-specific insulin receptor knockout in these tissues. Surprisingly, betaIRKO-MIRKO mice show an improvement rather than a deterioration of glucose tolerance when compared to betaIRKO mice. This is due to improved glucose-stimulated acute insulin release and redistribution of substrates with increased glucose uptake in adipose tissue and liver in vivo, without a significant decrease in muscle glucose uptake. Thus, insulin resistance in muscle leads to improved glucose-stimulated first-phase insulin secretion from beta-cells and shunting of substrates to nonmuscle tissues, collectively leading to improved glucose tolerance. These data suggest that muscle, either via changes in substrate availability or by acting as an endocrine tissue, communicates with and regulates insulin sensitivity in other tissues.

Elevated prostate specific antigen serum levels after intravesical instillation of bacillus Calmette-Guerin

PURPOSE

We determined whether intravesical bacillus Calmette-Guerin (BCG) instillation is associated with elevated prostate specific antigen (PSA).

MATERIALS AND METHODS

We treated 36 consecutive patients with bladder cancer with a 6-week course of BCG, followed by cystoscopy at 6 weeks. Blood samples for PSA determination were obtained before each BCG instillation and at cystoscopy with each patient also serving as a control. PSA elevation was defined as 2-fold the baseline level in at least 2 specimens and any PSA level greater than 4 ng./ml. was considered clinically significant. Digital rectal examination was done to identify firm nodules and prostate size. The prostate was examined histologically by transrectal ultrasound guided biopsy or after radical cystectomy.

RESULTS

We observed elevated PSA in 27 men (75%) during BCG treatment, of whom 15 (41.6%) had a clinically significant elevation. Overall average PSA increased from 1.3 ng./ml. before BCG instillation to 3.8 during treatment (range 0.1 to 21.5, p <0.0001). In those with a clinically significant elevation average PSA increased from 2.31 ng./ml. at baseline to 6.97 during treatment (p <0.0001) and returned to 3.86 ng./ml. 3 months after treatment. Palpation demonstrated prostatic findings in 10 patients, including firm nodules in 7, while there was significantly elevated PSA in 5 with firm nodules and 2 with diffuse prostatic enlargement. Histological examination of the prostate in 10 patients was diagnostic for granulomatous prostatitis, nonspecific inflammation and benign prostatic hyperplasia in 3, 3 and 4, respectively, of whom none had prostate cancer.

CONCLUSIONS

Intravesical BCG therapy is associated with significantly elevated PSA in up to 40% of cases. This effect is self-limited and PSA reverts to normal in 3 months. Therefore, we suggest that prostate biopsy be withheld in such patients and PSA monitored.

CL1-GFP: an androgen independent metastatic tumor model for prostate cancer

PURPOSE

The mechanisms responsible for tumor progression to androgen independence in prostate cancer (CaP) remain unknown. To characterize these changes and provide a basis for rational therapeutic strategies for advanced CaP, an in vivo model from a highly aggressive androgen independent CaP cell line with distinct cellular and molecular properties was developed.

MATERIALS AND METHODS

An aggressive androgen-independent cell line designated CL1 was derived from a slow-growing, and androgen-dependent, parental LNCaP cell line through in-vitro androgen-deprivation and selection. CL1 was stably transfected with a green fluorescence protein gene (CL1-GFP) and orthotopically injected into SCID mice. The pathologic behavior, histology, and molecular determinants of CL1 tumor and metastases were determined and characterized by standard light and fluorescent microscopy, and quantitative RT-PCR analysis.

RESULTS

CL1 is an anaplastic prostate cancer cell line which demonstrates extensive local invasion and metastases to various organs that can be visualized via GFP expression. When compared with parental LNCaP cells, RT-PCR analysis of the tumor revealed an over-expression of EGFR, b-FGF, VEGF, TGF-beta, IL-8, IL-6, and bcl-2 and a down regulated expression of the p53, E-cadherin and PTEN. In contrast to LNCaP cells, CL1 tumors express lower levels of androgen receptor and barely detectable PSA mRNA.

CONCLUSIONS

CL1-GFP represents an aggressive androgen-independent CaP tumor model derived through androgen deprivation whose pathologic development and molecular properties in animals resembles the clinical characteristics of hormone refractory prostate cancer (HRPC). Metastatic sites of CL1-GFP can be visualized with fluorescence microscopy offering a unique therapeutic model for the evaluation of drug sensitivity and other therapeutic modalities.